JPH03110838A - Deposited film formation method - Google Patents

Abstract

PURPOSE:To make it possible to form an Al-TiSi film of good quality as a conductor with good controllability and at a desired position by a method wherein the temperature on the electron donative surface of a substrate is maintained at the decomposition temperature or higher of specified gases and within the range of a temperature of 450 deg.C or lower in an atmosphere containing the specified gases and a tianium-containing Al film is selectively formed on the electron donative surface. CONSTITUTION:A substrate 1 having an electron donative surface and a non- electron donative surface is arranged in a space 2 for depositing a film. Then, alkylaluminium hydride-containing gas, titanium atom-containing gas and hydrogen gas are introduced in the space for depositing a film, the temperature of the electron donative surface is maintained at the decomposition temperature or higher of the alkylaluminium hydride and titanium atom-containing gases and within a range of temperature of 450 deg.C or lower and a titanium-containin Al film is selectively formed on the electron donative surface. Thereby, the low-resistance, dense and flat Al-Ti or Al-SiTi film can be selectively deposited on the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming a deposited film, and particularly to a method for forming Au-Ti which can be preferably applied to wiring of semiconductor integrated circuit devices and the like.

[Prior Art] Conventionally, in electronic devices and integrated circuits using semiconductors, electrodes and wiring are mainly made of aluminum (Au2), A
1-5i or A4-Ti, etc. have been used. Here, Al is inexpensive and has high electrical conductivity, and since a dense oxide film is formed on the surface, the inside is chemically protected and stabilized, and it has good adhesion with Si. It has many advantages such as: However, Au2 has a problem of disconnection due to so-called electromigration, and AJl-Ti has been studied to solve this problem.

By the way, as the degree of integration of integrated circuits such as LSIs has increased, miniaturization of wiring and multi-layer wiring have become especially necessary in recent years, so there are stricter demands than ever on conventional ^1 wiring. are starting to be issued. As dimensions become smaller due to increased integration, the surfaces of LSIs and the like are becoming increasingly uneven due to oxidation, diffusion, thin film deposition, etching, and the like. For example, electrodes and wiring metal must be deposited on a stepped surface without disconnection, or must be deposited in a deep and minute diameter pier hole. 4Mbit or 16
In Mbit DRAM (dynamic RAM), the aspect ratio of the pier hole (pier hole depth ÷ pier hole diameter) on which a metal such as /1-Ti must be deposited is 1.0 or more, and the pier hole diameter itself is 1 μI or less. Become. Therefore, Aj! can also be used for peer holes with large aspect ratios. - A technique that can deposit Ti is needed.

In particular, in order to make a reliable connection to a device under an insulating film such as 5in2, it is necessary to use A11-Ti to fill only the peer holes of the device rather than forming a film.
need to be deposited. For this purpose, a method is required in which An--Ti is deposited only on the Si or metal surface, and not on the insulation crotch of the 5in2 or the like.

An-Ti has conventionally been deposited by sputtering.

However, selective deposition or selective growth as described above cannot be achieved by conventionally used sputtering methods.

Since the sputtering method is a physical deposition method based on the flying of particles sputtered from a target in a vacuum, the film thickness becomes extremely thin at step portions and side walls of the insulating film, and in extreme cases, disconnection may occur. . And, uneven film thickness and disconnection are caused by L.
This will significantly reduce the reliability of SI.

By applying a bias to the substrate and using sputter etching and deposition on the substrate surface, Au2 is deposited in the peer hole.
A bias sputtering method has been developed in which deposition is performed so as to bury the surface. However, since a bias voltage of several hundred volts or more is applied to the substrate, charged particle damage may occur, for example, in MOS
- An adverse effect such as a change in the threshold value of the FET occurs.

Furthermore, since the etching action and the deposition action coexist, there is also the problem that the deposition rate is essentially not improved.

In order to solve the above problems, various types of C
VD (chemical vapor deposit)
ion) method has been proposed. These methods utilize some form of chemical reaction of the source gas during the film formation process. In plasma CVD and photo-CVO, decomposition of the source gas occurs in the gas phase, and the active species generated thereby further react on the substrate to form a film. Since these CVD methods involve reactions in a gas phase, surface coverage against irregularities on the substrate surface is good. However, carbon atoms contained in the source gas molecules are incorporated into the film. In particular, plasma CvD has problems such as damage caused by charged particles (so-called plasma damage) as in the case of sputtering.

In the thermal CVD method, a film grows mainly by a surface reaction on the substrate surface, so that it has good surface coverage over irregularities such as steps on the surface. Further, it can be expected that deposition within the pier hole is likely to occur. Furthermore, disconnections at stepped portions can be avoided.

For this reason, various thermal CVD methods have been studied as a method for forming IWA. - As a method for forming an If film by thermal CVD on a boat, a method is used in which organic aluminum is dispersed in a carrier gas, transported onto a heated substrate, and the gas molecules are thermally decomposed on the substrate to form a film. For example, Journal
of Electrochemical Society
In the example found in Vol. 131, page 2175 (1984), triisobutylaluminum (i-C4tL,) s Al2 (TIB
Using A), film forming temperature 260℃ 1 reaction tube pressure 0.5to
The film was formed using rr to form a film of 3.4 μΩ·cm.

In this case, for uniform film formation, T1Cl! , 4 has been adopted.

JP-A-63-33569 describes a method of forming a film by heating organic aluminum in the vicinity of the substrate instead of using TiCn4. In this method, Afl can be selectively deposited only on the metal or semiconductor surface from which the natural oxide film on the surface has been removed.

In this case, it is specified that a step of removing the natural oxide film on the substrate surface is required before introducing TIBA. Also,
Since TIBA can be used alone, there is no need to use a carrier gas other than TT8^, but it is stated that ^r gas may be used as a carrier gas. But T
No reaction between IBA and other gases (e.g. H2) is assumed, there is no mention of using H2 as a carrier gas, and trimethylaluminum (TMA) and triethylaluminum (TEA) are listed in addition to TIB^. However, there is no specific description of other organic metals. This is because the chemical properties of organometallics generally change greatly when the organic substituent attached to the metal element changes a little, so it is necessary to individually consider what kind of organometallic to use. This method not only has the disadvantage that the native oxide film must be removed, but also has the disadvantage that surface smoothness cannot be obtained. In addition, there is a restriction that the gas must be heated, and that the heating must be done near the substrate, and how close to the substrate the heating must be must be determined experimentally. There are also problems such as not being able to freely choose where to place the heater.

