JPH09275099A - Thin film forming apparatus and manufacture of semiconductor device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film forming apparatus such as a CVD device, etc., which can reduce production of foreign matter such as a reaction by product, etc., adhering to the inside of a reaction tube, and besides can easily clean the foreign matter, and the manufacture of a semiconductor device using it. SOLUTION: This is a CVD device which is equipped with a double structure of reactive tube which has an outer tube 1 as a first reactive tube and an inner tube 2 as a second reactive tube installed inside the outer tube 1, and in which a film such as a silicon nitride film, etc., is made on the wafer 7 installed inside the inner tube 2. This has such structure that reaction gas 9 passes the inner tube 2 and accumulates a film on the wafer 7, and then, a reaction gas 16 is exhausted from between the inner tube 2 and the outer tube 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming apparatus and a method of manufacturing a semiconductor device using the thin film forming apparatus, and more particularly to forming a thin film such as a silicon nitride film on the surface of a wafer by a CVD (Chemical Vapor Deposition) method. The present invention relates to a thin film forming apparatus and a semiconductor device manufacturing method using the same.

[0002]

2. Description of the Related Art The present inventor has studied a CVD apparatus used in a semiconductor integrated circuit device manufacturing technique. The following is a technique studied by the present inventors, and the outline is as follows.

That is, in a manufacturing process of a semiconductor integrated circuit device, a thin film such as a silicon nitride film, a silicon oxide film or a polycrystalline silicon film is formed by using a CVD device.

In this case, the CVD apparatus supplies one or several kinds of gas consisting of the elements constituting the thin film material to the reaction chamber, and forms a thin film on the surface of a wafer composed of a semiconductor substrate by a chemical reaction. There is. The chamber, which is the portion of the reaction chamber that is heated by the heater from the outside, is a single quartz tube.

[0005] Incidentally, as a literature describing a CVD apparatus, for example, on December 13, 1988, "Electronic Materials December 1988 Special Edition" p.
To p42.

[0006]

However, the above-mentioned C
When a silicon nitride film is formed using a VD device, for example, a reaction by-product adheres to the inner surface of the gas introduction portion in the form of powder, which winds up in the reaction chamber and adheres to the surface of the wafer during transfer or film formation. Therefore, there is a problem in that the yield of products such as semiconductor devices is reduced.

Further, in order to remove the reaction by-product adhering to the inner surface of the reaction chamber, it is necessary to remove the flange portion of the chamber and perform cleaning and drying.
Since it is necessary to perform operations such as confirmation of vacuum tightness after cleaning the reaction chamber, baking of the chamber as a reaction tube and adjustment and confirmation of the film thickness distribution of the thin film on the wafer during film formation, labor and work time are required. Are required, and the operating rate of the CVD apparatus is decreasing.

An object of the present invention is to reduce foreign substances such as reaction by-products adhering to the inside of a reaction tube and to easily clean the foreign substances, such as a thin film forming apparatus such as a CVD apparatus and a semiconductor device manufacturing method using the same. To provide.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0010]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, the thin film forming apparatus of the present invention is a double-structured reaction tube, and the outer tube as the first reaction tube and the second reaction tube installed inside the outer tube as the second reaction tube. An inner tube is provided, and a thin film is formed on a wafer installed inside the inner tube.

Further, the method of manufacturing a semiconductor device using the thin film forming apparatus of the present invention has a step of forming a thin film on a wafer by using the thin film forming apparatus which is a reaction tube having a double structure. That is, a thin film made of an insulating film or a conductive film is formed on a wafer for forming a semiconductor integrated circuit device or the like.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments, components having the same function are denoted by the same reference numerals, and redundant description will be omitted.

(Embodiment 1) FIG. 1 is a schematic view showing a partially broken CVD apparatus according to an embodiment of the present invention. FIG. 2 is a sectional view taken along the line AA in FIG.

As shown in FIGS. 1 and 2, the CVD apparatus of this embodiment has an outer tube 1 serving as a first reaction tube and a second reaction tube installed inside the outer tube 1. A flange 3 having an inner tube 2 and attached to one end of the outer tube 1.
The flange surface for keeping the vacuum tightness is installed in the reaction chamber 4.

