JPH02177425A - Wafer heat treatment device - Google Patents

Abstract

PURPOSE:To obtain a device which can cope with advancement of large diameter while achieving needs for miniaturization of the device, reduction of weight burden, etc., by forming a wafer support making use of a part of a surrounding body which surrounds the periphery of a group of semiconductor wafers, and enabling the support to be mounted on or removed from the surrounding body. CONSTITUTION:In a wafer heat treatment device where a number of semiconductor wafers are arranged in lines, along the axial direction of a container 2, inside the reaction container 2 which forms heating spaces 20, supports 4, which line up and hold said semiconductor wafers, are formed making use of a part of a surrounding body which almost surrounds at least the marginal circumference of said semiconductor group, and the supports are so constituted as to be capable of mounting and removal to said surrounding body. For example, in such a device as mentioned above where the reaction container 2 is arranged along the direction of an almost vertical axis, supporting parts 41-43, which line up and hold semiconductor wafers, are attached to the inner sidewalls of the arc-shaped supports 4, which are set in and fixed to an arc-shaped cavity 30, being formed by whittling the surface of the peripheral wall of the surrounding body made of cylindrical body into arc shape for cross section with an included angle smaller than 180 deg., and which form a part of the cylindrical body.

Description

[Detailed Description of the Invention] r. 1. Field of Industrial Application" The present invention is directed to a method of promoting e-diffusion that generates an oxide film, an insulating film, or a single crystal film (epitaxial) on the surface of a semiconductor under a hot atmosphere. Regarding wafer heat treatment JIF equipment such as furnaces, vapor phase growth equipment, etc., in particular, wafer heat treatment equipment in which a large number of semiconductor wafers are arranged in one IP layer along the axial direction of the container in a reaction vessel forming a heating space, especially a vertical type. The present invention relates to a wafer processing apparatus having a structure.

"Prior Art" For example, a film forming apparatus is known that forms another film on the oxide film on the surface of a plurality of semiconductor wafers while flowing a processing gas into the reaction space in which a plurality of semiconductor wafers are arranged. The VCM is classified into a horizontal type VCM in which the reaction vessel forming the reaction space is installed almost horizontally, and a vertical type device in which the reaction vessel is installed almost vertically, but the latter is more space-saving and easier to operate. In recent years, a number of vertically structured apparatuses for large wafers have been developed due to their advantages in terms of performance.

However, the disadvantage of a vertical structure device is that the semiconductor wafers stored in one reaction vessel are not on the same plane as in a horizontal structure device, but are stacked vertically vertically. The larger the number of sheets stored, the more the reaction container and the surrounding heating sources must be arranged vertically, which makes it more difficult to control the temperature inside the reaction container. A certain temperature gradient tends to occur from the top to the bottom, and as a result, the temperature of the reaction gas between the semiconductor wafers arranged above and below becomes non-uniform, resulting in a uniform film thickness between the semiconductor wafers. The problem arises that it becomes difficult to form.

Furthermore, in the prior art, the gas introduced from the upper end of the reactor is discharged from the outlet at the lower end of the reaction vessel while flowing in a direction perpendicular to the surface on which the semiconductor wafer is disposed (in the axial direction). As the heat treatment progresses on the surface of the semiconductor wafer, the gas flow in which the raw material gas is consumed moves sequentially to the lower semiconductor wafer surface.In other words, the lower the gas flow moves, the thinner the raw material gas concentration becomes, and the more the raw material gas is Variations in film thickness are likely to occur, and back-doping via gas flow from the upper wafer also occurs.

Therefore, in an apparatus having a vertical structure as described above, a cylindrical body functioning as a heat equalizer or a gas flow distribution body is placed around the group of semiconductor wafers stacked one on top of the other to overcome the above-mentioned drawbacks. In many cases, attempts are made to resolve the issue.

For example, JP-A-81-2120 and JP-A-81-19094.
In No. 8, a cylindrical body with many through holes was used to enable uniform contact of the processing gas, and in JP-A No. 1
No. 31-129823 attempts to prevent temperature fluctuations between wafers by using a carbon cylindrical body to function as a heat equalizing body.

``Problems to be solved by the invention'' However, interposing a cylindrical body between the reaction vessel and the group of semiconductor wafers increases the size of the equipment, and in addition, as in recent years, the diameter of the wafers has increased. As time goes by, its shortcomings become even greater.

Furthermore, if the gap between the group of semiconductor wafers and the cylindrical body is made small in order to eliminate the above-mentioned drawbacks, not only will the operability be greatly reduced, but it will also be difficult to obtain axial accuracy between the support body such as a boat and the cylindrical body. When a group of semiconductor wafers is loaded into/detached from a container, the cylindrical body may come into contact with the cylindrical body by mistake, resulting in accidents such as the wafers falling from a boat or other support.

