JP2578567Y2 - Heat treatment equipment - 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 for a plate-like body for forming an LSI or a liquid crystal film, and more particularly to a heat treatment apparatus in which the plate-like bodies can be vertically stacked.

[0002]

2. Description of the Related Art A vertical heat treatment apparatus has been widely used for heat treatment of a plurality of plate-like bodies, for example, LSI wafers. That is, in the vertical heat treatment apparatus, the longitudinal axis of the heat treatment tube is arranged to extend in the vertical direction, a plurality of semiconductor wafers are housed in the heat treatment tube by the holder, and a predetermined gas flows between the semiconductor wafers. The heat treatment is performed by heating to a temperature of 600 to 1200 ° C. by a heating source such as an electric furnace or an infrared ray lamp disposed outside the heat treatment tube. According to such a vertical heat treatment apparatus, it is possible to suppress the generation of particles or dust due to sliding between the heat treatment pipe and the holding body or the boat, as compared with the conventional horizontal heat treatment apparatus, and furthermore, space saving, etc. It has many advantages.

However, when the heat treatment tube is extended in order to increase the number of processed wafers in response to a demand for mass production, there arises a problem that the temperature distribution in the longitudinal axis direction and the concentration distribution of the processing gas tend to be non-uniform. So, for example,
Japanese Patent Application Laid-Open No. 60-153116 discloses a heat treatment pipe 51.
A plurality of wafers 52 can be placed on a support member 54 in a horizontal step shape in a heat treatment chamber 56 inside the support member 54. The support member 54 is rotatably suspended with respect to a heating source 55. The temperature distribution is made uniform by interposing a heat equalizing tube 58 between the substrate and the support member 54. Further, the concentration distribution is made uniform by controlling the supply pressure in consideration of the growth rate that decreases as the wafer grows. A technology (hereinafter, referred to as a first conventional technology) is disclosed (see FIG. 4).

Further, according to the prior art, as shown in FIG. 5, a wafer 52 is mounted on a support member 64 via a mounting jig 65, and the wafer 52 is turned on and off when the heating source 55 is turned on and off. Technology for preventing rapid heat and rapid cooling
It is called conventional technology. ) Is also disclosed.

However, in the first prior art, since the wafer 52 is locked by the groove a formed in the support member 54, gas processing near the groove a is not performed as expected. In the worst case, it could not withstand use and led to a decrease in yield. Further, in the first prior art, the support member 54 supports the peripheral portion of the wafer 52 at several places, and in particular, in consideration of loading and unloading before and after heat treatment,
Generally, the wafer 52 is deformed depending on the heat treatment process in order to support it at a peripheral portion that is less than the semicircle, and the yield of the entire wafer is reduced.

[0006] In return, in the second prior art, since the effect is not explicitly shown for mounting on the flat mounting jig 65, the effect of the former first prior art is not shown. Prevention of partial drop in yield of wafer 52 due to groove a,
And the wafer 52 due to deformation due to the support of several peripheral portions
Prevention of overall drop in yield is implied as a result.

[0007]

However, as the diameter of the member to be heat-treated becomes larger, or the material of the member to be heat-treated, the problem of deformation of the member to be heat-treated at a high temperature due to its own weight becomes apparent, as in recent years. It has become. Further, in the first prior art, the deposit formed on the back surface of the upper wafer falls on the upper surface of the lower wafer, inducing a serious defect called a so-called back dope, and lowering the yield of the entire wafer. I let it. In addition, in the above two prior arts,
Frequently, the wafers were arranged more densely than the limit, so that the processing gas did not flow evenly on the wafer surface, causing a defect of a so-called number failure. That is, when the support member in another heat treatment step formed so as to be able to be densely arranged to increase the number of processed sheets is diverted, and the difference in the reaction conditions is not carefully considered,
The above-mentioned number failure was induced.

[0008] In view of the drawbacks of the prior art, the present invention considers L
In order to prevent the deformation of the plate-like body by supporting the periphery of the plate-like body for forming the SI or liquid crystal film and to prevent uneven heat treatment of the plate-like body, and to make the flow of the processing gas on the surface uniform, The object of the present invention is to eliminate the obstacle of the number of sheets to prevent the deposit formed on the back surface of the upper plate member from falling onto the lower plate member, thereby eliminating the back dope. And

[0009]

In order to solve the above-mentioned problems, the present invention is configured such that a lid-like holding table formed on the upper surface so that the plate-like body can be placed thereon is vertically stacked and can be fitted. A plurality of through holes are formed in a peripheral wall surface (including both a cylindrical peripheral wall surface and a rectangular cylindrical peripheral wall surface) of the holding table. According to the present invention, a lid-like holding base formed on the upper surface so that the plate-like body can be placed thereon is vertically stacked so as to be fittable, and the holding base located at the lowest of the plurality of holding bases is provided. The stand is constituted by a heat shield that blocks heat radiation in the soaking area. In any of the above-mentioned inventions, it is preferable that the upper surface of the uppermost holding table among the plurality of holding tables is a closed surface.

