JPH09162129A - Semiconductor wafer processor, method for processing semiconductor wafer and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor wafer processor which can efficiently reduce the deposited quantity of reaction auxiliary products at low temperature parts with less gas without affecting a wafer film, and to provide a processing method of a semiconductor wafer and a semiconductor device. SOLUTION: The wafers 3 placed on the prescribed positions in a reaction tube 2 are heated by a heater 1. At the same time, film-forming gas is supplied from a gas supply port 4a, N2 gas is supplied from a dilution gas supply hole 13b and air is discharged from a discharge port 5b. Thus, film-forming gas is made to flow on the surfaces of the wafers 3 and the thin films are formed on the surfaces of the wafers 3 with heat reaction. The partial pressure of film-forming gas, which contributes on the deposition of the reaction auxiliary products, drops by diluting film-forming gas with N2 gas and N2 gas suppresses flow deposition so that the wall surface of the reaction tube 2 is protected from film-forming gas. Consequently, the deposition speed of the reaction auxiliary products adhered/deposited on the surface of the low temperature parts (near the opening parts of both ends) in the reaction tube 2 can be lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer processing apparatus used for forming circuits on a wafer in, for example, a semiconductor manufacturing process, and more particularly to a reaction by-product on a wall surface of a reaction tube of the processing apparatus. The present invention relates to a processing apparatus and a processing method for a semiconductor wafer in which adhesion and deposition may occur, and a semiconductor element manufactured by using the processing method.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices, various vacuum processing apparatuses such as a CVD apparatus and an etching apparatus are used for forming circuits on a wafer.

Generally, in this type of vacuum processing apparatus, there are cases in which minute dusts due to reaction by-products and the like are generated in the reaction container during the wafer processing process. However, when this minute dust adheres to the wafer surface. , Because it is the main cause of the yield in the manufacturing process of semiconductor elements and the decrease of the equipment operating rate,
It is necessary to take measures to prevent this.

As a method of reducing such minute dust, conventionally, there are (1) a method of reducing the amount of reaction by-products deposited on the wall surface of the reaction tube, and (2) a film which is hard to peel off. A method of appropriately cleaning has been proposed. Examples of known techniques relating to the former include the following.

[0005] Japanese Patent Laid-Open No. 2-224222 discloses a known technique in which a non-reactive gas of a vertical type reduced pressure vapor phase growth apparatus is introduced by introducing the non-reactive gas into a region where reaction by-products and the like tend to adhere. By utilizing the curtain, dilution, and cooling effects, the adhesion of reaction by-products and the like to the wall surface is reduced.

[0006]

On the other hand, recently, a so-called single-wafer CVD apparatus has been proposed. Known techniques related to this are as follows.

In this known technique, a flat reaction tube made of quartz or the like is provided in a heating space formed by two parallel plate heaters, and both longitudinal ends of the reaction tube are opened. , Single-wafer CVD with a metal gate valve or flange attached to its opening
An apparatus is provided.

Here, the single-wafer CV as in the above-mentioned known art.
Even in the D device, it is necessary to prevent the generation of fine dust, but when the method according to the above-mentioned known technique is applied, the following problems occur. This will be described in detail with reference to FIGS. 10 and 11.

In the single-wafer CVD according to the above-mentioned known technique, an O-ring seal is used to maintain the airtightness of the contact portion between the reaction tube and the metal gate valve flange. In the state of the art, the heat resistant temperature of the O-ring is about 200 to 300 ° C. Therefore, this portion is usually cooled (for example, liquid cooling with a refrigerant) to prevent the seal portion from reaching a high temperature. Therefore, the temperature in the region near the opening of the reaction tube becomes lower than that in the central portion of the reaction tube. The measurement result of the temperature distribution on the wall surface of the reaction tube is shown in FIG.

