JPS62174382A - Method and apparatus for depositing metallic alloy from vapor phase - Google Patents

Abstract

PURPOSE:To stably deposit a solid phase alloy essentially consisting of the metallic component of the main material at a high speed and high yield with high efficiency on the surface of a substrate, regardless of any substrate, by using a hollow cathode electrode discharge for a means for supplying excitation electrons. CONSTITUTION:The substrate 3 consisting of Al, etc., is heated by a heater element 8a in a holding body 8 of the substrate 3, then an inert gas such as H2 which is a plasma-generating gas is passed from a blow off port 2b of a hollow cathode electrode tube 1. The gaseous pressure in a reactor chamber 6 is maintained under about 1X10<-3>Torr and thereafter the voltage of a DC bias power source 4 is increased to generate the strongest plasma light in the above-mentioned electrode tube 1, by which the glow discharge is effected between the same and the anode substrate 3. A gaseous metallic compd. such as SiH4 is gradually passed to a grid electrode 9 and at the same time, the gaseous pressure in the chamber 6 is maintained under about 1-5X10<-4>Torr. The above-mentioned gas such as SiH4 is cracked by the above- mentioned plasma and the film of amorphous silicon, etc., is deposited on the surface of the substrate 3.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical field and purpose of the invention) The present invention utilizes plasma CVD (Chemical Vap
erl) deposition), that is, a method in which an alloy is deposited on a substrate by a decomposition reaction caused by collision of excited electrons and excited atoms or excited molecules with a gas phase metal compound, and a hollow cathode electrode discharge is used as a means for supplying excited electrons. This method is characterized by the use of high speed, high efficiency, and high yield, even on large areas and moving substrates, regardless of the substrate, while maintaining the same advantages as conventional microwave methods. It is possible to deposit a solid phase film mainly composed of metal components.

(Prior art and its problems) The so-called CVD method for depositing an alloy film from a vapor-phase metal compound is based on the thermal CVD method, in which the vapor-phase metal compound comes into contact with the surface of a substrate heated to a high temperature and receives decomposition energy. A method of forming an in-phase film on a substrate through a thermal decomposition reaction due to It is broadly divided into two methods: (1) a method of transmitting the electromagnetic waves to form a solid-phase film on a substrate, and (2) a method of changing the irradiated electromagnetic waves to ultraviolet light or laser light, which is the optical CVD method.

Furthermore, DC is used as a discharge means in plasma CVD method.
Electric discharge, radio wave discharge, so-called RF discharge, and microwave discharge have been put into practical use, and the above-mentioned types of electromagnetic waves are selected industrially depending on the type of substrate on which the alloy film is to be deposited and the characteristics expected of the deposited alloy film.

By the way, the electromagnetic waves currently being applied industrially are several kHz.
~Several 10MHz, especially 400kllz, 13.5
Electromagnetic waves in the 6MHz radio frequency band, with -i R
This method is called F glow discharge decomposition reaction. However, in this method, the energy of the electrons emitted from the electrode is 4~3e
V, the electron density is on the order of 101'-1010 cm-', and the electron temperature is on the order of 1014°. Therefore, the gas pressure required to maintain discharge is limited to approximately 0.1 to 10 torr, although it varies depending on the electrode spacing and discharge voltage, and from various industrial standpoints, the following problems arise: There is.

For example, when depositing an amorphous silicon photoresist film for electrophotography with a film thickness of 25 μm on an aluminum cylindrical substrate using SiH4 gas, the gas pressure is 0.5 torr and the RF output is 300 W (0.06 W/cm”). The electrodes are arranged so as to be capacitively coupled to a counter electrode with an area of 5000cm while maintaining a spacing of 40mm, and the substrate is heated at 300°±1°C.
Deposition is performed by heating to cause a decomposition reaction by RF glow discharge. However, with this, the deposition rate is at most 30-50
80 μm to obtain a film thickness of 25 μm
It takes a long time, ranging from minutes to 2.5 hours. Moreover, the feedstock gas is Si)1. The raw material gas utilization efficiency, which indicates the yield of Si atoms actually deposited on the substrate, is only 7 to 10% with respect to gas molecules. Therefore, the current situation is that the material cost of the finished product is unnecessarily high.

Furthermore, a drawback of this method is that the plasma discharge maintenance vacuum level is approximately 0.1 to 10 torr as mentioned above, and under this condition, the probability of collision of one radical molecule is high, so powder generated in the gas phase It is easy to create polymolecular particles with Therefore, it has the disadvantage of reducing the utilization efficiency of the feedstock and at the same time adhering to the substrate or the formed film, resulting in abnormal film deposits, resulting in photoelectric properties and image defects that are undesirable for an amorphous silicon photoreceptor. At the same time, this results in a decrease in manufacturing yield.

