JPH10223538A - Vertical heat-treating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the particle from growing during formation of, e.g. a thin film by CVD on the surface of a semiconductor wafer, using a vertical heat-treating apparatus. SOLUTION: Using a vertical single reaction tube 2 which is open at a lower end, an injector 42 for feeding a treating gas and exhaust pipe 44 are connected to a manifold attached to the lower end of this tube 2. A tubular member 61 is provided to cover the inner surface of a manifold 4 through a space and surround a lifting region of a wafer boat 5. Rings 62a, 62b are attached to the upper and lower edges of the tubular member 61 and have exhaust holes 63 to form a cover 6, having an exhaust space S with the inner wall of the manifold 4 for exhausting gaseous reaction products from the reaction tube 2, through the exhaust holes 63 and a space S. The reaction products condense in this space S and are confined therein, to suppress the particle from growing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical heat treatment apparatus for forming a thin film on a substrate to be processed by a chemical vapor reaction.

[0002]

2. Description of the Related Art As one method of forming a thin film such as a polysilicon film on a semiconductor wafer, low pressure CVD (Chemical V) is used.
There is an apor deposition method, and as a batch furnace for carrying out this method, a vertical heat treatment apparatus is becoming mainstream because of little entrainment of the atmosphere. A conventional vertical heat treatment apparatus will be described with reference to FIG. 13A. This apparatus inherits the structure of a horizontal heat treatment apparatus, and uses a double tube as a reaction tube. Reaction tube 1 is manifold
An outer tube 1a is provided on the chamber 10 and has an upper end closed and an open lower end, and an inner tube 1b provided in the outer tube 1a and open at both ends. A heating furnace 11 is provided around 1.

In such an apparatus, a large number of semiconductor wafers (hereinafter referred to as "wafers") W are carried into a reaction tube 1 by being held in a wafer boat 12 in a shelf shape, and the inside of the reaction tube 1 is an outer tube 1a.
A processing gas is introduced from the lower side of the inner pipe 1b through the gas supply pipe 14 while evacuating from the space between the inner pipe 1b and the exhaust pipe 13 and maintaining the atmosphere at a predetermined reduced pressure. To form a thin film, for example, a polysilicon film on the wafer W by a chemical vapor reaction of the processing gas.

As the degree of integration of semiconductor devices has increased, high accuracy has been required for the thickness of thin films, and accordingly high temperature stability is required during processing. In the above, since the space is formed on both sides of the tube wall of the inner tube 1b, the heat capacity is large,
Low thermal efficiency. For this reason, the temperature recovery (time until the temperature inside the reaction tube is increased after the wafer W is loaded and the temperature on the surface of the wafer W is stabilized) is long.

[0005] It is considered that this problem becomes more apparent as the size of the reaction tube increases as the wafer size increases. In the above-described polysilicon film formation processing,
The polysilicon film adheres to the outer tube 1a and the inner tube 1b. However, since this polysilicon film has a large reflectance, if it adheres to the reaction tube, radiant heat from the heating unit 11 is blocked, and the heating efficiency is further reduced. I will. For this reason, the present inventor has focused on a vertical heat treatment apparatus using a single-tube reaction tube having a smaller heat capacity and higher heating efficiency than the double-tube reaction tube 1.

Considering an apparatus in which a double-tube reaction tube is simply converted to a single-tube structure, a structure as shown in FIG. 13B is obtained. That is, the reaction tube 15 is closed at the upper end and open at the lower end, and the gas supply tube 16 is provided so as to protrude from the lower side of the manifold 10 and the tip is located at the upper side inside the reaction tube 15. ing. Other configurations are the same as those of the vertical heat treatment apparatus using the double-tube reaction tube. In such a vertical heat treatment apparatus, the inside of the reaction tube 15 is evacuated by the exhaust pipe 13 connected to the manifold 10, and the reaction tube 15 is exhausted.
The process gas supplied from the upper side is passed toward the lower side to perform a predetermined polysilicon film forming process.