Electrochemical 5ociety Japan Chapter 2nd Symposium (July 7, 1989) Proceedings page 75 shows 81
There is a description regarding film formation. In this method, a TIBA is used and the apparatus is designed so that the gas temperature to the TIB can be higher than the substrate temperature. This method can be regarded as a modification of the above-mentioned Japanese Patent Application Laid-Open No. 63-33569. Although this method also enables selective growth of 81 only on metals and semiconductors, it is not only difficult to precisely control the difference between the gas temperature and the substrate surface temperature, but also requires heating of the cylinder and piping. It has the disadvantage that it cannot be used. Moreover, with this method, a uniform continuous film cannot be obtained unless the film is thickened to a certain extent, and the flatness of the film is poor.

There are problems such as the selectivity of n-selective growth cannot be maintained for a very long time.

As mentioned above, the conventional method does not necessarily successfully produce selective growth at A°C, and even if it could, the flatness of the Al1 film
There are problems with resistance, purity, etc. Further, there was a problem that the film forming method was complicated and difficult to control.

[Problems to be Solved by the Invention] As described above, in the semiconductor technical field where higher integration has been desired in recent years, in order to provide a highly integrated and high-performance semiconductor device at a low price, There was much room for improvement.

The present invention was made in view of the above-mentioned technical problems, and an object of the present invention is to provide a deposited film forming method that can form a high-quality ^1-Ti film as a conductor at a desired position with good controllability. do.

[Means for Solving the Problems] In order to achieve the above object, the deposited film forming method of the present invention comprises: (a) a substrate having an electron-donating surface (A) and a non-electron-donating surface (B); (b) introducing a gas of alkyl aluminum hydride, a gas containing titanium atoms, and hydrogen gas into the space for forming a deposited film; (c) an alkyl aluminum hydride and Maintaining the temperature of the electron-donating surface (A) above the decomposition temperature of a gas containing titanium atoms and within a range of 450 to below;
The aluminum film containing titanium is coated on the electron-donating surface (A
).

Further, the method for forming a deposited film of the present invention includes (a) a step of disposing a substrate having an electron-donating surface (A) and a non-electron-donating surface (B) in a space for forming a deposited film; a step of introducing an alkyl aluminum hydride gas, a gas containing titanium atoms, a gas containing silicon atoms, and hydrogen gas into the space for forming the deposited film, and (c) the alkyl aluminum hydride, the gas containing titanium atoms, and maintaining the temperature of the electron-donating surface (A) within a range of not less than the decomposition temperature of the silicon atom-containing gas and not more than 450'C; (
It is characterized by having a step of selectively forming A).

[Function] First, a method for forming a deposited film using an organic metal will be outlined.

The decomposition reaction of organometallics, and thus the thin film deposition reaction, vary greatly depending on the type of metal atom, the means for causing the type 1 decomposition reaction of the alkyl bonded to the metal atom, and conditions such as atmospheric gas.

For example, in the case of M-R5 (M: Group III metal, R: alkyl group), trimethylgallium undergoes radical cleavage in which the Ga-CH* bond is broken during thermal decomposition, but triethylgallium undergoes thermal decomposition. Then, it decomposes into C21(, and leaves β.

C) Trimethylaluminum consisting of 13 groups and 81 groups (
TMA) has a dimeric structure at room temperature, and thermal decomposition is a radical decomposition in which the ^1-[:H3 group is cleaved, and at low temperatures below 150°C, it reacts with atmospheric H2 to produce CH4. , finally generates 8j2. However, at high temperatures of approximately 300°C or higher, H3 is added to the atmosphere.
Even if , the CH3 group pulls out 11 from the TMA molecule,
Finally, the AJ2-C compound is formed.

In addition, in the case of TMA, light or 112 spirit energy high frequency (
Approximately 13.5611!11Z) In a limited region of power in the plasma, the bridge e between two Au
Coupling of fts yields C21(6).

The key is CH3, which is the simplest alkyl group.

Even with organic metals consisting of C2H, iC, H9 groups and 8λ or Ga, the reaction form differs depending on the type of alkyl group, the type of metal atom, and the excitation decomposition method. The decomposition reactions must be very tightly controlled in order to be deposited. For example, when depositing triisobutylaluminum at 8° C., the conventional low-pressure CVD method, which mainly uses a thermal reaction, produces surface irregularities on the order of μm, resulting in poor surface morphology. In addition, hillocks occur due to heat treatment, and St back surface warpage occurs due to Si diffusion at the interface between 81 and Si, and migration resistance is also poor, making it difficult to use in VLSI processes.

For this reason, attempts have been made to precisely control the gas temperature and substrate temperature. However, the apparatus is complicated and is a single-wafer processing type that can perform deposition on only one wafer in one deposition process. Moreover, the deposition rate is at most 500
person/minute, it is not possible to achieve the throughput required for mass production.

Similarly, in the case of using TMA, attempts have been made to deposit one layer using plasma or light, but since plasma and light are used, the equipment is complicated, and since it is a single-wafer type equipment, the throughput is not sufficient. There is still room for improvement.

Dimethylaluminum hydride DM in the present invention
AI is a substance known as an alkyl metal, but it is impossible to predict what type of reaction form will result in the formation of a thin film until the deposited film is formed under all conditions. there were. For example, DMAII can be converted into optical CvD.
In the example of depositing +l, the surface morphology is inferior and the resistance value is several μΩ to 10 μΩ・cm, which is the bulk value (2
, 7 μΩ·cm) and was inferior in film thickness.

[Example] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

In the present invention, a CVD method is used to selectively deposit a high quality 81-Ti film having electromigration resistance as a conductive deposited film on a substrate.

In other words, at least one atom that becomes a component of the deposited film is
Dimethylaluminum hydride (DMAH) or monomethylaluminum hydride (MMAth), which is an organic metal, is used as a raw material gas containing Ti atoms, and a gas containing Ti atoms is used as a raw material gas.
And, using H2 as a reaction gas, A℃-Till selectively is deposited on the substrate by vapor phase growth using a mixture of these gases.
form i. Alternatively, a gas containing St atoms is further added as a source gas to form an AIL-St-Ti film.

Applicable substrates of the present invention include a first substrate surface material for forming the surface on which ^JZ-Ti is deposited, and Aj! −
and a second substrate surface material for forming a surface on which Ti is not deposited. As the first substrate surface material, a material having electron donating properties is used.

