JP3131601B2 - Heat treatment apparatus and heat treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment apparatus and a heat treatment.
About the method .

[0002]

2. Description of the Related Art In recent years, as a heat treatment apparatus used in a heat diffusion step or a film forming step in a semiconductor device manufacturing process, space saving, energy saving, and a large diameter of a semiconductor wafer to be processed have been achieved. Vertical heat treatment apparatuses have been developed for reasons such as easy handling of automation and the like.

[0003] Such a vertical heat treatment apparatus generally comprises a cylindrical reaction vessel made of quartz or the like and a reactor main body composed of a heater, a soaking tube, a heat insulating material, etc. provided so as to surround the periphery thereof. A vertically arranged wafer boat made of quartz or the like, in which a large number of semiconductor wafers are stacked and stored at predetermined intervals in a reaction vessel, is provided. The wafer boat is mounted above a cap section that seals an open section below the reactor body, and is loaded and unloaded into the reactor body from below by a lifting mechanism together with the cap section. You.

[0004]

However, in such a vertical heat treatment apparatus, it is desired to be able to efficiently perform a good treatment free of impurities and the like.

[0005] The present invention has been made to address such problems of the prior art, and it is an object of the present invention to provide a heat treatment apparatus and a heat treatment method capable of efficiently performing good treatment.

[0006]

According to the first aspect of the present invention,
A reaction vessel disposed substantially vertically and having a double-pipe structure by an outer cylinder and an inner cylinder concentrically housed in the outer cylinder, and a heating heater provided to surround the outside of the reaction vessel

[0006]

According to the first aspect of the present invention,
An outer cylinder and an inner cylinder concentrically accommodated in the outer cylinder have a double-pipe structure, and a reaction vessel disposed substantially vertically, and a heating heater provided to surround the outside of the reaction vessel. And an annular outer cylinder manifold for locking the outer cylinder to a base provided near the lower end of the reaction vessel; and the outer cylinder manifold .
An annular inner cylinder while locking the inner cylinder in the lower portion of the in manifold
A manifold , a disc-shaped lid abutting on a lower end of the inner cylinder manifold , which can be hermetically sealed; and a hermetically sealed mechanism provided through the substantially central portion of the lid. A rotating mechanism having a rotating shaft on which is disposed, a turntable provided at the upper end of the rotating shaft, and a motor for driving the rotating shaft; and a semiconductor installed on the turntable and comprising a semiconductor. The heat retaining cylinder on which the wafer boat on which the wafer is placed is placed, and the lid are moved up and down together with the rotating mechanism and the thermal retaining cylinder, and the wafer boat is loaded / unloaded into the reaction vessel. A lifting and lowering mechanism, and a scavenger part main body formed in a cylindrical container shape so as to surround the outer periphery and the lower surface of the outer cylinder manifold and the inner cylinder manifold , and having a lower surface provided with a passage opening having a diameter larger than the outer diameter of the lid. , Through the passage A scavenger unit having a shutter portion for approximately closed, and the processing gas introduction pipe for introducing a process gas into the inner cylinder, and an exhaust pipe provided between the lower end portion of the inner tube and the lower end of the outer cylinder It is characterized by having.

According to a second aspect of the present invention, there is provided a heat treatment method using the heat treatment apparatus according to the first aspect , wherein the inside of the reaction vessel is preliminarily heated by the heater, and the preheated reaction vessel is heated. said loads the wafer boat which the semiconductor wafer is positioned by the lifting mechanism, characterized the score facilities a predetermined process on the semiconductor wafer within.

According to a third aspect of the present invention, there is provided a heat treatment method using the heat treatment apparatus according to the first aspect, wherein after the processing of the semiconductor wafer in the reaction vessel is completed, hydrogen purging in the reaction vessel is performed. a nitrogen purge performed to remove the process gas, after a normal pressure in a nitrogen atmosphere, and wherein the unloading to Turkey the wafer boat in which the semiconductor wafer is positioned by the lifting mechanism.

[0009]

According to the present invention, an outer cylinder manifold and an inner cylinder manifold are provided.
A scavenger part body formed in a cylindrical container shape surrounding the outer periphery and the lower surface of the shield , and having a passage opening having a diameter larger than the outer diameter of the lid on the lower surface, and a scavenger part having a shutter part for substantially closing the passage opening. When the workpiece is unloaded, the remaining processing gas and reaction products from the reactor body are discharged in the direction of the load / unload position of the workpiece, and adhere as impurities to the processed semiconductor wafer. To prevent

The reaction vessel has a double-pipe structure with an outer cylinder and an inner cylinder concentrically housed in the outer cylinder, and is provided at a lower end of an annular outer cylinder manifold for locking the outer cylinder to the base. ,
The inner cylinder is locked by the inner cylinder manifold . Soshi
Thus, the processing gas is supplied into the inner cylinder and is exhausted from between the inner cylinder and the outer cylinder. Therefore, even if the reaction product adheres to the outer cylinder, Does not peel off and adhere to semiconductor wafers, etc.
It is only necessary to wash the inner cylinder locked by the door.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the apparatus of the present invention is applied to a vertical heat treatment apparatus will be described below with reference to the drawings.

