JPH03278431A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To form a conductor layer having a low resistance by heating a substrate in an atmosphere containing hydrogenated nitrogen or its derivative of predetermined number of nitrogen atoms, exposing the surface of semiconductor or conductor and then covering it with a conductor layer. CONSTITUTION:A contact hole 3 is formed in an SiO2 film 2 on an Si substrate 1 formed by a CVD method, arsenic is then ion implanted to form an n<+> type impurity injected region 1A, thereby forming a shallow p-n junction. A sample including an adhered matter 4 present on a semiconductor substrate in the bottom of the hole 3 is surface treated with hydrazine by using N2H4 as reactive gas, thereby reducing its contact resistance. Thus, a contact of low contact resistance and low leakage current can be formed, and an electrode and a wiring having a low resistance and excellent coverage can be formed.

Description

Detailed Description of the Invention [Table of Contents] Overview Industrial Application Fields Conventional Technology Problems to be Solved by the Invention Means for Solving the Problems Page 4 Pages 5 Pages 6 Pages 11 Pages 12 Function Examples Effects of the Invention 12 Pages 14 and 35 [Summary] Surface treatment of base substrates and conductors in order to realize contacts with low contact resistance and low leakage current and to form electrodes and wiring with low resistance and good coverage in the manufacture of semiconductor devices. Regarding the method for forming the film, we have developed a method for surface treatment at low temperatures with good reproducibility without causing damage to the underlying substrate or re-adhesion of contaminants, and a method for improving contact resistance and reducing the contact resistance without exposing the substrate to the atmosphere after surface treatment. The purpose of this study is to provide a method for depositing a conductive layer with low wiring resistance and good coverage.
The substrate 1 having a region made of a semiconductor or a conductor is heated in an atmosphere containing hydrogenated nitrogen or an organic compound of the hydrogenated nitrogen with two or more nitrogen atoms in the molecule to expose the surface of the semiconductor or conductor. After that, a metal compound gas and a gas of hydrogenated nitrogen having two or more nitrogen atoms in the molecule or a gas of an organic compound of the hydrogenated nitrogen are used to treat the metal or metal. The structure is configured to precipitate nitrides.

[Industrial application field]

The present invention relates to a method for manufacturing a semiconductor device, and in particular, to realize a contact with low contact resistance and low leakage current, and to form electrodes and wiring with low resistance and good coverage.
The present invention relates to a method for surface treatment of a base substrate and formation of a conductive film.

BACKGROUND ART In recent years, as a result of advances in the density and integration of semiconductor integrated circuits (ICs), devices having semiconductor elements and wiring structures with the minimum dimension of 1 μm or less have come into practical use. Furthermore, as ICs become more highly integrated, multilayer wiring has come to be used. As ICs become denser and more highly integrated, contact holes for making electrical connections also become smaller, leading to an increase in contact resistance.
Furthermore, the depth of the junctions that constitute the semiconductor element is also 0. 1μm
It becomes shallow to about the order of magnitude, and the p
Leakage due to n-junction damage has become more likely to occur. Since an increase in contact resistance and leakage current causes deterioration of the characteristics of a semiconductor device, it is required to reduce this as much as possible.

Furthermore, in order to improve the stability of wiring and electrodes against thermal cycles and the reliability of wiring, flattening of the substrate and improvement of the coverage of the conductive layer are required.

[Conventional technology]

BACKGROUND ART AI or Al alloys such as AlSi and AlCu deposited by sputtering have been widely used for electrodes and wiring of semiconductor devices. However, such materials whose main component is A1 tend to react with Si in the substrate and cause destruction of shallow pn junctions, and when the contact hole becomes as fine as 1 micron or less, coverage is poor with sputtering, and furthermore, It has become clear that there are problems in miniaturizing semiconductor devices, such as easy disconnection due to electromigration or stress migration. Therefore, instead of a material mainly composed of AI produced by sputtering, consideration is being given to using a high melting point metal or its silicide or nitride formed by vapor phase epitaxy (CVD).

Now, by sputtering or CVD, materials containing AI as a main component, high melting point metals, etc. can be applied to the Si substrate as a base.
It is known that when forming electrodes and wiring on a substrate such as the like, the cleanliness of the base greatly affects the contact resistance. If a natural oxide film or organic substance is attached to the surface of the base, it becomes a high-resistance layer and increases the contact resistance. In addition, when titanium (Ti) or the like is deposited on St and then heat-treated to form titanium silicide, natural oxide films and organic substances on the Si surface hinder the formation of silicide and increase the contact resistance. bring. Furthermore, tungsten (W) JL was produced using the CVD method.
When growing i, growth does not occur smoothly on a natural oxide film, etc., so layer formation may not proceed on it, or there may be abnormal erosion of the underlying St in the thin part of the natural oxide film. This leads to increased contact resistance and junction breakdown.

