JP2000303181A - Treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a malfunction of a plasma chemical vapor deposition(CVD) device and quality deterioration of a deposited product film by depositing fine powder of by-products in an exhausting means for the plasma CVD device. SOLUTION: A filament 6 of high melting point metal such as tungsten is set up in an exhaust duct 4 being an exhaust route between a plasma CVD chamber 3 and a vacuum pump 13 being an evacuating means leaving an interval of 5 cm from the inner wall surface of the duct 4. The fine powder of by-products from the plasma CVD chamber 3 is subjected to chemical reaction by the heated filament 6 and the reaction products thus obtained are collected on the inner wall surface of the duct 4 so that the by-products are deposited as a hardened film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate processing apparatus such as a plasma CVD apparatus, a thermal CVD apparatus, an optical CVD apparatus, and a sputtering apparatus used for forming a film in a process of manufacturing a semiconductor element or the like, or a dry processing apparatus used for film processing. The present invention relates to a processing apparatus such as a film processing apparatus such as an etching apparatus, and more particularly, to a processing apparatus characterized by its exhaust processing means.

[0002]

2. Description of the Related Art Conventionally, in a processing apparatus such as a substrate processing apparatus including a deposited film forming apparatus, an object to be processed (substrate, substrate, etc.) is caused by the adhesion of unreacted gas and by-products in the exhaust gas to exhaust means. The quality of the film) and the deterioration of the apparatus have been problems. Therefore, a technique has been developed in which the unreacted gas and by-products are treated by etching using a fluorine-based or chlorine-based gas or by heating an exhaust pipe.

For example, in a deposited film forming apparatus using a plasma CVD method, a source gas supplied into a vacuum vessel is turned into plasma by a plasma generating means to form a deposited film on a substrate installed in the vacuum vessel. However, after the source gas contributes to the formation of a deposited film in the vacuum vessel, it is exhausted by gas exhaust means (exhaust pipe, valve, vacuum pump) through an exhaust path.

When a silicon-based amorphous (amorphous) thin film or microcrystalline (microcrystalline) thin film is formed by the above-mentioned plasma CVD method, SiH ₄ or Si ₂ is generally used.
A raw material gas containing Si such as H ₆ is supplied and decomposed into a plasma state by high-frequency discharge while maintaining a constant pressure.
The thin film is formed on a substrate placed in a plasma.

However, in the conventional plasma CVD apparatus, fine powder is generated as a by-product during the formation of the deposited film, and adheres and deposits on the pressure control valve and the exhaust pipe of the exhaust means and the gate valve. There was a phenomenon that also deposited.

For this reason, the exhaust port is blocked by the deposited fine powder, causing pressure fluctuations during film formation, and the characteristics of the deposited film being reduced due to the backflow of the fine powder, resulting in a problem that the quality of the product is reduced. Occurred. Furthermore, the fine powder adhering to the exhaust means such as the exhaust pipe, the pressure regulating valve, the gate valve, and the vacuum pump causes an abnormality in the apparatus, so that it takes time to maintain the apparatus and lowers the operation rate of the apparatus. .

On the other hand, as a continuous production apparatus for silicon-based amorphous semiconductor devices, US Pat. No. 4,400,409 discloses a roll-to-roll method.
A continuous plasma CVD apparatus adopting the (Roll) method is disclosed.

According to this apparatus, a plurality of plasma CVD
Chambers, and while continuously depositing and forming a semiconductor of a conductivity type required in each of the plasma CVD chambers, the substrate is continuously moved in the longitudinal direction thereof, so that a large-area device having a semiconductor bond can be continuously formed. Can be formed.

As described above, if a roll-to-roll type continuous plasma CVD apparatus is used, devices can be manufactured continuously for a long time without stopping the manufacturing apparatus, so that high productivity can be obtained. .

However, even in the roll-to-roll type apparatus described above, under the condition that fine powder as a by-product is generated in the exhaust means, the fine powder adheres to the exhaust means and the continuous manufacturing time becomes longer. The fine powder adhering to the evacuation means accumulates, and the fine powder flowing backward also accumulates inside the plasma CVD chamber, so that the device manufactured as described above is liable to generate defects, and the plasma CVD chamber There is a problem in that a failure due to the clogging of the fine powder occurs in the exhaust means for exhausting the gas, which lowers the operation rate of the apparatus.

