JP2001110730A - Vertical heat treatment equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformize gas supply rate and treatment in the inter-face direction of a body to be treated, using a simple constitution. SOLUTION: In this vertical heat treatment equipment, plural bodies w to be treated are housed in a treatment vessel 2 to be supported in the height direction with prescribed intervals, and a treatment gas is introduced to the treatment container 2, and the bodies w to be treated can be treated at a prescribed temperature. This treatment chamber 2 is provided with a first gas inlet tube 8A, constituted of a straight tube erected from the lower part to the upper part whose top end is closed and whose tube wall, is equipped with gas blowout holes 16 formed with prescribed intervals for blasting the treatment gas to the bodies w to be treated and a second gas inlet tube 8B, constituted of a U-shaped tube ejected from the lower part to the upper part and bent from the upper part to the lower part whose top end is closed and whose tube wall bent to the lower part, is equipped with gas blowout holes 17 formed with prescribed intervals for blasting the treatment gas to the objects w to be treated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a vertical heat treatment apparatus.

[0002]

2. Description of the Related Art For example, in the manufacture of a semiconductor device, an object to be processed, such as a semiconductor wafer, is oxidized, diffused, annealed, and cooled.
As a semiconductor manufacturing apparatus for performing processing such as VD, for example, a batch-type vertical heat treatment apparatus capable of processing a large number of semiconductor wafers at one time is used. This vertical heat treatment equipment
A boat, which is a support that supports a number of semiconductor wafers arranged at predetermined intervals in the height direction, is housed in a processing container, and a processing gas is introduced into the processing container to perform predetermined processing on the semiconductor wafer at a predetermined temperature. For example, it is configured to perform a film forming process by CVD.

[0003] The processing vessel is provided with a gas introduction pipe for introducing a processing gas.
For example, the processing vessel is formed of a straight pipe that rises upward from below and has a closed end, and gas injection holes for injecting a processing gas to a semiconductor wafer are formed at predetermined intervals in the pipe wall (dispersed injector). Is also used).

[0004]

However, in the vertical heat treatment apparatus provided with the gas inlet tube, a pressure gradient occurs in the gas inlet tube, and the flow rate of the processing gas from the gas outlet hole is reduced by the gas flow in the gas inlet tube. Since the amount decreases as going from the introduction port side to the tip, the supply amount of the processing gas varies (non-uniform) between the surfaces of a plurality of semiconductor wafers supported by the boat or in the direction between the surfaces (height direction), There is a problem that the processing (for example, the film thickness in the film forming processing and the doping concentration in the diffusion processing) becomes non-uniform in the inter-plane direction.

In order to solve this problem, for example, the diameter of the gas outlet of the gas inlet pipe is increased from the gas inlet side to the tip (the former), or a plurality of gas inlet pipes having different lengths. And the like, each of which controls the gas flow rate (the latter) have been proposed. However, the former requires a great deal of time and adjustment to optimize the gas ejection amount, and is inflexible to change conditions. The latter has a problem that the equipment of the gas supply system becomes complicated and the cost increases.

Therefore, the present invention has been made in consideration of the above circumstances, and can achieve a uniform gas supply amount in the inter-plane direction of the object to be processed with a simple configuration, and can achieve uniform processing in the inter-plane direction. It is an object of the present invention to provide a vertical heat treatment apparatus that can be used.

[0007]

Means for Solving the Problems In the present invention, claim 1 is provided.
The invention according to the aspect described above, wherein a number of objects to be processed are supported at predetermined intervals in the height direction and accommodated in a processing container, and a processing gas is introduced into the processing container to process the objects at a predetermined temperature. In the mold type heat treatment apparatus, a gas injection hole for injecting a processing gas to a processing object is formed at a predetermined interval in the processing container from a straight pipe rising upward from below and having a closed end. And a U-shaped pipe that rises upward from the bottom and is folded back from the top and closed at the tip, and the pipe wall of the part folded back below the first gas introduction pipe with respect to the object to be processed. And a second gas introduction pipe in which gas ejection holes for injecting the processing gas are formed at predetermined intervals.

According to a second aspect of the present invention, in the vertical heat treatment apparatus of the first aspect, a flow control mechanism is provided in each of the first and second gas introduction pipes. It is characterized by having.

[0009]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view of a vertical heat treatment apparatus showing an embodiment of the present invention, FIG. 2 is a view showing a configuration of a gas introduction pipe in the vertical heat treatment apparatus, and FIG. FIG.

