JP3976090B2 - Wafer loading method in wafer heat treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wafer loading method in a semiconductor wafer heat treatment apparatus used for semiconductor wafer diffusion treatment, oxidation treatment, low pressure CVD, and the like, and more particularly to a wafer in a single wafer type semiconductor wafer heat treatment apparatus for storing wafers upright. It relates to a loading method.
[0002]
[Prior art]
Conventionally, when performing heat treatment of semiconductor wafers, a batch method has been adopted in which a plurality of wafers are stacked and mounted on a wafer boat, and batch heat treatment is performed in a reaction vessel. In this method, it is difficult to uniformly process the input wafer due to the turbulence of the air current generated in the vicinity of the contact portion between the wafer and the boat or the turbulence of the air current caused by stacking the wafers in multiple stages.
Also, as the wafer diameter increases, the batch processing method makes it difficult to produce boats and supporting parts corresponding to the weight burden, and the reaction vessel increases in size, the heating temperature distribution, and so on. This leads to uniform gas distribution and unnecessary increase in the heat source, and there are various problems that are difficult to deal with in the conventional batch system in order to cope with an increase in wafer diameter.
In addition, the next-generation semiconductor manufacturing process with high integration density such as 64M and 1G requires submicron accuracy. In batch systems that process multiple wafers at once, the wafer stacking position and gas flow inflow side The processing conditions vary between the two and the discharge side, and the stacked wafers affect each other, and particles and the like are generated from the contact portion of the boat, making high quality processing difficult.
[0003]
In order to solve the above problems, a single-wafer type heat treatment apparatus that performs heat treatment for every one or two wafers has attracted attention and various proposals have been made. For example, the heat treatment disclosed in JP-A-5-291154 is disclosed. In the apparatus, 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.
When the wafer is mounted horizontally, the wafer is bent due to its own weight, the reaction vessel becomes large, and the power source such as a heating source becomes large. There are problems such as.
[0004]
Therefore, the present inventors have been engaged in the development of a single wafer heat treatment apparatus in order to cope with an increase in wafer diameter and a high integration density of the next generation 64M, 1G, etc. Japanese Patent Application No. 8-24823 proposes a heat treatment apparatus for a semiconductor wafer having a single wafer reaction vessel having a shape that can secure a necessary minimum size and a wafer upright support device. (Non-public literature: JP 09-260297 A)
[0005]
In the above proposal, the wafer storage posture is an upright type, and in order to make the heat distribution on the wafer surface uniform and the reaction gas flow uniform, a flat dome shape that is flat with respect to the heat treatment surface of the wafer And the size of the reaction vessel is minimized.
That is, as shown in FIG. 7, a flat dome-shaped reaction vessel 50, a support jig 40 for supporting the wafer 10 upright in the vessel, and a pair of flat plates arranged facing the flat side of the reaction vessel 50 are provided. The reaction vessel 50 includes a heating element 60, and the reaction vessel 50 has a flange 51 made of non-transparent quartz glass welded to a lower opening 52a of the reaction vessel main body 52 made of transparent quartz glass. Inflow from the upper inflow hole 53 is discharged from the lower discharge hole 58.
The support jig 40 is made of quartz glass or silicon carbide, and a support jig main body 41 that supports the wafer upright, and a support rod 43 (extension part) that hangs down from the support jig main body 41 outside the container. And a base body 42 (extending portion) which is interposed in the middle of the support rod 43 and is sealed to the lower surface of the flange via an O-ring 54.
[0006]
[Problems to be solved by the invention]
In order to increase the efficiency of loading and unloading the wafer, the support jig adopts a two-sheet heat treatment method in which two wafers are supported upright so that the heat treatment surface faces the outside (the side facing the container side). There is a case. In this case, in order to facilitate loading / unloading of the wafer support jig, the support jig is pulled out from the lower opening of the reaction vessel as described above, and then tilted (laying down) in a substantially horizontal direction. Although two wafers are loaded / extracted, the upper wafer has the heat treatment surface on the upper side, and the lower wafer has the heat treatment surface on the lower side. Therefore, the heat treatment surface is laminated on the upper side. Two types of stockers are required: a first wafer stocker and a second wafer stocker having a heat treatment surface stacked on the lower side. As a result, not only the loading operation becomes complicated, but also automation becomes difficult.