FIG. 10 shows a single-wafer CVD apparatus having a structure similar to that of the above-mentioned known technology, in which a wafer having a length of 200 mm is arranged in a region of a distance of 200 mm to 400 mm from the gas inflow side, and a wafer region setting temperature is 600. ℃, 750 ℃, 8
It is the result of measuring the wall surface temperature distribution in three cases of 00 ° C. The horizontal axis is the distance from the gas inlet side of the reaction tube,
The vertical axis represents the wall temperature of the reaction tube. As shown in the figure, it can be seen that the wall surface temperature near the opening of the reaction tube is lower than that at the center of the reaction tube.

Measurement results of the deposition rate distribution of reaction by-products on the wall surface of the reaction tube when the film forming gas is caused to flow from one direction of the reaction tube to form a thin film on the wafer under the temperature distribution as described above. Is shown in FIG. FIG. 11 shows a reaction tube pressure of 200 Pa.
And 100 Pa, the results are shown for two cases, and the vertical axis represents the dimensionless deposition rate.

In FIG. 11, at the opening on the gas inflow side, the deposition rate is slow because the temperature is low, but gradually the thermal decomposition of the film-forming gas progresses, and the deposition rate increases.
The value becomes almost constant in the wafer region, and the deposition rate gradually decreases toward the opening on the exhaust side. However, there is a region (a distance from the gas inflow side of about 530 mm to 600 mm) where the deposition rate increases again in the low temperature part due to the reaction by-product generated in the high temperature part being transferred to the downstream side by the gas flow. . In the deposition region of this low temperature part, due to the low temperature and the high deposition rate, the reaction by-product does not deposit like the film like in the wafer region but deposits in the form of glass fragments that are easily peeled and scattered. I found out that

As shown in FIG. 11, the deposition rate of the reaction by-product itself is the largest in the wafer region, and the low temperature part where glass fragments are attached is relatively small. However, since the wafer region is at a high temperature, it is in a film-like deposition state in which it is difficult to peel off even at a high deposition rate. Therefore, after being deposited to some extent, for example, once every several hundred film forming processes. It suffices if it is removed by a normal cleaning operation in proportion. On the other hand, the reaction by-product attached to the low temperature part in the form of glass fragments is very easy to peel off,
Cleaning operations with the above-mentioned frequency cannot be used. Therefore, in the case of the single-wafer CVD apparatus, it is necessary to take some measures separately for the adhesion of the glassy reaction by-product to the low temperature part.

However, when the reaction by-product adhesion preventing method according to the known technique is applied to a single-wafer CVD apparatus as in the known technique, the known technique introduces a non-reactive gas into the upstream side of the wafer region in the flow direction. Therefore, as described above, it is not possible to sufficiently prevent the adhesion to the low temperature portion, which is the most important point in the single-wafer CVD apparatus. Therefore, in this case, the reaction by-products adhering to the low temperature portion in the form of glass fragments fluctuate due to pressure fluctuations and gas flow direction fluctuations due to wafer loading and unloading and film deposition gas switching, Dust may adhere to the wafers, which may reduce the operating rate of the device and the yield.

On the contrary, in order to obtain a sufficient anti-adhesion effect by the method according to the known technique, it is necessary to introduce a large amount of non-reactive gas, resulting in poor efficiency and high cost. Further, since the non-reactive gas passes through the wafer area, it may adversely affect the uniformity of the film formation on the wafer.

An object of the present invention is to reduce the amount of reaction by-products deposited at a low temperature portion without affecting the wafer film formation.
An object of the present invention is to provide a semiconductor wafer processing apparatus, a semiconductor wafer processing method, and a semiconductor element that can be efficiently reduced with a small amount of gas.

[0017]

In order to achieve the above object, according to the first concept of the present invention, a substantially flat reaction tube having openings at both ends in the longitudinal direction and openings at both ends of the reaction tube are provided. Any one of thin film formation and epitaxial growth on the wafer surface by storing and heating a semiconductor wafer in a reaction vessel having a flange provided in the section and exhausting it while supplying a reaction gas into the reaction vessel. In a semiconductor wafer processing apparatus that performs one of the processes, a dilution gas supply mechanism that supplies a dilution gas for diluting the reaction gas to a downstream side in the gas flow direction of the wafer arrangement position in the reaction tube is provided. An apparatus for processing a semiconductor wafer is provided.