A vertical heat treatment apparatus, which is a semiconductor manufacturing apparatus,
As shown in FIG. 1, a large number of, for example, about 150 workpieces, for example, semiconductor wafers w are arranged and supported at predetermined intervals in the height direction on a support bar and a support body 1 and accommodated in a reaction tube 2 as a processing vessel. Then, a processing gas is introduced into the reaction tube 2 and a predetermined heat treatment such as a CVD processing is performed on the semiconductor wafer w at a predetermined temperature.

A heater 3 is provided around the reaction tube 2 as heating means for heating the inside of the furnace to a desired temperature, for example, about 600 to 1200 ° C. The heater 3 is configured by arranging a heating resistance wire (heating resistor) 5 on the inner periphery of a cylindrical heat insulating material 4 surrounding the periphery of the reaction tube 2 in a meandering shape in the circumferential direction or a spiral shape in the longitudinal direction. ing. The heater 3
May be divided into a plurality of zones in the height direction, and may be configured so that the temperature can be controlled independently for each zone. The outside of the heat insulating material 4 is covered with a water cooling jacket (not shown).

The heater 3 is provided on a base plate 6. The heater 3 includes the reaction tube 2 and the heater 3
A forced air-cooled heater that can cool the furnace rapidly by blowing cooling air into the space between the furnace and the forced exhaust by a forced exhaust mechanism (not shown) provided on the ceiling of the heat insulating material 4. There may be. By employing the forced air-cooled heater, the vertical heat treatment apparatus can be configured as a rapid temperature raising / lowering furnace.

The reaction tube 2 is made of a material having heat resistance and corrosion resistance, for example, quartz, and is formed in a vertically long cylindrical shape whose upper end is closed and whose lower end is opened as a furnace port. In the present embodiment, a heat treatment in which the pressure in the furnace is reduced, for example, a reduced pressure CV
In order to make the furnace port highly airtight so that D processing is possible,
A short cylindrical manifold 7 is attached to the lower end of the reaction tube 2. The manifold 7 is made of a material having heat resistance and corrosion resistance, for example, stainless steel.

On the side wall of the manifold 7, there are introduced a gas introduction pipe 8 for introducing a processing gas or an inert gas into the furnace, and an introduction section (introduction port) 9 through which a thermometer (not shown) is inserted and hermetically fixed. An exhaust unit (exhaust port) 9 for exhausting the inside of the furnace is provided. An exhaust system provided with a pressure control mechanism is connected to the exhaust unit 13, and this exhaust system is connected to a factory exhaust system (not shown).

The upper end of the manifold 7 is attached and fixed to the base plate 6, and the lower end of the manifold 7 is opened as a furnace port. Below the reaction tube 2, a lid 11 which is in contact with a lower opening end of the manifold 7 via an unillustrated hermetic material such as an O-ring to hermetically close the furnace port is provided so as to be vertically movable by a lifting mechanism 12. I have. The boat 1 is placed on the lid 11 via a heat retaining tube 13. The boat 1 is moved into the reaction tube 2 by the elevating mechanism 12.
The opening and closing of the cover 11 is carried out. Further, the lid 11 is provided with a rotation mechanism 14 for rotating the boat 1 together with the heat retaining cylinder 13 in order to uniformly process the semiconductor wafer w in the plane.

The reaction tube 2 of the present embodiment has a double tube structure including an inner tube 2a and an outer tube 2b. The outer tube 2b
Has an upper end closed, a lower end opened, and a flange 2f at the open end. The outer tube 2b has its open end abutted on the upper end surface (upper open end) of the manifold 7 via an airtight member (not shown) such as an O-ring, and the flange portion 2f is fixed by the flange retainer 15.
It is installed on the manifold 7 in an airtight manner.

The upper and lower ends of the inner tube 2a are open. The lower end of the inner pipe 2a has a manifold 7
Is removably attached to the inner periphery of the lower end opening (furnace port) side of the tube and is concentrically arranged inside the outer tube 2b.

On the other hand, the gas introduction pipe 8 is connected to the gas introduction port 8.
The base end side of the a-side is bent in an L-shape, and is inserted and hermetically sealed in the introduction portion 9, and the front end side stands vertically inside the reaction tube 2 along the inner wall of the inner tube 2 a. is set up. As shown in FIG. 2, the gas introduction pipe 8 includes a first gas introduction pipe 8A that is a dispersion injector,
And a second gas introduction pipe 8B which is an inverse dispersion injector.

The first gas introduction pipe 8A is a straight pipe (straight pipe) made of quartz, which rises upward from below and has a closed end 8e. Are formed at predetermined intervals, for example, at the same interval as the arrangement pitch of the semiconductor wafers w. The gas diameters of many gas ejection holes 16 formed in the first gas introduction pipe 8A are all the same.
Further, the gas ejection holes 16 correspond to the upper positions of the respective semiconductor wafers w so that the processing gas is supplied horizontally along the processing surface (upper surface) of the respective semiconductor wafers w supported by the boat 1. Is formed.