On the other hand, the frequency of microwave discharge is 2.45 GHz, which is higher than the RF method, and is approved for industrial use, and its excited electron density is l Q 12 cm -3
That's high. Therefore, the gas pressure is 10-3 to 10-' to
Even under a high vacuum of rr, almost all of the reactive gas molecules such as SiH4 and H2 are decomposed to form a plasma state containing silane radicals. As a result, up to 500 people/sec can be placed on the board.
It is also possible to perform deposition at a deposition rate that is about 10 times or more than that of RF discharge, and it is possible to ensure raw material utilization efficiency of approximately 50% or more. Also, the gas pressure during the reaction is 1/103 of the RF method.
Since the plasma discharge can be maintained even at ~1/10' times, the probability of collision of one radical molecule is also low. For this reason, it has various advantages over the RF method, such as being able to produce a polymer with low absorption and high yield, and is an industrially effective method.

However, on the other hand, in this microwave method, the microwave energy oscillated by a magnetron oscillation tube is guided into the reactor chamber using a waveguide and emitted, so the directivity is good, so it can be divided into a space with a cross-sectional area almost equal to the shape of the launch tube. However, there is a drawback that plasma reaction does not occur effectively. Therefore, there is a drawback that the effective deposition area, ie, the substrate area, is forced to be significantly smaller than that of the RF method.

In addition to the above, a common drawback of the RF method and microwave is that
Since these RF waves and microwaves are compression waves of electrons, they have the disadvantage that the higher the frequency, the more easily they are susceptible to interference from reflected waves, and as a result, the generated plasma sometimes stops. Therefore, in order to maintain stable plasma, attempts have been made to eliminate the adverse effects of interference by a method of generating standing waves, such as the electron cyclotron resonance method, so-called ECR method.

However, even with this method, there are constraints on the external magnetic field, resonance conditions of the resonance box, substrate shape, magnetism and non-magnetism of the substrate,
Structure of so-called equipment for moving substrates, etc.

It is known that the degree of freedom regarding deposition conditions and substrate conditions is quite low, and that the adverse effects of interference as described above can only be eliminated under very limited conditions.

Therefore, regardless of the material of the substrate, it has a fundamental defect that cannot be used as an industrial manufacturing technique in which a CVD deposited film is continuously formed over a large area while moving the substrate.

The present invention maintains high-speed deposition performance equivalent to or higher than the above-mentioned microwave method, high utilization efficiency and yield of raw material gas, and can be applied to both magnetic and non-magnetic substrates, as well as large-area substrates and moving substrates. The purpose of the present invention is to provide a method and apparatus that can deposit metal films stably and continuously. Next, the present invention will be explained in detail using the drawings.

(Means and effects of the present invention for solving the problems) In order to expect the same deposition rate, raw material gas utilization efficiency, and yield as the microwave discharge method described above, 10-
It is necessary that stable discharge be maintained in a high vacuum atmosphere of 'torr or higher. For this 10-'
In a high vacuum atmosphere of more than torr, that is, a rough atmosphere with a molecular density of about 1012 cm:l in the reactor chamber, electrons collide and the energy of the electrons is transferred to the molecules of the gaseous metal compound, which causes excitation. It is required that the released electrons become radicals and reach the substrate, but in order to achieve this, the energy and density of the electrons that cause the radical reaction are important. In other words, although it is related to the ionization and potential magnitude of colliding molecules, in order for a gaseous metal compound to become a radical, an electron energy of 10 eV or more is usually required, and at the same time, the gaseous metal compound and the excited electrons are It is necessary to bring the probability of collision as close to 1 as possible, and for this purpose, the higher the density of electrons, the more advantageous it is. In addition to this, it is important to note that the lower the probability that excited radical electrons will collide with other radical electrons or unreacted metal compound gas molecules until they reach the substrate, the more likely it will be possible to prevent the formation of multimolecular particles. It is possible to deposit an alloy film without distortion in atomic arrangement.

The present invention is characterized by hollow cathode discharge, that is, basically, as shown in FIG. (4) Various effects that occur when applied, namely the electron avalanche ionization multiplication α effect in the opposing or hollow hollow cathode tube (1), the hollow cathode tube (1)
Plasma-generating gas molecules introduced into the tube are ionized by collision with electrons, and secondary electrons are generated by hitting the hollow cathode electrode tube (11), and the ionized gas molecules change from a metastable state in which they do not ionize. Photoelectronic action of light that occurs when returning to a stable state 7E1%
Furthermore, the hollow cathode discharge method, which obtains plasma by the secondary electron efficiency γ, in which the metastable molecules themselves collide with the hollow cathode electrode tube and emit secondary electrons, produces high-density plasma that cannot be obtained by ordinary DC glow discharge. The key point is that plasma containing electrons can be stably created even in a high vacuum atmosphere of 10-' torrO using scales.

If the hollow cathode electrode tube is used as a plasma generation source in this way, the density of electrons emitted from the hollow cathode tube will be 10" to 1010 electrons/c in the case of RF glow discharge.
1010~10” 7th, which is 100 times more than ffI3
The image shown in FIG. 3 is extremely large. ■The plasma between the hollow cathode electrode and the anode electrode has a gas pressure of 10-'
It can be maintained stably even under the high vacuum of Lorr. For example, in RF discharge, hydrogen gas is used to increase the gas pressure to 10-”t.
orr, plasma discharge cannot be maintained when the electrode spacing is 401 m, so as mentioned above, the electrode spacing is 10-1 to 10
Gas pressures of torr are commonly used.