That is, the reaction gas used for thin film formation or epitaxial growth on the wafer is, for example, a diluent gas supplied from a diluent gas supply mechanism having gas supply holes located near the openings at both ends of the reaction tube, such as nitrogen. Of the reaction gas that is diluted by the inert gas and contributes to the deposition of the reaction by-product, the partial pressure of the reaction gas decreases, and the diluent gas flows so as to protect the reaction tube wall surface from the reaction gas and suppresses the deposition. As a result, the deposition rate of the reaction by-product adhering and depositing on the surface of the low temperature portion of the reaction tube can be reduced, and as a result, the reaction by-product can be deposited in a film at a low speed.

Preferably, in the semiconductor wafer processing apparatus, the dilution gas supply mechanism is provided with a plurality of gas supply holes provided at a plurality of positions in the vicinity of two openings provided at both ends of the reaction tube. An apparatus for processing a semiconductor wafer is provided.

Further preferably, in the semiconductor wafer processing apparatus, there is provided a semiconductor wafer processing apparatus, wherein the diluent gas supply mechanism uses an inert gas as a diluent gas.

More preferably, in the semiconductor wafer processing apparatus, there is provided a semiconductor wafer processing apparatus, wherein the dilution gas supply mechanism uses nitrogen as an inert gas.

In order to achieve the above object, according to the second concept of the present invention, a substantially flat reaction tube having openings at both ends in the longitudinal direction and a reaction tube provided at the openings at both ends of the reaction tube are provided. A semiconductor wafer is housed and heated in a reaction container having a flange, and a reaction gas is supplied to the reaction container and exhausted to perform either one of thin film formation on the wafer surface and epitaxial growth. In the semiconductor wafer processing apparatus, a plurality of fins whose gas flow direction is substantially a plane direction are provided downstream of the wafer arrangement position in the reaction tube in the gas flow direction. Will be provided.

As a result, the surface area when the reaction by-products are deposited and deposited in the low temperature portion of the reaction tube is increased, and as a result, the deposition rate of the reaction by-products deposited and deposited on the surface of the low temperature portion of the reaction tube is reduced. The reaction by-product can be deposited in a film at a low speed.

In order to achieve the above object, according to the third concept of the present invention, a substantially flat reaction tube having openings at both ends in the longitudinal direction and a reaction tube provided at both ends of the reaction tube are provided. A semiconductor wafer is housed and heated in a reaction container having a flange, and a reaction gas is supplied to the reaction container and exhausted to perform either one of thin film formation on the wafer surface and epitaxial growth. In the method of processing a semiconductor wafer, the partial pressure of the reaction gas is set to 100 P.
A method of processing a semiconductor wafer is provided which is a or less.

That is, by setting such a relatively low pressure, the amount of reaction by-products generated can be reduced. Further, since the gas flow rate in the reaction tube, that is, the flow velocity, can be increased, the high deposition area formed in the low temperature portion near the opening at both ends of the reaction tube is moved to the downstream side in the gas direction, so as to move to the outer side area in the reaction tube or outside the reaction tube. It is possible to form a high deposition area in the. As a result, the deposition rate of the reaction by-product adhering and depositing on the surface of the low temperature portion of the reaction tube can be reduced, and the reaction by-product can be deposited in a film at a low speed.

In order to achieve the above object, according to a fourth concept of the present invention, a polysilicon film for gate electrode wiring, a phosphorus-doped polysilicon film, an oxide film / phosphorus glass film for interlayer insulation, and Si ₃ for capacitor insulation
There is provided a semiconductor element having at least one of N ₄ films, wherein the at least one film is formed by using the semiconductor wafer processing apparatus.

In order to achieve the above object, according to a fifth concept of the present invention, a polysilicon film for gate electrode wiring, a phosphorus-doped polysilicon film, an oxide film / phosphorus glass film for interlayer insulation, and Si ₃ for capacitor insulation
There is provided a semiconductor device having at least one film of N ₄ films, wherein the at least one film is formed by the method for processing a semiconductor wafer.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIG. This embodiment is an embodiment of a so-called hot wall type single wafer CVD apparatus.