[0010] The upper surface of the lid-like holding table does not necessarily have to be a closed surface, but may have a honeycomb-like hole. Further, in the lid-like holding base stacked vertically, the size of the through-hole perforated in the holding base differs depending on the position where the holding base is vertically stacked, and is, for example, arranged in a lower layer. The case where the through-hole of the holding base is larger than the through-hole arranged in the upper layer is also included in the scope of the present invention. Further, the through-holes are, for example, perforated in the holding table in a plurality of stages, the through-holes in the upper row are perforated downward toward the inside of the support, and the through-holes in the lower row are perforated downward toward the outside of the support. For example, the present invention is included in the scope of the present invention even if the through hole is inclined to any side. Further, the upper surface of the lid-like holding table on which the wafer is mounted is a mere flat surface, a concave surface conforming to the outer peripheral shape of the wafer, and a step in which the concave portion is further depressed at the central portion to support only the peripheral portion of the wafer. Concave surface, etc.
Any shape is included in the scope of the present invention.

[0011]

According to this technical means, the plate-like body is placed on the upper surface of the lid-like holding base, and the lid-like support base is vertically stacked, so that the plate-like body is entirely or reversely formed on the back surface. Since the plate is supported by the periphery, the plate can be prevented from being deformed by heat treatment. Further, since the lid-like holding table is vertically stacked, the peripheral surface / wall surface of the holding table plays a role of a buffer tube provided in the heat treatment chamber as a whole, and receives a thermal shock transmitted from the heating source to the reaction tube. As a result, it becomes possible to set a suitable heating environment for the plate-like body by softening and leveling uneven temperature distribution. Further, by mounting the plate-like body on the lid-like holding stand, the plate-like body can be carried into and out of the heat treatment chamber via the lid-like holding stand.

Further, according to the present invention, since the upper surface of the lid-like holding base is a closed surface, the plate-like body is supported on the entire back surface or on the periphery of the back surface, so that film formation on the back surface is impossible. In addition, since the plate-shaped body is housed in the lid-shaped holding table, the deposited material due to the plate-shaped body located in the upper layer does not fall to the plate-shaped body in the lower layer, so-called back doping. Obstacles can be eliminated.

Further, according to the present invention, by forming a through hole in the peripheral surface or the wall surface of the lid-like holding base, the processing gas can be uniformly introduced and discharged into the lid-like holding base. A film can be uniformly formed on the surface of the body. In addition, by changing the size of the through-holes according to the position of the holding pedestal vertically stacked, and by giving a slope to the through-holes that are drilled in a plurality of rows in one support, each plate-shaped The flow of the processing gas can be adjusted for each body, and a uniform film can be formed while suppressing the variation within the batch between the plate bodies and the variation within each plate body.

Further, in the present invention, since the lowermost holding base is a heat shield in which, for example, quartz wool or other heat insulating material is sealed, heat in the heat treatment chamber is prevented from conducting or radiating to the base side. It becomes possible.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely described. It is only an example.

FIG. 1 is a diagram showing the overall configuration of a heat treatment apparatus according to an embodiment of the present invention.
A cylindrical bell-shaped reaction vessel 12 provided on the base 11 and provided with a gas inlet 14 at the top end; a plurality of infrared heaters 18 surrounded around the reaction vessel 12; Excluding the infrared heater 18, including a heat retaining cylinder 23, a plurality of lid-like holding stands 21 stacked on the heat retaining cylinder 23, and a cap 22 placed on the uppermost layer of the holding stand 21. Each member is formed of a quartz glass material.

A processing gas discharge hole 15 is provided below the reaction vessel 12, and a suction pump (not shown) is connected to a downstream side thereof. Introduced, the holding table 21 and the cap 22
The wafer 20 that has passed through the plurality of through holes 24 provided on the peripheral surface of the
After coming into contact with the upper surface, the exhaust pipe 15 can exhaust air.