Therefore, in RF discharge, the probability of radical electrons colliding with other radicals or unreacted gas molecules is high, but in hollow cathode discharge, the probability is extremely small, about 1/10' to 10' of that in the case of the RF method. Therefore, by using the hollow cathode discharge method, for example, by placing the substrate under a plasma with a gas pressure of 10-'torr and an electron density of 1010 to 1012 particles/cm', it is possible to prevent the formation of polymolecular particles. High-speed deposition is possible with efficient use of gaseous raw materials. In addition, since the hollow cathode method is basically a DC glow, unlike the RF method and the micro method, it does not generate reflected waves due to the substrate surface or the arrangement of the acta chamber (reaction tank). Therefore, not only is there almost no restriction on the shape of the substrate shape 9 reaction tank, the substrate can be moved continuously, and furthermore, if an anode electrode is provided, there is no need to use the substrate itself as an anode, and glow sunlight can be used. Placing the substrate within the pillars provides a degree of freedom in which the alloy film can be deposited. For example, in the above explanation, the hollow cathode electrode tube (1) was made into a hollow cylindrical shape, but in the case of a wide, large-area substrate, as shown in FIG. 2(a) (
As shown in the front sectional view and side sectional view shown in b), the hollow cathode electrode tube (1) is formed into a U-shaped cross section that is longer than the width of the substrate (3), and is pulled by a vacuum pulling device (5). A substrate ( 3
), it is possible to deposit an alloy film even on a large-area substrate.

Furthermore, for example, when the substrate (3) to be deposited is cylindrical, two long sets of U-shaped cross sections are formed, as shown in the front sectional view and top sectional view shown in FIG. Hollow cathode electrode tubes (1) are placed and fixed in the reactor chamber (6) at intervals, and the cylindrical substrate (3
) can deposit an alloy film. Therefore, there is a high degree of freedom regarding the shape of the hollow cathode electrode depending on the type of substrate and the structure (and the CVO deposited film can be formed at low cost by industrial mass production.

In addition, in the present invention, as mentioned above, high-energy electrons collide with the deposited film at high density and with high probability, so-called electron damage cannot be ignored, and if this continues, the desired crystallographic and electrical morphology of the film will not be achieved. becomes difficult to obtain. However, this difficulty can be eliminated by the invention described below.

For example, as shown in FIG. 1, FIG. 2, and FIG. 3, a gas outlet (2b) for plasma generation is provided at the innermost part of the hollow cathode electrode tube (11), and from there the gas outlet (2b) is connected to the NZ.

Inert gas such as Arz, He, Ht, etc. is introduced into the opening of the electrode (
2c), a plasma is generated in the excited electron flow running from the cathode to the anode electrode. On the other hand, a grid electrode (9) having an outlet (9a) is provided between the hollow cathode electrode tube (1) and the anode substrate (3) so that the main material metal compound gas can be blown out at right angles to the plasma flow. The plasma from the hollow cathode electrode is connected to the grid electrode (9) from which the main material metal compound gas is blown out.
).

This adjusts the electric field of the electrons flying from the hollow cathode electrode tube (1) toward the anode substrate (3) at high speed and weakens the kinetic energy of the electrons, thereby reducing electron damage. It can be prevented.

As another method, as shown in the cross-sectional view in FIG. It is also an effective means to arrange a magnet and use an external divergent magnetic field from this magnet to cause the electrons to reach the substrate surface while performing cyclotron motion.

In other words, the electrons generated within the hollow cathode tube (11) are
As the magnetic field generated by the external magnet α diverges and weakens in the direction of the substrate (3), the emitted electrons are attracted to the potential between the electrodes and approach the anode substrate (3) while continuing their cyclotron motion. At this time, the metal compound gas molecules and the electrons collide with each other with a higher probability to form radicals due to the cyclotron movement and high density. As the magnetic field gets weaker as it approaches the anode substrate (3) surface, the kinetic energy of the electrons is consumed by cyclotron motion, so most of the electrons that reach the substrate (3) surface break bonds with the atomic arrangement of the deposited film. It can be made to have only a small amount of kinetic energy that has no effect.

Conversely, it is possible to adjust the distance between the hollow cathode electrode and the anode substrate and the electric field and magnetic field between the electrodes to conditions that do not cause electron damage to the deposited film, and this method uses microwaves and electromagnetic waves. There is no need for a means to stably sustain plasma generation using a resonance box as in the case of the present invention. Note that the reduction in deposition rate due to the grid electrode (9) is at most 20% compared to the case without the grid electrode.
It's only a degree of destruction. Furthermore, when using an external magnetic field, the generated electron density does not tend to decrease when observing the electrode current, but rather increases. In other words, the present invention is a device that is easier to heat than examples that use microwaves or electromagnetic waves.
It can be said that it has a basic principle that allows stable plasma to be obtained with good controllability.