[0007]

By the way, in the vertical heat treatment apparatus using the reaction tube 15 having the single tube structure, the manifold is used.
An O-ring 17 is interposed at the joint between the mold 10 and the reaction tube 15, and the O-ring 17 is made of resin and is deteriorated at a temperature of, for example, 200 ° C. or more.
The portion of the manifold 10 is cooled to a temperature of 200 ° C. or less.

In the above-described film forming process, the processing gas and the reaction product in a gaseous state are exhausted to the outside through the exhaust pipe 13. However, since the manifold 10 is cooled as described above, In this region, the reaction product changes to a solid state, and adheres to the inner peripheral surface of the manifold 10, especially the inner wall near the exhaust port (not shown). The reaction product gradually accumulates during the process, and when the deposition amount increases, the reaction product peels off from the inner wall of the manifold 10 and becomes particles. Therefore, the wafer boat 12 is loaded into the reaction tube 15.
When it is unloaded, it passes by this side,
It is considered that the wafer mounted on the wafer boat 12 is contaminated by the particles generated here.

An object of the present invention is to provide a CV on a surface of a substrate to be processed.
An object of the present invention is to provide a vertical heat treatment apparatus capable of suppressing generation of particles when forming a thin film by the D process.

[0010]

SUMMARY OF THE INVENTION The present invention provides a single vertical reaction tube having an open lower end, and a cylindrical manifold provided at the lower end of the reaction tube and connected to an exhaust pipe. -And
A heating unit provided to surround the periphery of the reaction tube, a holder for holding a plurality of substrates to be processed in a shelf shape, and carrying in the reaction tube from below, and supplying a processing gas into the reaction tube. A gas supply pipe for forming a thin film on a substrate to be processed by a chemical vapor reaction, wherein the inner peripheral surface of the manifold is covered via a space, and A cylindrical member provided so as to surround the elevating area is provided, and gas in the reaction tube is exhausted by the exhaust pipe through a space formed in the cylindrical member.

At this time, an exhaust hole is formed between the upper edge portion of the cylindrical member and the manifold or the inner peripheral surface of the reaction tube. In this case, gas in the reaction tube is exhausted from the exhaust hole through the space. Exhausted from pipe. Along the inner peripheral surface of the tubular member,
An inert gas supply pipe for flowing the inert gas upward from below may be provided.

The present invention also provides a vertical reaction tube, a holder for holding a plurality of substrates to be processed in a shelf shape, and carrying in the reaction tube from below, and exhausting the gas in the reaction tube from below. A vertical processing apparatus for forming a thin film on a substrate to be processed by a chemical vapor reaction, wherein the processing gas supply port is open at a position higher than the upper end of the holder. And a gas rectifying member provided on the top plate of the holder.

[0013]

FIG. 1 is a view showing a vertical heat treatment apparatus used in an embodiment of the present invention. In the figure, reference numeral 2 denotes a reaction tube, which is formed of a single vertical quartz tube having an upper end closed and an open lower end. A heating furnace 3 is arranged around the reaction tube 2 so as to surround the reaction tube 2, and the heating furnace 3 is provided with a heater 32 formed of a resistance heating element forming a heating unit on an inner peripheral surface of a heat insulator 31. You.

A metal manifold 4 is provided below the reaction tube 2, and a flange at the lower end of the reaction tube 2 is fixed in a state sandwiched between the manifold 4 and the base plate 40. Reaction tube flange and manifold
An O-ring 41 is interposed at the junction with the screen 4.

An injector 42, which is a gas supply pipe, is provided in the manifold 4 so as to protrude therefrom.
2 is bent in an L-shape and extends along a wafer boat described later, is bent in an inverted J-shape at a position higher than the top of the wafer boat, and has a tip almost at the center of the top of the wafer boat. And is provided at a position slightly higher than the top. Further, an exhaust pipe 44 is connected to an exhaust port 43 formed in the manifold 4. Such a manifold 4 is cooled to 200 ° C. by a cooling means (not shown).
The cooling means is composed of, for example, a cooling water flow path formed inside the manifold 4 and cooling water flowing through this flow path.