For this reason, the surface of the underlying substrate has generally been cleaned prior to the deposition of a conductive film for forming electrodes and wiring. Conventional surface pretreatment methods include wet etching using a solution containing HF, sputtering using Ar ions, SF, and BCl.
Plasma etching treatment using a reactive gas such as 3, or H2, or a combination of these gases, H2 or NH
8 reduction treatment by heat treatment in an atmosphere, etc.

However, wet etching using a solution containing HF requires washing with water and drying, and is exposed to the atmosphere after the treatment, so a new natural oxide film may be formed during this process, or human error may occur. There is a problem that new organic contaminants are attached. In sputtering and plasma etching processes, charged particles damage the underlying substrate, and in plasma etching processes that use reactive gases, the underlying substrate can be etched, resulting in destruction of shallow junctions, and halides and There is a problem with redeposition of etching by-products.

In reduction treatment by heat treatment in H2, NH, atmosphere, at least 700℃ or higher, usually 900~100''C
This requires high-temperature processing, leading to problems such as the bond becoming deeper due to thermal diffusion of impurities and the substrate being damaged by heat. In addition, since the A1 electrode wiring melts at such high temperatures, it cannot be applied when there is an At electrode wiring underneath, and furthermore, the interlayer insulation film is made of phosphosilicate glass (PS).
When G) or borophosphosilicate glass (BPSG) is used, there is a problem in that the insulating film becomes soft and the shapes of contact holes and the like become distorted. A method for surface treatment at low temperatures with good reproducibility without causing damage to the underlying substrate or redeposition of contaminants has not yet been found.

In order to lower the contact resistance, if a high melting point metal or its silicide or nitride is used instead of AI as the material for the electrodes and wiring in the contact section, such materials will inhibit the reaction between the St of the substrate and the AI electrodes and wiring. Since it also acts as a barrier layer to prevent
The junction is less likely to be destroyed by spikes caused by reactions with the wiring layer. Therefore, it is possible to reduce leakage current caused by junction breakdown.

The problems of coverage and migration of AI wiring by sputtering can also be greatly improved by depositing W by CVD. However, in the CVD growth of W, silanes (SiH) such as tungsten hexafluoride (WF6)
4) It is possible to form a W layer at a relatively low temperature by using a reduction reaction such as It also has the drawbacks of high resistance and poor coverage. CVD using hydrogen reduction of WF
Although coverage is better in this case than in silane reduction, the disadvantage is that the reaction temperature is high and corrosive gas products are formed, resulting in more Si erosion on the substrate and a higher leakage current. There is.

Furthermore, W produced by CVD has poor adhesion to SiO□ and PSG and is easily peeled off. For this reason, a method is used in which an adhesion layer of TiN or the like which also serves as a contact barrier layer is first formed on the base substrate by sputtering, and then a W layer is formed thereon by CVD. However, when sputtering is used to form this adhesion layer, coverage deteriorates at stepped portions such as contact holes, which leads to abnormal growth or non-growth of W, resulting in increased contact resistance and peeling of wiring. was there.

Furthermore, since the pretreatment and formation of the adhesion layer and the formation of W are performed using separate equipment, there is a high possibility that dust etc. will adhere to the substrate during handling, and this is one of the factors that leads to a decrease in yield. It had become.

[Problem to be solved by the invention]

The present invention was created to eliminate the drawbacks of such conventional methods, and provides a base material for realizing contacts with low contact resistance and low leakage current, and for forming electrodes and wiring with low resistance and good coverage. A method for surface treatment at low temperatures with good reproducibility without causing damage or re-adhesion of contaminants to a substrate, and a conductor with low contact resistance and wiring resistance without exposing the substrate to the atmosphere following such surface treatment. The object is to provide a method for depositing layers with good coverage.

[Means for Solving the Problems] This purpose is to provide hydrogenated nitrogen having two or more nitrogen atoms in the molecule, or hydrogenated nitrogen, or The substrate 1 having a region made of a semiconductor or a conductor is heated in an atmosphere containing a hydrogenated nitrogen derivative to perform a surface treatment to expose the surface of the semiconductor or conductor, and then a metal compound gas and molecules are heated. This is achieved by depositing the metal or metal nitride using a mixed gas containing two or more hydrogenated nitrogen atoms or an organic compound gas of the hydrogenated nitrogen.