[0007]
The present invention relates to a wafer heat treatment apparatus in which a quartz glass wafer support jig, in which two wafer support grooves are arranged back to back so that two wafers can be supported upright, can be unloaded from a reaction vessel. It is an object of the present invention to provide a wafer loading method that can easily achieve automation with a simple structure in the wafer loading method.
[0008]
[Means for Solving the Problems]
The present invention relates to a wafer loading method in a wafer heat treatment apparatus in which a quartz glass wafer support jig in which two wafers are arranged back to back in a wafer support groove can be loaded or unloaded from a reaction vessel.
The two wafers are supported with their back surfaces back to back so that the heat treatment surface is located outside at the standing position of the support jig, and the first and second sides on both the left and right sides of the standing position of the support jig . And the support jig is configured so that the two wafers can be laid back-to-back toward the left and right wafer loading sides via a raising / lowering mechanism, and the support jig is The first wafer positioned on the upper side in the state of being laid down on the wafer loading portion is loaded or unloaded with the heat treatment surface on the upper side, and then the support jig is inverted and laid on the second loading portion, At the position of one wafer loading section, the second wafer positioned on the lower side is loaded or removed with the heat treatment surface facing upward.
According to this invention, the upper wafer is inserted at the first loading position, and the lower wafer is inserted at the inverted second loading position, so that the heat treatment is performed only by one wafer stocker in which the heat treatment surfaces are stacked on the upper side. Each surface can be loaded outward, and as a result, the loading operation can be facilitated and automated.
[0009]
Further, in the wafer loading method in the wafer heat treatment apparatus, the quartz glass wafer support jig in which the two wafers are disposed back to back in the wafer support groove as described in claim 2 can be loaded or unloaded from the reaction vessel. ,
At the standing position of the support jig, the two wafers are supported back to back so that the heat treatment surface is located outside, and one wafer loading portion is provided on one side of the support jig standing position. The support jig is configured such that the two wafers can be laid back-to-back with the raising / lowering mechanism facing the wafer loading side, and the support jig is laid down on a single wafer loading portion. The first wafer located on the upper side is loaded or unloaded with the heat treatment surface facing upward, and then the support jig is erected and the erected support jig is rotated by 180 ° about the vertical axis , and then again. When loading or unloading the first wafer, the second wafer located on the lower side is loaded or unloaded with the heat treatment surface facing upward. It may be.
In this invention as well, in order to load the wafer after being turned 180 °, the upper wafer is apparently always inserted, and the heat treatment surface is formed by only one wafer stocker in which the heat treatment surfaces are stacked on the upper side. In addition to being able to achieve loading and facilitating the loading operation, it is not only necessary to prepare wafer stockers on both the left and right sides as described in claim 1, but only on one side. It is enough to have two wafer stockers.
In any case, it is preferable that the support groove of the support jig located on the heat treatment surface side is configured to expand in a tapered shape toward the wafer insertion end side.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, 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 unless otherwise specified, but are merely illustrative examples. Only.
FIG. 1 and FIG. 2 are schematic configuration diagrams showing an example of a single wafer heat treatment apparatus according to an embodiment of the present invention. FIG. 1 shows a heat treatment for one wafer, and FIG. 2 shows a heat treatment for two wafers. To do.
[0011]
The heat treatment apparatus shown in FIG. 1 includes a flat dome-shaped reaction vessel 50, a support jig 40 for supporting the wafer upright in the vessel, and a pair of flat plate-like heating elements disposed facing the flat side of the reaction vessel 50. The reaction vessel 50 has a flat dome shape that is flat with respect to the heat treatment surface of the wafer, and the reaction vessel 50 is kept to a minimum size, and the reaction vessel 50 is an integral unit made of transparent quartz glass. A flange 51 made of a non-transparent quartz glass plate is welded to the reaction vessel main body 52 having the configuration.