The outer tube 1 is an external reaction tube in a reaction tube having a double structure, and is installed horizontally with respect to the reaction chamber 4, and its main portion has a rectangular cross section. It is made of silicon carbide (SiC) or quartz as a material, and has a mechanical strength that can withstand the pressure difference between the outside and the inside, and is transparent and has a good cleaning effect. The outer dimensions of the outer tube 1 are about 250 to 350 mm in width and 30 to 60 m.
The height is about m and the length is about 500 to 900 mm.
A gas exhaust port 1 a is provided at an end of the outer tube 1.

The inner tube 2 is an internal reaction tube in a double-structured reaction tube, and the main part has a rectangular cross section, and is made of silicon carbide or quartz. The outer dimensions of the inner tube 2 are smaller than the outer dimensions of the outer tube 1 by about 5 to 20 mm. A gas introduction port 2 a is provided at the end of the inner tube 2. Further, a spacer 5 is provided below the inner tube 2, and when the inner tube 2 is placed on the outer tube 1,
A gap is formed between them by the spacer 5. A wafer jig 6 is installed inside the inner tube 2 so as to move from the reaction chamber 4 to the transfer robot 8
The wafer 7 can be set on the wafer jig 6.

A gas introducing section 10 for supplying a reaction gas 9 is connected to the upper portion of the reaction chamber 4, and the reaction gas 9 supplied from the gas introducing section 10 is provided at the end of the inner tube 2. The gas is introduced into the gas inlet 2a. In this case, the gas introduction part 10 is equipped with a porous filter made of a nickel alloy or stainless steel so as to uniformly mix a plurality of kinds of gases as the reaction gas 9. A gate valve 11 is installed in the transfer section of the wafer 7 in the center of the reaction chamber 4. An exhaust gas treatment block 12 equipped with a filter made of aluminum alloy or stainless steel is installed in the lower part of the reaction chamber 4 and serves as a unit for removing foreign matters such as reaction by-products in the exhaust gas 16. ing. A vacuum processor 13 is connected to the lower portion of the vacuum processor 13 via a gas pipe 14. Therefore, the vacuum processor 13 can bring the insides of the outer tube 1 and the inner tube 2 into a vacuum state, and further, the exhaust gas 16 can be introduced into the exhaust pipe 15.

Outside the outer tube 1, for heating the inside of the outer tube 1 and the inner tube 2, for example, a heating mechanism 1 such as a resistance heater.
7 is installed. The heating mechanism 17 shown is
The outer tube 1 is installed under the wafer 7 and under the outer tube 1. However, depending on the design specifications, the upper tube 1 on the wafer 7, the upper outer tube 1 around the outer tube 1, and the outer tube 1 around the outer tube 1. It is possible to adopt a mode in which the heating mechanism 17 is installed in multiple zones in the lower part of the outer tube 1 around the heating mechanism 17 installed in the lower part.

The operation of the CVD apparatus of this embodiment is as follows.

That is, a wafer 7 for manufacturing, for example, a semiconductor integrated circuit device or the like by the transfer robot 8 on the wafer jig 6 installed inside the inner tube 2.
After setting 2 sheets at the same time, the gate valve 11 is closed. Next, after replacing the air or the like existing inside the outer tube 1 and the inner tube 2 with nitrogen gas or the like by using the vacuum processor 13, the inside of the outer tube 1 and the inner tube 2 is heated to a predetermined degree by the heating mechanism 17. While maintaining the temperature and controlling the pressure to a predetermined depressurized state by the vacuum processor 13, a reaction gas 9 composed of, for example, dichlorosilane (SiH ₂ Cl ₂ ) and ammonia is introduced from the gas introduction part 10 through the gas introduction port 2a. Supply inside 2. In this state, the wafer 7
A silicon nitride film having a predetermined film quality is deposited on the surface of the substrate with a predetermined film thickness. In this case, the exhaust gas 16 after the chemical reaction after the silicon nitride film is deposited on the surface of the wafer 7 by the reaction gas 9 passes between the outer tube 1 and the inner tube 2, and the exhaust gas of the outer tube 1 is exhausted. The exhaust gas treatment block 12 is reached through the port 1 a and then exhausted through the exhaust pipe 15.