Furthermore, as described above, the plasma generating gas is an inert gas, and the structure is such that it is blown out from the outlet (2b) provided at the innermost part of the hollow cathode electrode tube (1) toward the opening direction. This is a major feature of the present invention for stabilizing the discharge caused by the hollow cathode electrode tube (11) and extending its life. That is, if reactive gas exists on the inner surface of the hollow cathode tube (1), the surface of the electrode metal An insulating or high-resistance film is deposited on top of the electrode, causing non-uniformity in the electric field within the electrode due to changes in impedance, resulting in localized arc generation and plasma distortion, making the glow discharge unstable. Also, local spatter causes evaporative wear and tear of the hollow cathode electrode tube.However, by blowing out inert gas toward the opening side as in the present invention, reactive gas can be wiped away from the inner surface of the electrode and prevented. According to experiments, when SiH4 gas is used as the main material metal compound gas, H2 gas is heated to a vacuum degree of 10-' tor.
It was confirmed that Si was not deposited on the inner surface of the hollow cathode tube by flowing about 5 to 203 ccM with respect to r. Note that it is also possible to select a gas that combines with a metal compound through a plasma reaction as the plasma-generating gas and to incorporate the gas into an alloy, or to select a gas that does not form an alloy at all.

Next, an example of an apparatus used to implement the present invention will be described.

[I] (Structure for depositing a metal film on a flat substrate) FIG. 5 is a partial cross-sectional view, and in the figure (1) is a hollow cathode electrode tube, which is similar to that shown in FIG. It is formed from the parts shown. In FIG. 1, (2) is the hollow cathode metal, that is, the cathode electrode part, (2a) is its terminal, (
2b) is a plasma generating gas outlet, (2c) is an opening, and this hollow cathode electrode tube (1) has a diameter of 3 fins to 151i1 and a length of 100n+ to 150nm, for example.
It is made in the shape of a hollow cylinder with a lid of size 1.

The inner surface is made of a high melting point metal such as Ni, Mo, or W.

It is coated with a metal such as Mg to a thickness of about 1 to 51N to prevent it from melting due to temperature rise due to discharge. Ql) is an electrode supporting metal that surrounds the cathode electrode metal part (2) leaving the gas outlet (2b) and opening (2c) of the electrode tube (1). (2) is the support protrusion (12a
), and is made of, for example, Pyrex glass or quartz glass to cover the electrode support metal αυ, and has a plasma generating gas introduction tube (
12b) is made, and thus the hollow cathode electrode tube (1) is formed. And this introduction pipe (1
2b) into the internal space of the hollow cathode electrode tube (1) through the outlet (2b) to inject an inert plasma-generating gas, such as Nt, which does not deposit metal and does not react with the electrode metal.
, Arz, He, H2, etc. are caused to flow in the direction of the lower end opening (2c). Note that the hollow cathode electrode tube (1
) has a large output, the temperature of the electrode metal (2) increases until the vapor pressure cannot be ignored due to being hit by high-density electrons, causing an adverse effect. Therefore, for example, if the material of the electrode supporting metal aυ is copper, which has high thermal conductivity, the water cooling cylinder (1
2c) Use a more cooling method.

Next, returning to FIG. 5, (6) is a cylindrical reactor chamber with both ends closed, and an insulator (13a
), an insulator for airtight penetration of the conductor for applying power to the grid electrode (13b), an insulator for airtight penetration of the conductor for applying power to the substrate (13c), an insulator for airtight penetration of the conductor for voltage application of the anode substrate (3) The lower reactor chamber (13d) is formed from a lower reactor chamber (13d) and an upper reactor chamber (05) placed thereon through an insulator circle and hermetically coupled thereto. Then, an airtight gasket (1
Insert the hollow cathode electrode tube (1) through 5b),
By screwing the lid (15c) onto the cylindrical support (15a), the hollow cathode electrode tube (1) is inserted into the reactor chamber (6) while the inert plasma generating gas introduction tube (12b) is pulled out. Fix it. Note that the reactor chamber (6) is made to have a diameter of 300 mm and an internal volume of 20 A, for example. (5) is a vacuum evacuation device, which consists of a rough evacuation pump (7), a diffusion pump αω, etc. Next, (8) is a substrate holder, (8a) is a heater element for heating the substrate, and α comb is a heater power source, which heats the substrate (3) placed thereon to, for example, about 300±1'C. do. Further, the substrate holder (8) is installed in the reactor chamber ( (9)
is a grid electrode that also serves as an introduction pipe for the main material metal compound gas, and this is, for example, a 5-dragon pitch with a diameter of Q, 5
It is formed by winding a stainless steel pipe with a diameter of 311 and having dragon-shaped blow-off holes (9a) in the - row into a ring shape with a diameter of 4 (1+m) so that the blow-off holes (9a) are located at right angles to the central axis. Then, align the substrate (3) so that its center axis is coaxial with the center axes of the substrate (3) and the hollow cathode tube (1).
) away from the substrate (3) and hollow cathode tube (1).
The main material metal compound gas is blown into the plasma formed between the anode and cathode through the blow-off hole (9a). (N4 is a DC bias voltage, α9 is a grid potential adjustment resistor, the hollow cathode electrode tube (1) is kept at a negative potential, and the substrate (3) is kept at a positive potential. The plasma generating gas blown out from the outlet (2b) of (1) causes the hollow cathode electrode tube (
Plasma is created between 11 and the anode substrate (3), but in principle, either one of the lower reactor chambers (I), which is electrically isolated by the upper reactor chamber α9 and the insulator Q4), can be used as the anode. Plasma can be generated if the substrate (3) and substrate holder (8) are
The plasma is localized on the substrate (3) by anodizing only the substrate (3). Further, the grid electrode (9) is maintained at a negative potential by a DC bias power supply (4), and its potential is adjusted by an adjustment resistor α. (The second is the supply source of the plasma generation gas and the main material metal compound gas, such as H, CI,
, B, H, /H2, BJ, /SiH4, SiH4, etc. (21a) (21b) (21c) (
21d) formed from (21e). (22a) (
22b) (22c) (22d) (22e) (2
2f) is a gas flow rate regulator, in which a cylinder of inert gas H2 is connected to the inert gas introduction pipe (12b), and these cylinders are connected to an introduction pipe of the main material metal compound gas of the grid electrode (9). (9a), but if necessary, select a gas that combines with the metal compound gas through a plasma reaction as the plasma generating gas, and select a gas to be alloyed and incorporated, or select a gas that does not alloy at all. is also possible. Next, the operating procedure and CVD deposition results will be explained.