In the reaction tube 2, a large number of wafers W, for example, 150 wafers are placed on a wafer boat 5 which is a holding tool in a shelf shape, that is, in a substantially horizontal state, and are vertically spaced from each other. The wafer boat 5 is held on a lid 51 via a heat insulating cylinder 52 which is a heat insulator. The lid 51 is mounted on a boat elevator 53 for loading and unloading the wafer boat 5 into and out of the reaction tube 2, and has a role of closing the lower end opening of the manifold 4 when at the upper limit position.

A cover for covering the inner peripheral surface of the manifold 4 through a space is provided inside the reaction tube 2 and the manifold 4.
6 are provided. The cover 6 is made of, for example, quartz. As shown in FIG. 2 (a), ring bodies 62 are provided on both upper and lower edges of a circular cylindrical member 61 surrounding the elevating area of the wafer boat 5.
a and 62b are provided in a flange shape.

The upper ring body 62a is located in a region where a reaction product generated by a chemical vapor reaction to be described later exists in a gaseous state, for example, in a region near a lower portion of the reaction tube 2, and its outer peripheral surface is formed, for example. It is provided so as to be joined to the inner surface of the reaction tube 2. The outer peripheral surface of the ring body 62b is
The lower surface of the ring body 62b is provided on the inner peripheral surface of the manifold 4 below the inert gas supply pipe 64, for example. It is configured to be supported by a protruding portion projecting from the surface.

The cylindrical member 61 is a reaction tube 2 of the wafer boat 5.
It is arranged so as to surround the hoistway inside, and is provided so as to cover the outer periphery of the heat retaining cylinder 52 when the wafer boat 5 is carried in. As described above, the exhaust port 43 is covered by the ring members 62a and 62b and the cylindrical member 61, and an exhaust space S which is a closed area surrounded by the cover 6 is formed inside the manifold 4.

The upper ring body 62a is provided with the injector 42 projecting therefrom.
As shown in (b), a plurality of exhaust holes 63 for ventilating between the internal region of the reaction tube 2 and the exhaust space S are formed at equal intervals in the circumferential direction. On the lower side of the manifold 4, for example, an inert gas supply pipe 64 is provided so as to protrude between the lower surface of the ring body 62 b and the lid 51.

Next, the process of the method of the present invention using the above-described apparatus will be described. First, the temperature of the processing area in the reaction tube 2 is set to, for example, 400 ° C., and, for example, 150 wafers of 12-inch size,
And lifted up the boat elevator 53 to carry it into the reaction tube 2 from the lower end opening.

Next, the inside of the reaction tube 2 is evacuated by a vacuum pump (not shown) through an exhaust pipe 44, and the power of the heater 32 is raised as shown by a dotted line a in FIG. The method of raising the temperature after loading the wafer W into the reaction tube 2 is as shown by a solid line b in FIG. 2 when processing is performed at a high temperature rising rate up to a temperature slightly lower than the processing temperature, for example, at 600 ° C. To about 550 ° C., the surface of the wafer W is heated at a rate of 15 ° C./min.
After that, the power of the heater 32 is reduced to reduce the temperature rising rate,
Temperature control is performed to stabilize at the set temperature of 600 ° C.

After the surface of the wafer W is stabilized at a set temperature (processing temperature), for example, 600 ° C., a processing gas, for example, SiH ₄ gas is injected into the reaction tube 2 from the upper end (tip) of the injector 42.
The inert gas is supplied at a flow rate of 00 SCCM, and nitrogen gas, which is an inert gas, is supplied as a purge gas from the inert gas supply pipe 64 between the tubular member 61 and the heat retaining cylinder 52 at a flow rate of 50 SCCM. A polysilicon film is formed on the wafer W by a chemical vapor phase reaction of SiH ₄ gas by controlling the pressure to be 0.2 Torr by evacuating from the lower side through the exhaust pipe 44.

