JPS60223113A - Forming method of thin-film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a thin film forming method that combines ion beam deposition and vacuum evaporation.

[Prior art]

The present inventors proposed a novel method for forming a thin film by combining ion irradiation and vacuum deposition in Japanese Patent Application Laid-Open No. 58-2022.

That is, in this method, when forming a thin metal compound film on the surface of a substrate by ion beam deposition, the substrate is irradiated with accelerated ions, and the vapor of the metal substance is applied to the substrate simultaneously or alternately with the ion irradiation. The method is to irradiate the area. According to this method, the active energy and kinetic energy of accelerated ions are used to chemically bond the evaporation substance and the ions, thereby making it possible to form a new material on the substrate.

FIG. 2 is a schematic diagram showing a typical apparatus for carrying out this thin film forming method. A gas to be ionized, for example nitrogen, is introduced into the ion source 2 via the leak pulp 1;
After being ionized here, they are accelerated by an accelerator 3 and given a predetermined ion acceleration energy. The ions are then introduced into the analysis magnet 4, where only the required ion species are magnetically selected and supplied to the reaction chamber 5.

The reaction chamber 5 is equipped with a vacuum pump (for example, a vacuum molecular pump) 6.
The vacuum is maintained at a high vacuum of 10 Torr or less. The substrate 7 is fixed to a substrate holder 8, and is irradiated with the above-mentioned ion species. During irradiation, it is desirable to allow the ion species to pass through the converging lens 9 in order to uniformly irradiate the substrate 7 with the ion species.

Reference numeral 10 denotes a vapor deposition device disposed below the base 7, and an appropriate heating method such as electron beam heating or laser beam heating is used for heating this device. This contains, for example, an evaporation source containing aluminum (AI). AI
The amount and rate of evaporation of the evaporation source containing .
It can be measured by

Further, the number of atoms of the ion species, that is, the ion current can be accurately measured by a current integrator 13 equipped with a secondary electron repulsion electrode 12.

A bias power supply 14 whose voltage can be adjusted is connected between the base body 7 and the secondary electron repulsion electrode 12 so as to apply a negative bias voltage to the base body 7 .

In such an apparatus, a predetermined amount of vapor is deposited on the substrate 7 at a predetermined position, and a predetermined ion species is irradiated thereon with a predetermined ion acceleration energy, and at the same time, a predetermined negative bias voltage is applied to the substrate 7. For example, a metal compound thin film such as an AIN film is formed on the surface of the substrate.

However, in this thin film forming method, the ion source 2
The path of the ion species irradiated toward the substrate 7 and the path of the vapor deposition material irradiated toward the substrate 7 from the metal vapor deposition apparatus are not in the same direction. Therefore, according to the apparatus shown in FIG. 2, the vapor deposition material is injected at an inclined angle toward the substrate 7, and due to minute irregularities on the surface of the substrate 7 or the film forming surface, shadow areas where the vapor deposition material is not irradiated are microscopic. There was a problem that uniform surface irradiation was not performed.

Further, it is considered that the ionic species easily reach a high excitation level on the substrate 7, but the other vapor deposited substance is not activated. Therefore, it is preferable that the vapor deposition substance acquires an activation energy state and is vapor deposited on the substrate 7, since this facilitates the progress of reactive bonding with ion atoms.

Furthermore, in thin film forming apparatuses based on conventional methods, when ion generation gas is introduced into the plasma generation region of the ion source to generate ions, all the simultaneously generated electrons pass through the wall of the ion source. It flows to the earth,
As a result, a high amount of electron energy was being wasted.

[Purpose of the invention]

The present invention has been completed in view of the above, and its purpose is to provide a method for forming a thin film by combining ion beam deposition and vacuum evaporation, in which the path of the ion beam and the path of the vapor deposited material are set in the same direction. It is an object of the present invention to provide a thin film forming method capable of producing a desired composite thin film with high quality by performing uniform surface irradiation without any surface irradiation.

Another object of the present invention is to provide a method for forming a thin film in which activation of the vapor material to be deposited is performed simultaneously with the generation of high-energy ions during ion beam deposition.

[Summary of the invention]

According to the present invention, there is provided an evaporation means for a deposition substance, a plasma generation region for dissociating an ion generation gas into ions and electrons, an ion beam acceleration region for accelerating the generated ions and irradiating them onto a substrate, and an ion beam irradiation region. and the substrates on which the deposition material is to be deposited are arranged in this order and in substantially linear alignment, and the vapor of the deposition material is passed through the plasma generation region and the ion beam acceleration region to form a thin metal compound film on the substrates. A method for forming a thin film is provided.