The structure of the CVD apparatus according to the present embodiment is shown in FIG.
3 to FIG. 1 is a horizontal sectional view showing the overall configuration of the CVD apparatus according to the present embodiment, FIG. 2 is a side sectional view thereof, and FIG. 3 shows a detailed structure of a dilution gas supply hole portion.
It is a middle III-III cross-sectional view.

In FIGS. 1 and 2, the hot wall type CVD apparatus 100 is arranged with its axis line substantially horizontal.
The reaction tube 2 has a flat shape with both ends open, and is made of, for example, quartz, and the wafer 3 is arranged inside the reaction tube 2 in substantially two layers, that is, a wafer 3 having a length of 200 mm, for example.
Supporting rectangular plates 8a and 8b, a flat plate-shaped heater 1 forming a heating furnace which is arranged above and below the reaction tube 2 with the reaction tube 2 interposed therebetween, and both ends of the reaction tube 2. To the metal flanges 9a and 9b, the O-rings 18a and 18b for sealing the contact portions between the reaction tube 2 and the flanges 9a and 9b, and the reaction tube 2 within the thickness of the flanges 9a and 9b. Gas supply ports 4a and 4b, which are arranged in a direction perpendicular to the axis and are formed upward from the center, and an exhaust port 5 which is formed downward from the center, respectively.
a, 5b, a heat insulating material 7 provided on the outside of the heater 1 in the radial direction so as to cover the heater 1, and a gate coupled to the outside of the flanges 9a, 9b in the axial direction and abutting on the central openings of the flanges 9a, 9b, respectively. Valves 10a and 10b, a plurality of dilution gas supply holes 13a and 13b circumferentially provided on the wall surface of the reaction tube 2 for supplying a dilution gas such as N ₂ gas into the reaction tube 2, and the dilution gas supply Holes 13a, 1
Diluting gas supply pipe 1 for introducing N ₂ gas to 3b respectively
1a, 11b and these dilution gas supply pipes 11a, 11b
It is mainly composed of gas reservoirs 12a and 12b for distributing the N ₂ gas introduced from the above into the respective dilution gas supply holes 13a and 13b.

The heater 1 has a structure in which it can be divided into a plurality of parts, and the heat generation amount of each is adjusted so that the temperature distribution of the wafer 3 (described later) becomes uniform. In addition, the heat insulating material 7 provided outside the heater 1 reduces heat radiation to the surroundings and reduces power consumption.

The support plates 8a and 8b are notched in the region where the fork 19 moves, and are provided in two stages above and below so that one wafer can be placed on each of them. That is, one or two wafers 3 are processed at the same time.

Next, the procedure of the film forming method by the CVD apparatus having the above-mentioned structure will be described. First, when one gate valve 10a is opened, two wafers 3 and 3 (or one wafer 3) are released from the opened gate valve 1a.
0a, is placed on the fork 19 and is inserted into the reaction tube 2 in a horizontal state.

Next, the inserted wafer 3 is transferred to the fork 1.
9 is transferred to the support plates 8a and 8b, and is arranged, for example, in a region having a distance of 200 mm to 400 mm from the gas inflow side. Then, the fork 19 is pulled out and the gate valve 10a is closed.

The mounted wafer 3 is heated by the heater 1, and at the same time, the film forming gas is supplied from the gas supply port 4a (or 4b) and the side to which the film forming gas is supplied and the wafer 3 are simultaneously supplied. An N ₂ gas is supplied from a dilution gas supply hole 13b (or 13a) arranged on the opposite side of the wafer, and an exhaust port 5b (or 5a) on the opposite side of the wafer 3 is supplied with the film forming gas. Exhaust from. Then, by adjusting the inside of the reaction tube 2 to a desired temperature (for example, a temperature at which the wafer region setting temperature becomes 600 ° C. to 800 ° C.) and a pressure, the deposition gas is almost parallel to the surface of the wafer 3 by a white arrow (or As indicated by the black arrow), a thin film is formed on the surface of the wafer 3 by thermal reaction.