[Effect]

In the present invention, hydrogenation of two or more nitrogen atoms in the molecule, such as hydrazine (Nz Ha ) with strong reducing power or its derivative methylhydrazine (Nz H, (CHi) 4-), is used for surface treatment of the base substrate. Since heat treatment is performed in an atmosphere containing nitrogen or a derivative of nitrogen hydride, natural oxide films on the underlying surface can be removed at low temperatures with good reproducibility, and the underlying substrate will not be damaged during the treatment process. ,
In addition, the A1 constituting the base substrate will not melt or the PSG etc. will not soften, and even if a conductive layer is deposited on it, abnormal growth will not occur, resulting in an increase in contact resistance and leakage current. does not occur. Furthermore, in the formation of the conductor layer, highly reactive hydrazine (r'1zH4
) or its derivative methylhydrazine (N, H, (
Because hydrogenated nitrogen or derivatives of hydrogenated nitrogen having two or more nitrogen atoms in the molecule, such as CH3), -, ), is used, metals and metal nitrides can be easily precipitated from metal compound gas. can. And the by-products of the reaction are
Since it is a volatile nitrogen compound or low-order hydrocarbon, it is difficult to be incorporated into precipitated metals, etc., and there is almost no increase in resistance as with W due to conventional silane reduction. Furthermore, by performing deposition under surface reaction rate-determining conditions due to the reaction between H and source gas due to the dissociation of N-H bonds on the substrate surface, the thickness of the deposited layer can be made uniform, and even the thickness of the deposited layer can be made uniform. Can be layered with good coverage.

In addition, the same hydrazine (NzH4) or its derivative methylhydrazine (
Since gases such as N, H, (CH, )a-□) can be used, surface treatment and conductor layer deposition can be performed continuously in the same equipment by simply switching the gas. Since the substrate is not exposed to the atmosphere, adhesion of natural oxide films, dust, etc. can be prevented, contact resistance can be prevented from increasing, and manufacturing yields can also be improved. The barrier layer or adhesion layer, such as TiN, and the electrode/wiring layer, such as W, can be formed continuously with good coverage using the CVD method. No peeling of layers occurs.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the figures, the same numbers or symbols are given to the same or corresponding parts.

FIG. 11 is a diagram showing the configuration of the first device used in the example. This apparatus is configured so that surface treatment and formation of a conductive layer can be performed in one reaction chamber by simply switching gases. The substrate 23 to be processed is placed on a quartz window 22 provided at the bottom of the reaction chamber 21, and heated to a predetermined temperature by a heating source (not shown) such as a heater or an infrared lamp provided below the quartz window. It is now possible to do so.

N2H4 for substrate surface treatment and conductor layer formation
The gas 28 is supplied into the reaction chamber 21 via a mass flow controller 29 from a gas inlet 26 through a gas shower 25 arranged to face the surface of the substrate 23 to be processed. In the state of liquid or highly concentrated gas, N, H, and others decompose when they come into contact with metals, so it is desirable to treat piping and the like with Teflon to prevent them from coming into direct contact with metals.

Gases 31 such as TiC1 and WF6 for forming the conductor layer and Ar gas 33 and H2 gas as carrier gases are as follows:
Each of the gases is supplied into the reaction chamber 21 from a gas inlet 27 via a mass flow controller 29 and a gas shower 25 . The pressure inside the reaction chamber 21 is determined by the exhaust speed of the vacuum pump connected to the exhaust port 34 and the gas inlet 26,27.
This is controlled by adjusting the flow rate of the gas introduced.

FIG. 12 is a diagram showing the configuration of the second device used in the example. This apparatus is configured to connect a surface treatment chamber for surface treatment of a substrate and a plurality of CVD chambers through a load rotor chamber so that substrates can be treated in separate reaction chambers without being exposed to the atmosphere.

A load/unload (L/1L) chamber 361, a surface treatment chamber 37, and a CVD chamber 38, 39 are connected to the load rotor chamber 35 through gate valves 41, respectively. The substrate to be processed is in the L/UL chamber 36.
It is carried into either the surface treatment chamber 37 or the CVD chamber 38 or 39 via the load lock chamber 35, where it is subjected to predetermined processing, and after all the processing is completed, it is transferred to the LZUL chamber 36 again.
It is now being removed from the For example, the substrate surface can be pretreated in the surface treatment chamber 37, W can be grown in the CVD chamber 38, and TiN can be grown in the CVD chamber 39.