This electron donating property will be explained in detail below.

An electron-donating material is one in which free electrons exist in the substrate or free electrons are intentionally generated.For example, a chemical reaction occurs through electron transfer with raw material gas molecules attached to the surface of the substrate. A material with a surface that is promoted. For example, metals and semiconductors generally correspond to this.

It also includes those in which a thin oxide film exists on the surface of a metal or semiconductor. This is because a chemical reaction occurs between the substrate and the attached raw material molecules due to electron exchange.

Specifically, semiconductors such as single crystal silicon, polycrystalline silicon, and amorphous silicon, Ga and In as group III elements
, A binary system, a ternary system, or a quaternary system III-V consisting of a combination of A°C and P, As, and N as group II elements
Group compound semiconductors, tungsten, molybdenum, tantalum, tungsten silicide, titanium silicide, aluminum, aluminum silicon, titanium aluminum,
Titanium night ride.

Includes metal 1 alloys such as copper, aluminum silicon copper, aluminum palladium, titanium, molybdenum silicide, tantalum silicide, and their silicides.

On the other hand, as a material forming the surface on which -Tt is not selectively deposited, that is, a non-electron-donating material, silicon oxide is used by thermal oxidation, CVD, etc.

Glass or oxide film such as BSG, PSG, BPSG, thermal nitride film, plasma VCVD, low pressure CVD, ECR-CVD
This is a silicon nitride film or the like formed by a method or the like.

On a substrate having such a configuration, +1-Ti is deposited only by a simple thermal reaction in a reaction system of source gas and H2. For example, the thermal reaction in a reaction system such as DMAH and 11° is basically considered to be. DMAH has a dimeric structure at room temperature. Also, T1Cl! , 4, etc. Ajlj
-Ti alloy is formed when Ti reaches the substrate surface.
This is because Cl2 is decomposed by a surface chemical reaction and Ti is incorporated into the film. Even with MMAH2, high quality AjZ-Ti could be deposited by thermal reaction, as shown in the examples below.

MMA) 12 has a vapor pressure of 0.01 to 0.0 at room temperature. ITor
Because of the low r, it is difficult to transport a large amount of raw materials, and the upper limit of the deposition rate in the present invention is several hundred people/min. It is most desirable to use DMA11, which preferably has a vapor pressure of ITorr at room temperature.

FIG. 1 is a schematic diagram showing a deposited film forming apparatus to which the present invention can be applied.

Here, 1 is a substrate for forming an Al1-Ti film. A substrate 1 is placed on a substrate holder 3 provided inside a reaction tube 2 for forming a substantially closed space for forming a deposited film as seen in the figure. The material constituting the reaction tube 2 is preferably quartz, but it may also be made of metal. In this case, it is desirable to cool the reaction tube. Further, the substrate holder 3 is made of metal, and is provided with a heater 4 so as to heat the substrate placed thereon. The substrate temperature can be controlled by controlling the heat generation temperature of the heater 4.

The gas supply system is configured as follows.

Reference numeral 5 denotes a gas mixer, which mixes the raw material gas and the reaction gas and supplies the mixture into the reaction tube 2 . Reference numeral 6 denotes a raw material gas vaporizer provided to vaporize organic metals as raw material gases.

Since the organic metal used in the present invention is in a liquid state at room temperature, it is passed through the organic metal liquid as a carrier gas in the vaporizer 6 to form a saturated vapor, and then introduced into the mixer 5.

The exhaust system is configured as follows.

Reference numeral 7 denotes a gate valve, which is opened when a large volume of gas is evacuated, such as when evacuating the inside of the reaction tube 2 before forming a deposited film. 8
is a slow leak valve, which is used for reaction tube 2 during deposition film formation.
Used when evacuation of a small volume, such as when adjusting internal pressure. Reference numeral 9 denotes an exhaust unit, which is composed of an exhaust pump such as a turbo molecular pump.

The transport system for the substrate 1 is configured as follows.

Reference numeral 10 denotes a substrate transfer chamber capable of accommodating substrates before and after the formation of a deposited film, and is evacuated by opening a valve 11. Reference numeral 12 denotes an exhaust unit for evacuating the transfer chamber, and is composed of an exhaust pump such as a turbo molecular pump.

The valve 13 is opened only when the substrate 1 is transferred between the reaction chamber and the transfer space.

As shown in FIG. 1, in the gas generation chamber 6 for generating source gas, liquid D is kept at room temperature.
For MAH, H2 or Ar(
or other inert gas) to generate gaseous DMAH, which is transported to the mixer 5. Ti
ck4 and H2 as a reaction gas are transported to the mixer 5 from another route, either separately or mixed in advance. The flow rate of each gas is adjusted so that its partial pressure becomes a desired value.

Although MMAH2 may be used as the raw material gas, MA)I is most preferable since it has a vapor pressure sufficient to reach ITorr at room temperature. Alternatively, DMAH and MMA)+2 may be used in combination.

Further, as the gas containing Ti as the second raw material gas, T
i(:j&,, T1Cu4.Ti(lr4.Ti(
ct(3)4 etc. can be used, but 200-:1
Tick 4, Ti (cH
3) 4 is desirable.

FIGS. 2(a) to 2(e) show selective growth of an An--Ti film according to the present invention.

FIG. 2(a) is a diagram schematically showing a cross section of a substrate before formation of a +l deposited film according to the present invention. 90 is a substrate made of an electron-donating material, and 91 is a thin film made of a non-electron-donating material.

A mixed gas containing DMAH as a raw material gas and H2 as a reaction gas is DMAH and Ti[:n 4
When supplied onto the substrate 1 heated within the temperature range above the decomposition temperature of
is precipitated, and a continuous An--Ti film is formed as shown in FIG. 2(b). Here, the pressure inside the reaction tube 2 is 10-
3 to 760 Torr is desirable, and the DMA8 partial pressure is 1.5 x 10-' to 1.3 Xl0- of the pressure inside the reaction tube.
'Double is preferred.

If An-Ti is continued to be deposited under the above conditions, Fig. 2(c)
As shown in Fig. 2(d), 4-Ti
The film grows to the top level of thin film 91. Further, when grown under the same conditions, the An--Ti film can be grown to a thickness of 2000 Å or more with almost no growth in the lateral direction, as shown in FIG. 2(e). this is,
This is the most characteristic feature of the deposited film according to the present invention, and it can be understood how a high quality film can be formed with good selectivity.

