JP3412735B2 - Wafer heat treatment equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to the diffusion process of the semiconductor wafer, oxidation, relates to a semiconductor wafer heat treatment equipment such as those used in vacuum CVD, in particular of single wafer for accommodating the wafer upright in a semiconductor wafer Ru <br/> relates to a heat treatment equipment.

[0002]

2. Description of the Related Art Conventionally, when heat-treating semiconductor wafers, a batch method has been adopted in which a plurality of wafers are stacked and placed on a wafer boat and heat-treated collectively in a reaction vessel. In this method, it is difficult to uniformly process the input wafer due to the turbulence of the air flow generated near the contact portion between the wafer and the boat and the turbulence of the air flow due to the multi-layered stacking of the wafers. Further, as the diameter of the wafer is increased, it is difficult to manufacture a boat and a supporting portion corresponding to the weight burden in the batch processing method, and the reaction vessel is increased in size due to the increase in the diameter, and the heating temperature distribution and the like. There are various problems that are difficult to deal with by the conventional batch method in order to deal with the uniform gas distribution and the unnecessary increase of the heating source, and to cope with the large diameter of the wafer. In addition, 64 of the next generation
Submicron precision is required in high-density integrated semiconductor manufacturing processes such as M and 1G, and in a batch system that processes multiple wafers at a time, the stacking position of wafers and the gas flow inflow side and exhaust side are each different. High-quality processing is difficult because the processing conditions vary and the stacked wafers affect each other, and particles and the like are generated from the contact portion of the boat.

In order to solve the above problems, a single-wafer type heat treatment apparatus for performing heat treatment on every one or two wafers has attracted attention and various proposals have been made.
In the heat treatment apparatus disclosed in Japanese Patent No. 91154, a wafer placed horizontally on the susceptor is heated in a low-pressure reaction gas atmosphere by a heating source provided below the susceptor to form a film on the wafer. I am doing it. When the wafer is placed horizontally, the wafer is bent due to its own weight, the reaction container becomes large, and the power source such as a heating source also becomes large. There is a problem such as.

[0004] It is an object of the present invention have found that large diameter of the wafer and the next generation of 64M, in order to deal with the high integration density of 1G, etc., have been Tsu engaged in the development of single-wafer of the wafer heat treatment apparatus, Proposed in Japanese Patent Application No. 8-24823 for a semiconductor wafer heat treatment apparatus equipped with a single-wafer reaction vessel having a shape capable of ensuring a necessary minimum size with respect to the size of the stored wafer and an upright supporting device for the wafer. is doing. ( Non
(Publication: JP-A-9-260297 )

In the above proposal, the wafer is stored in the upright type, and in order to make the heat distribution on the wafer surface uniform and the reaction gas flow distribution uniform, the wafer is flattened with respect to the heat-treated surface. It has a flat curved surface shape so that the size of the reaction vessel can be suppressed to a necessary minimum. That is, as shown in FIG. 7, a reaction container 50 having a flat spherical container shape.
And a supporting jig 40 for vertically supporting the wafer 10 in the container
And a pair of flat plate-shaped heat generating elements 60 arranged on the flat side of the reaction vessel 50, and the reaction vessel 50 is a lower opening 52 of a reaction vessel body 52 made of transparent quartz glass.
A flange 51 made of non-transparent quartz glass is welded to a, and the reaction gas is allowed to flow in through an upper inflow hole 53 of the container 52 and discharged through a lower exhaust hole 58 of the container 52 as required. The supporting jig 40 is made of quartz glass or silicon carbide, and has a supporting jig main body 41 that supports the wafer upright, and a supporting rod 43 (extending portion) that hangs from the supporting jig main body 41 to the outside of the container. A base body 42 (extension portion) which is interposed in the middle of the support rod 43 and seals the lower surface of the flange via an O-ring 54.