During this time, each of the reaction chambers 37, 38, 39 can be kept in a steady state, and a plurality of substrates can be processed simultaneously as in an assembly line.

FIG. 13 is a diagram showing the configuration of a third apparatus used in the example. One surface treatment chamber 57a, 57b and two film forming chambers 58a, 5
8b, and has a configuration designed to improve processing capacity. In the figure, 51 is a gate valve, and 59 is an exhaust device. This device can also be used in the same way as the device shown in FIG.

Pretreatment of the substrate using hydrazine when forming a W layer on a silicon substrate using the apparatus shown in FIG. 11 will be described below.

1(a) to (c) are diagrams showing the steps of this embodiment. In the figures, 1 is a mold silicon (Si) substrate, 2 is a silicon dioxide (SiO2) film, 3 is a contact hole, and 4 is a
is a deposit, and 5 is a W layer. FIG. 1(a) shows a sample before being carried into the apparatus. First, this sample was made of a 5,000-layer thick Si substrate 1 on a p-type Si substrate 1 with a diameter of 6 inches and a plane orientation of (100). , a film 2 is formed by the CVD method, a contact hole 3 is formed in this 5in2 film 2 by a combination of known photolithography and etching, and then n-type impurities are introduced by ion implantation of arsenic (As). A region IA is formed to form a shallow pn junction. On the semiconductor substrate at the bottom of the contact hole 3, there is deposit 4 consisting of etching residue, organic matter and other contaminants deposited during the process, and a natural oxide film.
exists. This sample was placed in the reaction chamber 21 of the apparatus shown in FIG. 11, and subjected to surface treatment using hydrazine. The reaction gas used was N, H, and the carrier gas used was H2, He, or Ar, each with a flow rate of 10 sccm and a pressure of 0. Heat treatment was performed for 30 seconds while changing the temperature of the substrate under the conditions of ITorr (FIG. 1(b)).

Then, in the same apparatus, using W F b and hydrazine, the process was carried out as shown in Fig. 1(c) (,
A contact was formed by selectively growing W on the substrate within the contact hole. The conditions for the growth of W are as follows. NzH4 and WF were used as reaction gases, and their flow rates were 10 sec and 15 sec, H2 was used as a carrier gas at 50 sccm, and the pressure was 0. I
Torr, and the substrate temperature was 300°C. W grows through the following reaction.

3NzHa + 2WI'a→3Ng + 12) IP
+ 2W (1) Also, when we measured the contact resistance of each of the samples prepared in this way, we found that the contact resistance of those that had been surface-treated at a substrate temperature of 200°C or higher was clearly lower than that of those that had not been surface-treated.
It has been found that cleaning occurs when heat treatment is performed at a temperature of 200° C. or higher in an atmosphere of H. The temperature of the substrate is 200
It is effective at temperatures above 900°C, but at temperatures above 900°C, the Si substrate may be nitrided by hydrazine itself or by-product nitrogen, and the previously cleaned surface may be covered with nitrides. The temperature is preferably from 200"C to 900℃ or less. From the viewpoint of obtaining good effects at the lowest possible temperature, it is most preferable to keep the substrate temperature at about 300℃. The chemical reaction between N, H, and deposits is as follows. It is as follows.

If the deposit is 5in2, N2H4+ S10□→ Nt + 2HzO+ Si
(2) Or 2NzHa + Sin□→2Nz + 2HzO+
5iH4(3) If the deposit is organic, jNJ4 + CRH+e → jNz + a
cHa + bCJa+・ ・ ・ ・ (4
) If the deposit is AltO, 3NJa + 2A1zO: +→3Nz + 4AI
+68zO (5) The above reaction will be explained using FIG. 2.

Figure 2 shows the free energy of formation (−ΔG
) is plotted against absolute temperature (K). The reaction of equation (3) occurs at temperatures above 600°C, -
Since ΔG becomes positive, the reaction progresses in the direction of the arrow. (
In the reaction of formula (2), at temperatures below 1050, =ΔG is negative, so if the reaction of formula (2) and the reaction of formula (3) are concerted reactions, the reaction of formula (3) is Occurs on a priority basis.
That is, the surface of the Si substrate is cleaned. Note that the natural oxide film on the surface is not stable 5iOz, but has a weak bond expressed by 5iOX, so in reality, as mentioned above, the surface remains clean even at temperatures below 200℃ (~473K). It is thought that this will occur.