Furthermore, in the above-mentioned apparatus, since a boat or other support body is required for arranging the group of semiconductor wafers by 11M together with the above-mentioned cylindrical body, the amount of ffi (negative 1u) is inevitably large, which is particularly important for mass production. Therefore, as the number of wafers processed increases, this problem becomes more serious.

SUMMARY OF THE INVENTION In view of the drawbacks of the prior art, it is an object of the present invention to provide a wafer heat treatment apparatus that can accommodate larger diameters while meeting the requirements of downsizing and reducing the weight of the apparatus.

Another object of the present invention is to provide a wafer heat treatment apparatus that can easily facilitate and automate handling operations during loading/unloading.

``Means to solve problems'' The present invention aims to achieve this technical problem.

■It has a surrounding body that almost surrounds at least the periphery of the semiconductor wafer group.The surrounding body is generally arranged concentrically with the container axis (when the wafer group is -R1 only). It also includes cases in which the wafers are arranged eccentrically (in the case where multiple groups of wafers are installed).

Further, the enclosing body is generally a cylindrical or polygonal cylindrical body with a sealed or open end, but is not limited thereto.

■ A support body for aligning and holding the semiconductor wafers is formed using a part of the surrounding body. ■ The support body is configured to be detachable from the main body side of the surrounding body. .

Note that the present invention is preferably applied to an apparatus having a vertical structure, although it is not limited to a horizontal or vertical type as long as the apparatus has a large number of semiconductor wafers aligned along the axis of the container.

The specific configuration that satisfies the requirements of ■ and ■ above is as follows:
For example, in a device with a vertical structure, as shown in Figure 1,
At least one on the peripheral wall surface of the surrounding body 3 formed of a cylindrical body.
An arcuate space 3G is formed by cutting into an arcuate cross section with an included angle smaller than 80@, and an arcuate support (hereinafter referred to as boat 4) that is fitted and fixed in the space 30 and forms a part of the surrounding body 3. It is preferable that supporting parts 41 to 43 for holding the semiconductor wafers 5 in alignment are attached to the inner wall surface of the arcuate boat 4.

In this case, the wavy bow is not formed by vertically long negative boats 4, but is divided into a plurality of pieces so as to be able to support a predetermined number of wafers, and the divided boats 4 are connected to each other in the empty space 3 of the heavy metal cylinder.
It is best to configure the plant so that it can be planted in sequence.

Even if the cylindrical surrounding body 3 is 411 m long as a heat soaking tube,
It is also possible to form a large number of gas conduction parts scattered on the circumferential surface of the cylindrical body and to make the cylindrical body function as a gas flow regulating cylinder.

Further, by configuring the cylindrical body 3 so that the processing gas that has entered the cylindrical body through the gas conduction portion opened on the circumferential surface thereof can come into direct contact with the wafer surface, a more preferable film thickness can be produced.

Furthermore, by integrating a cylindrical heat insulating material in the lower part of the cylindrical body, it is possible to further improve the heat insulating effect -15 and to further reduce the diameter of the blast furnace core tube.

"Embodiments" Hereinafter, preferred embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, the dimensions, materials, shapes, relative positions, etc. of the structural aS products described in this example are unless otherwise specified.

This is not intended to limit the scope of the invention, but is merely an illustrative example.

FIG. 1 shows a wafer heat treatment apparatus according to an embodiment of the present invention.

This device consists of a disc-shaped base l, and a cylindrical dome-shaped reaction vessel 2 installed on the base l and having a gas inlet 21 at its tip.
, an infrared heater 6 surrounded by the container 27711111, a cylindrical heat-insulating cylinder 7 installed on the base 1 concentrically with the container 2 within the reaction container 2, and the heat-insulating fi
? It consists of a cylindrical enclosure 3 standing upright along the outer periphery of the enclosure 3, and boats 4 fitted vertically into arcuate spaces 30 formed by cutting out the peripheral wall surface of the enclosure 3, excluding the infrared heater 6. Each material is made of quartz glass.

Next, each of these great materials will be explained in detail.

The base 1 is provided with an exhaust port 11 that passes through the center of the heat insulating cylinder 7 along its central axis, and a suction pump 1 is provided on the downstream side of the base 1.
The processing gas is introduced into the reaction chamber through the gas inlet 21 by a wheel connecting the two, and is configured such that the processing gas can be exhausted through the exhaust port 11 after contacting the surface of the wafer/15.

Said heat retention? , 2? A heat insulating material such as quartz cotton 71 is enclosed to prevent the heat within one reaction chamber 20 from escaping to the base 1 side.