The second gas introduction pipe 8B is a quartz U-shaped pipe that rises upward from below and is folded downward from above and closed at the tip 8e, and is folded downward and extended therefrom. Gas ejection holes 17 for injecting the processing gas to the semiconductor wafer w are formed at predetermined intervals, for example, at the same interval as the arrangement pitch of the semiconductor wafers w. That is, the second gas introduction pipe 8B has a vertical rising portion 8h and a vertical falling portion 8g extending downward from the upper end of the rising portion 8h via the inverted U-shaped bent portion 8u. The gas ejection holes 17 formed in the downward portion 8g correspond to the gas ejection holes 16 of the first gas introduction pipe 8A in an upside-down relationship.

The gas ejection hole 1 of the second gas introduction pipe 8B
7 is the same as the gas ejection hole 16 of the first gas introduction pipe 8A,
The holes have the same diameter, and are formed corresponding to the positions of the respective semiconductor wafers w supported by the boat 1. The gas inlet 16 of the first gas inlet 8A and the gas outlet 17 of the second gas inlet 8B may have the same or different diameters.

The gas inlets 8a of the first gas inlet pipe 8A and the second gas inlet pipe 8B are connected to gas supply systems 18a and 18b communicating with a gas supply source, respectively. Are provided with flow control mechanisms 19a and 19b. In this case, the gas supply sources may be common, or may be separate sources that supply the same type of processing gas.

In the first gas introduction pipe 8A, while the amount of the processing gas ejected from the gas ejection holes 16 decreases as going upward the gas introduction pipe 8A, the second gas
On the other hand, in the gas introduction pipe 8B, since the ejection amount of the processing gas decreases toward the lower side of the gas introduction pipe 8B, by combining these two gas introduction pipes 8A and 8B, the semiconductor wafer w has a simple configuration. Thus, the gas supply amount in the inter-plane direction can be made uniform.

In FIG. 2, the first gas introduction pipe 8 is shown in order to illustrate a state in which the gas supply amount becomes uniform in the plane direction.
Although the configuration in which A and the second gas introduction pipe 8B are arranged to face each other is shown, specifically, the first gas introduction pipe 8A and the second gas introduction pipe 8B are arranged as shown in FIG. , Are arranged in parallel in the reaction tube 2.

Next, the operation of the vertical heat treatment apparatus having the above configuration will be described. The boat 1 in which a large number of semiconductor wafers w are arranged and stored at a predetermined pitch in the height direction is placed on the heat retaining cylinder 13, and the lid 11 is raised by the elevating mechanism 12, so that the boat 1 is placed in the reaction tube 2. While being placed in the reactor core, the lower end opening (furnace port) of the manifold 7 is sealed with the lid 11.

Next, after replacing the inside of the reaction tube 2 with an inert gas, for example, nitrogen gas, the inside of the reaction tube 2 is heated to a predetermined temperature by the heater 3, and the first and second gases are introduced into the semiconductor wafer w. A predetermined process, for example, a CVD process or a diffusion process is performed by supplying a process gas from the tubes 8A and 8B. In this case, the processing gas is supplied from the processing gas supply source to the processing gas supply system 1.
The flow control mechanisms 19a, 19b are respectively connected to the first gas introduction pipe 8A and the second gas introduction pipe 8B via 8a, 18b.
Is supplied at a controlled flow rate.

The first gas introduction pipe 8A is provided with a gas outlet 16
While the amount of processing gas ejected from the nozzle decreases as it goes above the gas introduction pipe 8A, the second gas introduction pipe 8B conversely reduces the amount of processing gas ejected below the gas introduction pipe 8B. These two gas introduction pipes 8
By combining A and 8B, the gas supply amount in the inter-plane direction of the semiconductor wafer w can be made uniform, and the uniform processing in the inter-plane direction, for example, the film thickness can be made uniform in CVD processing, and the doping concentration can be made in diffusion processing. Uniformity can be achieved.

As described above, according to the vertical heat treatment apparatus, a large number of semiconductor wafers w are supported at predetermined intervals in the height direction and accommodated in the reaction tube 2, and a processing gas is introduced into the reaction tube 2. In a vertical heat treatment apparatus for processing a semiconductor wafer w at a predetermined temperature, a straight pipe rising upward from below and having a closed end 8e is closed in the reaction tube 2, and the pipe wall is processed on the semiconductor wafer w. Gas outlet 16 for injecting gas
Are formed at predetermined intervals, and a U-shaped pipe which rises from below and turns up from above and is turned down from above to close the end, and the pipe wall of the portion turned down below In the second, gas injection holes 17 for injecting a processing gas to the semiconductor wafer w are formed at predetermined intervals.
Is provided, the gas supply amount in the inter-plane direction of the semiconductor wafer w can be made uniform with a simple configuration, the processing in the inter-plane direction can be made uniform, and the yield can be improved. I can do it.