Therefore, conventionally, as a method for controlling the adhesion of the fine powder of such a by-product to the exhaust system, Japanese Patent Application Laid-Open No.
JP-A-114570, JP-A-1-313833, JP-A-4-136175, JP-A-8-133
Various technologies are disclosed in, for example, JP-A-889-89 and JP-A-8-299784.

For example, Japanese Patent Application Laid-Open No. 60-114570 discloses that by heating an exhaust pipe and a fine powder trap, the fine powder is not a low-density soft fine powder but a high-density hard fine powder which can be easily processed. A method of collecting is disclosed.

Japanese Patent Application Laid-Open No. 1-312833 discloses that a second reaction chamber and a heating means are provided between an airtight container and an exhaust system to completely remove unreacted gas not thermally decomposed in a reaction section. A technique for disassembling is disclosed.

Japanese Unexamined Patent Publication (Kokai) No. 4-136175 discloses that an unreacted gas in an exhaust gas is reacted to form a film so as to reduce the amount of untreated gas in an exhaust pipe, thereby reducing fine particles or film fragments. A thin film forming apparatus that prevents generation of dust and does not deteriorate a vacuum pump and a toxic gas processing apparatus is disclosed.

Japanese Patent Application Laid-Open No. 8-133889 discloses a method in which an exhaust pipe is penetrated inside a substrate heater and a film is deposited while heating the exhaust pipe.

Japanese Unexamined Patent Publication No. Hei 8-299784 discloses that an unreacted gas in exhaust gas is thermally decomposed by providing a heating trap means comprising a baffle plate in a trap passage container provided in the middle of the exhaust passage. An almost completely trapping technique is disclosed.

With such a technique, it is possible to collect or treat unreacted gas in the exhaust pipe or fine powder generated from the unreacted gas, and the problems caused by these are reduced. I have.

[0018]

However, in the exhaust gas processing method described above, the processing method of by-products cannot be said to be sufficient. In particular, when a deposited film is formed by a plasma CVD method, SiH ₄ or S to increase the deposition rate
When the flow rate of the source gas such as i ₂ H ₆ and the RF power are increased,
The exhaust gas processing method as described above does not solve the problem that the fine powder adheres and accumulates in the exhaust means at the stage preceding the heating trap or adheres and accumulates behind the fine powder. Therefore, when a deposited film is formed continuously for a long time by a method such as a roll-to-roll method, the exhaust port is blocked by fine powder accumulated in an exhaust pipe or a valve, thereby causing a change in a film forming pressure. In addition, the accumulated fine powder flows back into the deposited film forming container, causing a deterioration in the film quality of the deposited film. Furthermore, valves, exhaust piping, which are exhaust means of the device,
An abnormality occurs in the vacuum pump, and time is required for maintenance for avoiding the abnormality, and the operation rate of the apparatus is reduced.

The problem to be solved by the present invention is, as described above, a processing apparatus capable of performing a good process without causing defects in an object to be processed (substrate, deposited film) in a long-time process. Specifically, in a processing apparatus for processing a substrate or a film by a plasma CVD method, a sputtering method, an etching method, or the like, a valve, an exhaust pipe, and a vacuum pump which are exhaust means at a subsequent stage are not provided. It is an object of the present invention to provide a processing apparatus capable of preventing the adhesion and deposition of a fine powder of a reaction gas or a by-product and preventing a trouble due to clogging of the fine powder in an exhaust means and capable of performing a continuous processing for a long time. .

[0020]

Means for Solving the Problems The present invention is characterized by the following constitution in order to solve the above problems.

A processing apparatus according to the present invention is a processing apparatus having a processing chamber for processing a substrate or a film and an exhaust means for exhausting the processing chamber, wherein the processing chamber is connected to the exhaust means. A chemical reaction generating means for causing a chemical reaction to at least one of the unreacted gas and by-products during the processing in the exhaust path, and a distance from the chemical reaction generating means to a region within 5 cm. And a means for recovering a chemical reaction product generated by the chemical reaction generating means.