[Means to solve the problem]

Next, the present invention will be described in detail.

FIG. 1 is a schematic layout diagram of a thin film forming apparatus of the present invention.

In the figure, a vapor deposition material 16 is held by a holding mechanism 15, a plasma generation region 17 for dissociating the ion generation gas into ions and electrons, and a substrate 1 for accelerating the generated ions.
It is a distinctive feature of the invention that the ion beam acceleration region 19 for irradiation onto the ion beam 8 and the substrate 18 supported by the support mechanism 20 are arranged in this order and in substantially-linear alignment. .

That is, in the figure, at the bottom of the plasma generation chamber 29,
For example, a holding mechanism 15 such as a copper hearth containing a vapor deposition material 16 such as metal aluminum (kl) is provided, and a plasma generation region 17 is provided above it. A gas introduction pipe 22 for introducing the gas is provided, and a filament 23 for emitting thermionic electrons and a magnet coil 1v24 for plasma generation are arranged around the gas introduction pipe 22. Between the plasma generation region 17 and the ion beam acceleration region 19 above it, there is provided an extraction electrode 25 in the form of a grid or lattice, for example, for extracting ions generated in the plasma generation region 17 to the ion beam acceleration region 19. It will be done.

In this ion beam acceleration region 19, there is an acceleration mechanism, a so-called lens 26, for accelerating the extracted ions in the form of a beam.
is placed. Although this lens 26 is not shown,
It may consist of extraction lenses, deceleration lenses and acceleration lenses known per se, alone or in combination. Above this acceleration region 19 in the reaction chamber 27, a substrate 18 is supported by a support mechanism 20 and is irradiated with ions and steam.

At one end of the reaction chamber 27, a flow of reactant atoms and molecules is directed toward the substrate 1.
A gas outlet 28 connected to a vacuum pump (not shown) for gas suction is provided perpendicular to the gas outlet 8 . Therefore, depending on the way this gas flows, gases adsorbed inside the reaction chamber 27, such as water, oxygen, organic substances, etc., are prevented from reaching the substrate 18.

Further, the base body 18 and the vapor deposition substance holding mechanism 15 are connected to the DC power source 30 such that the base body 18 has a negative polarity and the holding mechanism 15 has a positive polarity. In the illustrated example, this DC power supply 30 includes a variable negative power supply 30a for ion acceleration and a variable positive power supply 30a for electron acceleration connected in series with each other via a ground.
It consists of b.

The plasma generation chamber 29 is grounded via a resistor to prevent electrons from flowing out, and the extraction electrode 25 is connected to a variable negative power source 31 that applies a bias voltage to enable extraction of ions.
It is connected to the.

Furthermore, an electron focusing magnet coil/l' 32 is arranged between the plasma generation region 17 and the vapor deposition material 16 to accelerate the electrons generated in the plasma generation region toward the vapor deposition material 16 in the form of a beam. be done.

f gas 2 for ion generation guided through the gas introduction pipe 22
1 is a plasma generation chamber 2 having a plasma generation region 17;
9, the filament 23 emits thermoelectrons, and as plasma is generated, the plasma generation magnet coil lv2+KjD increases the plasma generation efficiency and dissociates ions and electrons in the plasma generation region 17. generate.

Due to the action of the extraction electrode 25 to which a negative bias voltage is applied, the generated ions are moved outside the plasma generation region 17, that is, into the reaction chamber 27, which is maintained at a high vacuum of 10''-' Torr or less by a vacuum pump. The ions are taken out, focused and accelerated by the action of the lens 26, and irradiated as an ion accelerated beam onto the substrate 18 to which a negative bias voltage is applied.

According to the present invention, the kinetic energy of the ions is preferably set at b O,01 KeV to 100 KeV per atom, preferably from 0.1 KeV to 40 KeV, and depending on the material, the kinetic energy is set to a desired value. It becomes easier to form a composite thin film.1 Furthermore, according to this apparatus, the electrons in the plasma generation region 17 are used as a source of a heating electron beam for the vacuum evaporation means described below.

That is, according to the vacuum evaporation means provided in the thin film forming apparatus of the present invention, a holding mechanism 15 for a copper hearth in which the evaporation substance 16 is housed is attached to a part of the wall surface of the plasma generation chamber 17. Further, by applying voltage between the holding mechanism 16 and the base body 18 so that the holding mechanism 16 becomes positive by the variable positive power source 30b for electron acceleration, the electrons in the plasma generation region 17 are The evaporation material 6 is irradiated in the form of a beam, thereby heating the evaporation material 16 and making it easier to evaporate. When the evaporated metal material passes through the plasma generation region 17, its ionization is highly activated and is deposited on the substrate 18.