As a result of analysis using Ausch electron spectroscopy and photoelectron spectroscopy, no impurities such as carbon or oxygen were found to be present in this film.

The resistivity of the deposited film thus formed is as follows:
In the case of 0 people, the resistivity is 3.0 to 6.0 μΩ·cm at room temperature, which is almost equal to the Aj2 bulk resistivity, resulting in a continuous and flat film. Further, even if the film thickness is 1 μm, the resistivity will still be approximately 3.0 to 8.0 μΩ·Cl11 at room temperature, and a sufficiently dense film will be formed even if the film is thick. The reflectance in the visible light wavelength region is also approximately 80%, and a thin film with excellent surface flatness can be deposited.

As mentioned above, the substrate temperature is desirably above the decomposition temperature of the source gas containing +l and the source gas containing Ti and below 450°C.
The temperature is preferably 20 to 450°C, and when deposition is performed under these conditions, the deposition rate is extremely high at 100 to 700 people/min when the DMA8 partial pressure is 10-' to 1O-3 Torr, which is suitable for VLSI. A sufficiently high deposition rate can be obtained as a 1l-Ti deposition technique.

More preferably, the substrate temperature is 250°C to 350°C,
The AJ2-Ti film deposited under these conditions has strong orientation, and even after heat treatment at 450°C for 1 hour, the AJ2-Ti film on the Si single crystal or St polycrystalline substrate is of good quality with no hillocks or spikes. It becomes an An-Ti film. Further, such AJZ-Tili has better electromigration resistance than the An film.

In the apparatus shown in the first figure, AJZ-Ti can only be deposited on one substrate in one deposition. Approximately 70
Although a deposition rate of 0 person/minute can be obtained, this is insufficient for depositing a large number of sheets in a short period of time.

As a deposited film forming apparatus that improves this point, there is a low pressure CvD apparatus that can load a large number of wafers at the same time and deposit An-Ti. Since β deposition according to the present invention uses a surface reaction on the surface of a heated electron-donating substrate, a hot wall type reduced pressure CV where only the substrate is heated is used.
If method D is used, AJZ-Ti containing 0.5 to 2.0% Ti can be deposited by adding pMAIl and a Ti source gas such as H2TiCλ4.

The reaction tube pressure is 0.05 to 760 Torr, preferably 0
．． 1~G, 8Torr, substrate temperature 160℃~450
°C, preferably 220 °C to 400 °C, DMAI (partial pressure is IX 10-S times the reaction tube internal pressure to 1.3 Xl0-3
times, and the pressure inside the reaction tube of T1Cu4 is I
(The range is 1-' to I x 10-' times ^I1.-
Ti is deposited only on the electron-donating substrate.

FIG. 3 is a schematic diagram showing a deposited film forming apparatus to which the present invention can be applied.

57 is a substrate for forming a λ film. 50 is an outer reaction tube made of quartz that forms a space for forming a deposited film that is substantially closed to the surroundings; 51 is an outer reaction tube made of quartz that is installed to separate the flow of gas in the outer reaction tube 50; The inner reaction tube 54 is a metal flange for opening and closing the opening of the outer reaction tube 50, and the base 57 is installed in a base holder 56 provided inside the inner reaction tube 51. Note that the base holder 56 is preferably made of quartz.

Furthermore, the present device can control the substrate temperature using the heater section 59. The pressure inside the reaction tube 50 is controlled by the gas exhaust port 5.
The exhaust system connected via the exhaust system 3 can be controlled.

In addition, the raw material gas is supplied to the reaction tube from the raw material gas introduction line 52 (similar to the apparatus shown in FIG. 1, having a first gas system, a second gas system, and a mixer (all not shown)). 50 is introduced inside. The raw material gas is indicated by arrow 58 in Fig. 3.
As shown in , when passing through the inside of the inner reaction tube 51, it reacts on the surface of the substrate 57 and deposits Al2-Ti on the surface of the substrate. The gas after the reaction passes through the gap formed by the inner reaction tube 51 and the outer reaction tube 50 and is exhausted from the gas exhaust port 53.

When taking out and putting in the base, the metal flange 54 is lowered together with the base holder 56 and the base 57 by an elevator (not shown), and moved to a predetermined position to attach and detach the base.

By forming a deposited film under the conditions described above using such an apparatus, high quality Al2 can be obtained on all wafers in the apparatus.
-Ti film can be formed at the same time.

As mentioned above, AIL-TttM according to the present invention
The film obtained by this method is dense, has an extremely low content of impurities such as carbon, has a resistivity close to that of a bulk film, and has a high surface smoothness, so that the remarkable effects described below can be obtained.

■Decrease in hillocks Hillocks are caused by partial migration of A℃ when the internal stress during film formation is released in the heat treatment process, resulting in Aj
2. Convex portions are formed on the surface. A similar phenomenon also occurs due to local migration due to energization.

The ρ-Tf film formed according to the present invention has almost no internal stress and is in a state close to single crystal. Therefore 45
10' to 1
Whereas 06 hillocks/cm2 occur, according to the present invention, the number of hillocks can be significantly reduced to 0 to 10 hillocks/cm2. Since there are almost no convex portions on the u-Ti surface as described above, the resist film thickness and the interlayer insulating film can be made thinner, which is advantageous for miniaturization and planarization.

■Improving electromigration resistance Electromigration is a phenomenon in which wiring atoms move due to the flow of high-density current. This phenomenon generates and grows voids along one grain boundary, which reduces the cross-sectional area and causes heat generation and disconnection of the wiring. Even in the conventional sputtering method, migration resistance has been improved by adding Cu, Ti, etc. to Al1-5t to form an alloy.

Migration resistance is generally evaluated based on the average wiring life.

The wiring according to the above conventional method is 250℃, 1 x 106A/
cm' current conduction test conditions, an average wiring life of IXIO2 to 103 hours was obtained (in the case of a wiring cross-sectional area of 1 μm2). On the other hand, the AIL-Ti film obtained by the <8n -Ti film formation method according to the present invention has an average wiring life of 103 to 5 x 1 G' hours for a wiring with a cross-sectional area of 1 μm2, according to the above test. Ta.