On the other hand, 2NJ4+ 3Si 4 Si3Ng + 4Hz
Although the reaction (6) is also expected, direct nitriding of Si usually does not occur at a high temperature of 1000° C. or higher even if NH is used. Also, 5iJa + 3NZ) 14 → 5Nz
+3St)(a) Since -ΔG becomes positive at temperatures above 700°C, the reaction proceeds to decompose 5iJ4 formed at -1, and in fact, the reaction of equation (5) It is believed that nitrides are not formed.

In equation (4), -ΔG is negative over the entire temperature range, so it seems that no reaction can occur. However, the oxide film formed on the surface does not have a thermally stable structure like Ai,03, but is a natural oxide film with weak bonding strength like AlX0y, so 1Nz) I4+ AIX Oy →i Nz + xA
The l + yH2° reaction occurs easily and the surface is cleaned.

Figure 3 shows a sample formed by keeping the substrate temperature constant at 300'C, changing the surface treatment time, and then growing about 4000 W in the contact hole under the conditions described above. Contact resistance (R
) and surface treatment time. For comparison, Figure 3 shows the contact resistance value when wet etching was performed for 10 to 20 seconds using a dilute solution of As is clear from the figure, the longer the surface treatment time with hydrazine is, the smaller the contact resistance becomes. It can be seen that the contact resistance is lower than in the case.

Figure 4 shows the samples used for the measurements in Figure 3, one in which contacts were formed by CVD growth of W after hydrazine treatment for 30 seconds, and one in which contacts were formed by depositing AI after wet etching treatment. FIG. 2 is a diagram showing the results of investigating the relationship between diode leakage current and anil. In the figure, (1) shows the leakage current after hydrazine treatment for 30 seconds, without annealing, after annealing at 450'C for 30 minutes, and after annealing for 130 minutes at 450'C, and (2) shows the leakage current after wet etching treatment. No annealing, 45
It shows the leakage current after annealing at 0″C for 30 minutes.

As is clear from the figure, the W/
The leakage current of a diode with an St contact is smaller than the leakage current of a diode with an Al/Si contact according to the conventional method, and is particularly smaller by more than an order of magnitude when annealing is performed at 450° C. or higher.

Next, Si
An example of surface treatment of a substrate will be described below.

Note that in this example, the same Si substrate and device as used in the first example were used.

First, with the temperature of the substrate at 350°C, the substrate is brought into contact with a dimethyl hydrazine atmosphere for surface treatment, the reaction chamber is once evacuated, and then a W F b atmosphere is introduced, and the substrate is brought into contact with the atmosphere, and the St of the substrate is W was deposited on the substrate by reduction of WF.

FIG. 5 is a graph in which the value of sheet resistance, which is proportional to the reciprocal of the thickness of W deposited on the substrate, is plotted against the time that the substrate is in contact with the WFh atmosphere.

For comparison, the figure also shows the results for a substrate that was not subjected to any particular surface treatment.

For substrates surface-treated with dimethylhydrazine, W
F, the sheet resistance is almost constant regardless of the time of contact with the atmosphere, but in the case of a substrate without surface treatment,
When WF is in contact with the atmosphere for 5 seconds, its sheet resistance shows the value of a Si substrate, and W hardly grows, but as time passes, the sheet resistance decreases to about 4Ω.
/ Becomes a mouth.

Generally, WF and Si react as shown in equation (8) below, 2WFi + 3Si→ 2k + 3SiFa
(8) The reaction ends when W is precipitated on the substrate and the exposed portion of Si disappears (Tungsten a
nd 0ther Refractory Metal
s for VLSI Application, v
ols, I-IVMRS, Pjtsburgh,
PA, (1986-1989), ). This corresponds to the fact that the sheet resistance becomes constant.

On the other hand, if oxides etc. exist on the surface of the St substrate, W F
It is known that & enters into the substrate through the gap, and as a result, the W film becomes thicker than when the substrate is clean (H, H, Busta and C, H, T
ang, J, E], electrochem, Soc, +
vol, 133+1195 (1986);
T, Ohba, Y, Ouyama, S, Inoue.
, and M.

Maeda, Tungsten and 0ther
Refractory Metals for VLS
I Application, vol. II,
59 (1987), ), that is, the sheet resistance of a substrate surface-treated with dimethylhydrazine quickly becomes constant and, moreover, exhibits a higher value than the sheet resistance of a substrate without surface treatment. The surface was cleaned by the dimethylhydrazine treatment, and a thin -like W film was quickly formed on the surface, indicating that the erosion of the substrate did not stop.