(Operation procedure) Open the vacuum reactor chamber (6) and place the AL substrate (3) with the size of 50X50X3 dragon mouth onto the substrate holder (8).
After fixing it on the top, close it and first pull it to 10-'torr with the rough vacuum pump αη of the vacuum evacuation device (5), then switch to the diffusion pump aω and apply 2Xl0-htorr.
Pull to rr.

During this time, the substrate (3) is heated by the heater element (8a) embedded in the substrate holder (8) and the power supply α barrel, and its temperature is maintained at 300±1°C.

Next, 5 to 20 SccM of N2 gas, which is a plasma generating gas, is flowed from the outlet (2b) (see Figure 1) of the hollow cathode electrode tube (1), and the main valve orifice (
After adjusting the gas pressure in the reactor chamber (6) to about I x 10-3 torr by adjusting step 3), the DC bias power supply voltage is increased to about 100 to 250 cm. Then, the strongest plasma light is generated inside the hollow cathode electrode tube (1), and a glow discharge appears between the anode substrates (3). 2 shows how a high-density electron flow flows in the plasma between the hollow cathode electrode tube (11) and the anode substrate (3).
A large discharge current reaching ~30A flows. Note that if the voltage is increased and the discharge current is too large, the metal in the hollow cathode tube (11) will be hit with high energy and metal vapor will be mixed into the plasma generation gas. The amount of electrons is further increased by emitting electrons, but this occurs when the hollow cathode electrode tube (11) is formed from the same type of metal material as the deposited metal during the formation of the CVD film, or when the deposited metal film is intentionally This is not preferred unless it is necessary to mix hollow cathode electrode metal.Therefore, the cathode current must be appropriately selected in relation to the film thickness.

Next, gradually flow 1103 cc of 100χ Si II a gas into the grid electrode (9), and at the same time adjust the main valve orifice (2) to bring the gas pressure in the reactor chamber (6) to 1 to 5 X 10-' torr. do. Then, the interference colors change one after another and an amorphous silicon film begins to deposit on the surface of the substrate (3). After performing CVD deposition for 10 minutes, the main material metal compound gas S i II
, the gas supply is stopped, and the DC bias voltage is further cut off to stop the plasma reaction. Then, the supply of N2 gas, which is a plasma generating gas, is stopped and the reactor chamber (
6) At the same time as creating a high vacuum inside, the heating of the substrate (3) by the heater element a was also stopped and allowed to cool naturally.
After waiting for the temperature to drop below 0° C., N2 gas is fed into the reactor chamber (6) to bring it to atmospheric pressure, the dust actor chamber (6) is opened, and the substrate (3) is taken out.

(Deposition Results) The amorphous silicon film deposited on the AL substrate (3) through the above process has a thickness of about 10 to 12 μm. Therefore, the deposition rate will be 167 to 200 people/sec.

Furthermore, according to observation using a quadrupole mass spectrometer installed between the diffusion pump αQ and the reactor chamber (6), during the plasma decomposition of SiH4 gas, which is the main material metal compound gas, less than 5% of Sil14 and SiHz, Sit
(It is thought that S i II a is almost 100% decomposed in the plasma, and the raw material gas utilization efficiency at this time is 46%. This is significantly higher than the utilization efficiency of 5 to 10%, and is a great industrial advantage.