According to the present invention described above, it is possible to irradiate the substrate with the ion beam and the vapor-promoting substance at the same time from completely the same %, and to perform uniform area irradiation without shadows, resulting in a homogeneous and highly It becomes possible to form high-quality thin films.

In addition, by irradiating the substrate with the vapor material through the plasma generation region and the ion acceleration region, it is possible to highly activate the vapor material, and the reaction between the vapor deposition material and ions can more easily occur. becomes possible.

Further, electrons generated in the plasma generation region are effectively used for heating and evaporating the vapor deposition material, leading to a reduction in energy costs and making it possible to simplify the configuration of the vapor deposition apparatus.

Of course, the heating of the vapor deposition material is not limited to this, and laser beam heating and heating with a heater can be used alone or in combination with electron beam heating.

The negative voltage (El) for ion acceleration applied to the substrate is from -0.01 to 29 KV, especially from -0.1 to 1.
The negative voltage (E2) applied to the extraction electrode is suitable in the range of 0.0 to 0.01 to 100.
K.V.

In particular, it is between minus 5 and 40 KV. Furthermore, the positive voltage (E3) applied to the deposition material is suitably in the range of 1 to 20 KV, particularly in the range of 4 to 10 Ω'.

Using such a device, the substrate 18 is set at a predetermined position, the interior of the reaction chamber 27 is maintained at a predetermined degree of vacuum, and the vapor deposition device is operated to blow off vapor material from the vapor deposition material 16 containing AI to generate plasma. A predetermined amount of vapor is deposited on the substrate 18 through the region 17, and ion species containing at least nitrogen are irradiated therewith with a predetermined ion acceleration energy, and at the same time the substrate 18 is evaporated with a predetermined ion acceleration energy.
By applying a predetermined negative bias to 8, the surface of the base 18 is
A MN film is formed.

In addition, when using nitrogen gas, the main ion species are cod, N+ ions are reeds, and the irradiation amount of these ions can be measured using the Faraday cup 33a and calorimeter 331 in Fig. 1).
Let's do good. Further, the film thickness is measured using a film thickness monitor meter 34 using crystal oscillation shown in FIG.

The adjustment of the atomic ratio of AI is based on the electron acceleration voltage (E
3) and by changing the current to the electron converging lens 32 to change the amount of evaporation of metal aluminum.

The AJ/N composition ratio in the film can be determined by the following method. That is, the AJ/N composition ratio is determined by the Rutherford feedback scattering method, and based on the results, calibration is performed with the measured values of the film thickness monitor 34, Faraday cup 33a, and calorimeter 331). A curve is formed to indicate the AllIN composition ratio in the film.

The base 18 is heated using a ceramic heater (not shown).
You can do it well.

According to the present invention, it is believed that it is relatively easy for the nitrogen ionic species to reach the high energy level of the SP3 hybrid orbital on the substrate. Therefore, regarding the other M, the vaporized aluminum is ionized while passing through the plasma generation region 17, acquires an activation energy state, and is deposited on the substrate, making it easier to form SP'' bonds with nitrogen atoms.

Furthermore, according to the present invention, the path taken by the nitrogen ion species toward the substrate is the same as the path taken by the AI toward the substrate, and is generally perpendicular to the substrate, making it possible to perform uniform surface irradiation without shadows. can.

Therefore, a desired thin film can be efficiently formed at a high film formation rate.

The substrate may be made of any material, such as ceramics, cemented carbide, cermet, or various metals or alloys. However, if the substrate is an electrical insulator, the properties of the deposited film formed there will be different between charged and uncharged locations, and variations in the properties of the entire film are likely to occur. The base is preferably an electrical conductor. However, even if the material is an electrical insulator, a thin film of a gas conductor may be formed on its surface by a conventional method.

Further, the vapor deposition materials include, for example, aluminum, silicon, boron, titanium, thallium, tungsten, chromium, and iron.

Furthermore, the ion species include, for example, nitrogen, hydrogen,
Sources of substances that form compounds with metals or are inert, such as oxygen, halogens, carbon or argon, are used.

〔Example〕

Examples of the present invention will be described below.

(Example 1) A high quality Alx film was formed using the apparatus shown in FIG.