By the way, the polysilicon film adheres to the inner surface of the reaction tube 2 and the reflectance of the polysilicon film is large. Therefore, the unit radiated from the heating furnace 3 into the reaction tube 2 during the repetition of the process. The amount of heat per hour decreases. However, since the reaction tube 2 is a single quartz tube (single tube), the polysilicon film is not formed over the inner and outer stages as in the case of the conventional double tube, and is blocked by the polysilicon film. Less radiant heat. Since the inner and outer double spaces are not formed by using the inner wall of the inner tube as a partition wall as in the case of a double tube, the heat capacity is small. Therefore, heater 3
The followability of the temperature of the wafer W to the temperature change of 2 is improved, and the temperature controllability is improved.

Here, when the rate of temperature rise in the processing region is high, first, the heater power is increased at once, and the wafer W
When the temperature approaches the set temperature, the heater power drops to perform delicate control. If the temperature of the wafer W does not follow well, it takes a long time for the temperature of the wafer W to converge at this stage, and the temperature becomes lower than the set temperature. When performing delicate temperature control from a slightly lower temperature, the time until the temperature stabilizes to the set temperature depends on the quality of the temperature control, and by using a single tube as the reaction tube 2, this time Becomes shorter. Since the temperature controllability is good, the rate of temperature rise of the wafer W until the temperature reaches a temperature slightly lower than the set temperature can be increased, and as a result, the temperature recovery can be accelerated and a high throughput can be obtained.

As described above, using a single tube as the reaction tube 2,
The method of performing VD processing is very effective when the wafer size is 8 inches or more and the processing temperature range is 300 to 650 ° C. When the wafer size is 6 inches or less, the heat capacity of the reaction tube is small, the temperature followability of the wafer W is not so bad, and there is no problem with the conventional method. On the other hand, the time required for the wafer W to reach the set temperature after the wafer W is loaded into the reaction tube 2 and the temperature is started after the wafer W is transported into the reaction tube 2 is set within 20 minutes. This is effective when high stability is required for the temperature, that is, when the allowable temperature range is narrow.

In the above-described process, when the exhaust gas is exhausted through the exhaust pipe 44, the inside of the reaction tube 2 is exhausted through the exhaust hole 63 of the cover 6, whereby the processing gas and the gas phase generated by the chemical gas phase reaction are produced. The gas in the reaction tube 2 such as the reaction product in the state flows inside the reaction tube 2 from the upper side to the lower side as shown by a solid line in FIG. At this time, the manifold
Although the chamber 4 is cooled as described above, the vicinity of the exhaust hole 63 of the cover 6 is in a temperature range where the reaction product exists in a gaseous state, so that the processing gas and the reaction product are in a gaseous state. Air is exhausted into the exhaust space S through the exhaust hole 63.

Further, in the region between the cylindrical member 61 and the heat retaining cylinder 52, an inert gas such as nitrogen (N ₂ ) gas is purged as a purge gas by an inert gas supply pipe 64 as shown by a chain line in FIG. Since the gas flows along the outer surface of the heat retaining cylinder 52 and the inner surface of the tubular member 61 from the side toward the upper side, the processing gas and the like hardly flow into this region.

As described above, the manifold 4 is cooled to, for example, 200 ° C. in order to suppress the deterioration of the O-ring, and the exhaust space S is lower than the temperature at which the reaction product in the gas phase solidifies. Has become. Therefore, the exhaust hole 6 is provided in this space S.
The reaction product sucked in the gaseous state from 3 solidifies here to a solid state, for example, the inner surface of the cover 6 or the manifold.
It adheres to the inner wall surface of the field 4. During the process, the reaction products gradually accumulate on these adhered surfaces, but since the reaction products are confined in the exhaust space S, they cannot be scattered as particles in the reaction tube 2. In addition, generation of particles due to the deposition of reaction products is prevented.