When the film forming process is completed, the gate valve 10
a is opened, the fork 19 is reinserted into the reaction tube 2 through the gate valve 10a, and the wafer 3 is transferred from the support plate 8 to the fork 19 and then the fork 1 is opened.
9 is pulled out, and the wafer 3 is taken out from the reaction tube 2.

The operation of the film formation of the present embodiment as described above will be described below. The wall surface temperature distribution of the reaction tube 2 (that is, the gas temperature distribution) in the CVD apparatus 100 having the above-described configuration is the distribution shown in FIG. 10 as described above. That is, since the flanges 9a and 9b are cooled in order to lower the temperature of the seal portion to the heat resistant temperature of the O-ring or lower, the temperature in the vicinity of the opening of the reaction tube 2 is lower than that in the central portion of the reaction tube 2 in the axial direction. Has become.

Here, in the CVD apparatus 100 of the present embodiment, when forming a film on the wafer 3 under such a temperature distribution, the film forming gas is a diluent gas located near the openings of both ends of the reaction tube 2. By being diluted with the N ₂ gas supplied from the supply holes 13a and 13b, the partial pressure of the film forming gas that contributes to the deposition of the reaction by-product is reduced, and the N ₂ gas is removed from the film forming gas into the reaction tube 2 It flows so as to protect the wall surface and suppresses deposition. As a result, it is possible to reduce the deposition rate of the reaction by-product adhering and depositing on the surface of the low temperature part of the reaction tube 2 (near the openings at both ends), and as a result, the reaction by-product is deposited in a film at a low speed. You can This is shown in FIG.

Similar to FIG. 11 described above, FIG. 4 shows a reaction by-product on the wall surface of the reaction tube 2 when a film forming gas is flown from one direction of the reaction tube 2 in the CVD apparatus 100 to form a thin film on the wafer 3. It shows the measurement result of the deposition rate distribution of the substance, and the results for two cases of the pressure inside the reaction tube 2 of 200 Pa and 100 Pa are shown with the dimensionless deposition rate taken on the vertical axis.

In FIG. 4, similar to FIG. 11 in the prior art, the deposition rate is slow in the vicinity of the opening on the gas inflow side of the low temperature (distance from the gas inflow side of 0 mm to 100 mm), but the heat of the film forming gas As the decomposition progresses, the deposition rate increases, and the wafer area (distance from the gas inflow side is 200 mm
Is about 400 mm) and the value is almost constant. Then, the deposition rate gradually decreases toward the opening on the exhaust side. At this time, in the conventional structure shown in FIG. 11, the reaction by-product generated in the high temperature part is transferred to the downstream side by the gas flow, so that in the low temperature part region near the distance 530 mm to 600 mm from the gas inflow side. The deposition rate increased again, and the reaction by-products were peeled off and adhered in the form of glass fragments that are easily scattered. However, in the CVD apparatus 100 of the present embodiment, as described above, the action of the N ₂ gas supplied from the dilution gas supply holes 13a and 13b suppresses the increase in the deposition rate in the low temperature region, and as a result, the exhaust side opening It can be seen that the deposition rate almost monotonically decreases toward the part.

Therefore, deposits are prevented from rising or falling due to pressure fluctuations / fluctuations in the gas flow direction due to the loading / unloading of the wafer 3 and the switching of the film forming gas, and the adhesion of dust to the wafer 3 is prevented. Therefore, it is possible to prevent a decrease in yield and device operating rate.

In the first embodiment, the dilution gas supply holes 13a (or 13b) are provided on the wall surface of the reaction tube 2 at a plurality of positions, but the present invention is not limited to this. That is, the reaction tube 2
The structure may be provided only at one location on the wall surface. Also in this case, the same effect is obtained.

Further, in the first embodiment, N ₂ gas was used as an example of the inert gas, but the present invention is not limited to this, and other gas may be used. Also in this case, the same effect is obtained.