Note that the dark resistance of the amorphous silicon film obtained under the above reaction conditions was 10'Ω.

[■] (Configuration of apparatus for performing deposition on a cylindrical substrate) A case will be described in which an amorphous St film is deposited on an aluminum cylindrical substrate with a diameter of 100 m and a length of 330 m.

Cross sections U arranged at the intervals described above according to FIG.
As two sets of long hollow cathode electrode tubes (1),
The length is 500 mm longer than the width of the board (3), and the depth is 60 mm.
The width of the opening part (2c) is 3 fins, and the innermost part has a diameter of 0.
．． A 5-piece plasma generating gas outlet (2b) provided at 10-piece intervals is used, and the openings (2c) are attached to a mandrel (not shown), and a dummy drum (total) is used.
200u+ from the surface of the cylindrical substrate (3) sandwiched by
They were placed parallel to each other so that they were separated. - As a grid electrode (9) that also serves as an introduction pipe for the oyster material metal compound gas, the diameter of the outlet (9a) is arranged in a row at 10-diameter intervals, the diameter of which is changed sequentially so that the amount of gas blown out is uniform in the longitudinal direction. 6.3 straight tubes are used, and this is connected to a line connecting the center of the cylindrical substrate (3) and the center of the two sets of hollow cathode electrode tubes (1), as shown in Figure 3(b). Hollow cathode electrode tubes (1
) and the cylindrical substrate (3), that is, the main material metal compound gas was released in a direction perpendicular to the electric field between the anode and the cathode.

In addition, (12b) is a plasma generating gas introduction tube, (6) a beam actor chamber, (6a) is a gate valve, (4) is a DC bias power supply, and the side is a grid potential adjustment resistor, (2a)
) is the cathode terminal.

(Operating Procedures and Deposition Results) Taking the case of forming an amorphous 1tSi film on an electrophotographic photosensitive drum as an example, we will first describe the case in which no potential is applied to the grid electrode (9), and then discuss the case in which the grid potential is changed. explain.

An aluminum substrate is used as the cylindrical substrate (3), which is pre-cleaned with a weak alkaline aqueous solution and then dried. The adhesive chamber (6) in the strictly controlled clean room JB is opened and the heater element is heated. A mantle (not shown) containing a built-in capacitor is attached to a cylindrical substrate support. Then, both ends are sandwiched between dummy drums (totals) with a length of approximately 60 mm so that the entire length of the substrate (3) is located within the uniform plasma. ・50 mm Next, the reactor chamber (6) is closed and evacuated. After evacuating to 10-3 torr or less using the rough vacuum pump of device (5),
After switching to the diffusion pump and evacuating the inside of the reactor chamber to below 2×10-' torr, the substrate (3) was heated to 300± torr using the heating element in the mandrel.
Heat to 1°C. After that, adjust the orifice of the may valve so that the degree of vacuum becomes I x 10-' torr while flowing high-purity hydrogen gas at 150 S ccM into each hollow cathode electrode tube (1) while drawing it with a diffusion pump. . Next, while rotating the mandrel at a speed of 10 revolutions per minute using an electric motor (not shown), the voltage between the hollow cathode tube (1) and the substrate (3) is set to 300 to 500 . ) to generate a hydrogen plasma that emits white light toward the substrate (3). Note that the rotation of the substrate (3) does not cause the plasma to become unstable. Then, while surrounding the grid electrode (9) with plasma, B z t is emitted from the outlet (9a) of the main material metal compound gas.
500 SccM of SiH4 gas mixed with lb gas was gradually introduced into the reactor chamber (6) until the degree of vacuum was 5.
The orifice of the main valve is adjusted to maintain x10-' torr.

Then, through a monitoring window (not shown), Sil14 and B2116 come in contact with the hydrogen plasma that emits white light, and a decomposition reaction immediately occurs to generate silane radicals. This can be seen from the distribution of pink plasma emission near the surface. Also, since the area that emits pink light at this time does not reach the hollow cathode electrode tube (1), it is clear that the SiH
Diffusion of a gas molecules or silane radicals in the actor chamber (6) is limited to a narrow range, and as soon as the hydrogen plasma and SiH4 gas come into contact, they obtain decomposition energy and become silane radicals, which are precipitated in the same phase on the substrate (3). The area to which the silicon deposited film adheres in the chamber is the surface of the grid electrode (9) for blowing out the main material metal compound gas, the surface of the cylindrical substrate (3), and the dummy drum (toward) to form an amorphous silicon film. This can also be seen from the fact that no polymer powder was produced or deposited anywhere.

After 5003 ccM of SiH4 gas was steadily flowed and deposition was performed for 30 minutes, the supply of SiH4 gas was stopped and the applied voltage for discharge was set to OV. Subsequently, the supply of N2 gas, which is a plasma generating gas, is stopped, and at the same time, the power supply to the heater element of the mandrel is stopped to stop heating, and the mandrel is left in a high vacuum until the temperature of the mandrel falls to about 100° C. or less. After that, N2 gas is introduced to bring the inside of the reactor chamber (6) to atmospheric pressure, and then the reactor chamber (6) is opened and the cylindrical substrate (3) on which the amorphous silicon film is deposited is taken out.