According to the above proposal, the reaction container 50 has a vacuum strength even if it is thin. Because it is thin, it can be made lightweight. Good gas flow along the inner curved surface. However, the processing space in the reaction vessel 50 is 600-
In order to perform the heat treatment at a high temperature of about 1000 ° C., the heat in the processing space propagates to the outside of the container 50 via the support rod 43,
Further, since the apparatus shown in FIG. 7 saves space by matching the space inside the container with the shape of the wafer, it is difficult to maintain heat drop and thermal uniformity, and as a result, high-quality wafer heat treatment becomes difficult. When the support rod 43 is made of transparent quartz glass, not only high temperature propagates to the seal portion of the flange, but also when a lifting jig or an undulating jig, which will be described later, is arranged on the base end side of the support rod 43. Heat transfer also occurs in the part, and it is a problem from the cost and the like to construct a heat-resistant jig including them.

In order to eliminate such a defect, the supporting jig 4
Although it is possible to form 0 itself with non- transparent SiC or the like, since SiC has a large amount of impurities and particles are more likely to be generated than silica glass when the above-mentioned configuration is adopted, high quality wafer heat treatment is consequently performed. It will be difficult.

[0008]

In view of the above-mentioned drawbacks of the prior art, the present invention is capable of increasing the size of an apparatus while maintaining heat drop and soaking even when a quartz glass wafer supporting jig is used. suppressing the generation of suppression or particles, Ru der intended to provide a can maintain a high heat shielding properties single wafer heat treatment apparatus.

[0009]

The invention according to claim 1 is
Formed to achieve a pre-Symbol purpose, a quartz glass wafer support jig to one or two upright support the semiconductor wafer, the supporting jig Tsutsumihi support semiconductor wafer to the heat treatment space of the wafer And a quartz glass reaction container that is uprightly supported in the container.
Has a spherical curved surface that can store c on both sides,
Flatly curved surfaces on both front and back sides of a wafer stored upright inside
Formed by a flat spherical container made into a planar shape,
A flange provided on the lower opening of the polarization plane spherical container, whereas the
The support jig supports the wafer upright in the reaction vessel.
Support jig main body and the outside of the reaction vessel from the support jig main body
A support rod that hangs on the middle of the support rod,
Seal the flange through the O-ring on the bottom surface of the flange
Consists of a base body, and from the heat treatment area of the support rod
Foamed or non-foamed areas around the base body
It is made of transparent quartz glass and has a heat insulation function.
The reaction vessel is preferably made of a transparent quartz glass body with an integral structure.
A non-transparent quartz glass body in the lower opening of the reaction vessel.
It is characterized in that the flange is welded and joined.
It

According to this invention, as in the prior art, since the reaction vessel on the heat treatment surface side of the wafer is flattened, the heating element can be moved closer to that portion, resulting in downsizing of the apparatus. The power source such as the heating source can also be reduced. Further, the heat distribution of the radiant heat to the inner surface of the reaction vessel and the distribution of the reaction gas flow are made uniform, and the necessary minimum size can be secured for the size of the wafer to be stored, and high temperature heat treatment is possible. Therefore, it is possible to obtain a high-efficiency, high-precision single-wafer-type wafer heat treatment apparatus.

In particular, the present invention relates to the reaction container lower opening 5
High-temperature heat treatment at the heat treatment space at least a portion of said support jig made of quartz glass extending portion to the non-transparent by AwaIri or other means extending from 2a is, the non <br / > Even if the heat in the processing space is blocked by the transparent part and tries to propagate to the outside of the container through the support rod 43, it is blocked by the non- transparent part, and it is possible to maintain the heat drop and the uniform heat distribution in the processing space. As a result, high quality wafer heat treatment can be performed. The base body integrated with the support rod is also made of a non- transparent quartz glass material and functions as a part of the extending portion.

With this, there is no risk of high temperature propagating to the sealing portion of the flange, and when an elevating jig or an undulating jig, which will be described later, is arranged on the base end side of the supporting rod together with the non- transparent portion of the supporting rod 43, that portion is provided. However, there is no risk of heat transfer, and it is not necessary to construct them with a heat resistant jig.

In this case, a vertically moving means is provided so that the wafer supporting jig can be loaded from the reaction container, and the supporting jig is undulated on the wafer loading side when the supporting jig is loaded from the reaction container. It is characterized by being configured as possible.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be exemplarily described in detail below 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 illustrative examples. Only. 1 and 2 are schematic configuration diagrams showing an example of a single-wafer type heat treatment apparatus according to an embodiment of the present invention, FIG. 1 is a heat treatment for one wafer, and FIG. 2 is a heat treatment for two wafers. To do.