That is, the 81 substrate was placed on the support mechanism 20, and the inside of the reaction chamber 27 was brought to a vacuum level of 2.times.IQ Torr in advance. Next, high purity N2 gas was introduced into the plasma generation chamber 17 to generate N2+ and N+ ions, and these ions were irradiated onto the substrate through the acceleration region. At this time, the electrons generated in the plasma generation chamber 17 are transferred to high-purity AJ, which is the evaporation material 16.
It is highly activated by irradiation and acceleration and is deposited on the substrate.

The conditions for forming the Alx film are as follows.

Reaction chamber vacuum degree I x 10-' Torr or less Negative voltage for ion acceleration 2 KV Ion acceleration energy 20 KθV When the film was opened for 1 hour, an Alx film of 9000゛λ was formed.

According to this embodiment, AI! Since the atoms are also excited, a high-quality, dense Alx film can be obtained and has excellent adhesion to the substrate.

When a comb-shaped electrode was formed on this AJN thin film and the sound speed of Rayleigh waves propagating on its surface was measured, it was found to be 5,700 ff/S, indicating that it has excellent characteristics of a SAW element.

For example, Ti, Ta can be used instead of AJ as the evaporative substance 16.

When metals such as W and Or were used, high purity nitride thin films of the respective metals were similarly obtained.

(Example 2) In the above example, hydrogen gas was used instead of nitrogen gas, and 81 was used instead of N. Amorphous silicon M capable of controlling valence electrons was produced using a mixture of i ppm of B2H6 in hydrogen gas as a doping gas.

(Example 3) A TiC film was obtained in the same manner.

That is, substrate 1B--Cemented carbide drill vapor deposition material 16...T1 metal ion generating gas 21...CH4 gas was used for 1 hour to coat a 1 μm thick TiC film.

The drill was vibrated and rotated.

Ion irradiation increases the nuclear generation density and increases Wk-axis TI.
Since C grows and T1 atoms are also deposited in a highly activated state, the density and adhesion are improved. Furthermore, 2
Since the components are irradiated in the same direction, a film with uniform composition can be formed. The life of the drill obtained in this example was improved by about twice as compared to RF ion brating.

(Example 4) Substrate 18...S1 single crystal deposited material 16...Ad gold metal ion generation gas 21...Oxygen gas was deposited for 1 hour to form an Altos film of 6000λ.

When the electrical insulation properties of this AlzOa film were measured, the surface resistance was 10 Ω·1.

In addition, in this method, CH
By using 4 gases, an AlaCs film was formed.

〔Effect of the invention〕

According to the thin film forming method of the present invention, since the ionic current and the amount of deposited material can be accurately measured, the composition ratio of the thin film material to be synthesized can be arbitrarily selected as desired, and a thin film material with an arbitrary concentration distribution can be manufactured. can.

Therefore, thin films of any material having a stoichiometric composition ranging from metal films to cermet films to dielectric films can be manufactured.

Further, the method of the present invention can be applied to both methods for producing crystalline films and amorphous films, and can easily and effectively produce thin films of extremely high purity substances.

In addition, in the present invention, the illumination of the ion beam and the course of the evaporated material can be set in the same direction to perform uniform surface irradiation without shadows, and furthermore, the illumination of the ion beam and the course of the evaporated material can be performed in the same direction, and furthermore, the illumination of the ion beam and the material to be evaporated can be performed at the same time as high-energy ions are generated during ion beam deposition. Activation of the vapor substance to be performed takes place. This makes it possible to provide a metal composite thin film of even higher quality.

[Brief explanation of drawings]

FIG. 1 is a layout diagram of a thin film forming apparatus used to carry out the method of the present invention, and FIG. 2 is a layout diagram of a thin film forming apparatus already proposed. 16... Vapor deposition material 17... Plasma generation region 7.
18...Base 19...Ion beam acceleration region 25
...Extractor electrode patent applicant Ryo Hayami, designated agent by the Director of the Agency of Industrial Science and Technology, Mifu agent, patent attorney Katsuhiko Tahara, patent applicant, Kyocera Corporation representative, patent attorney Katsuhiko Tahara Figure 1

Claims (1)

[Claims] A means for evaporating the evaporation material, a plasma generation region for dissociating the ion generation gas into ions and electrons, an ion beam acceleration region for accelerating the generated ions and irradiating them onto the substrate, and a means for evaporating the ion beam and the evaporation material. The substrates to be deposited are arranged in this order and in substantially-linear alignment, and the vapor of the deposition material is passed through the plasma generation region and the ion beam acceleration region to form a thin metallization film on the substrates. Thin film formation method.