The reaction vessel 1 includes an outer cylinder 2 made of, for example, quartz.
And an inner cylinder 3 made of, for example, quartz concentrically housed in the outer cylinder 2.
The outer cylinder 2 is fixed to a base plate 4 by an outer cylinder manifold 5, and the inner cylinder 3 is fixed to a lower end of the outer cylinder manifold 5 by an inner cylinder manifold 6. A heating heater 7, a heat insulating material 8, and the like are provided so as to surround the reaction vessel 1, thereby forming a reaction furnace main body.

The lower end of the reaction vessel 1, that is, the lower end of the inner cylinder manifold 6 is hermetically sealed by a disk-shaped cap 9 made of stainless steel or the like, for example, an O-ring 10.
It is configured to be sealed through

A rotary shaft 11 is inserted substantially at the center of the cap portion 9, and the periphery of the rotary shaft 11 is sealed.
The seal is hermetically sealed by a sealing mechanism, for example, a magnetic fluid seal unit 12. The upper end of the rotating shaft 11 is fixed to a turntable 13. Above the turntable 13, a heat insulating cylinder 14 filled with a heat insulating material or the like while maintaining a predetermined gap with the inner cylinder 3 of the reaction vessel 1 is installed. A wafer boat 16 made of, for example, quartz in which wafers 15 are stacked and housed at a predetermined pitch is mounted. The lower end of the rotating shaft 11 is provided with an elevating mechanism for loading and unloading the wafer boat 16, the heat retaining cylinder 14, the turntable 13 and the cap 9 into and from the reaction vessel 1, for example, a boat elevator. The motor 17 is connected to a rotating mechanism installed in an arm 18 of the motor 17, for example, a motor 19.

On the lower surface of the base plate 4, a scavenger in the shape of a cylindrical container is formed so as to surround the outer periphery and the lower surface of the outer cylinder manifold 5 and the inner cylinder manifold 6 supporting the reaction vessel 1. The unit main body 20 is installed. The scavenger portion main body 20 is formed of an aluminum material, and has an aluminum oxide film formed on the surface thereof by, for example, anodic oxidation. An exhaust port 21 connected to an exhaust system (not shown) is provided on a side surface of the scavenger unit main body 20, and a cap portion for loading / unloading an object to be processed is provided on a lower surface thereof. A passage opening 20a having a diameter larger than the outer diameter is provided. A shutter 22 is provided which can be opened and closed by a drive mechanism (not shown) so that the passage opening 20a is closed with a slight gap left on the outer periphery. And a scavenger section. The shutter portion 22 is also formed of an aluminum material having an aluminum oxide film on the surface, similarly to the scavenger portion main body 20.

At the lower end of the reaction vessel 1, there is provided an L-shaped processing gas introduction pipe 23 which is vertically provided in the inner cylinder 3.
The gas discharge part of the processing gas introduction pipe 23 is connected to the wafer boat 1
It is open toward the sixth side. An exhaust pipe 24 connected to a vacuum pump (not shown) is provided at a lower end of the outer cylinder 2 of the reaction vessel 1 so as to discharge a processing gas from a gap between the outer cylinder 2 and the inner cylinder 3.

In the vertical heat treatment apparatus having such a structure, for example, the reaction vessel 1 in a pre-heating state of about 800 ° C.
Wafer board containing semiconductor wafer 15 in inner cylinder 3
The turntable 13 having the tower 16 mounted thereon is inserted together with the cap portion 9 by a boat elevator 17, and the reaction container 1 is sealed by the cap portion 9. Thereafter, while the inside of the reaction vessel 1 is maintained at a predetermined degree of vacuum, for example, about 10 Torr, source gases such as SiH ₂ Cl ₂ , HCl
, H ₂ are supplied to perform processing of the semiconductor wafer 15, for example, silicon epitaxial growth.

Since the inside of the reaction vessel 1 is preliminarily heated as described above, the processing can be performed efficiently with high throughput.

After the processing is completed, a hydrogen purge and a nitrogen purge are performed to remove the processing gas, and the atmosphere is set to a normal pressure in a nitrogen atmosphere. 16 is lowered. When the wafer boat 16 reaches a predetermined position, the shutter 22 is closed, the inside of the scavenger unit main body 20 is evacuated, and the apparatus enters a standby state for the next processing cycle.

Since the processing gas is removed by performing a hydrogen purge and a nitrogen purge in this manner, and the wafer boat 16 is unloaded after the atmospheric pressure is set in a nitrogen atmosphere, the processing gas is removed. Can be prevented from leaking to the outside.