The film thus formed had a deposited film thickness of 20 to 30 μm, and analysis using an ion microanalyzer confirmed that this film was a silicon-boron-hydrogen alloy. Also, the deposition rate at this time was 153
The utilization efficiency of raw material gas per person/sec was about 53%.

Furthermore, the dark resistivity indicating photoconductivity is 5×10”Ω・
It was confirmed that the method could be applied to electrophotographic resistors.

Next, an example will be described in which a metal film having a three-layer structure is formed on an aluminum cylindrical substrate (3) by changing the composition of the main material metal compound gas using the same procedure. High purity Si
By reacting a mixture of 100 S ccM of N2 gas containing 200 SccM L and 13zL of 2000 PPM for 17 minutes while maintaining the discharge voltage at 300 V while supplying the main material metal compound gas from the grid electrode (9). First, a P+ layer having a thickness of about 5 μm was formed on the surface of the substrate (3). Next, S containing Bzl'L gas mixed with IOPPM
iH4 gas was supplied at 5003 ccM and the discharge voltage was 3.
00 ■ for 300 minutes to form a π layer with a film thickness of about 25 μm, and finally high purity SiH4 gas was added at 50 S cc.
A high-purity CH4 gas of 500 S cc M was supplied and reacted for 3 minutes at a discharge voltage of 300 μm to form a SiC layer of approximately 3,000 layers. At this time, N2 gas was used as the plasma generating gas and was continuously flowed into the reactor chamber (6) at 5003 ccM, so that the hydrogen plasma was not extinguished even when layer formation was switched.

As for the photoelectric properties of the amorphous silicon photoreceptor thus prepared, an electrostatic charging potential of 600 V was obtained on the drum surface in corona charging with a positive charging voltage of 6.5 kV, and when it was left in a dark place for 5 seconds. The subsequent surface charging potential was 150V. From this, the dark decay rate becomes 25%, but such a rapid dark decay rate is not suitable for practical use as an electrophotographic photoreceptor. As mentioned above, the cause of this is that high-energy electrons in the plasma collide with the deposited film at a high density, breaking atomic bonds and creating charge trap centers, or forming energy levels localized near the conductor. This is thought to be due to the fact that the surface charge easily escapes to the substrate (3) as a result of receiving so-called electron damage.In order to eliminate this defect, the grid electrode (9) must be biased to a negative polarity. Thus, control for bending the excited electrons flowing from the hollow cathode electrode tube (1) toward the anode substrate (3) becomes extremely effective.

Next, the effect of changing the voltage of the grid electrode (9) under the same apparatus configuration and deposition conditions as above will be explained. The voltage of the grid electrode (9) is 1/10 to 1/2 of the discharge voltage.
Observing the spread state of the pink luminescent plasma near the grid electrode (9) when the voltage of the grid electrode (9) is Ov, the hollow cathode electrode tube (
A white light hydrogen plasma region extending from 1) wraps around the grid electrode (9) and reaches the surface of the substrate (3). However, when SiH4 gas, which is the main material metal compound gas, is introduced from the grid electrode (9), the area where pink silane radicals emit light is between the grid electrode (9) and the substrate surface (3).
) is a localized plasma region. When the voltage of the grid electrode (9) is increased from Ov, the pink plasma light in contact with the surface of the grid electrode (9) becomes thinner, and when the voltage is further increased, the surface of the grid electrode (9) becomes a dark area. Become. That is, since the grid electrode (9) is biased more cathodically as the voltage increases, excited electrons flying from the hollow cathode electrode toward the anode substrate (3) are bent due to the grid potential and easily collide with the anode substrate. (
3) cannot be reached at a high speed and the discharge current becomes small, and at the same time, the plasma light emitting region also becomes slightly pinkish in the vicinity of the substrate (3) surface.

The film quality obtained in this way was applied to the grid electrode voltage at 60°C.
When evaluating the photoreceptor characteristics when the discharge voltage was set to 300 V, the corona charge voltage was 6.5 kV.
The surface charge potential at this time is 700V, and the potential after being left in the dark for 5 seconds is 500V, and the dark decay rate is 70%. This photoconductive property is sufficient for use as a photoreceptor for electrophotography. Furthermore, the deposition rate is reduced by about 20%, which means that a film having the ability to accept a high potential can be obtained even though it is thinner than the film thickness when no voltage is applied to the grid electrode. This shows that the scope of application of the present invention is not limited to mere deposited coating of CVD films, but can also be applied to cases in which the deposited films are provided with electrical functions.