Therefore, according to the present invention, for example, when the wiring width is 0.8 .mu.m, a wiring layer thickness of 0.3 .mu.m is sufficient for practical use. In other words, since the thickness of the wiring layer can be reduced, the unevenness on the semiconductor surface after the wiring has been installed can be minimized, and high reliability can be obtained for normal current flow. It is also possible through a very simple process.

■Reduction of alloy bits in contact area Due to heat treatment during the wiring process, All in the wiring material and 54 in the substrate undergo a eutectic reaction, and eutectic of Al2 and St, called alloy pits, form into the substrate in the form of spikes. penetration, which can result in the destruction of shallow joints.

As a countermeasure, if the bonding depth is 0.3μm or more,
When a t-5i alloy is used and the junction depth is 0.2 μm or less, Ti, W, and Mo-based barrier metal technology is generally used.

However, there are still issues to be improved, such as the complexity of etching and the increase in contact resistance. The A°C-Ti formed according to the present invention can suppress the generation of alloy bits at the contact portion with the base crystal even by heat treatment during the wiring process, and can provide wiring with good contact properties. In other words, even if the junction is made shallow to about 0.1 μm, A
Wiring can be done using only l1-Ti material without destroying the junction.

0 Improvement of surface smoothness (improvement of patterning properties of wiring) Conventionally, the roughness of the surface of metal thin films has caused inconveniences in the patterning process of wiring, the alignment process for the mask and the substrate, and the etching process.

In other words, the surface of the conventional Aj2CVD has irregularities of several μm and has poor surface morphology, which causes 1) diffuse reflection of the alignment signal on the surface, which increases the noise level and makes it impossible to identify the original alignment signal.

2) In order to cover large surface irregularities, the resist film thickness must be increased, which is contrary to miniaturization.

3) If the surface morphology is poor, halation occurs locally due to internal reflection of the resist, resulting in resist residue.

4) If the surface morphology is poor, there are drawbacks such as the sidewalls becoming jagged during the wiring etching process due to the unevenness.

According to the present invention, the surface morphology of the II-Ti film formed is dramatically improved, and all of the above-mentioned drawbacks are improved.

■Improved resistance in contact holes and through holes.

When the size of the contact hole becomes as small as 1 μa+x1 μm or less, Si in the interconnect precipitates and covers the base of the contact hole during heat treatment in the interconnect process, and the resistance between the interconnect and the element increases significantly.

According to the present invention, since a dense film is formed by surface reaction, it has been confirmed that Al2-Ti completely filled in contact holes and through holes has a resistivity of 3.0 to 6.0 .mu..OMEGA.cI11. Also, the contact resistance is 10” in the Si part in a 0.6 μm x 0.6 μm hole.
When it has an impurity of CI+-', I X 10-'Ω・
About cm2 can be achieved.

In other words, according to the present invention, it is possible to completely embed the wiring material into the minute hole, and to obtain good contact with the substrate. Therefore, the present invention can greatly contribute to improving the in-hole resistance and contact resistance, which have been the biggest problems in microprocesses of 1 μm or less.

In other words, in the patterning process, the alignment accuracy 3σ = 0.15μ at the line width of the exposure machine's resolution performance limit.
m can be achieved, and wiring with smooth sides without causing halation is possible.

■It is possible to lower the temperature or eliminate heat treatment during the wiring process.

As explained in detail above, by applying the present invention to a wiring formation method for semiconductor integrated circuits, it is possible to significantly improve yield and promote cost reduction compared to conventional ^1-Ti wiring. It becomes possible.

(Example 1) First, the procedure for forming an Al2-Ti film is as follows. Using the apparatus shown in FIG. 1, the inside of the reaction tube 2 is evacuated to approximately I.times.10-'Torr using the exhaust equipment 9. However, even if the degree of vacuum in the reaction tube 2 is worse than 1 x 1O-8 Torr, Al1-Ti can be formed.

After cleaning the St wafer, the transfer chamber IO is released to atmospheric pressure and the St wafer is cleaned.
Load the uwe into the transfer chamber. Almost the transport room! ×10-'
After exhausting to Torr, the gate valve 13 is opened and the wafer is mounted on the wafer holder 3.

After attaching the wafer to the wafer holder 3, the gate valve 13 is closed and the vacuum level of the reaction chamber 2 is approximately 1×10-'To.
Exhaust until rr.

In this embodiment, DMA)I is supplied from the first gas line. H2 was used as the carrier gas for the DMAH line.

The second gas line is for ■2, the third gas line is for 112
Diluted Ti (referred to as lJZ4).

112 is supplied from the second gas line, and the opening degree of the slow leak valve 8 is adjusted to bring the pressure inside the reaction tube 2 to a predetermined value. Typical pressure in this example is approximately 1.5 Torr. Thereafter, the heater 4 is energized to heat the wafer. After the wafer temperature reaches the predetermined temperature, the DM^■ line Ti
TiC diluted with DMA) 1112 from CJ24 line
j! , is introduced into the reaction tube. Total pressure is approximately 1.5 T
orr, and the DMA8 partial pressure is approximately l, 5×10-'T
orr. When DMA) I is introduced into reaction tube 2, AJ
Z-Ti is deposited. TiCJ2.4 partial pressure is 1.5X
10-'TO "" After the predetermined deposition time has passed, the supply of DMAH and TiCj24 is stopped. Next, the heating of the heater 4 is stopped and the wafer is cooled. The supply of H2 gas is stopped and the inside of the reaction tube is After evacuating the air, the wafer is transferred to a transfer chamber, and only the transfer chamber is brought to atmospheric pressure, after which the wafer is taken out.

The above is an outline of the AJZ-Ti film forming procedure.

Next, sample preparation in this example will be explained.

Hydrogen combustion method (112
:4jZ/M, 02: 2Il/M) by 1000
Thermal oxidation was carried out at a temperature of °C.

The film thickness is 7,000 ± 500, and the refractive index is 1.46.
Met. Apply photoresist to the entire surface of this Si substrate,
A desired pattern is printed using an exposure machine.

The pattern is 0.25μm Xo, 25μm N100
It appears to have various holes of μm x 100 μm. After developing the photoresist, reactive ion etching (R
5102 as the base using photoresist as a mask using IE) etc.
was etched to partially expose the Si substrate. In this way, 0.25μm x O, 25μm ~ 100
Prepare 130 samples with 5in2 holes of various sizes (μm x 100μ), set the substrate temperature in 13 ways, and at each substrate temperature follow the procedure described above to adjust the total pressure to 1.5 Torr and DMA8 partial pressure to 1.5X. 10'''TorrTi
AIL-Til! was deposited under the following conditions: (:42), partial pressure 1.5 x 1O-6 Torr.