The reaction vessel 2 is formed into a cylindrical dome shape using a transparent quartz glass material that suppresses infrared absorption.

A pressure-resistant sealing means 22 is interposed on the opening side in contact with the base 1 to make the inside of one reaction chamber 20 a sealed space, and the inside of the reaction chamber 20 can be opened using an elevating member (not shown).

The enclosure 3 is made of a translucent quartz glass material containing air bubbles and is formed into a cylindrical shape with openings at both upper and lower ends in order to achieve a predetermined heat uniformity. 311
The through holes 31 are used to allow the processing gas to enter the surrounding body 3.

The surrounding body 3 extends at least t on its peripheral wall surface.
ea @ smaller included angle α, specifically approximately 120”
An arcuate space 30 is formed by cutting vertically into a rectangular shape from the upper end to the vicinity of the mounting position of the heat insulating cylinder 7 with a front and rear included angle α, and a plurality of arcuate bows 4 are fitted into the space 30. Configure to be fixed.

Although not clearly shown in FIG. 1, a lid may be provided to prevent the processing gas from entering directly through the upper opening of the enclosure 3. In this case, an arcuate boat reef may be fitted into the enclosure 3. After fitting, a lid body may be installed on the top surface, or the arc-shaped boat 4
A lid body may be fixed to itself.

As shown in FIGS. 3 and 4, the arc-shaped boat 4 includes an arc-shaped plate 40 formed by dividing an arc-shaped portion forming a part of the peripheral wall surface of the surrounding body 3 into a plurality of pieces in a direction orthogonal to the axis; It consists of three support rods 41 to 43 arranged along the axial direction on the inner wall surface side of the arcuate plate 40, and wafer holding grooves 1+W 44 are carved in multi-step form on the support rods 41 to 43. The structure is such that the wafer 5 fitted and held by the wafer 44 can be placed in a thin layer slightly above the holding position. The arc-shaped plate 40 has a large number of through holes 31 scattered on its circumferential surface, and the through holes 3
The cylindrical body is formed so that the processing gas can enter the cylindrical body by using N.

A semi-cylindrical fitting fi45 that can be engaged with a locking tool 48 is provided on its outer peripheral surface, and fitting to and removal from the enclosure 3 is facilitated by using the fitting portion 45 and the locking tool 4B. This makes it possible to facilitate and automate the handling operation of the arc-shaped boat 4.

The mounting positions of the support rods 41 to 43 are not particularly limited, but the support rods 42 and 43 are attached to the arc-shaped boat 4 by means of 1 bar that fixes the support rods 42 and 43 located on both sides along the side edges. It can function as a guide when guiding into the empty space 30 of the enclosure 3 from the upper position, and as a means for fitting and fixing to the enclosure 3 after being guided.

Incidentally, the arc-shaped boat 4 and the surrounding body 3 can be made of silicon, a compound thereof, or graphite in addition to the quartz glass material, so that the temperature uniformity of the rewafer 20 can be further achieved.

Furthermore, since the arc-shaped bow 4 is made of quartz glass and the surrounding body 3 is made of silicone, the surrounding body 3 is rarely removed.
It is also possible to facilitate cleaning of the arcuate boat 4 while providing strength to the sides.

Next, the boat attachment and detachment operations of this embodiment will be explained.

First, the reaction chamber 20 is opened by lifting the reaction container 2 upward, and then the arc-shaped boat 4 with a predetermined number of wafers 5 mounted thereon is moved above the enclosure 3 using the support rods 42 and 43 as guides, as shown in FIG. It will be installed sequentially.

After the mounting is completed, the arc-shaped plate 40 of the boat 4 is fitted into the space 30 of the enclosure 3 and functions as a part of the surrounding wall, so that the entire outer periphery of the wafer 5 is surrounded. .

Next, after lowering the reaction container 2 and sealing the reaction chamber 20, the processing gas is flowed through the gas inlet 21 while being heated to and maintained at a predetermined temperature by the infrared heater 8.

Then, the processing gas introduced into the reaction chamber 20 is transferred to the arc-shaped plate 4
0 is introduced into the surrounding body 3 through a through hole 31 bored in the peripheral wall surface of the surrounding body 3, and after contacting the surface of the wafer 5, is discharged to the outside through an exhaust port 11 provided in the heat insulating cylinder 7.

At this time, the through hole 31 is inserted into the wafer 5 as shown in FIG.
The perforation wheels corresponding to the JAW spacing of , which is preferable, allow fresh gas to constantly come into contact with the surface of the wafer 5 .

Further, the through holes 31 are not necessarily provided around the entire circumference of the surrounding body 3, but may be formed only on one side of the arcuate plate 40 and its vicinity, so that new gas always flows in only one direction.