As described above, the particles are confined outside the elevating area of the wafer boat 5, so that when the wafer boat 5 is loaded and unloaded in the reaction tube 2,
The wafer W mounted on the wafer boat 5 is prevented from being contaminated by particles.

Since the exhaust space S is formed between the cylindrical member 61 and the inner peripheral surface of the manifold 4, the inner peripheral surface of the cylindrical member 61 is larger than the inner peripheral surface of the manifold 4. The temperature is high, so that the reaction product does not easily adhere to the inner peripheral surface of the tubular member 61.

Further, since the processing gas and the like are exhausted from the exhaust hole 63 formed in the ring body 62a into the exhaust space S, the processing gas and the like hardly enter the inner peripheral surface side of the cylindrical member 61, and As described above, the nitrogen gas flows through the region between the cylindrical member 61 and the heat retaining cylinder 52, so that the processing gas or the like hardly enters. As described above, since the processing gas and the like hardly flow along the inner peripheral surface of the cylindrical member 61 and the outer peripheral surface of the heat retaining cylinder 52, the amount of the reaction product adhered to these surfaces is extremely small. Therefore, the degree of particle contamination of the wafer W caused by the reaction products deposited in this region is considerably reduced.

Further, by providing the cover 6, the gas flow in the reaction tube 2 can be made uniform. In other words, when the inside of the reaction tube 2 is evacuated by the exhaust pipe 44, the inside of the reaction tube 2 is evacuated through the exhaust hole 63 formed in the cover 6. Since the processing gas and the like are disposed uniformly in the reaction tube 62a, the processing gas and the like are substantially uniformly dispersed in the cross section of the reaction tube 2. Therefore, since the processing gas is uniformly supplied in the plane of the wafer W, the in-plane uniformity of the thickness of the formed polysilicon film can be improved.

In the above embodiment, the cover 6 may be configured as shown in FIG. Cover 6 shown in FIG.
A ring 62a is provided in a flange shape on the upper edge of the tubular member 61, and the lower end of the tubular member 61 is supported by a protruding portion projecting from the inner peripheral surface of the manifold 4. ing. Other configurations are the same as those of the cover 6 shown in FIG.

The exhaust holes 6 formed in the cover 6
3 may be formed, for example, as shown in FIG. FIG.
The example shown in (a) is an example in which many exhaust holes 63 are provided on the side opposite to the side to which the exhaust pipe is connected. In this way, the degree of exhaust of one exhaust hole 63 is large on the side to which the exhaust pipe is connected, but the number of exhaust holes 63 is small,
On the other hand, on the side opposite to the side where the exhaust pipe is connected, the degree of exhaust of one exhaust hole 63 is small, but since the number of exhaust holes 63 is large, the degree of exhaust on the side where the exhaust pipe is connected and the opposite side And the flow of the processing gas can be made more uniform. By increasing the size of the exhaust hole 63 on the side opposite to the side to which the exhaust pipe is connected,
The degree of exhaust may be controlled. Further FIG.
As shown in (b), the exhaust hole 63 may be formed in a slit shape.

Further, the cylindrical member 61 may be attached to the inner surface of the reaction tube 2 or the manifold 4 by, for example, an arm or the like, and the ring member 62 may not be provided. Further, for example, as shown in FIG.
May be provided so as to be in contact with. In this case, the wafer boat 5
Is carried into the reaction tube 2, an exhaust space S, which is a closed area surrounded by the cover 6 and the lid 51, is formed inside the manifold 4. Further, the ring body 62a may be joined to the inner peripheral surface of the manifold 4 in a region where the reaction product exists in a gaseous state.