The heat treatment apparatus shown in FIG. 1 has a flat spherical reaction vessel 50, a support jig 40 for uprightly supporting a wafer in the vessel, and a pair of flat plates arranged facing the flat side of the reaction vessel 50. A heating element 60, and the reaction container 50 is a flat spherical surface having a flat curved surface shape with respect to the heat-treated surface of the wafer.
The reaction container 50 is formed in a container shape, and the size of the reaction container 50 is suppressed to a necessary minimum. The reaction container 50 has a reaction container main body 52 made of transparent quartz glass and a flange 51 made of a non-transparent quartz glass plate welded thereto. . It should be noted that the reaction gas is made to flow in through the upper inflow hole 53 of the container body 52 and discharged through the lower exhaust hole 58, if necessary.

The support jig 40 is made of a quartz glass material, and has a support jig main body 41 for vertically supporting the wafer and a support rod 43 hanging from the support jig main body 41 to the outside of the container 50.
(Extended portion) and a base body 42 which is interposed in the middle of the support rod 43 and is hermetically sealed to the lower surface of the flange 51 via an O-ring 54. The wafer support jig 40 is the wafer 10.
The wafer can be taken in and out through the container lower opening 52a by raising the reaction container 50 by the elevating means 59 engaging with the flange 51 of the reaction container 50 or lowering the supporting jig 40 itself while supporting the wafer. Configured.

When the wafer is loaded, the supporting jig 4
The O-ring 54 interposed between the base body 42 of No. 0 and the flange 51 is pressed to be hermetically sealed. Also,
At the time of heat treatment, under a predetermined reduced pressure, the reaction gas is fed from the reaction gas supply pipe 53 into the reaction container 50 and discharged from the discharge pipe 58 to form various films. In this case, the reaction gas flows from the upper part of the reaction vessel 50 to the respective heat treatment surfaces 1 of the wafer 10.
A uniform flow is formed by forming a stream along with 0a. Also, the wafer support jig should be 1
There are a three-point system in which a wafer is supported at three points, a four-point system in which four wafers are supported, and the like, but the wafer is not particularly limited. In FIG. 2, the back surfaces of the two wafers 10 are supported back to back so that the heat-treated surfaces of the two wafers 10 are located outside.

In FIG. 3, the structure of the reaction vessel 50 used in the heat treatment apparatus of FIGS. 1 and 2 is shown in a front view (A) and a side view (B), respectively. to, capacity
Spherical curve that can store uprightly supported wafers in container 50
With the spherical surface on both sides, the spherical curved surface
Flat sphere with curved surfaces on both front and back sides
Formed by a surface container and below the flat spherical container
A flange 52 is provided in the opening, and the reaction container 40 in the shape of a flat spherical container is formed of a transparent quartz glass body in an integral structure,
Only the flange 51 is welded and joined with a non-transparent quartz glass body,
The structure prevents the heat from propagating from the reaction container body 52 to the lower part through the flange 51. As shown in the drawing, the flat reaction container 50 formed by a continuous body of flat spherical surfaces enables the design of a lean form that enables a minimum necessary size for an upright wafer to be stored, and It has high vacuum strength and high thermal shock resistance. Therefore, the space efficiency is increased, the heat of diffusion treatment is radiated, and the continuous curved surface of the inner surface allows the reaction gas to flow without stagnation, thereby enabling uniform film formation.

FIG. 4 shows a wafer supporting jig 40 of the present invention.
Is shown. FIG. 4A is a perspective view of a single-wafer 3-point type wafer supporting jig 40. The supporting groove members 4 are provided on the bottom of the inner peripheral surface of the semicircular arcuate disk-shaped supporting base 45 and the left and right upper end surfaces.
Fix 6 The groove shape of the support groove member 46 may be Y-shape, V-shape, etc. as shown in (B), but the back surfaces of the two wafers 10 are back to back so that the heat-treated surfaces are located outside. In the case of supporting the wafer on the heat treatment surface side as a guide, the groove walls 462 on both outer sides are tapered with the central partition wall 461 interposed therebetween as shown in (C). Half Y shape). Then, from the center of the lower surface of the support base 45 to the support rod 4
3 is suspended, and a base body 42 for contacting the flange 51 is fixed at an intermediate position thereof. Then, the midway position of the support rod 43, specifically, the base body 42 neighboring area 43a and the base body 42 which are out of the heat treatment area are made of quartz glass containing bubbles so as to be non-transparent and have a heat shielding function.