A second embodiment of the present invention will be described with reference to FIGS. The present embodiment is an embodiment in which a deposit adsorbing mechanism including a large number of fins is provided as a deposition rate reducing unit in the low temperature section. Members equivalent to those in the first embodiment are denoted by the same reference numerals. Hot wall type C according to the present embodiment
The configuration of the VD device 200 is shown in FIGS. Figure 5 is CV
6 is a side sectional view showing a configuration of the D device 200, FIG. 6 is a VI-VI horizontal sectional view in FIG. 5 showing a detailed structure of a fin installation portion, and FIG. 7 is a by-product adsorption mechanism (described later) from FIG. It is the perspective view which took out and showed only one.

5 to 7, hot wall type C
The VD device 200 is the CVD device 100 of the first embodiment.
The difference from the above is that the dilution gas supply holes 13a and 13b and the dilution gas supply pipes 11a and 1 are used as the deposition rate reducing means in the low temperature part.
1b and the gas reservoirs 12a and 12b, instead of the by-product adsorption mechanisms 214a and 214b near the openings of both ends of the reaction tube 2.
Is provided. These by-product adsorption mechanisms 214a and 214b are shown in FIG.
As shown by taking a as an example, it is provided with a plurality of fins 215 for increasing the surface area on which the reaction by-product is adhered and deposited, the fins 215 whose flow direction is substantially the surface direction. Although not shown, the by-product adsorption mechanism 214b has the same structure as the by-product adsorption mechanism 214a.

The other structure is almost the same as that of the CVD apparatus 100 of the first embodiment.

The procedure of the film forming method by the CVD apparatus 200 having the above structure is almost the same as the film forming procedure by the CVD apparatus of the first embodiment except that the N ₂ gas is not supplied.

According to the present embodiment, the by-product adsorption mechanism 214a (or 214b) is arranged in the low temperature region where the deposition rate increases again as shown in FIG. 11 in the conventional structure, and the reaction by-product adheres. The surface area deposited increases. That is, for example, when the film-forming gas is supplied from the gas supply port 4a and exhausted from the exhaust port 5b to flow the film-forming gas as shown by the white arrow, the film formation from the gas supply port 4b is performed by the action of the by-product adsorption mechanism 214b. When the gas is supplied and the film forming gas is exhausted from the exhaust port 5a and flows as shown by the black arrow, the reaction by-product adhering and depositing on the surface of the low temperature part of the reaction tube 2 is caused by the function of the by-product adsorption mechanism 214a. Since the deposition rate can be reduced, as a result, the reaction by-products can be deposited in a film at a low speed.

Therefore, the deposits are prevented from rising or falling due to the pressure fluctuation and the gas flow direction fluctuation caused by the loading / unloading of the wafer 3 and the switching of the film forming gas, and the adhesion of dust to the wafer 3 is prevented. Therefore, it is possible to prevent a decrease in yield and device operating rate.

In the second embodiment, the by-product adsorption mechanism 214a (or 214b) including the plurality of fins 215 shown in FIG. 7 is used, but the present invention is not limited to this. That is, for example, as shown in FIG. 8, in addition to the plurality of fins 215 whose plate surface direction is substantially horizontal,
A plurality of fins 21 whose plate surface direction is substantially vertical
A by-product adsorption mechanism 216 including 7 may be used. In this case, the same effect can be obtained.

FIG. 9 and FIG. 11 show the third embodiment of the present invention.
This will be described below. The present embodiment is an embodiment in which a member for reducing the deposition rate in the low temperature part is not particularly provided and the deposition rate in the low temperature part is reduced by controlling the pressure in the reaction tube. Members equivalent to those of the first and second embodiments are denoted by the same reference numerals.

Hot wall type CVD according to the present embodiment
A side sectional view showing the configuration of the device 300 is shown in FIG. In FIG. 9, the hot-wall CVD apparatus 300 is different from the CVD apparatus 200 of the second embodiment in that the by-product adsorption mechanisms 214a and 214b near the openings at both ends of the reaction tube 2 are removed. . Other configurations are almost the same as those of the CVD apparatus 200 of the second embodiment. That is, C
The VD device 300 is not particularly provided with a member for reducing the deposition rate in the low temperature region near the openings at both ends of the reaction tube 2.