If necessary, the reaction gas flows from the upper inlet hole 53 of the container body 52 and is discharged from the lower outlet hole 58.
[0012]
The support jig 40 is made of a quartz glass material, and a support jig main body 41 that supports the wafer upright, a support rod 43 (extension part) that hangs out of the container 50 from the support jig main body 41, and the support The base body 42 is interposed in the middle of the rod 43 and sealed on the lower surface of the flange 51 via an O-ring 54.
While the wafer support jig 40 is supporting the wafer 10, the wafer is moved into the container by raising or lowering the reaction container 50 by the lifting means 59 engaged with the flange 51 of the reaction container 50 or lowering the support jig 40 itself. It is configured to be able to be taken in and out from the lower opening 52a.
[0013]
When the wafer is loaded, the O-ring 54 interposed between the base body 42 and the flange 51 of the support jig 40 can be pressed and sealed. Further, during the heat treatment, the reaction gas is sent into the reaction vessel 50 from the reaction gas supply pipe 53 and discharged from the discharge pipe 58 under a predetermined reduced pressure, and various film formations are performed.
In this case, the reaction gas flows from the upper part of the reaction vessel 50 along the respective heat treatment surfaces 10a of the wafer 10 without any stagnation, thereby enabling uniform film formation.
Further, as will be described later, the wafer support jig includes a three-point method for supporting one wafer at three locations, a four-point method for supporting at four locations, and the like, but is not particularly limited.
In FIG. 2, the back surfaces of the two wafers 10 are supported back to back so that the heat treatment surfaces of the two wafers 10 are located outside.
[0014]
FIG. 3 is a front view (A) and a side view (B) of the structure of the reaction vessel 50 used in the heat treatment apparatus shown in FIGS. 1 and 2, respectively. A flat dome-shaped reaction vessel 40 with a flange 51 having curved surfaces on both sides is formed in a single structure with a transparent quartz glass body, and only the flange 51 is welded and joined with a non-transparent quartz glass body. In this structure, heat propagation to the lower part is prevented.
As shown in the figure, the flat reaction vessel 50 formed of a continuous body of flat spherical surfaces enables the design of a lean configuration that enables the necessary minimum size for the upright wafer to be stored, and It has high vacuum strength and high thermal shock resistance.
For this reason, space efficiency is increased, diffusion treatment heat can be radiated, and a continuous curved surface on the inner surface allows a flow of reaction gas to flow, thereby enabling uniform film formation.
[0015]
FIG. 4 shows a schematic configuration of the wafer support jig 40 of the present invention.
FIG. 4A is a perspective view of a one-piece, three-point wafer support jig 40. Support groove members 46 are formed on the bottom of the inner peripheral surface and the left and right upper end surfaces of a semicircular arc-shaped disk-shaped support base 45. FIG. Stick.
The groove shape of the support groove member 46 may be Y-shaped or V-shaped as shown in (B), but the back surfaces of the two wafers 10 are back-to-back so that the heat-treated surfaces of the two wafers 10 are located outside. As shown in FIG. 2C, the outer groove walls 462 are tapered with the central partition wall 461 interposed therebetween so that the heat treatment surface side of the wafer is expanded in a tapered shape as a guide. (Half Y-shape).
Then, the support bar 43 is suspended from the center of the lower surface of the support base 45, and a base body 42 for contacting the flange 51 is fixed at an intermediate position.
Then, the intermediate position of the support rod 43, specifically, the base body 42 vicinity area 43a and the base body 42 which are out of the heat treatment area are formed of foamed quartz glass and are made non-transparent so as to have a heat blocking function.
[0016]
Next, a wafer loading method in the heat treatment apparatus based on the embodiment will be described.