Furthermore, for comparison, we measured the sheet resistance of a substrate that had been surface treated by hydrogen reduction at 700°C and then brought into contact with WF and an atmosphere, and found that it was 30 to 80 Ω/mouth, which was higher than that of the surface treated with dimethylhydrazine in this example. It almost matches the processed one. This shows that dimethylhydrazine treatment at 350°C achieves the same level of cleaning as hydrogen reduction at 700°C. In this example,
Needless to say, the processing temperature is lower and thermal damage is reduced.

11. An example in which a nitride layer as a barrier layer and an adhesion layer and a metal layer as an electrode/wiring layer are successively grown on a substrate on which an insulating film having contact holes is deposited will be described below. .

Note that the substrate and device used are the same as those used in the first and second examples. Figures 6(,a) to (
c) is a diagram showing the process of this example, and in the diagram 401
1 is a barrier layer, and other members corresponding to those in FIG. 1 are given the same numbers.

First, a pscrl with a thickness of about 5,000 thick is formed on a silicon substrate 1 by a known CVD method to form a glabellar insulating film 2, and the glabellar insulating film 2 is selectively etched with a width of about 5,000 by, for example, reactive ion etching. A contact hole 3 for a person is formed. Then, as described in the first embodiment, surface treatment is performed to expose the surface of the substrate 1 at the bottom of the contact hole 3 as shown in FIG. 6(a). Next, without taking the substrate out of the apparatus, the reaction gas is changed, and as shown in FIG. A barrier layer 401 is formed by a CVD method. The growth conditions are as follows. TiCl4 was used as the reaction gas.
H2 was introduced into the reaction chamber for 50 seconds using N2H as a carrier gas for 20 seconds,
Adjust the pressure to 0°1 to 1. Q Torr, and the substrate temperature was 600°C. The reaction that occurs at this time is 2NzHa
+ 2TiC14→ 2TiN + N2
+8HCI (9), TiN precipitates, and by the way, if the substrate temperature is below 500℃, N2H4
+ TiCl4 → Ti + Nz + 4)
Ti is precipitated by the reaction of ICI (10).

Next, the supply of TiC1a is switched to the supply of WF, and a W layer 5 having a thickness of about 5000 layers is formed on the TiN barrier layer. The conditions for the growth of W are as follows. The reaction gas is WF, 10scc+a, Nz H4
l Qsccm, He as carrier gas 1005
cc11 were respectively introduced into the reaction chamber, the pressure was set at 0.1 to 10, Q Torr, and the temperature of the substrate was set at 380°C.

Finally, if necessary, by etching the W layer 5 and the TiN barrier layer 401 by, for example, reactive ion etching, the TiN barrier layer 401 and the WIii 5 are embedded in the contact hole 3, as shown in FIG.
A wiring structure as shown in c) is obtained. Note that it is also possible to pattern the TiN barrier layer 401 and W layer 5 on the interlayer insulating film into a wiring shape to form a direct wiring.

In this example, the barrier layer is formed by CVD method instead of sputtering method as in the conventional method, so the formed TiN barrier layer 401 is denser and the contact hole 3
Inward coverage is also good.

The same applies to the W layer 5. Furthermore, unlike in the case of silane reduction growth, reaction by-products are not incorporated into the W layer, making it possible to obtain a W layer with low resistance.

Figure 7 shows the specific resistance and A of the W layer formed by the method of this example.
The reflectance for I is plotted against the growth temperature (substrate temperature). In the figure, the solid line corresponds to the wl formed by the method of this embodiment, and the dashed line corresponds to the conventional example (1
) corresponds to the W layer formed by conventional silane reduction, and the conventional example (2) indicated by the - dotted chain line corresponds to the W layer formed by conventional hydrogen reduction.

(The growth conditions for silane reduction are 5 sec for WF6,
SiH4 is 5 sec, H2 is 100 sec
The pressure is Q, l Torr.
The conditions for growth by hydrogen reduction are WF, 10 sccm,
H.

is a mixed gas of 1000 sccm and the pressure is 5 Torr.
It is. ] As is clear from FIG. 7, with the conventional method, a W layer with low resistivity and high reflectance could not be obtained, but with the method of this example, the growth temperature was approximately 350°C.
When the temperature is from .degree. C. to 450.degree. C., a W layer is formed which has a lower resistivity and a higher reflectance than the conventional one.