AIL-TI deposited by changing the substrate temperature to 13 levels
The membranes were evaluated using various evaluation methods. Table 1 shows the results.
Shown below.

(Left below) 5i in the temperature range of 160°C to 450°C with the above sample.
L was not deposited on n2, and Ax-rt (o, 銚) was deposited only on the portion where Si was opened and Si was exposed. Note that similar selective deposition properties were maintained even when deposition was performed continuously for 2 hours in the above-mentioned temperature range.

In addition, 300-4% of TfCn 4 + H2 was added just before the reaction tube.
Heating at 00°C further reduced the CII content.

(Example 2) First, the procedure for forming a 4l-Ti film is as follows. The inside of the reaction tube 2 is heated to approximately 1 x 1O-8 Tor by the exhaust equipment 9.
Exhaust to r. The degree of vacuum inside the reaction tube 2 is 1 x 10-'
Al1-Ti can be formed even if the temperature is worse than Torr.

After cleaning the S1 wafer, the transfer chamber IO is released to atmospheric pressure and the S1 wafer is cleaned.
t Load the wafer into the transfer chamber. Transfer chamber approximately 1x 1O
After exhausting to -6 Torr, the gate valve 13 is opened and the wafer is mounted on the wafer holder 3.

After mounting the wafer on the wafer holder 3, the gate valve 1
3 is closed, and the vacuum level of reaction chamber 2 is approximately lXl0-'Torr.
Exhaust until

In this embodiment, the first gas line is for DMA)l.

The carrier gas for the DMAH line was 8". The second gas line was for +2, and the third gas line was for TiCl2 diluted with hydrogen.

Flow ■2 from the second gas line, slow leak valve 8
The pressure inside the reaction tube 2 is set to a desired value by adjusting the opening degree of the reaction tube 2.

Typical pressure in this example is approximately 1.5 Torr. Thereafter, the heater 4 is energized to heat the cube. After the wafer temperature reaches the desired temperature, the DMAH line, Ti
DMAI+ from Cl24 line.

TiCl24 diluted with H2 is introduced into the reaction tube. The total pressure is approximately 1.5 Torr, and DMA) 1 partial pressure is approximately 1
．． It is assumed to be 5×10-'Torr. The partial pressure of TiCl2 is 1
．． 5 x 10-'Torr. When DMA11 is introduced into reaction tube 2, ^12-Ti is deposited. After the desired deposition time has elapsed, the supply of DMAH is stopped. Next, heating of the heater 4 is stopped and the wafer is cooled. (2) After stopping the gas supply and evacuating the inside of the reaction tube, the wafer is transferred to the transfer chamber, and only the transfer chamber is brought to atmospheric pressure, and then the wafer is taken out. The above is the outline of An-Ti film formation.

The deposited film thus formed had similar results to those of Example 1 in terms of resistivity, carbon content, average wiring life, deposition rate, hillock density, spike occurrence, and reflectance.

Furthermore, the selective deposition properties depending on the substrate were also the same as in Example 1.

(Example 3) Using the low pressure CVD apparatus shown in FIG.
11! was formed.

Preparation of Sample 2-1 A thermally oxidized 5in2 film as a second substrate surface material that is non-electron donating is formed on single crystal silicon as a first substrate surface material that is electron donative. Buttering was performed by a photolithography process as shown in 1, and the single crystal silicon surface was partially exposed.

At this time, the thickness of the thermally oxidized 5i02 film was 7,000 mm, and the size of the exposed portion of the single crystal silicon, that is, the opening, was 3 μm×3 μm. Sample 2-1 was prepared in this way. (
Below, such a sample is referred to as “thermal oxidation 5iOz (hereinafter T
-5iO2)/monocrystalline silicon (single crystal silicon).

Preparation of Samples 2-2 to 2-179 Sample 2-2 is an oxide film (
(hereinafter abbreviated as Sin)/Single crystal silicon sample 2-3
is a boron-doped oxide film (
Sample 2-4 is a phosphorus-doped oxide film (hereinafter abbreviated as PSG)/l-crystalline silicon formed by atmospheric pressure CVD; Sample 2-5 is a film formed by atmospheric pressure CVD. Phosphorous and boron doped Bi oxide (hereinafter abbreviated as BPSG)/
! #Crystalline silicon, sample 2-6 is a nitride film (hereinafter abbreviated as P-5iN) formed by plasma CVD/! l-crystalline silicon, Sample 2-7 is a thermal nitride film (hereinafter abbreviated as T-5iN)/
! #Crystalline silicon, sample 2-8 is a nitride film (hereinafter abbreviated as LP-5iN)/single crystal silicon formed by low pressure DCVD, and sample 2-9 is a nitride film (hereinafter referred to as E
CR-5iN)/single crystal silicon. Furthermore, samples 2-11 to 2-179 shown in Table 2 were prepared by combining the electron-donating first substrate surface material and the non-electron-donating second substrate surface material. Single crystal silicon (J!I-crystal St) as the first substrate surface material
, polycrystalline silicon (polycrystalline Si), amorphous silicon (
amorphous St), tungsten (W), molybdenum (Mo
), tantalum (Ta), tungsten silicide (W
Si), titanium silicide (TiSi).

Aluminum (AjZ), aluminum silicon (Aj
2-5i), titanium aluminum (Aβ-Ti), titanium nitride (Ti-N), copper (cu), aluminum silicon copper (AfL-5t-Gu), aluminum palladium (1-Pd), titanium (Ti) , molybdenum silicide (Most) tantalum silicide (Ta
Si) was used. These samples and A4203
Substrate, 5i02 glass substrate shown in Figure 3 using reduced pressure CV
Put it in the O device and put it in the same badge ^I1. -A Ti film was formed. Film forming conditions are reaction tube pressure 0.3 Torr, DMAH
Partial pressure 3. Ox 1G-'Torr, TiCl14 partial pressure 1X10'''Torr, substrate temperature 300°C, and film formation time 15 minutes.

As a result of film formation under these conditions, samples 2-1 to 2
For all samples patterned up to -179, An was present only on the electron-donating first substrate surface.
Deposition of a -Ti (1,5%) film took place, completely filling the 7000 in depth opening.