First, as shown in FIG. 5, when a single wafer is supported upright on the support jig 40, the support rod 43 hangs down from the wafer support base 45 of the wafer support jig main body 41. As described above, after the support jig 40 is extracted from the lower opening 52a of the reaction vessel 50 as described above ((1) → (2)), it is tilted (laid down) in a substantially horizontal direction ( (2) → (3)) After the heat-treated wafer 10 is extracted and loaded into the treated wafer stocker 62, the untreated wafer is pulled out from the untreated wafer storage stocker 63, and the support jig 40 After being loaded, it stands up and performs a predetermined process.
[0017]
In order to increase efficiency, as shown in FIG. 2, when a two-sheet heat treatment method in which two wafers 10 are supported upright by the support jig 40 is adopted, as shown in FIG. First and second wafer loading portions 70A and 70B each having a processed wafer stocker 62 and an unprocessed wafer storage stocker 63 arranged on both the left and right sides of the tool 40 standing position are provided, and the support jig 40 is raised and lowered. It is configured to be able to be laid down toward the left and right wafer loading sides via a mechanism.
Then, as described above, after the support jig 40 supporting the two wafers upright is pulled out from the lower opening 52a of the reaction vessel 50 ((1) → (2)), it is almost directed to the first wafer loading section 70A side. Tilt (lay down) in the horizontal direction ((2) → (3)), the first wafer 10 after the heat treatment located above the support groove 462 is pulled out and loaded into the treated wafer stocker 62. The unprocessed wafer is pulled out from the processed wafer storage stocker 63 and loaded into the upper support groove 462.
[0018]
Next, the support jig 40 is turned upside down 180 ° on the second loading portion side (3 → 4), and then the second wafer after the heat treatment positioned below the support groove 462. After 102 is extracted and loaded into the processed wafer stocker 62, the unprocessed wafer is pulled out from the unprocessed wafer storage stocker 63 and loaded into the lower support groove 462.
After the two wafers 101 and 102 are loaded on the support jig 40, the support jig 40 is erected to perform a predetermined process.
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 tapered shape toward the wafer insertion end side. The generation of particles is prevented without the wafer heat-treated surface colliding with 46.
[0019]
According to this 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 in which the heat treatment surfaces are stacked on the upper side is used. Can be loaded outward, and as a result, the loading operation can be facilitated and automated.
[0020]
Further, a wafer loading method as shown in FIG. 8 may be adopted.
That is, one wafer loading portion 70A in which a processed wafer stocker 62 and an unprocessed wafer storage stocker 63 are arranged on one side of the support jig 40 standing position is provided, and the support jig 40 has a undulation mechanism (not shown). Through the wafer loading side and configured to be rotatable by 180 ° about the axis.
Then, as described above, after the support jig 40 supporting the two wafers upright is pulled out from the lower opening 52a of the reaction vessel 50 ((1) → (2)), it is substantially horizontal to the one wafer loading portion 70A side. The first wafer 10 after heat treatment positioned above the support groove 462 is extracted and loaded into the treated wafer stocker 62, and then untreated. An untreated wafer is pulled out from the wafer storage stocker 63 and loaded into the upper support groove 462. (▲ 3 ▼)
[0021]
Next, the support jig 40 is erected upright and rotated about the axis of 180 °, and then (4) is tilted (laid down) substantially horizontally toward the one wafer loading portion 70A ( 4 ▼ → (5)), the second wafer 10 on the upper side of the support groove 462 (the second wafer 10 after the heat treatment positioned on the lower side by 180 ° inversion becomes the upper side) is extracted and the processed wafer stocker is removed. Then, the unprocessed wafer is pulled out from the unprocessed wafer storage stocker 63 and loaded into the lower support groove 462 which is on the upper side by reversing 180 °. (▲ 5 ▼)
After the two wafers are loaded on the support jig 40, the support jig 40 is erected to perform a predetermined process. (▲ 5 ▼ → ▲ 1 ▼)
[0022]
According to this embodiment, since the upper wafer and the lower wafer can be inserted in the same direction position, the heat treatment surface is directed outward by only one wafer stocker in which the heat treatment surfaces are stacked on the upper side. It can be loaded, and as a result, the loading operation can be facilitated and automated.