Next, another embodiment of the present invention will be described. This embodiment is different from the above-described embodiment in that a gas rectifying member 7 is provided above a wafer boat 5 in a vertical heat treatment apparatus, for example, as shown in FIGS. The gas rectifying member 7 is for uniformizing the flow of the processing gas introduced from the injector 42 serving as the processing gas supply unit until the processing gas reaches the wafer W. The gas rectifying member 7 is provided on the upper surface of the top plate 5a of the wafer boat 5 with a spacing member 7 made of quartz.
For example, a straightening plate 72 made of a circular quartz plate is
It is constituted by providing in a stepped manner.

Here, when processing a 12-inch wafer, the length of the spacing member 71 is, for example, 10 mm, and the current plate 72 is almost the same size as the top plate 5a, and has a thickness of 4 mm and a diameter of 340 mm. is there. As described above, such a gas rectifying member 7 is made of a heat insulating material such as quartz. Other configurations are the same as those of the vertical heat treatment apparatus shown in FIG.

When the gas rectifying member 7 is provided in this manner, the processing gas supplied from the distal end portion of the injector 42 hits the rectifying plate 72 of the gas rectifying member 7 and the flow path is expanded.
The gap between the two straightening plates 72, the straightening plate 72 and the top plate 5a
It flows downward while entering and leaving the gap between the two. In this way, a flow path is secured by the gas rectifying member 7, thereby increasing the flow distance of the processing gas between the injector 42 and the wafer W. Therefore, the processing gas gradually rectifies while passing through this flow path. When the gas reaches the wafer W mounted on the wafer boat 5, the gas flow becomes uniform. Therefore, since the processing gas can be uniformly supplied to the wafer W, a heat treatment with high in-plane uniformity can be performed.

Further, since the flow path is secured by the gas rectifying member 7 as described above, the time required for the processing gas to reach the wafer boat 5 becomes longer. For this reason, the processing gas is heated for a long time, so that the processing gas is sufficiently heated to a reaction temperature before reaching the wafer W mounted on the upper side of the wafer boat 5. be able to.
Therefore, a predetermined heat treatment can be performed on the wafer W mounted on the upper side of the wafer boat 5.

Here, in the prior art, the flow of the processing gas is not uniform on the upper side of the wafer boat 5, and the temperature of the processing gas is not sufficiently raised to the reaction temperature, so that it is difficult to perform a uniform heat treatment. Therefore, the dummy wafer was placed in this area. In the present embodiment, the gas rectifying member 7
Is provided, the flow of the processing gas becomes uniform, and the temperature of the processing gas is sufficiently raised.
Uniform heat treatment can be performed even in the upper region of
For this reason, the dummy wafer may not be placed, or even if it is placed, the number of dummy wafers may be small. Therefore, many wafers W for processing can be mounted on the wafer boat 5, so that the number of processed wafers W increases,
Put is improved.

In this embodiment, the gas rectifying member may be configured as shown in FIG. FIG.
The gas rectifying member 73 shown in FIG. 10A is an example in which one rectifying plate 72 is used and the length of the spacing member 71 is increased.
In the example shown in (b), the gas rectifying member 74 is formed of a quartz cylindrical body. Such a gas rectifying member 7
Even when the processing gas 3 and 74 are provided, the flow path of the processing gas can be secured, so that the gas flow can be made uniform before the processing gas is supplied to the wafer W, and the gas temperature can be sufficiently raised. can do.

In the above-described two embodiments, the injector 42 for supplying gas is provided as shown in FIG.
In addition to the structure shown in FIG. 11, the injector 42 is bent above the wafer boat 5, as shown in FIG. 11, and the downstream end is provided from the bent portion so that the tip extends to the lower side of the wafer boat 5. Alternatively, the supply holes 42a may be formed on the downstream side from the bent portion so as to gradually decrease the interval toward the distal end.

In the injector 42, the supply amount of the processing gas can be controlled to be uniform in the length direction of the reaction tube 2. In other words, in the injector 42, the gas pressure decreases toward the distal end,
The amount of the processing gas supplied from the supply hole 42a decreases toward the distal end. Therefore, by providing a large number of supply holes 42a toward the front end side, it is possible to control the amount of the processing gas supplied from the supply holes 42a to be uniform in the longitudinal direction of the reaction tube. Instead of changing the distance between the supply holes 42a, the supply holes 42a
May be made larger.