According to the CVD apparatus of this embodiment, the first
Is equipped with a double-structured reaction tube consisting of an outer tube 1 as a reaction tube and an inner tube 2 as a second reaction tube, and heats the inside of the outer tube 1 and the inner tube 2 from the outside of the outer tube 1. Since the mechanism 17 can control the temperature to a predetermined high temperature, the reaction gas 9 and its exhaust gas 16 flow to the gas exhaust port 1a in a high temperature state, so that the adhesion of foreign matters such as reaction by-products to the inner tube 2 is prevented. Can be reduced. In addition, the gas introduction part 10 is provided with a porous filter so that a plurality of kinds of gases as the reaction gas 9 can be mixed uniformly, so that the reaction by-product in the inner tube 2 is generated. It is possible to reduce the adhesion of foreign matter such as.

As a result, it is possible to prevent the generation of foreign matters such as reaction by-products that wind up inside the inner tube 2, so that when a thin film such as a silicon nitride film is formed on the surface of the wafer 7, the reaction by-products of the wafer and the thin film are formed. Since a foreign matter such as a product is not added, a high performance thin film can be formed. Therefore, the manufacturing yield of products such as semiconductor devices using a thin film such as a silicon nitride film can be improved.

According to the CVD apparatus of this embodiment, the first
Since the reaction tube having a double structure including the outer tube 1 as the reaction tube and the inner tube 2 as the second reaction tube is provided, the outer tube 1 and the inner tube can be used under various use conditions and for a long time. When removing foreign matters such as reaction by-products adhering to the inner surface of the tube 2, the outer tube 1 is removed from the reaction chamber 4, the inner tube 2 is removed from the outer tube 1, and the outer tube 1 and the inner tube 2 are independent. Can be washed. In addition, since the outer tube 1 has much less foreign matter such as reaction by-products attached to its inner surface than the inner tube 2, there is almost no need to perform a cleaning process on the outer tube 1, and the reaction by-products, etc. The simple operation of replacing the inner tube 2 with a new inner tube 2 at the stage where the foreign matter adheres is sufficient.

Therefore, according to the CVD apparatus of this embodiment, the outer tube 1 and the inner tube 2 are
Since it is possible to simplify the cleaning process of foreign matter such as the reaction by-product of (1), the labor and maintenance such as working time can be reduced, and the operation rate of the device can be improved.

According to the CVD apparatus of the present embodiment, various thin films made of an insulating film such as a silicon oxide film or a conductive film such as a polycrystalline silicon film can be formed in addition to the silicon nitride film.

(Embodiment 2) FIGS. 3 to 8 are schematic cross-sectional views showing the steps of manufacturing a semiconductor device using a CVD apparatus according to another embodiment of the present invention. The manufacturing method of the semiconductor device according to the present embodiment will be described with reference to FIG.

First, a field insulating film 19 made of a silicon oxide film is formed in a device isolation region, which is a selective region on the surface of a semiconductor substrate 18 made of, for example, p-type silicon single crystal, by using a thermal oxidation process. Although not shown, a channel stopper film for preventing inversion is formed under the field insulating film 19 (FIG. 3).

Next, the gate insulating film 20 made of silicon oxide is formed in the active region surrounded by the field insulating film 19.
And the gate electrode 21 made of polycrystalline silicon is formed on the gate insulating film 20 according to the CV of the first embodiment.
D device is used. The gate electrode 21 is formed by sequentially depositing an insulating film 22 made of a polycrystalline silicon film and a silicon oxide film on the semiconductor substrate 18 and sequentially etching these. After that, a sidewall insulating film 23 made of a silicon oxide film is formed on the sidewall of the gate electrode 21. Next, an n-type impurity such as phosphorus is ion-implanted into the semiconductor substrate 18 to form an n-type semiconductor region 24 serving as a source and a drain (FIG. 4).

After that, an insulating film 25 made of a silicon oxide film or the like is formed on the semiconductor substrate 18 by using the above-described CVD apparatus of the first embodiment, and then a contact hole is formed in a selective region of the insulating film 25. A contact electrode 26 is formed in that region (FIG. 5).

Next, after the insulating film 27 made of a silicon oxide film or the like is formed on the semiconductor substrate 18 by using the above-described CVD apparatus of the first embodiment, through holes are formed in the selective regions. (Fig. 6).