^The film quality of the J2-Ti film was determined at the substrate temperature of 30 as shown in Example 1.
The properties were the same as those at 0°C and were very good. On the other hand, no Al--Ti film was deposited on the surface of the second substrate, which was electron-donating, and perfect selectivity was obtained. It is non-electron donating.
No l1-Ti film was deposited at all.

(Example 4) Using the reduced pressure CVO apparatus shown in FIG. 3, an Al2-Ti film was formed on a substrate having the configuration described below.

Polycrystalline St as an electron-donating first substrate surface material was formed on a thermal oxide film as a non-electron-donating second substrate surface material, and a photolithography process as shown in Example 1 was carried out. Patterning was performed to partially expose the surface of the thermal oxide film.

At this time, the thickness of the polycrystalline silicon film was 2000, and the size of the exposed portion of the thermal oxide film, that is, the opening was 3 μn+3 μm. Let us call such a sample 1-1. The second substrate surface material (T-5iO2, CVD
-5jO2,BSG,PSG,BPSG,P-5iN,
T-5iN.

LP-5iN, ECR-5:N) and the electron-donating first substrate surface material (polycrystalline St, amorphous St,
^fl, W, Mo, Ta.

WSi, TiSi, TaSi, AIL-5t, ^A
-Ti, TiN, Cu, Al2-5t-Cu,
By the combination of ^1-Pd, Ti, Mo-5t),
Sample 1-1-1-169 shown in Table 3 was prepared.

The reduced pressure Cv of these samples is shown in FIG.

AIL-Ti film was formed within the same badge. The film forming conditions were a reaction tube pressure of 0.3 Torr and a partial pressure of DMAt1 of 3. Ox to-5 Torr, TiCA4 partial pressure I
X 10-'Torr, substrate temperature 300°C, film formation time 1
It's 5 minutes. As a result of film formation under these conditions, in all samples 1-1 to 1-169, all <<
No Al-Ti film is deposited, and about 7000 Al-Ti are deposited only on the first substrate surface, which is electron-donating;
Complete selectivity was obtained. Note that the deposited /l-Ti
The film quality of the film was very good, showing the same properties as those shown in Example 1 at a substrate temperature of 300°C.

(Example 5) Using MMAH2 as the raw material gas, total pressure 1.5 Torr MMA)I2 partial pressure 5 x 10-'TorrTi
CJ! , the partial pressure was set to 1.5 x 10-' Torr, and the deposition was carried out in the same manner as in Example 1.
In the substrate temperature range of 160° C. to 400° C., an Al1-Ti film containing no carbon impurities and excellent in flatness, denseness, and selectivity depending on the substrate surface material was deposited as in Example 1.

(Example 6) First ^f1. The procedure for forming a -3t-Ti film is as follows. Using the apparatus shown in FIG. 1, the inside of the reaction tube 2 is evacuated to approximately 1.times.10-' Torr using the exhaust equipment 9.

However, the degree of vacuum inside reaction tube 2 is 1 x 1O-8 Torr.
Even if it is worse, Al1-5i-Ti will form a film.

After cleaning the Si wafer, the transfer chamber 10 is released to atmospheric pressure and the Si wafer is cleaned.
Load the wafer into the transfer chamber. The transfer chamber is approximately l x 10-'
After exhausting the air to Torr, the gate valve 13 is opened and the quench is mounted on the wafer holder 3.

After mounting the wafer on the wafer holder 3, the gate valve 1
3 is closed, and the vacuum degree of reaction chamber 2 is approximately 1x10-8 Torr.
Exhaust until r.

In this embodiment, DMAH is supplied from the first gas line. H2 was used as the carrier gas for the DMAH line.

The second gas line is for H2, the third gas line is for TiCl diluted with H2, and the fourth gas line is for Si2H6. Further, the third gas line, mixer, and reaction tube are preheated and set at 180°C±10°C.

Flow H2 from the second gas line and slow leak valve 8
The pressure inside the reaction tube 2 is brought to a predetermined value by adjusting the opening degree of the reaction tube 2.

Typical pressure in this example is approximately 1.5 Torr. Thereafter, the heater 4 is energized to heat the wafer. After the wafer temperature reaches the predetermined temperature, [IMAI (line,
TiC standing, line, 5i2H, DMA from line
H, TiCl4, and 5iJa are introduced into the reaction tube. The total pressure is approximately 1.5 Torr, and the partial pressure of DMA) is approximately 1.5 x 10'' Torr.TiCj14
Partial pressure is 1×10-'Torr, 5i2)16 partial pressure is I
X 1O-5 Torr.

When 5iJ6 and DMAH are introduced into reaction tube 2, A, +2
-5tTj is deposited. After the predetermined deposition time has elapsed,
DM^tl, Stop the supply of Ti(:Il, 4 and 5i2H,).

Next, heating of the heater 4 is stopped and the wafer is cooled. H2
After stopping the gas supply and evacuating the inside of the reaction tube, the wafer is transferred to the transfer chamber, and after only the transfer chamber is brought to atmospheric pressure, the wafer is taken out. The above is an outline of the AJZ-Si-Ti film forming procedure.

Next, sample preparation in this example will be explained.

Hydrogen combustion method (H2:
31/M, 02: 2JZ/M) at a temperature of 1000°C.

Prepare the above-mentioned wafer with an oxide film, and follow the procedure described above to obtain a total pressure of 1.5 Torr 1) MA) 1 partial pressure of 1.5 x 10-'
TorrTiCu4 partial pressure I X 10-'Tor
rSt, 'H, partial pressure I X 1O-5TOrr
5000 people deposited AjZ-5i-Ti films under the following conditions,
Using normal photolithography techniques, Aj
Patterning was performed so that 2-5i-Ti was left in a width of 2.4.6 μm.

As a result of evaluating the film deposited by varying the deposition substrate temperature (Ts), favorable results corresponding to those shown in Table 1 were obtained.

(Example 7) A substrate AfL-5t-Ti film having the structure described below was formed using the low pressure CVD apparatus shown in FIG.

On single crystal silicon as an electron-donating first substrate surface material, thermally oxidized 5i02@ is formed as a non-electron-donating second substrate surface material, and patterned by a photolithography process, The single crystal silicon surface was partially exposed.

The thickness of the thermally oxidized 5in2 film at this time was 7000 mm, and the exposed portion of the single crystal silicon, that is, the size of the opening was 3 μm×3 μm. A sample was prepared in this way (hereinafter referred to as "thermally oxidized SiO□" (hereinafter T-5i02
(abbreviated as "monocrystalline silicon").