Further, as the injector 42, FIG.
12A, the supply port 42a is extended upward along the wafer boat 5 to the upper side of the top plate of the wafer boat 5 as shown in FIG. 12A, and the upper end as shown in FIG. A part whose part is bent in an L shape can be used.
At this time, in the injector 42 having a configuration that does not bend as shown in FIG. 12C, a plurality of supply holes 42a are provided to adjust the size and arrangement interval of the holes, as shown in the example shown in FIG. It is desirable to control the supply.

[0046]

According to the first to third aspects of the present invention, generation of particles can be suppressed when a thin film is formed on a surface of a substrate to be processed by a CVD process using a vertical heat treatment apparatus. According to the invention of claim 4, the flow of the processing gas can be rectified before being supplied to the surface of the substrate to be processed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of a vertical heat treatment apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view and a plan view showing an example of a cover.

FIG. 3 is a characteristic diagram showing a change over time of a heater power and a surface temperature of a wafer in association with each other.

FIG. 4 is a cross-sectional view for explaining the operation of the cover.

FIG. 5 is a perspective view and a sectional view showing another example of a cover.

FIG. 6 is a plan view showing another example of the exhaust hole.

FIG. 7 is a cross-sectional view illustrating an example of a vertical heat treatment primer according to another embodiment of the present invention.

FIG. 8 is a perspective view showing a gas rectifying member.

FIG. 9 is an explanatory diagram for explaining an operation of the gas rectifying member.

FIG. 10 is a perspective view showing another example of the gas flow regulating member.

FIG. 11 is an explanatory diagram showing another example of the injector.

FIG. 12 is an external view showing still another example of the injector.

FIG. 13 is a cross-sectional view showing a conventional vertical heat treatment apparatus.

[Explanation of symbols]

 2 Reaction tube 3 Heating furnace 4 Manifold 42 Injector 44 Exhaust tube 5 Wafer boat 6 Cover 61 Cylindrical member 62a, 62b Ring body 63 Exhaust hole 7, 73, 74 Gas rectifying member

Claims (4)

[Claims] 1. A single vertical reaction tube having an open lower end, a cylindrical manifold provided at the lower end of the reaction tube and connected to an exhaust pipe, A heating unit provided so as to surround the periphery, a holder for holding a plurality of substrates to be processed in a shelf shape, and carrying in from the lower side of the reaction tube;
A gas supply pipe for supplying a processing gas into the inside of the reaction tube, and forming a thin film on the substrate to be processed by a chemical vapor reaction. And cover through
A vertical heat treatment apparatus characterized in that a cylindrical member is provided so as to surround an elevating region of the holder, and gas in the reaction tube is exhausted by the exhaust pipe through a space formed in the cylindrical member. 2. An exhaust hole is formed between an upper edge portion of the cylindrical member and an inner peripheral surface of the manifold or the reaction tube, and gas in the reaction tube flows from the exhaust tube through the exhaust hole to the exhaust tube through the space. The vertical heat treatment apparatus according to claim 1, wherein the apparatus is evacuated. 3. The method according to claim 1, wherein an inert gas supply pipe is provided along the inner peripheral surface of the tubular member so as to allow the inert gas to flow upward from below. Vertical heat treatment equipment. 4. A vertical reaction tube, a holder for holding a plurality of substrates to be processed in a shelf shape, and carrying in the reaction tube from below, and an exhaust for exhausting gas in the reaction tube from below. A vertical processing apparatus for forming a thin film on a substrate to be processed by a chemical vapor reaction, wherein a processing gas supply unit having a gas supply port opened at a position higher than an upper end of the holder; A vertical heat treatment apparatus comprising: a gas rectifying member provided on a top plate of a holder.