In the above-described manufacturing process of the semiconductor device, the n-channel MOSFET is formed on the semiconductor substrate 18, but various semiconductors such as p-channel MOSFET other than n-channel MOSFET, bipolar transistor, capacitive element, etc. are formed on the semiconductor substrate 18. A mode in which an element is formed can be adopted.

Next, a barrier metal film 28 made of titanium is formed on the semiconductor substrate 18 by a sputtering method, and then a metal film 29 made of aluminum is formed on the surface of the barrier metal film 28 by a sputtering method. Form. Thereafter, a barrier metal film 30 made of titanium is formed on the metal film 29 by using a sputtering method. In this case, the barrier metal film 28 and the barrier metal film 30
May be in the form of a refractory metal film using an alloy such as titanium, tungsten, molybdenum or TiW. Further, the metal film 29 may be in the form of a metal film using copper or gold (FIG. 7).

After that, an unnecessary portion of the barrier metal film 28 / metal film 29 / barrier metal film 30 as a wiring layer is removed by using a photolithography technique and a selective etching technique to form a wiring pattern (FIG. 8). Next, after forming a multi-layered wiring layer as needed, a passivation film (not shown) is formed to complete the manufacturing process of the semiconductor device.

According to the method of manufacturing the semiconductor device of the present embodiment, the polycrystalline silicon film as the gate electrode 21, the silicon oxide film as the insulating film 25, and the insulating film are formed by using the CVD apparatus of the first embodiment. By forming the silicon oxide film as the film 27, generation of foreign matters such as reaction by-products can be suppressed in the manufacturing process thereof.
A thin film such as a high-performance gate electrode 21 can be formed, and the manufacturing yield of semiconductor devices can be improved.

In the method of manufacturing the semiconductor device according to the present embodiment described above, the gate electrode 21 and insulating film 2 in the semiconductor device are used.
5 and the insulating film 27 are formed by using the above-described CVD apparatus of the first embodiment, but manufacture of a polycrystalline silicon film and an insulating film in a single semiconductor device including a field effect transistor or a bipolar transistor. The CVD apparatus according to the first embodiment described in the art can be used.

The invention made by the present inventor has been specifically described above based on the embodiments of the present invention, but the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the scope of the invention. It goes without saying that it can be changed.

For example, as a thin film forming apparatus of the present invention and a semiconductor device manufacturing method using the same, a thin film such as a single crystal silicon film may be formed by using an epitaxial growth method in addition to the CVD apparatus of the first embodiment. It can be applied to a thin film forming apparatus such as an epitaxial growth apparatus to be formed and a semiconductor device manufacturing method using the same.

[0039]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1). According to the thin film forming apparatus of the present invention,
It is equipped with a double-structured reaction tube consisting of an outer tube as a first reaction tube and an inner tube as a second reaction tube, and the inside of the outer tube and the inner tube is heated by a heating mechanism from the outside of the outer tube. Since it can be controlled to a high temperature, the reaction gas and its exhaust gas flow to the gas exhaust port in a high temperature state, so that adhesion of foreign matters such as reaction by-products in the inner tube can be reduced. In addition, since the gas introduction part is equipped with a porous filter to uniformly mix a plurality of types of gases as reaction gases, foreign substances such as reaction by-products in the inner tube are introduced. Can be reduced.

As a result, it is possible to prevent the generation of foreign matters such as reaction by-products that wind up inside the inner tube, so that when a thin film such as a silicon nitride film is formed on the surface of the wafer, the reaction by-products on the wafer and the thin film are formed. Since a foreign matter such as is not added, a high-performance thin film can be formed. Therefore, the manufacturing yield of products such as semiconductor devices using a thin film such as a silicon nitride film can be improved.

(2). According to the thin film forming apparatus of the present invention,
Since the reaction tube having a double structure including the outer tube as the first reaction tube and the inner tube as the second reaction tube is provided, the outer tube and the inner tube can be used under various usage conditions and long-term use. When removing foreign matters such as reaction by-products attached to the inner surface of the outer tube, the outer tube can be removed from the reaction chamber, the inner tube can be removed from the outer tube, and the outer tube and the inner tube can be independently cleaned. In addition, since the outer tube has very few foreign substances such as reaction by-products attached to its inner surface as compared with the inner tube, there is almost no need to perform cleaning treatment of the outer tube, and foreign substances such as reaction by-products do not need to be cleaned. All you have to do is replace the inner tube at the stage where it was attached with a new inner tube.