Furthermore, by attaching the buffer plate 33 to the inner surface of the enclosure 3 facing the wafers at the bottom of the boat, it is possible to control the flow rate in a preferable manner.

Returning to the original position, after the prescribed heat treatment is completed, the reaction chamber 'jA2 is raised to open the reaction chamber 20, thereby making it possible to easily remove the arcuate boat 4 from the surrounding body 3 by performing an operation opposite to the mounting operation. I can do it.

In this embodiment, the stacked semiconductor wafers 5, the surrounding body 3, and the reaction vessel 2 are all arranged concentrically, and the structure is particularly suitable for heat treatment of large-diameter wafers 5. When the diameter is large and the number of wafers to be processed is large, arc-shaped spaces 3o are formed on both sides of the facing peripheral wall surface of the surrounding body 3, and the stacked semiconductor wafers 5 are arranged in two rows parallel to the axis of the container. Cars arranged in a stacked manner are also possible.

FIG. 2 shows another embodiment of the present invention, in which the enclosure 3 and the heat-retaining tube 7 are not provided separately as in the previous embodiment, but are integrally formed in a continuous manner below the enclosure 3. This not only makes it possible to enhance the heat insulation effect without increasing the outer diameter of the surrounding body 3, but also makes it easy to obtain axial accuracy between the heat retaining cylinder part and the surrounding body, and allows the surrounding body 3 to pass through the center of the base l. Even if it is fixedly installed on the support stand 1B supported by the rotating shaft 19 and configured to be rotatable, it is possible to have a configuration without shaft runout.

Furthermore, in this embodiment, the surrounding body 3 including the arcuate plate 40
The structure is such that gas can directly enter from the upper opening of the surrounding body 3 without making any through holes 31 in the surrounding wall surface.

FIG. 5 shows another embodiment in which the shape of the through hole 31 is devised. It is formed into a 39-shape.

This makes it possible to form a uniform film even more smoothly.

"Effect of Expression 11" As described above, according to the present invention, since the wafer support is constructed using a part of the peripheral wall surface of the surrounding body 3 that surrounds the group of semiconductor wafers, the support is There is no need to install the support separately inside the enclosure, and as a result, even when the diameter of the wafer becomes large, there is no need to unnecessarily increase the size of the equipment, and the support body can be easily mounted outside or above the enclosure. Since the container can be taken out or loaded, not only the operability is greatly improved, but also accidents such as wafer falling when loading/unloading a group of semiconductor wafers into/from a container can be greatly prevented.

Also, a part of the surrounding body functions as a boat for stacking and arranging groups of semiconductor wafers.

Naturally, the weight burden is also reduced.

It has various effects such as

[Brief explanation of the drawing]

1, 2, and 5 all show heat treatment apparatuses according to embodiments of the first and second inventions, in which FIG. 1 is a partially cutaway perspective view, FIG. m2 is a front sectional view, FIG. 5 is a perspective view of the main part. FIG. 3 is a perspective view of the wafer support used in FIG.
Figure tS4 is an operational diagram showing the installed state. l 2

Claims (1)

[Scope of Claims] 1) In a wafer heat treatment apparatus in which a large number of semiconductor wafers are aligned along the axial direction of the container in a reaction container that forms a heating space, the wafer heat treatment apparatus substantially surrounds at least the periphery of the group of semiconductor wafers. A wafer heat processing apparatus characterized in that a support body for aligning and holding the semiconductor wafers is formed using a part of a surrounding body, and the support body is configured to be detachable from the surrounding body. 2) In the wafer heat treatment apparatus according to claim 1, wherein the reaction vessel is installed substantially along the vertical axis direction, on the peripheral wall surface of the surrounding body formed of a cylindrical body with a sealed or open end,
It consists of an arcuate cavity formed by cutting into an arcuate cross-section with an included angle of at least 180°, and an arcuate support that is fitted and fixed in the cavity and forms a part of the cylindrical body; A wafer heat treatment apparatus characterized in that a support part for holding the semiconductor wafers in alignment is attached to the inner wall surface of the arc-shaped support body. 3) A support is formed using an arc-shaped plate obtained by dividing an arc-shaped portion corresponding to the arc-shaped space along a direction substantially perpendicular to the axis of the cylindrical body, and the plurality of supports are connected to the cylindrical body. Claim 2)
The wafer heat treatment apparatus described. 4) Opening a large number of gas conducting portions on the circumferential surface of the cylindrical body,
The wafer heat processing apparatus according to claim 2, characterized in that the processing gas that has entered the cylindrical body through the gas conduction portion is configured to be able to directly contact the wafer surface. 5) The wafer heat processing apparatus according to claim 2, wherein a cylindrical heat insulating material is integrally formed in the lower part of the cylindrical body.