Similarly, the samples shown below were prepared.

Oxide film (hereinafter abbreviated as SiO□)/single crystal silicon formed by atmospheric pressure CVD, phosphorous-doped oxide film (hereinafter abbreviated as PSG) formed by atmospheric pressure CVD/single crystal silicon, film formed by atmospheric pressure CVD Phosphorous and boron doped oxide film (hereinafter referred to as BSP)
(abbreviated as G)/single crystal silicon.

These samples and AJZ 203 substrate, SiO
□Put the glass substrate into the reduced pressure CvD device shown in Figure 3,
A film of 8°C-5i-Ti@ was formed within the same badge.

The film forming conditions were: reaction tube pressure 0.3 Torr, DMAH partial pressure 3 x 1G-5 Torr, Ti (42a partial pressure 1
x 10-'Torr, 5i2Ha partial pressure 1 x 10
-'Torr, substrate temperature 3 substrate temperature 3 pancreas 0.

As a result of film formation under these conditions, all patterned samples had Afl. Deposition of -5i-Ti film occurs, and 70
The opening, which was 00 people deep, was completely filled. Aj2
- The film quality of the St-Ti film was very good, showing the same properties as those shown in Example 1 at a substrate temperature of 300°C. On the other hand, on the surface of the second substrate, which has a valve electron donating property,
- No St-Ti film was deposited and perfect selectivity was obtained. A℃203 substrate and 5i which are non-electron donating
02 glass substrate also has AjZ. -5i-Ti film was not deposited at all.

(Example 8) A total pressure of 1.5 Torr [IMAI (partial pressure 5 x 10-' Torr) was applied in the same manner as in Example 6.
rSi2H. Partial pressure 1 x 1 (1-5 Torr
Set the substrate temperature (Tsub) to 300℃, and set the TiCl24 partial pressure to 5 x 10-'To
Deposition was performed while varying the Ti content (wt%) within the range of rr to I×10 −′ Torr to form an Aρ-5t-Ti film with a Ti content (wt%) of 0.3% to 4%. Almost the same results as in Example 1 were obtained regarding resistivity, carbon content, average wiring life, deposition rate, and hillock density. Also, as in Example 2, selective deposition properties due to the substrate surface material were confirmed over the entire region.

(Example 9) Total pressure: 1.5 Torr DMAH partial pressure: 5 X 10-'TorrT
iCJZ4 partial pressure I
Depositions were performed varying from rr to 1×10”” Torr. Si content in the formed A1-5i-Ti film (
wt%) changed from 0.005% to 5% almost in proportion to the 5iJ6 partial pressure. The same results as in Example 1 were obtained regarding resistivity, average wiring life, deposition rate, and hillock density. However, in the sample having a Si content of 4% or more, precipitates thought to be St were formed in the film, the surface morphology deteriorated, and the reflectance became 60% or less. The reflectance of the sample with an St content of less than 4% was 80 to 95%, which was the same as in Example 6. In addition, selective deposition depending on the substrate surface material was confirmed in all regions.

(Example 10) The total pressure was adjusted to 1.5 TorrDMAH partial pressure using the same procedure as in Example 6.
5 x 10-'TorrSiJ,
1 x 1O-5TorrTiCIL, partial pressure set as I x 1O-6Torr, Ai-S
i-Ti was deposited.

In the substrate temperature range of 160°C to 400°C, Al1-5 is flat and dense with excellent migration resistance and has excellent selectivity due to the substrate surface material, as in Example 6.
A t-Ti film was obtained.

[Effects of the Invention] As explained above, according to the present invention, low resistance, a! Dense and flat ^ll-Ti or Aj! -5iTi films could be selectively deposited onto the substrate.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of a deposited film forming apparatus to which the present invention can be applied, FIG. 2 is a schematic cross-sectional view illustrating a deposited film forming method according to the present invention, and FIG. 3 is a schematic diagram showing an example of a deposited film forming apparatus to which the present invention can be applied. FIG. 3 is a schematic diagram showing another example of a deposited film forming apparatus. ...substrate, ...reaction tube, ...substrate holder, ...heater, ...mixer, ...vaporizer, ...gate valve, ...slow leak valve, 9... - Exhaust unit, 10... Transfer chamber, 11... Valve, 12-... Exhaust unit, 50... Quartz outer reaction tube, 51... Quartz inner reaction tube, 52... Source gas Inlet port, 53... Gas exhaust port, 54... Metal flange, 56... Base holder, 57... Base body, 58... Gas flow, 59... Heater section. 54 Figure 3

Claims (1)

[Claims] 1) (a) A step of disposing a substrate having an electron-donating surface (A) and a non-electron-donating surface (B) in a space for forming a deposited film, (b) Alkylaluminum (c) introducing a hydride gas, a gas containing titanium atoms, and hydrogen gas into the space for forming the deposited film; maintaining the temperature of the electron-donating surface (A) within a range;
The aluminum film containing titanium is coated on the electron-donating surface (A
) A method for forming a deposited film, characterized by comprising a step of selectively forming. 2) The deposited film forming method according to claim 1, wherein the alkyl aluminum hydride is dimethyl aluminum hydride. 3) The deposited film forming method according to claim 1, wherein the alkyl aluminum hydride is monomethyl aluminum hydride. 4) The deposited film forming method according to claim 1, wherein the gas containing titanium atoms is TiCl_4. 5) (a) Step of placing a substrate having an electron donating surface (A) and a non-electron donating surface (B) in a space for forming a deposited film, (b) Alkylaluminum hydride gas and titanium atoms (c) introducing the alkyl aluminum hydride, the titanium atom-containing gas, and the silicon atom-containing gas into the deposited film forming space; The temperature of the electron-donating surface (A) is maintained within a range of not less than the decomposition temperature and not more than 450° C., and the aluminum film containing titanium and silicon is coated on the electron-donating surface (A).
) A method for forming a deposited film, characterized by comprising a step of selectively forming. 6) The deposited film forming method according to claim 5, wherein the alkyl aluminum hydride is dimethyl aluminum hydride. 7) The deposited film forming method according to claim 5, wherein the alkyl aluminum hydride is monomethyl aluminum hydride. 8) The deposited film forming method according to claim 5, wherein the gas containing titanium atoms is TiCl_4.