Next, a wafer loading method of the heat treatment apparatus based on the above embodiment will be described. First, as shown in FIG. 5, when one wafer is uprightly supported by the support jig 40, the wafer is supported on the base end side of the support rod 43 of the wafer support jig main body 41 which is suspended from the wafer support base 45. An undulating mechanism is provided, and after the supporting jig 40 is pulled out from the lower opening 52a of the reaction container 50 as described above (→
), Tilting (laying down) in a substantially horizontal direction (→), extracting the one wafer 10 after the heat treatment and loading it into the treated wafer stocker 62, and then the untreated wafer from the untreated wafer storage stocker 63. After being pulled out and loaded on the support jig 40, it is erected and subjected to a predetermined process.

In order to improve efficiency, as shown in FIG. 2, in the case of adopting the two-sheet heat treatment method of vertically supporting the two wafers 10 on the supporting jig 40, as shown in FIG. First and second wafer loading sections 70A and 70B, in which a processed wafer stocker 62 and an unprocessed wafer storage stocker 63 are respectively arranged on both left and right sides of the support jig 40 upright, are provided. It is configured that 40 can be laid down toward the respective wafer loading sides on the left and right sides via the undulating mechanism. Then, as described above, the support jig 40 supporting the two wafers upright is mounted on the lower opening 52a of the reaction container 50.
After being pulled out (→), the first wafer loading unit 70
The first wafer 10 after the heat treatment, which is tilted (laid down) in the substantially horizontal direction to the A side (→), is extracted from the upper side of the support groove 462 and loaded into the processed wafer stocker 62, and then the unprocessed wafer is stored. An unprocessed wafer is pulled out from the storage stocker 63 and loaded in the upper support groove 462.

Next, after the supporting jig 40 is inverted and laid 180 degrees on the side of the second loading portion (→), the second wafer 102 after the heat treatment located below the supporting groove 462 is taken out. After being loaded into the treated wafer stocker 62, the untreated wafer is pulled out from the untreated wafer storage stocker 63 and loaded into the lower support groove 462. After loading the two wafers 101 and 102 on the support jig 40,
Stand up and perform predetermined processing. In this case, as shown in FIG. 4C, the support groove 46 of the support jig main body 41 located on the heat treatment surface 10a side of the wafer 10 is expanded in a taper shape toward the wafer insertion end side, and thus the support groove is formed. The generation of particles is prevented without the wafer heat-treated surface coming into contact with 46.

According to such an embodiment, the upper wafer is inserted at the first loading position and the lower wafer is inserted at the inverted second loading position, so that only the wafer stocker having the heat treatment surface laminated on the upper side can be used. Each of the heat treatment surfaces can be loaded outward, and as a result, the loading operation can be facilitated and automated.

Further, a wafer loading system as shown in FIG. 8 may be adopted. That is, one wafer loading section 70A in which the processed wafer stocker 62 and the unprocessed wafer storage stocker 63 are arranged on one side of the standing position of the support jig 40.
The support jig 40 is provided so as to face the wafer loading side through a hoisting mechanism (not shown) and is 180 ° about the axis.
It is configured to be rotatable. Then, as described above, after the support jig 40 that vertically supports the two wafers is pulled out from the lower opening 52a of the reaction container 50 (→), it is tilted (laid down) substantially horizontally to the one wafer loading section 70A side. ) (→
), The first after the heat treatment, which is located above the support groove 462.
Wafer Stocker 62
Then, the untreated wafer is pulled out from the untreated wafer storage stocker 63 and loaded into the upper support groove 462. ()

Next, after the supporting jig 40 is erected upright and rotated about the axis of 180 °, () it is tilted (laid down) substantially horizontally to the side of the one wafer loading section 70A (→). ), The second wafer 10 on the upper side of the support groove 462 (the second wafer 10 after the heat treatment, which is positioned on the lower side due to 180 ° inversion, becomes the upper side) is extracted and loaded into the treated wafer stocker 62, Then, the unprocessed wafer is pulled out from the unprocessed wafer storage stocker 63, and is inverted by 180 ° to be loaded into the lower support groove 462 which is on the upper side. () After loading two wafers on the support jig 40, the wafer is erected and a predetermined process is performed. (→)

According to this embodiment, since the upper wafer and the lower wafer can be inserted in the same direction,
With only one wafer stocker having the heat-treated surface laminated on the upper side, the heat-treated surfaces can be loaded outward, respectively, and as a result, the loading operation can be facilitated and automated.