In the present invention, it is preferable that the means for recovering the chemical reaction product generated by the chemical reaction generating means also serves as a wall surface of the exhaust path, and may be constituted by a louver or the like.

As the chemical reaction generating means according to the present invention, for example, a high melting point metal filament is preferably used. Further, it is preferable that the high melting point metal filament contains at least one of tungsten, molybdenum, and rhenium.

In the present invention, fine particles of unreacted gas and by-products contained in the exhaust gas exhausted from the processing chamber are introduced into an exhaust path having a chemical reaction generating means to cause a chemical reaction. The product is deposited as a hard film on a collecting means and collected.

[0025]

FIG. 1 is a schematic sectional view of an embodiment of a deposited film forming apparatus which is a processing apparatus of the present invention. The apparatus shown in FIG. 1 has a plasma CVD chamber 3 as a processing chamber in a vacuum vessel 1, and a raw material gas is supplied to the plasma CVD chamber 3.
The gas is supplied from the gas supply means 2 provided on one side, and a deposited film forming process is performed in the plasma CVD chamber 3 by high-frequency glow discharge. Further, fine powder generated from unreacted gas or by-products after the formation of the deposited film is exhausted through an exhaust duct 4 and an exhaust pipe 5 which are exhaust paths provided in the other side of the plasma CVD chamber 3. It is discharged to the vacuum pump 13.
A high-melting metal filament 6 is provided as a chemical reaction generating means in an exhaust duct 4 provided between the plasma CVD chamber 3 and the vacuum pump 13. In this example, the inner wall surface of the exhaust duct 4 also serves as a means for recovering a chemical reaction product.

FIG. 2 shows a partially enlarged cross-sectional view of the exhaust duct 4. In the present invention, a chemical reaction product collecting means is provided within 5 cm from the chemical reaction generating means. Therefore, in this example, as shown in 2, the wall surfaces 15a, 15a,
When the 15b and the distance of the refractory metal filaments 6 and L _1, L _2, L ₁ and L ₂ so that within 5 cm, refractory metal filaments 6 are installed.

Between the plasma region in the plasma CVD chamber 3 and the high melting point metal filament 6, a structure having no irregularities is formed so as to prevent stagnation in the gas flow. In the exhaust pipe 5, a pressure regulating valve 11, a gate valve 12
Is provided.

The substrate holder 10 in the plasma CVD chamber 3
A substrate (not shown), which is an object to be processed, is placed thereon, and a source gas or a diluent gas is supplied into the plasma CVD chamber 3 to deposit a film on the substrate. At that time, the plasma CVD chamber 3 is heated by the heater 8 and the substrate is heated by the heater 7. Further, RF power is supplied from the RF power supply 9.

The unreacted gas and by-product exhausted from the plasma CVD chamber 3 are introduced into an exhaust duct 4. Refractory metal filament 6 installed in exhaust duct 4
Is heated by the power supply by the power controller 14 to cause a chemical reaction of the introduced unreacted gas and by-products, and a chemical reaction product generated by the chemical reaction is located near the refractory metal filament 6. Exhaust duct 4
Are adhered and collected on the wall surfaces 15a and 15b.

In the present invention, since the unreacted gas and by-products undergo a chemical reaction, and the recovery means is disposed near the chemical reaction inducing means, the products can be efficiently recovered. It is possible to greatly reduce the adhesion and accumulation of fine powder in the exhaust pipe 5 and the valves 11 and 12, which are exhaust means behind the exhaust duct, and to recover the fine powder of by-products as a hard film. Therefore, the back diffusion of the fine powder deposited in the exhaust duct 4 is also prevented, and the deterioration of the deposited film due to the back flow of the fine powder into the processing chamber is prevented.

The refractory metal filament used in the present invention preferably contains at least one of tungsten, molybdenum and rhenium. For example, those formed of any of these metals or alloys, and modified metals or modified alloys containing additives can be used.