The vertical heat treatment apparatus can achieve the above-described effects with a simple configuration in which an inverse dispersion injector 8B is added to the conventional dispersion injector 8A, and requires only two gas supply systems. Costs can also be reduced. Further, the first gas introduction pipe 8A and the second
Each gas supply system 18a, 18b of the gas introduction pipe 8B of
Since the flow control mechanisms 19a and 19b are provided, it is possible to easily adjust the balance of the supply amount of the processing gas in the direction between the surfaces of the semiconductor wafer w.

The present invention relates to a process of doping a silicon film with D-Poly (for example, using phosphine as a process gas and phosphorus), a process of P-Doped-Polysilicon.
Also called. ) Or F-Poly (a process in which the temperature in the furnace is kept constant without giving a temperature gradient, and a silicon film is formed using, for example, monosilane as a processing gas; Flat-Poly)
It is also called ysilicon. ) Can be applied to each process.

Although the preferred embodiments of the present invention have been described in detail with reference to the drawings, the present invention is not limited to the above-discussed preferred embodiments, and various design changes and the like are possible without departing from the gist of the present invention. Is possible. For example, in order to secure a horizontal flow of the processing gas in the reaction tube, an exhaust port may be formed in the tube wall of the inner tube facing the first and second gas introduction tubes. In the embodiment, the reaction tube which is the processing vessel has a double tube structure, but may have a single tube structure. The vertical heat treatment apparatus according to the present invention is applicable not only to CVD processing and diffusion processing but also to other processing such as oxidation processing. As the object to be processed, for example, a glass substrate, an LCD substrate, or the like can be applied other than the semiconductor wafer.

[0032]

In summary, according to the present invention, the following effects can be obtained.

(1) According to the first aspect of the invention, a large number of objects to be processed are supported at predetermined intervals in the height direction and accommodated in a processing container, and a processing gas is introduced into the processing container. In a vertical heat treatment apparatus for processing an object to be processed at a predetermined temperature, the processing vessel comprises a straight pipe rising upward from below and having a closed end, and a processing gas is applied to the pipe wall to the object to be processed. A first gas introduction pipe formed with gas ejection holes to be injected at predetermined intervals, and a U-shaped pipe that rises upward from below and is folded back from above and closed at the tip,
A second gas introduction pipe having gas ejection holes for injecting a processing gas to the object to be processed at a predetermined interval is provided on a pipe wall of a portion turned down below the pipe wall. The gas supply amount in the inter-surface direction of the workpiece can be made uniform,
Processing can be made uniform in the inter-plane direction.

(2) According to the second aspect of the present invention, since each of the gas supply systems of the first gas introduction pipe and the second gas introduction pipe is provided with a flow control mechanism, The balance of the supply amount of the processing gas in the inter-body direction can be easily adjusted.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a vertical heat treatment apparatus showing an embodiment of the present invention.

FIG. 2 is a view showing a configuration of a gas introduction pipe in the vertical heat treatment apparatus.

FIG. 3 is a schematic cross-sectional view taken along line AA of FIG. 1 excluding a heater.

[Description of Signs] w Semiconductor wafer (object to be processed) 2 Reaction tube (processing vessel) 8A First gas introduction tube 8B Second gas introduction tube 16, 17 Gas ejection holes 18a, 18b Gas supply system 19a, 19b Flow rate Control mechanism

Claims (2)

[Claims] 1. A process for supporting a large number of workpieces at predetermined intervals in a height direction to accommodate them in a processing vessel, introducing a processing gas into the processing vessel, and processing the workpieces at a predetermined temperature. In the mold type heat treatment apparatus, a gas injection hole for injecting a processing gas to a processing object is formed at a predetermined interval in the processing container from a straight pipe rising upward from below and having a closed end. And a U-shaped pipe that rises upward from the bottom and is folded back from the top and closed at the tip, and the pipe wall of the part folded back below the first gas introduction pipe with respect to the object to be processed. And a second gas introduction pipe having gas ejection holes for injecting the treatment gas at predetermined intervals. 2. The vertical heat treatment apparatus according to claim 1, wherein a flow rate control mechanism is provided in each of the gas supply systems of the first gas introduction pipe and the second gas introduction pipe.