Therefore, according to the thin film forming apparatus of the present invention, the cleaning process of foreign matters such as reaction by-products of the outer tube and the inner tube can be simplified, so that the labor and the maintenance such as working time can be reduced, and the apparatus can be reduced. The operating rate of can be improved.

(3). According to the method for manufacturing a semiconductor device of the present invention, the thin film forming apparatus of the present invention is used to form a thin film such as a polycrystalline silicon film as a gate electrode and a silicon oxide film as an insulating film. Since the generation of foreign matters such as reaction by-products in the manufacturing process can be suppressed, a high-performance thin film can be formed and the manufacturing yield of semiconductor devices such as semiconductor devices can be increased.

[Brief description of drawings]

FIG. 1 is a schematic view showing a partially broken view of a CVD apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a schematic cross-sectional view showing a manufacturing process of a semiconductor device using a CVD apparatus which is another embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view showing a manufacturing process of a semiconductor device using a CVD apparatus which is another embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view showing a manufacturing process of a semiconductor device using a CVD apparatus which is another embodiment of the present invention.

FIG. 6 is a schematic cross-sectional view showing a manufacturing process of a semiconductor device using a CVD apparatus which is another embodiment of the present invention.

FIG. 7 is a schematic cross-sectional view showing a manufacturing process of a semiconductor device using a CVD apparatus which is another embodiment of the present invention.

FIG. 8 is a schematic cross-sectional view showing a manufacturing process of a semiconductor device using a CVD apparatus which is another embodiment of the present invention.

[Explanation of symbols]

 1 Outer Tube 1a Gas Exhaust Port 2 Inner Tube 2a Gas Inlet Port 3 Flange 4 Reaction Chamber 5 Separator 6 Wafer Jig 7 Wafer 8 Transfer Robot 9 Reactive Gas 10 Gas Inlet 11 Gate Valve 12 Exhaust Gas Processing Block 13 Vacuum Processor 14 Gas pipe 15 Exhaust pipe 16 Exhaust gas 17 Heating mechanism 18 Semiconductor substrate 19 Field insulating film 20 Gate insulating film 21 Gate electrode 22 Insulating film 23 Sidewall insulating film 24 Semiconductor region 25 Insulating film 26 Contact electrode 27 Insulating film 28 Barrier metal film 29 Metal film 30 Barrier metal film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadashi Terasaki 3-14-20 Higashi-Nakano, Nakano-ku, Tokyo Kokusai Electric Co., Ltd.

Claims (9)

[Claims] 1. A wafer having an outer tube as a first reaction tube and an inner tube as a second reaction tube installed inside the outer tube, wherein the wafer is installed inside the inner tube. A thin film forming apparatus characterized in that a thin film is formed on a substrate. 2. The thin film forming apparatus according to claim 1, wherein
The outer tube is provided with a flange at one end thereof, and is provided with a gas exhaust port at a part thereof, and the inner tube is provided with a gas introduction port at a part thereof,
The thin film forming apparatus, wherein the gas supplied from the gas inlet passes through the inner tube, is exhausted from between the inner tube and the outer tube, and is exhausted through the gas exhaust port. 3. The thin film forming apparatus according to claim 1, further comprising a heating mechanism outside the outer tube. 4. The thin film forming apparatus according to claim 1, wherein the outer tube and the inner tube are formed of silicon carbide or quartz as a material. apparatus. 5. The thin film forming apparatus according to claim 1, wherein the wafer is set on a wafer jig installed inside the inner tube using a transfer robot. A thin film forming apparatus. 6. The thin film forming apparatus according to claim 1, wherein the thin film forming apparatus is a CVD apparatus. 7. A method of manufacturing a semiconductor device, comprising a step of forming a thin film on a wafer by using the thin film forming apparatus according to claim 1. 8. The method of manufacturing a semiconductor device according to claim 7, wherein the thin film forming apparatus is a CVD apparatus, and the wafer is a wafer for forming a semiconductor integrated circuit. Method. 9. The method of manufacturing a semiconductor device according to claim 7, wherein the thin film forming device is a CVD device, the wafer is a wafer for forming a semiconductor device, and is formed on the wafer. A method of manufacturing a semiconductor device, wherein the thin film is an insulating film or a conductive film.