The chemical reaction product recovery means includes:
In addition to the above-mentioned structure which also serves as the wall surface of the exhaust duct 4, a plate-like thing, a tray (pan) -like thing, a mesh-like thing, a stick-like thing, and a thing which also serves as a chemical reaction generating means can be given.

[0033]

(Example 1) In this example, a deposited film of amorphous silicon was formed on a glass substrate using a plasma CVD apparatus having the structure shown in FIG. The plasma CVD chamber 3 has a width of 500 mm (in the depth direction in FIG. 1) and a length of 850 m.
m and a height of 40 mm. An exhaust duct 4 is provided on the exhaust side of the plasma CVD chamber 3, and as a high melting point metal filament 6, as shown in FIG.
A filament wound spirally around a support 32 made of alumina ceramics at a pitch of 3 mm was used. The distances L ₁ and L ₂ between the filament 6 and the wall surface of the exhaust duct 4 are 1
cm.

The film forming process proceeded according to the following procedure. First, the inside of the vacuum vessel 1 was evacuated to 1 Pa or less by the vacuum pump 13. Subsequently, 133 sccm of argon gas was introduced, and the internal pressure of the plasma CVD chamber 3 was adjusted to 133 P by adjusting the opening of the pressure adjusting valve 11 inside the exhaust pipe 5.
a.

Next, the substrate heater 7 in the vacuum vessel 1
The heating of the plasma CVD chamber heater 8 was controlled to a predetermined temperature. Left at this state for 2 hours, after the temperature of the plasma CVD chamber 3 is stabilized, stopping the argon gas, the raw material gas 80scc of SiH ₄ from the gas supply means 2
m and a diluted H ₂ gas of 1600 sccm.

Next, the power controller 14 is turned on,
3000 W of electric power was applied to the filament 6. After a lapse of 10 minutes, RF power (120 W) is applied and plasma CV
Plasma was generated in the D chamber 3 to deposit an amorphous silicon film on a glass substrate.

After a lapse of 6 hours, the supply of the RF power is stopped,
Next, the power supply to the filament 6 was stopped, and the supply of the raw material, the dilution gas, and the heater power was stopped. Next, the vacuum pump 13 in the vacuum vessel 1 was purged, and the inside of the apparatus was brought to atmospheric pressure with N ₂ gas.

Further, the above steps were repeated again, and after forming a deposited film for a total of 12 hours, the film was opened to the atmosphere.

Thereafter, the state of the deposited amorphous silicon film was observed, and it was confirmed that a fine film was formed without adhering fine powder of by-products. Conventionally, pressure fluctuations were caused by fine powder adhering to the exhaust valve during film formation, but this phenomenon was not observed. Further, film-formed deposits adhered to the exhaust duct wall surface. In addition, filament 6
No fine powder adhered to the exhaust pipe and the inner surface of the pressure regulating valve at the rear (downstream direction of the gas flow), and the amount of the fine powder recovered from these was almost 0 g.

Example 2 A deposited film was formed under the same conditions as in Example 1 except that the film formation time was 30 minutes. Thereafter, an aluminum electrode was deposited on the deposited amorphous silicon film, the light-dark conductivity ratio was measured, and the film characteristics were evaluated. The film quality has an SN ratio (σ _p / σ _d : value obtained by dividing photoconductivity by dark conductivity) of 2 × 1.
It is 0 ⁵ or more good film was confirmed.

(Embodiment 3) The distances L ₁ and L ₂ between the filament 6 and the wall surfaces 15 a and 15 b of the exhaust duct 4 are each set to 1
The deposition state of the unreacted gas exhausted from the plasma CVD chamber 3 and the chemical reaction product of by-products was confirmed by changing the thickness in the range of about 6 cm. The deposited film was formed in the same manner as in Example 1 except that L ₁ and L ₂ were made variable and the film forming time was set to 3 hours. Table 1 shows the results. ◎ ○ in the table
The content of Δ × is shown below. The state of the chemical reaction of the by-product was visually determined.

