JPS6173881A - Vapor growth device - Google Patents

Abstract

PURPOSE:To form a thin alloy film having compsn. over a wide range by gener ating glow discharge between a hollow cathode and anode and sputtering a cathode material on a substrate, cracking the reacting gas introduced by the glow discharge into a reaction vessel and depositing the same on the substrate. CONSTITUTION:The cylindrical hollow cathode 3 and anode 4 consisting of prescribed elements are disposed in proximity to each other in a vacuum vessel 1. A buffer gas introducing pipe 9 for sputtering is communicated with one aperture of the cathode 3 and a substrate supporting base 5 holding a substrate 6 for forming a thin film thereon is positioned to face the other aperture. An introducing pipe 8 for the reactive gas contg. the other prescribed element is further provided in the vessel 1. The device which excecutes simultaneously a plasma CVD method and sputtering method is thus obtd.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention relates to a vapor phase growth apparatus for producing thin alloy films on substrates. rPrior art and its problems] Plasma CV is a method for depositing an amorphous thin film by decomposing source gas through a plasma reaction using glow discharge.
This method is called the D method and is used for the production of hydrogenated amorphous silicon films, but this method can only be used when a suitable reaction gas containing the desired thin film material can be obtained. On the other hand, sputtering is another typical thin film production method using glow discharge. In this method, the material to be deposited is placed on the target bridge (cathode in DC discharge).
As a result, a glow discharge is generated, and the target material, which has been swabbed by positive ions, is deposited on a substrate placed nearby or on a counter electrode. This method has the advantage that there is no restriction that the raw material must be a gas phase compound as in plasma CVD, and that thin films of high melting point substances can be easily created. There were drawbacks such as difficulty in creating thin films containing large amounts of hydrogen.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and provide a vapor phase growth apparatus that combines the features of plasma CVD and sputtering methods and is capable of producing alloy thin films with compositions selected over a wide range.

[Key points of the invention]

In the vapor phase growth apparatus according to the present invention, a cylindrical hollow cathode and an anode made of a predetermined element are arranged in close proximity in a vacuum chamber,
A buffer gas introduction tube for sputtering is connected to one opening of the hollow cathode, a thin film forming substrate support is opposed to the other opening, and a reaction gas introduction tube containing other predetermined elements is connected to the vacuum chamber. By communicating with each other, a plasma CVD method and a sputtering method are performed simultaneously to form an alloy thin film made of a predetermined element on a substrate.

[Embodiments of the invention]

FIG. 1 shows an embodiment of the present invention, in which a vacuum W! (2) is connected to a vacuum system via an exhaust pipe 2. In this vacuum Ht, a hollow cylindrical hollow pole 3 is disposed vertically, and a disk anode 4 is disposed horizontally adjacent thereto. A support stand 5 is installed above the hollow cathode 3, and this support stand 5 has a built-in heater 7 capable of heating a substrate 6 mounted thereon. These parts, including the support stand 5, are electrically floated from other equipment systems.A reactive gas introduction pipe 8 and a sputtering buffer gas introduction pipe 9 are inserted into the vacuum chamber 1 from below to introduce the buffer gas. The tip of the tube 9 is connected to the lower mouth of the hollow cathode 3. The cathode 3 and anode 4 are connected to a DC power supply lO outside the tank. Next, a method for producing an alloy thin film using this apparatus will be described. The inside of the vacuum chamber 1 is evacuated through the exhaust pipe 2, and the cathode 3. A direct current voltage is applied between the anodes 4 using StO to generate a glow discharge. The reactive gas is decomposed by high-speed electrons and light during the glow discharge formed near the electrodes and deposited on the substrate 6. On the other hand, a gas for efficiently sputtering the cathode material is introduced into the hollow cathode 3 from the buffer gas introduction tube 9, and gas is introduced into the hollow cathode 3 through the collision of gas ions in the high-density gas plasma formed inside the hollow cathode. The material for the cathode 3 is sputtered and deposited on a substrate 6. It is effective to place the substrate 6 facing downward so that flakes and dust attached to the electrodes etc. do not fall onto it. For example, silane ( When SIH*) or disilane (SIJ&) is supplied from the inlet tube 8, the hollow cathode 3 is made of carbon, and argon is used as the buffer gas supplied from the inlet tube 9, hydrogenated amorphous silicon carbide ( a-3iC:H) is generated.The growth rate of the film and the ratio of silicon to carbon in the film can be controlled by changing the gas flow ratio of silane and argon, the total gas pressure, and the discharge current.Hollow If the cathode 3 is made of titanium, an amorphous silicon/titanium alloy can be produced.When attempting to produce an amorphous silicon/titanium alloy by the plasma CVD method, titanium chloride (TiC14) is added to the reaction gas, resulting in The presence of chlorine in the alloy prevents the desired properties from being obtained, but by using the apparatus according to the present invention, a chlorine-free amorphous silicon-titanium alloy can be obtained. It is sufficient to arrange multiple electrodes vertically and horizontally at appropriate intervals according to the size of the
Figure 2 shows five hollow cylindrical cathodes 11 and a disk-shaped anode 1i1.
Each hollow cathode 11 and the DC power supply 13 are connected via an independent variable resistor I4, and each hollow cathode 1
The power flowing through 1 can be adjusted, and amorphous alloy '3M can be uniformly produced on a large area of the substrate. Hollow cathode 3 used in the device according to the invention 1
1 is not limited to a hollow cylinder, but may be a hollow cone or any other shape commonly used as a hollow cathode.

【Effect of the invention】

The present invention generates glow discharge between a hollow cathode and an i-piece to sputter cathode material onto a substrate facing the hollow cathode, and at the same time utilizes the glow discharge to generate a reaction that is introduced into the same reaction tank. The vapor phase growth apparatus is configured to produce an amorphous alloy thin film by decomposing the gas and depositing the decomposition products on the substrate. With this apparatus, it has become possible to create thin films of alloys of materials, particularly amorphous alloys, which could previously only be formed using plasma CVD or sputtering methods. As a result, it is now possible to create thin films made by synthesizing hydrogenated amorphous silicon with various materials, which can be used extremely effectively for the development of new materials that can be used in passivation technology for amorphous silicon and LSI. I can do it.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of this invention, and FIG. 2 is a sectional view of an embodiment of this invention. FIG. 3 is a diagram of an example of electrode arrangement in the case of having a plurality of poles, viewed from the base side. l: Vacuum chamber, 3.11i cylindrical hollow cathode, 4°11=
Disk-shaped anode, 5: Substrate support, 6: Substrate, 8: Reaction gas introduction tube, 9: Buffing gas for spafter Figure 1

Claims (1)

[Claims] 1) A cylindrical hollow cathode and an anode made of a predetermined element are placed in close proximity in a vacuum chamber, one opening of the hollow cathode is connected to a buffer gas introduction tube for sputtering, and the other opening is connected to a thin film. A vapor phase growth apparatus characterized in that production substrate supports face each other and a vacuum chamber is further connected to a reaction gas introduction tube containing another predetermined element.