FIG. 8 is a diagram comparing the coverage rate of the W layer according to the method of this embodiment with that of the W layer according to the conventional method.
In the figure, conventional example (1) and conventional example (2) correspond to those in FIG. As shown in the upper part of FIG. 8, the cutout ratio is expressed as a percentage of the film thickness on the side wall of the contact hole to the film thickness on the flat area of the substrate. wlO by the method of this example
The coverage rate is higher than that of the W layer using the conventional method, and is close to 100%. Note that N2 for WF,
Reduce the flow rate of H4, for example WF, /Nz H4=1
If it is set to about 0/2, the growth rate will decrease, but the coverage can be improved.

Although this embodiment has described an example in which a W layer is formed on the barrier layer, a Cu layer or an A1 layer may be formed instead of the W layer. In the growth of Cu, a halogen compound of Cu or a complex such as Cu(H,FA)z can be used as a reactive gas. Further, in the growth of AI, a halogen compound of AI, an organic AI compound such as alkylated AI, etc. can be used.

FIG. 9 shows a contact layer 40 made of Ti or the like before forming a barrier layer in order to further reduce contact resistance.
FIG. 4 is a diagram showing a cross section when 0 is formed. Tt as a contact layer consists of TiCl4 and NzH4 in the reaction gas.
It can be formed by using a growth temperature of 500° C. or lower. After this, if the barrier layer, W or Cu or A1 layer is formed as mentioned above,
The wiring structure is completed. According to the present invention, even such a multilayer structure can be formed within the same apparatus without exposing the substrate to the atmosphere.

Next, an example of forming a multilayer wiring structure using the manufacturing apparatus shown in FIGS. 11 to 13 will be described.

FIG. 10 is a diagram showing the steps of this example.

10(a) to 10(b) are basically the same as FIG. 1(a) to 10(c) of the first embodiment. After the step in FIG. 10(b), the WF of the reaction gas
6 is changed to T i C1a, and a TiN layer (or Ti layer) 6 is formed on the entire surface as an adhesion reinforcing layer (FIG. 10(C)). The growth of this adhesion reinforcing layer is performed under the following conditions. The flow rates of reaction gas T i C1a, N, and H are both 1Qsccm, and the flow rate of carrier gas H2 is 100
secm, and the pressure was Q, 2 Torr.
The substrate temperature was between 400°C and 800°C, but temperatures between 500'C and 700°C are preferred for TiN growth.

If the temperature of the substrate is lower than 500''C, Ti will precipitate instead of TiN.

Next, the reactive gas is switched to WF6 again, and a W layer is formed on the TiN layer 6 to a thickness of, for example, 3,000 layers under the same conditions as when forming the W layer 5.

This is then patterned to form a W wiring layer 7 (FIG. 10(d)). Thereafter, as shown in FIG. 10(e), a 5iOz film 8 having a thickness of, for example, 4,000 is formed as a glabellar insulating layer to cover the W wiring layer 7, and a contact hole 9 is opened therein. This was again set in the reaction chamber of the device and subjected to the same surface treatment as in the first embodiment to remove any deposits such as oxides adhering to the W wiring layer 7 in the contact hole 9. remove. Finally, as shown in FIG. 10(f), in the same manner as the formation of the W layer 5,
A W layer 11 having a thickness of about 4000 layers is formed in the contact hole 9. Immediately thereafter, the reactive gas is switched to AICII, and an AI layer 12, which will become the second layer wiring, is grown over the entire surface. For the formation of A11i, instead of AlC1, AI (CH3):l and AI (i-C4H7)
Organic AI compounds such as :+ can also be used.
In this way, a multilayer wiring structure is formed.

In addition, in the above examples, W was used as the metal halide.
F6. Although TiC1, AlClff are used, other materials include Mo, V, Zr, and Cu.

Halides of Au and Pt can also be used.
In addition, as organometallic compounds and metal complexes, W (Co
), , Au (HFA) can also be used.

In addition, as hydrogenated nitrogen, Nz Hz, NS H5
can also be used. As a derivative of hydrogenated nitrogen, NZ
In addition to Hz(CHz)z, N2H(CH3)3,
N, H, (CH3), N, H, (CH,l) can also be used.

〔Effect of the invention〕

According to the present invention, in the manufacture of semiconductor devices, it is possible to perform surface treatment at low temperatures with good reproducibility without causing damage to the underlying substrate or redeposition of contaminants, and after such surface treatment, the substrate is exposed to the atmosphere. Since a conductive layer with low contact resistance and wiring resistance can be deposited with good coverage without exposing the material, it is possible to form contacts with low contact resistance and low leakage current, and electrodes with low resistance and good coverage can be formed.・Wiring can be formed.