The main part of this embodiment is that the pressure in the reaction tube 2 is controlled in the procedure of the film forming method. That is, film formation is performed while controlling the pressure in the reaction tube 2 so that the film formation gas partial pressure during film formation on the surface of the wafer 3 is approximately 100 Pa or less. The other film forming procedure is almost the same as the film forming procedure of the second embodiment.

As shown in FIG. 11 mentioned above, the lower the pressure in the reaction tube 2 is, the more the amount of reaction by-products generated in the reaction tube 2 can be reduced, and the gas flow rate in the reaction tube 2 can be reduced. That is, since the flow velocity can be increased, the high deposition region formed in the low temperature part near the opening at both ends of the reaction tube 2 is moved to the downstream side in the gas direction, and the outer side region in the reaction tube 2 (for example, the distance from the gas inflow side). 570 mm to 600 mm or outside the reaction tube (for example, 600 m from the gas inflow side)
A high deposition area can be formed at a distance (m or more). As a result, the deposition rate of the reaction by-product adhering and depositing on the surface of the low temperature portion of the reaction tube 2 can be reduced, and the reaction by-product can be deposited in a film at a low speed. At this time, the present inventors determined from the results shown in FIG. 11 that a sufficient deposition rate lowering effect can be obtained if the pressure inside the reaction tube 2 is 100 Pa or less.

Therefore, the deposits are prevented from rising or falling due to the pressure fluctuation and the gas flow direction fluctuation caused by the loading / unloading of the wafer 3 and the switching of the film forming gas, and the adhesion of dust to the wafer 3 is prevented. Therefore, it is possible to prevent a decrease in yield and device operating rate.

In the first to third embodiments, the CV is used.
Although the embodiment of the D apparatus has been described, the present invention is not limited to this, and may be applied to, for example, an epitaxial growth apparatus that causes the surface of the wafer 3 to grow epitaxially, and similar effects can be obtained in these cases.

Of course, of the above-described first, second, and third embodiments,
At least two device configurations and film formation methods may be used in combination, and in these cases, the combined effects of the respective combined embodiments can be obtained.

Furthermore, as another embodiment, the CVD apparatuses 100, 200, 30 according to the first to third embodiments described above.
A polysilicon film for gate electrode wiring of a semiconductor device manufactured by using 0, a phosphorus-doped polysilicon film, an oxide film / phosphorus glass film for an interlayer insulating film, and a Si ₃ N ₄ film for a capacitor insulating film. If the semiconductor element provided is used, it is possible to secure good quality in which dust is hardly attached to the wafer 3.

[0059]

EFFECTS OF THE INVENTION According to the present invention, the deposition rate of the reaction by-product adhering and depositing on the surface of the low temperature portion of the reaction tube can be reduced, and as a result, the reaction by-product is deposited in a film at a low speed. be able to. Therefore, deposits are prevented from rising or falling due to pressure fluctuations or gas flow direction fluctuations due to wafer loading / unloading or reaction gas switching, and it is possible to prevent dust from adhering to the wafer.
It is possible to prevent a decrease in yield and device operating rate.

[Brief description of the drawings]

FIG. 1 is a horizontal sectional view showing the overall configuration of a CVD apparatus according to a first embodiment of the present invention.

FIG. 2 is a side sectional view of the CVD apparatus shown in FIG.

3 is a cross-sectional view taken along the line III-III in FIG.

4 is a diagram showing a measurement result of a deposition rate distribution of a reaction by-product on a wall surface of a reaction tube when a thin film is formed by the CVD apparatus shown in FIG.

FIG. 5 is a side sectional view showing an overall configuration of a CVD apparatus according to a second embodiment of the present invention.

6 is a horizontal sectional view taken along the line VI-VI in FIG.

FIG. 7 is a perspective view showing only a by-product adsorption mechanism taken out from FIG.

FIG. 8 is a perspective view showing a modified example of a by-product adsorption mechanism.