[0042]

[Table 1]

×: No film formation, fine powder adhesion and deposition △: Film formation, fine powder adhesion ○: Film formation, minute amount of fine powder adhesion ◎: Film formation, no fine powder adhesion

(Example 4) In order to confirm the level of the effect of the present invention depending on the position of the chemical reaction product recovery means in the present invention, a film was formed under severe conditions which are not usually used. Specifically, 240 sccm of SiH ₄ gas, diluted H ₂ gas
A film was formed under the same conditions as in Example 3 except that RF power of 350 W was supplied at a flow rate of gas of 4800 sccm. Table 2 shows the results.

[0045]

[Table 2]

From the results shown in Tables 1 and 2, unreacted gas and by-products in the exhaust gas are chemically reacted by the chemical reaction generating means using the filament, and the products are deposited and collected as a film. Requires that the distance between the filament and the exhaust duct wall be 5 cm or less, preferably 3 cm
Below, it was found that it was more preferably 1 cm or less.

[0047]

According to the present invention, a fine powder of unreacted gas and by-products exhausted from the processing chamber, particularly a fine powder deposited inside the exhaust means, is provided in the exhaust path immediately after the processing chamber. 5c between the reaction generating means and the chemical reaction product collecting means
m and collected as a membrane and high-density solids. Therefore, in the processing apparatus of the present invention, the fine powder is prevented from adhering and accumulating to the exhaust pipes, valves, vacuum pumps, and the like serving as the exhaust means, thereby reducing the exhaust conductance and improving the operation failure of the conductance valve and the vacuum pump. can do.

In addition, the back-diffusion of fine powder of by-products generated and attached to the exhaust means into the processing chamber, which is a problem in the conventional processing apparatus, is also prevented, and the optimum processing conditions are maintained for a long time. Therefore, high-quality substrate processing and film processing can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of one embodiment of a plasma CVD apparatus which is a processing apparatus of the present invention.

FIG. 2 is a partially enlarged cross-sectional view of the exhaust duct of FIG.

FIG. 3 is a view showing a form of a high melting point metal filament used in an example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Gas supply means 3 Plasma CVD chamber 4 Exhaust duct 5 Exhaust pipe 6 High melting point metal filament 7 Substrate heater 8 Plasma CVD chamber heater 9 RF power supply 10 Substrate holder 11 Pressure control valve 12 Gate valve 13 Vacuum pump 14 Electric power Controller 15a, 15b Exhaust duct wall surface 31 High melting point metal filament 32 Support

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/31 H05H 1/46 A H05H 1/46 H01L 21/302 B (72) Inventor Yasuyoshi Takai Tokyo 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Shotaro Okabe 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Yuzo Koda Shimomaruko, Ota-ku, Tokyo 3-30-2 Canon Inc. (72) Inventor Naoshi Yoshizato 3-30-2 Shimomaruko, Ota-ku, Tokyo Incorporated Canon Inc. (72) Inventor Masahiro Kanai 3-30 Shimomaruko, Ota-ku, Tokyo No. 2 Canon Inc. F term (reference) 4K030 BA30 CA06 EA12 FA01 KA46 KA49 4K057 DA19 DA20 DD01 DM38 DM40 5F004 AA16 BD03 BD04 BD05 5F045 AA08 BB20 EG07

Claims (5)

[Claims] 1. A processing apparatus comprising: a processing chamber for processing a substrate or a film; and an exhaust unit for exhausting the processing chamber, wherein the exhaust unit communicates with the processing chamber and the exhaust unit. A chemical reaction generating means for causing a chemical reaction to at least one of the unreacted gas and the by-product at the time of the treatment, wherein the chemical reaction generating means is disposed in a region within a distance of 5 cm from the chemical reaction generating means. A processing apparatus comprising means for recovering a chemical reaction product generated by the means. 2. The processing apparatus according to claim 1, wherein said collection means also serves as a wall surface of said exhaust path. 3. The processing apparatus according to claim 1, wherein said processing apparatus is an apparatus for forming a deposited film on a substrate by a plasma CVD method. 4. The processing apparatus according to claim 1, wherein said chemical reaction generating means has at least a high melting point metal filament. 5. The processing apparatus according to claim 1, wherein the high melting point metal filament contains at least one of tungsten, molybdenum, and rhenium.