As a result, it is possible to improve the performance and manufacturing yield of semiconductor devices such as ICs that are particularly highly dense and highly integrated, which in turn has the effect of further increasing the density and integration of semiconductor devices. be.

[Brief explanation of drawings]

Figure 1 is a diagram showing the process of the first example, Figure 2 is a diagram showing the temperature dependence of the reaction of hydrazine, Figure 3 is a diagram showing the relationship between surface treatment time and contact resistance, and Figure 4 is a diagram showing the relationship between surface treatment time and contact resistance. A diagram showing the relationship between leakage IT flow and annealing, FIG. 5 is a diagram showing the effect of the second embodiment, FIG. 6 is a diagram showing the process of the third embodiment, and FIG. 7 is a diagram showing the third embodiment. FIG. 8 is a diagram showing the effect of the third embodiment. FIG. 9 is a diagram showing a modification of the third embodiment. FIG. 10 is a diagram showing the process of the fourth embodiment. 11 is a diagram showing the configuration of the first device used in the example, FIG. 12 is a diagram showing the configuration of the second device used in the example, and FIG. 13 is a diagram showing the configuration of the second device used in the example. 3 is a diagram showing the configuration of the device No. 3. FIG. In the figure, 1, 2.8, 3.9, 4.11, 5.7.11, 6, 12, 400, 401 are silicon substrate, insulation layer contact hole deposit tungsten layer adhesion reinforcement layer wiring layer contact layer The barrier layer 21 is the reaction chamber 22, the quartz window 23, the substrate to be processed 25, the gas jaws 28, 31, the reaction gas 29, the mass flow controllers 32, 3
3 is the carrier gas 34 is the exhaust port 35 is the load lock chamber 37, 57 is the processing chamber 3B, 39.58 is the film forming chamber 41, 51 is the gate valve 36, 50.56 is the loading/unloading chamber 59
indicates the exhaust system.

Claims (8)

[Claims] (1) A substrate having a semiconductor or a conductor is heated in an atmosphere containing hydrogenated nitrogen or a derivative of the hydrogenated nitrogen having two or more nitrogen atoms in the molecule, and the surface of the semiconductor or conductor is exposed. 1. A method for manufacturing a semiconductor device, comprising the steps of: exposing the exposed semiconductor or conductor; and thereafter depositing a conductive layer on the exposed semiconductor or conductor. (2) Heating a substrate having an insulating film covering at least a part of the surface of a semiconductor or conductor in an atmosphere containing hydrogenated nitrogen or a derivative of hydrogenated nitrogen having two or more nitrogen atoms in the molecule; A method for manufacturing a semiconductor device, comprising the steps of: removing at least a portion of the insulating film. (3) The substrate is heated to a temperature of 200° C. to 900° C. in an atmosphere containing hydrogenated nitrogen or a derivative of hydrogenated nitrogen in which the number of nitrogen atoms in the molecule is 2 or more. Alternatively, the method for manufacturing a semiconductor device according to 2. (4) The substrate is heated in an atmosphere containing hydrogenated nitrogen having two or more nitrogen atoms in the molecule, or a derivative of the hydrogenated nitrogen, and a metal compound, so that the metal or metallic nitrogen is deposited on the substrate. A method for manufacturing a semiconductor device, comprising a step of precipitating a compound contained therein. (5) Heating a semiconductor or a substrate in which both a conductor and an insulator are exposed in an atmosphere containing hydrogenated nitrogen having two or more nitrogen atoms in the molecule or a derivative of the hydrogenated nitrogen and a metal compound. Then, on the semiconductor or conductor of the substrate,
A method for manufacturing a semiconductor device, comprising selectively depositing the metal. (6) The method of manufacturing a semiconductor device according to claim 1, wherein the conductor layer is deposited and formed by the step according to claim 4 or 5. (7) A claim characterized in that the step of exposing the semiconductor or conductor surface of the substrate and the step of depositing the conductor layer are performed sequentially without exposing the substrate to the atmosphere in between. 7. The method for manufacturing a semiconductor device according to 1 or 6. (8) The substrate is heated to a first temperature in an atmosphere containing hydrogenated nitrogen having two or more nitrogen atoms in the molecule or a derivative of the hydrogenated nitrogen, and a metal compound, and the The method is characterized by comprising a step of depositing a metal, and a step of heating the substrate in the atmosphere to a second temperature higher than the first temperature to deposit a nitrogen-containing compound of the metal on the substrate. A method for manufacturing a semiconductor device.