[0023]
【The invention's effect】
As described above, according to the present invention, the quartz glass wafer support jig 40 in which two wafer support grooves are arranged back to back in a corresponding position so that two wafers can be supported upright is loaded from the reaction vessel 50. Automation can be achieved easily and with a simple structure in the wafer loading method in the wafer heat treatment apparatus constructed as possible.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a schematic configuration when a single wafer is stored in a single wafer heat treatment apparatus as a precondition of the present invention.
FIG. 2 is a cross-sectional view showing a schematic configuration of a single wafer heat treatment apparatus to which the present invention is applied when two wafers are stored in FIG.
3 is a view showing the structure of the reaction vessel used in FIG. 1, in which (A) is a front view and (B) is a side view.
4 shows the configuration of the wafer support jig of FIG. 1, (A) is a perspective view showing the case of supporting one wafer at three points, and (B) is one groove support for supporting one wafer. It is a perspective view which shows a groove member, (C) is a perspective view which shows the 2 groove | channel support groove member for two wafer support.
FIG. 5 is an operation diagram showing a wafer loading method in a wafer heat treatment apparatus in which one wafer is disposed on a wafer support jig.
FIG. 6 is a view showing a method of loading a wafer in a wafer heat treatment apparatus according to the present invention in which a quartz glass wafer support jig in which two wafers are arranged back to back in a wafer support groove can be loaded from a reaction vessel. FIG.
FIG. 7 is a cross-sectional view showing a schematic configuration when a single wafer is accommodated in the single wafer heat treatment apparatus of the prior application technique.
FIG. 8 is a view showing a method of loading a wafer in a wafer heat treatment apparatus according to the present invention in which a quartz glass wafer support jig in which two wafers are disposed back to back in a wafer support groove can be loaded from a reaction vessel. FIG.
[Explanation of symbols]
40 support jig 41 support jig body 42 base body 43 support rod (extension part)
50 Reaction vessel 60 Flat heating element 51 Flange 52 Reaction vessel body 53 Upper inlet hole 58 Lower outlet hole

Claims (3)

In a wafer loading method in a wafer heat treatment apparatus in which a quartz glass wafer support jig in which two wafers are arranged back to back in a wafer support groove can be loaded or unloaded from a reaction vessel,
The two wafers are supported with their back surfaces back to back so that the heat treatment surface is located outside at the standing position of the support jig, and the first and second sides on both the left and right sides of the standing position of the support jig . And the support jig is configured so that the two wafers can be laid back-to-back toward the left and right wafer loading sides via a hoisting mechanism, and the support jig is The first wafer positioned on the upper side in the state of being laid down on the wafer loading section is loaded or unloaded with the heat treatment surface facing up, and then the support jig is inverted and laid on the second loading section, 2. A wafer loading method comprising: loading or unloading a second wafer located on the lower side at the position of one wafer loading portion with the heat treatment surface facing upward. In a wafer loading method in a wafer heat treatment apparatus in which a quartz glass wafer support jig in which two wafers are arranged back to back in a wafer support groove can be loaded or unloaded from a reaction vessel,
At the standing position of the support jig, the two wafers are supported back to back so that the heat treatment surface is located outside, and one wafer loading portion is provided on one side of the support jig standing position. The support jig is configured such that the two wafers can be laid back-to-back with the raising / lowering mechanism facing the wafer loading side, and the support jig is laid down on a single wafer loading portion. The first wafer located on the upper side is loaded or unloaded with the heat treatment surface facing upward, and then the support jig is erected and the erected support jig is rotated by 180 ° about the vertical axis , and then again. When loading or unloading the first wafer, the second wafer located on the lower side is loaded or unloaded with the heat treatment surface facing upward. Wafer loading method to.   3. The wafer loading method according to claim 1, wherein the support groove of the support jig located on the heat treatment surface side is configured to expand in a tapered shape toward the wafer insertion end side.

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