As described above, by forming the scavenger portion from the aluminum material having the aluminum oxide film on the surface, even when some processing gas or reaction product remains in the reaction vessel in the standby state of the reaction furnace main body. ,
Since the corrosion resistance is greatly improved by the aluminum oxide film, it hardly rusts. Therefore, it is possible to prevent occurrence of a defect of the object to be processed due to dropping of rust or the like, and it is possible to sufficiently exhibit the original function of the scavenger portion.

The reaction vessel 1 has a double-pipe structure with an outer cylinder 2 and an inner cylinder 3 concentrically accommodated in the outer cylinder 2, and an outer cylinder manifold 5 for locking the outer cylinder to a base plate 4. Since the inner cylinder 3 is locked to the lower end of the inner cylinder 3 by the inner cylinder manifold 6, it is possible to remove only the inner cylinder 3 and wash only the inner cylinder 3 while the outer cylinder 2 having the airtight seal portion is mounted. it can. Thus, the reaction vessel 1 can be easily and quickly cleaned in a short time without performing a vacuum leak check or the like every time the cleaning is performed, and good processing can be efficiently performed in a clean atmosphere. The processing gas is supplied into the inner cylinder 3 by the processing gas introduction pipe 23,
Since the exhaust gas is exhausted from between the inner cylinder 3 and the outer cylinder 2 by 4, even if a reaction product or the like adheres to the outer cylinder 2, the reaction product is peeled off and the semiconductor wafer 15 or the like is removed. Does not adhere to

Furthermore, since the processing is performed while rotating the wafer boat 16 on the turntable 13 by the motor 19, the semiconductor wafer 15 can be uniformly and favorably processed.

In the above embodiment, the case where the scavenger is formed of an aluminum material having an aluminum oxide film on the surface has been described. However, the above-described scavenger may be formed of stainless steel instead of the aluminum material. In this case, it is preferable to apply Teflon coating or nickel plating on the surface. This effectively prevents rust while maintaining heat resistance,
An effect similar to that of the above-described embodiment can be obtained.

[0025]

As described above, the heat treatment apparatus of the present invention
According to the heat treatment method , good treatment can be efficiently performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a main part of a vertical heat treatment apparatus according to one embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reaction container, 2 ... Outer cylinder, 3 ... Inner cylinder, 5 ... Outer cylinder manifold, 6 ... Inner cylinder manifold, 7 ... Heating heater, 9 ... Cap part , 15 ... semiconductor wafer, 1
6 Wafer boat, 17 Lifting mechanism, 20 Scavenger body, 22 Shutter section.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-114522 (JP, A) JP-A-61-161711 (JP, A) JP-A-62-152432 (JP, A) 20426 (JP, U) Jpn. Sho 62-8633 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/22 511 H01L 21/22 501 H01L 21/31

Claims (3)

(57) [Claims] 1. A reaction vessel disposed substantially vertically, having a double pipe structure comprising an outer cylinder and an inner cylinder concentrically housed in the outer cylinder, and provided so as to surround the outside of the reaction vessel. was heated for heat - data and the the outer cylinder manifold annular locking the lower end the outer tube to a substrate provided in the vicinity of the reaction vessel, locking the inner tube to the lower end of the outer cylinder manifold An annular inner cylinder manifold , a disc-shaped lid which is in contact with a lower end of the inner cylinder manifold and which can be hermetically sealed, and which is provided so as to penetrate a substantially central portion of the lid, A rotary shaft having a hermetic seal mechanism disposed in a portion thereof, a turntable provided at an upper end of the rotary shaft, and a motor for driving the rotary shaft; and The wafer boat on which the semiconductor wafer is placed A heat retaining cylinder to be placed; an elevating mechanism for moving the lid up and down together with the rotating mechanism and the heat retaining cylinder to load and unload the wafer boat into the reaction vessel; and the outer cylinder manifold And a scavenger body formed in a cylindrical container shape so as to surround the outer periphery and the lower surface of the inner cylinder manifold and having a lower surface provided with a passage opening having a diameter larger than the outer diameter of the lid, and a shutter for substantially closing the passage opening A processing gas introduction pipe for introducing a processing gas into the inner cylinder; and a scavenger part provided between a lower end of the outer cylinder and a lower end of the inner cylinder.
Heat treatment apparatus is characterized in that comprising an exhaust pipe was. 2. A heat treatment method using the heat treatment apparatus according to claim 1, wherein the inside of the reaction vessel is preliminarily heated by the heating heater, and the inside of the preheated reaction vessel is moved up and down. A heat treatment method characterized by loading the wafer boat on which the semiconductor wafer is placed by a mechanism and performing a predetermined process on the semiconductor wafer. 3. A heat treatment method using the heat treatment apparatus according to claim 1, wherein after the processing of the semiconductor wafer in the reaction vessel is completed, a hydrogen purge and a nitrogen purge in the reaction vessel are performed. A heat treatment method, comprising removing a gas, bringing the semiconductor wafer to a normal pressure state in a nitrogen atmosphere, and then unloading the wafer boat on which the semiconductor wafer is placed by the elevating mechanism. "