Furthermore, the CVD method of the present invention can be applied not only to the deposition of the amorphous silicon alloy film described above, but also to the production of polycrystalline silicon, epitaxial silicon films, and even GaAs films. It can also be applied to the field of coating to improve mechanical strength.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the method of the present invention, Fig. 2 is a diagram showing an apparatus for depositing while moving a large-area flat substrate, Fig. 3 is a diagram showing an apparatus for depositing on a cylindrical substrate, and Fig. 4 is an external view. FIG. 5 is a diagram showing an apparatus for controlling the plasma state by a magnetic field, and is a configuration diagram when depositing on a flat substrate. +1)...Hollow cathode electrode tube, (2)...Cathode (hollow cathode electrode metal), (2a)...Cathode terminal, (2b)...Gas outlet, (2c)...Opening Part, (3)...Substrate, (4)...DC bias power supply, (5)...Evacuation device, (6)...Reactor chamber, (6a)...Gate valve, (7 )...Rail, (8)...Substrate holder, (8a)...Heater element, (9)...Grid electrode that also serves as the introduction of main material metal compound gas, (9a)... Air outlet, α
Φ...Magnet, a...Electrode support metal, (2)...Electric insulator, (12a)...Support part, (12b)...
Plasma generation gas introduction pipe, Q3...lower reactor chamber, (13a) (13b) (13c) (13d)
αa...Insulator, α order...Upper reactor chamber, (
15a)...Cylindrical support part of hollow cathode electrode tube,
(15b)...Putskin, (15c)...Lid part, α
e...Diffusion pump, αη...Roughing vacuum pump, α
Odor: Heater power supply for substrate heating, a9: Resistor for grid electrode potential adjustment, (2m: Gas supply source, (21a)
) ~(21e)...Cylinder, (22a) ~(22
f) -Flow rate regulator, (to)...dummy drum, (company)...main valve orifice. Figure 1

Claims (12)

[Claims] (1) In the CVD method, which uses a gas containing a metal component as the main material and deposits a solid film mainly composed of the metal component as the main material on a substrate in a mixed gas of other gases that act as auxiliary materials, the reaction mode is is a plasma glow discharge, and the plasma generated by exciting plasma-generating gas molecules other than the main material metal component gas with electrons emitted from a hollow cathode electrode tube decomposes the main material metal compound gas, and the surface temperature is controlled. A method for depositing a metal alloy from a vapor phase, the method comprising depositing a solid phase alloy film on a substrate. (2) A hollow cathode electrode tube that generates a glow discharge between it and the anode, an introduction section for plasma-generating gas that is excited by the electrons emitted from the glow discharge and becomes plasma, and is decomposed by the generated plasma. Depositing an alloy metal from a gas phase, comprising: an introduction section for a main material metal compound gas to be decomposed; and a substrate support having a heating section for the substrate positioned in the decomposed main material metal compound gas atmosphere. A device that allows (3) In claim 1, a plasma state is formed by introducing into the hollow cathode a gaseous element that reacts with a gas containing the main material metal to form an alloy and deposits it on the substrate. A method for depositing alloy metals from the gas phase. (4) A gas containing a main material metal component is introduced into a plasma of other gases to cause a decomposition reaction of main material metal compound gas molecules.
A method for depositing alloy metals from a vapor phase as described in Section 1. (5) A conductive part that also serves as an introduction part for the gas containing the main metal component is provided in the plasma of a gas other than the gas containing the main metal component, and the potential of the conductive part is controlled to prevent electron damage to the deposited film. A method for depositing alloy metals from the vapor phase as claimed in claim 1, characterized in that the influence is controlled. (6) A magnet is provided to apply a coaxial external magnetic field to the outer periphery of the electron flow generated from the hollow cathode electrode tube, and the energy of the electrons colliding with the substrate is adjusted by controlling the magnetic field of the magnet, and the deposited film is Claim 1 characterized in that the influence of electron damage is controlled.
A method for depositing alloy metals from a vapor phase as described in Section 1. (7) Excite hydrogen gas with a hollow cathode electrode tube,
From the gas phase according to claim 1, the resulting hydrogen plasma decomposes silane gas and diborane gas to produce an electrophotographic amorphous Si-B-H alloy on the surface of the cylindrical substrate. A method of depositing alloy metals. (8) Depositing an alloy metal from a gas phase according to claim 2, characterized in that a grid electrode is provided between the hollow cathode electrode tube and the substrate support, which also serves as an introduction tube for the main material metal compound gas. Device. (9) An apparatus for depositing an alloy metal from a vapor phase according to claim 2, further comprising a hollow cathode electrode and a magnet for applying an external magnetic field that shares the central axis of the hollow cathode electrode. (10) A second claim characterized in that a hollow cathode electrode tube having a U-shaped cross section that is longer than the width of the substrate is provided, and the flat substrate is moved under the hollow cathode electrode tube.
An apparatus for depositing alloy metals from the vapor phase as described in Section 1. (11) A cylindrical substrate is formed to be rotatable, and a hollow cathode electrode tube having a length longer than the U-shaped cross-sectional substrate is provided opposite to the substrate. An apparatus for depositing alloy metals from the vapor phase as described in Section 1. (12) An apparatus for depositing alloy metal from a gas phase according to claim 2, characterized in that a gas outlet is provided at the innermost part of the hollow cathode electrode tube.