[0027]

As described above, according to the present invention , even when the wafer supporting jig 40 made of quartz glass is used, heat drop and soaking property are maintained and the size of the apparatus is suppressed and particles are generated. Can keep high heat insulation
It

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration in the case where one wafer is stored in a single-wafer heat treatment apparatus of the present invention.

FIG. 2 is a cross-sectional view showing a schematic configuration when two wafers are stored in FIG.

FIG. 3 is a view showing the structure of a reaction vessel used in FIG.
(A) is a front view and (B) is a side view.

FIG. 4 shows the structure of the wafer supporting jig shown in FIG. 1, (A)
Is a perspective view showing the case of supporting one wafer at three points,
(B) is a perspective view showing a single-groove supporting groove member for supporting one wafer, and (C) is a perspective view showing a two-groove supporting groove member for supporting two wafers.

FIG. 5 is an operation diagram showing a wafer loading method of a wafer heat treatment apparatus in which one wafer is arranged on a wafer supporting jig.

FIG. 6 is an operation diagram showing a wafer loading method of a wafer heat treatment apparatus in which a wafer supporting jig made of quartz glass in which two wafers are respectively placed back to back in a wafer supporting groove can be loaded from a reaction container.

FIG. 7 is a cross-sectional view showing a schematic configuration in the case where one wafer is stored in the single-wafer heat treatment apparatus of the prior application technique.

FIG. 8 is an operation diagram showing a wafer loading method of a wafer heat treatment apparatus in which a wafer supporting jig made of quartz glass in which two wafers are respectively placed back to back in a wafer supporting groove can be loaded from a reaction container.

[Explanation of symbols]

40 Support jig 41 Support jig body 42 Base body 43 Support bar (extension part) 50 reaction vessels 60 Flat heating element 51 flange 52 Reaction vessel body 53 Upper inlet 58 Lower discharge hole

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeharu Suzuki 353 Moto Nakayama, Nanyo City, Yamagata Prefecture (56) Reference JP-A-2-69932 (JP, A) JP-A-8-143329 (JP, A) Special Kai 63-17300 (JP, A) JP 63-252996 (JP, A) JP 1-283921 (JP, A) JP 4-260700 (JP, A) JP 5-291154 ( JP, A) JP 7-237927 (JP, A) JP 7-300341 (JP, A) JP 9-260297 (JP, A) Actual development 5-43540 (JP, U) (58) ) Fields surveyed (Int.Cl. ⁷ , DB name) C30B 1/00-35/00 C03B 20/00 H01L 21/22 H01L 21/205

Claims (2)

(57) [Claims] 1. A quartz glass wafer supporting jig for supporting one or two semiconductor wafers upright, and a quartz glass reaction for covering a semiconductor wafer supported by the supporting jig to form a heat treatment space for the wafer. The reaction container is used to store wafers that are supported upright in the container.
It has a spherical surface that can be stored on both sides, and inside the spherical surface
Curved surfaces on both front and back sides of wafers stored upright are flat curved
And a flat spherical container
A flange is provided at the lower opening of the spherical container , while the supporting jig raises the wafer upright in the reaction container.
The support jig body that supports the
The support rod that hangs outside the reaction container, and is inserted in the middle of the support rod.
The lower surface of the flange through an O-ring.
It consists of a hermetically sealed base body, and heat treatment of the support rod.
Foams around the base body and the base body that are out of the realm
It is made of non-transparent quartz glass and has a heat insulation function
Wafer thermal processing apparatus characterized by allowed. 2. The reaction container is integrally made of a transparent quartz glass body.
A non-transparent quartz glass is formed in the lower opening of the reaction vessel.
With the configuration in which the flange welded and joined with a lath body is provided
Wafer thermal processing apparatus according to claim 1, wherein the a.