FIG. 9 is a side sectional view showing a configuration of a CVD apparatus according to a third embodiment of the present invention.

FIG. 10 is a diagram showing a measurement result of a temperature distribution on a wall surface of a reaction tube in a CVD apparatus having a conventional structure.

FIG. 11 is a diagram showing a measurement result of a deposition rate distribution of a reaction by-product on a wall surface of a reaction tube when a thin film is formed in a CVD apparatus having a conventional structure.

[Explanation of symbols]

 1 Heater 2 Reaction Tube 3 Wafer 4a, b Gas Supply Port 5a, b Exhaust Port 7 Heat Insulating Material 8a, b Support Plate 9a, b Flange 10a, b Gate Valve 11a, b Diluting Gas Supply Pipe 12a, b Gas Reservoir 13a, b Diluting gas supply hole 18a, b O-ring 100 CVD apparatus 200 CVD apparatus 214a, b By-product adsorption mechanism 215 Fin 216 By-product adsorption mechanism 217 Fin 300 CVD apparatus

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyo Nishiuchi 5-20-1, Josuihoncho, Kodaira-shi, Tokyo Incorporated company Hitachi Ltd. Semiconductor Division

Claims (8)

[Claims] 1. A semiconductor wafer is housed and heated in a reaction vessel provided with a substantially flat reaction tube having openings at both ends in the longitudinal direction and flanges provided at the openings at both ends of the reaction tube, In a semiconductor wafer processing apparatus that performs one of thin film formation and epitaxial growth processing on a wafer surface by exhausting while supplying a reaction gas into the reaction container, a diluent gas for diluting the reaction gas is used. A processing apparatus for semiconductor wafers, characterized in that a dilution gas supply mechanism for supplying the diluted gas to the downstream side of the wafer arrangement position in the reaction tube in the gas flow direction is provided. 2. The semiconductor wafer processing apparatus according to claim 1, wherein the dilution gas supply mechanism includes gas supply holes provided at a plurality of positions near two openings provided at both ends of the reaction tube. A semiconductor wafer processing apparatus characterized by the above. 3. The semiconductor wafer processing apparatus according to claim 1, wherein the diluent gas supply mechanism uses an inert gas as a diluent gas. 4. The semiconductor wafer processing apparatus according to claim 3, wherein the dilution gas supply mechanism uses nitrogen as an inert gas. 5. A semiconductor wafer is housed and heated in a reaction container having a substantially flat reaction tube having openings at both ends in the longitudinal direction and flanges provided at the openings at both ends of the reaction tube, In a semiconductor wafer processing apparatus that performs one of thin film formation and epitaxial growth processing on a wafer surface by supplying a reaction gas into the reaction vessel and exhausting the gas, a gas is supplied from the wafer placement position in the reaction tube. An apparatus for processing a semiconductor wafer, characterized in that a plurality of fins whose gas flow direction is substantially a surface direction are provided on the downstream side in the flow direction. 6. A semiconductor wafer is housed and heated in a reaction container provided with a substantially flat reaction tube having openings at both ends in the longitudinal direction and flanges provided at the openings at both ends of the reaction tube, In a method for processing a semiconductor wafer, in which a reaction gas is exhausted while being supplied to the reaction container to perform a thin film formation on a wafer surface or an epitaxial growth, a partial pressure of the reaction gas is set to 100 Pa or less. A method of processing a semiconductor wafer, comprising: 7. A polysilicon film for gate electrode wiring, a phosphorus-doped polysilicon film, an oxide film / phosphorus glass film for interlayer insulation, and a Si ₃ N ₄ film for capacitor insulation. A semiconductor element, wherein the at least one film is formed by using the semiconductor wafer processing apparatus according to claim 1. 8. A polysilicon film for gate electrode wiring, a phosphorus-doped polysilicon film, an oxide film / phosphorus glass film for interlayer insulation, and a Si ₃ N ₄ film for capacitor insulation. A semiconductor element, wherein the at least one film is formed by the method for processing a semiconductor wafer according to claim 6.