The reaction vessel 12 is formed in a cylindrical bell shape using a transparent quartz glass material having low absorption of infrared rays.
An opening side in contact with the base 11 is formed in a pressure-resistant seal shape so that the inside of the reaction chamber 13 is a sealed space, and the reaction chamber 13 can be opened using a lifting member (not shown). .

2 (a), 2 (b) and 2 (c) are perspective views of a holder, a cap and a heat retaining cylinder according to the embodiment of the present invention, respectively. In order to obtain thermal properties, a translucent quartz glass material containing air bubbles is used to form a cylindrical lid having an open lower end, and a large number of through holes 24 having a predetermined inclination angle are formed on the peripheral surfaces of the holding table 21 and the cap 22. The processing gas is formed so as to be able to enter and discharge into the holding table 21 and the cap 22 through the through hole 24. A sink corresponding to the outer diameter and thickness of the wafer 20 is engraved on the closed surface of the upper surface of the holding table 21 and the heat retaining cylinder 23. When the wafer 20 is placed in the sink, the sink is easily formed. The upper surface of the wafer is formed so as not to move and to be able to contact the processing gas.

The heat insulating tube 23 is filled with quartz wool 26 and other heat insulating materials so that heat in the reaction chamber 13 does not escape to the base 11 side. A fitting groove 25 is fitted to the upper surface edges of the heat retaining cylinder 23 and the holding table 21, and a fitting groove 25 is fitted to the cap-shaped lower end of the cap 22 and the holding table 21 to fit the fitting groove 25. An edge is provided, and the holding table 21 is stacked and mounted on the heat retaining cylinder 23, and the cap 22 is formed so as to be mounted on the uppermost layer.

FIGS. 3 (a), 3 (b) and 3 (c) are perspective views of a holder, a cap and a heat insulator according to another embodiment of the present invention, respectively. 3
Reference numeral 3 denotes a member used for heat treatment of the glass substrate 30 instead of the wafer 20. Since the glass substrate 30 is rectangular, the holding table 21 is formed except that each member is also formed in a rectangular shape. , Cap 22 and heat retaining cylinder 23.

[0022]

According to the present invention, as described above, the LS
By avoiding point support of the peripheral portion of the plate-shaped member for forming the film for liquid crystal or liquid crystal, by supporting the peripheral portion or the entire surface, deformation of the plate-shaped member is prevented, and heat treatment of the plate-shaped member is made uniform. In addition, the plate-like body can be carried in and out of the heat treatment chamber via the lid-like holding table. In addition, it is possible to prevent the deposit formed on the back surface of the upper plate member from falling onto the lower plate member, thereby eliminating the back dope. Furthermore, by separately storing the plate-like bodies in the holding table, the flow of the processing gas on the surface is made uniform,
Thus, it is possible to eliminate the obstacle of the number of sheets. And so on.

[0023]

[Brief description of the drawings]

FIG. 1 is an overall sectional view of a heat treatment apparatus according to an embodiment of the present invention.

FIGS. 2 (a), (b) and (c) are perspective views of a holding table, a cap and a heat retaining cylinder according to the embodiment of the present invention, respectively.

FIGS. 3 (a), 3 (b) and 3 (c) are perspective views of a holding table, a cap and a heat retaining cylinder according to another embodiment of the present invention, respectively.

FIG. 4 is an overall configuration diagram of a heat treatment apparatus according to the related art.

FIG. 5 is a front view of another support member of the heat treatment apparatus according to the related art.

[Explanation of symbols]

20 30 plate-like body 21 31 holder 2
4 Through hole 23 33 Heat insulation cylinder

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) H01L 21/324 H01L 21/22 511 H01L 21/205

Claims (3)

(57) [Scope of request for utility model registration] 1. A heat treatment apparatus capable of vertically stacking plate-like members for forming an LSI or a liquid crystal film by vertically stacking a lid-like holding table on which the plate-like members can be placed on the upper surface. A heat treatment apparatus configured to be fittable and having a plurality of through holes formed in a peripheral wall surface of the holding table. 2. A heat treatment apparatus capable of vertically stacking plate-like bodies for forming an LSI or liquid crystal film by vertically stacking a lid-like holding table on which the plate-like bodies can be placed on the upper surface. A heat treatment apparatus characterized in that the lowermost one of the plurality of holding tables is formed of a heat shield that blocks heat radiation in the soaking area, while being configured to be fittable. 3. The heat treatment apparatus according to claim 1, wherein an upper surface of the uppermost one of the plurality of holding tables is a closed surface.