KR102205381B1 - Substrate treatment apparatus - Google Patents

Abstract

A substrate processing apparatus capable of improving the in-plane uniformity of substrate processing is provided.
The substrate processing apparatus of one embodiment is mounted on a processing container, a rotation shaft extending in an up-down direction, and a support provided at an upper end of the rotation shaft, and on the support part; A circuit comprising a substrate holding tool for holding a plurality of substrates at predetermined intervals in the vertical direction and approximately horizontally, and the support unit and the substrate holding unit disposed in a predetermined region of the support unit and rotated around the rotation axis It has a center of gravity positioning member that adjusts the position of the center of gravity of the whole.

Description

Substrate processing apparatus {SUBSTRATE TREATMENT APPARATUS}

The present invention relates to a substrate processing apparatus.

Conventionally, using a wafer boat that is rotatably installed around a predetermined rotation axis in a processing container and holds a plurality of substrates substantially horizontally with predetermined intervals in the vertical direction, collectively (batch) a plurality of substrates. A vertical heat treatment apparatus that performs furnace heat treatment is known.

As a wafer boat, for example, a plurality of struts are provided between a top plate and a bottom plate arranged vertically opposite to each other, a plurality of grooves are formed at substantially equal intervals on the inner surface of each of the struts, and the peripheral edge of the wafer is inserted into the groove to be supported. The resulting structure is known (see, for example, Patent Document 1). In addition, for example, a structure in which a plurality of posts are provided between the top plate and the bottom plate arranged vertically opposite to each other, a ring member having a flat support surface is installed on the plurality of posts, and the wafer is supported on the support surface of the ring member. It is known (see, for example, Patent Document 2).

By the way, in such a wafer boat, the support|pillar is arrange|positioned on the side opposite to the side where a wafer is inserted, and the support|pillar is not arrange|positioned at the side where a wafer is inserted. This is to prevent interference between the wafer and the posts when inserting the wafer. For this reason, the position of the center of gravity of the rotating body including the wafer boat rotating around the rotating shaft is inclined from the center of the rotating shaft toward the side where the posts are arranged. If the position of the center of gravity of the rotating body is skewed, the wafer boat rotates in a tilted state, so that the inner surface of the processing container and the wafer boat come into contact with each other. Therefore, in order to avoid contact between the inner surface of the processing container and the wafer boat, a sufficient gap is provided between the inner surface of the processing container and the wafer boat so that they do not come into contact with each other.

Japanese Patent Publication No. 2011-222653 Japanese Patent Publication No. 2010-062446

However, as the gap between the inner surface of the processing container and the wafer boat increases, the amount of processing gas supplied to the central region of the wafer decreases, and the in-plane uniformity of the substrate processing decreases.

Accordingly, an object of the present invention is to provide a substrate processing apparatus capable of improving the in-plane uniformity of substrate processing.

In order to achieve the above object, a substrate processing apparatus according to one embodiment of the present invention includes a processing container, a rotation shaft extending in a vertical direction, and a rotation shaft extending in a vertical direction, and a rotation shaft installed at an upper end of the rotation shaft. A support portion, a substrate holding device that is mounted on the support portion and holds a plurality of substrates substantially horizontally with predetermined intervals in the vertical direction; the support portion disposed in a predetermined region of the support portion and rotating around the rotation axis; and It has a center of gravity position adjustment member for adjusting the position of the center of gravity of the rotating body including the substrate holding device.

According to the disclosed substrate processing apparatus, in-plane uniformity of substrate processing can be improved.

1 is a schematic longitudinal sectional view of a substrate processing apparatus according to an embodiment of the present invention.
Fig. 2 is a schematic perspective view showing the configuration of a rotating body of the substrate processing apparatus of Fig. 1;
Figure 3 is an enlarged perspective view of the vicinity of the thermal insulation box of the rotating body of Figure 2;
4 is an enlarged cross-sectional view of the rotating body of FIG. 2 in the vicinity of the thermal insulation container.
Fig. 5 is a table showing the relationship between the number of wafers held by the wafer boat and the position of the counter weight.
Fig. 6 is a diagram explaining the amount of eccentricity from the center of the axis of the rotating body.
7 is a diagram showing a relationship between a wafer position and the in-plane uniformity of a silicon nitride film formed on the wafer.
Fig. 8 is a diagram explaining the position of a wafer held by a wafer boat.

Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings. In addition, in the present specification and drawings, for substantially the same configurations, duplicate descriptions are omitted by denoting the same numbers.

(Substrate processing device)

A substrate processing apparatus according to an embodiment of the present invention will be described. 1 is a schematic longitudinal sectional view of a substrate processing apparatus according to an embodiment of the present invention.

As shown in FIG. 1, the substrate processing apparatus 1 has a substantially cylindrical processing container 4 whose longitudinal direction is a vertical direction. The processing container 4 has a double-pipe structure including an outer cylinder 6 having a ceiling and an inner cylinder 8 having a ceiling, which is concentrically disposed inside the outer cylinder 6. The lower end of the inner cylinder 8 has a flange protruding outward, and is fixed to the inner wall of the outer cylinder 6 by welding or the like. The lower end of the outer cylinder 6 has a flange protruding outward, and the lower surface of the flange of the outer cylinder 6 is supported by an annular bottom flange 10 made of stainless steel or the like. The bottom flange 10 is fixed to the base plate by fixing means such as bolts.

To the opening of the lower end of the bottom flange 10, a substantially disk-shaped cap 14 made of, for example, stainless steel is attached to be hermetically sealed through a sealing member 16 such as a ring or the like. In addition, a rotation shaft 20 extending in the vertical direction, which can be rotated in an airtight state by a magnetic fluid seal 18, is inserted into the substantially central portion of the cap portion 14, for example. The lower end of the rotary shaft 20 is connected to the rotary mechanism 22, and a table 24 made of, for example, stainless steel is fixed to the upper end of the rotary shaft 20.

On the table 24, a thermal insulation tube 26 made of quartz is provided, for example. Further, on the thermal insulation tube 26, a wafer boat 28 made of quartz, for example, is mounted. The wafer boat 28 holds a plurality of wafers W in the processing container 4 substantially horizontally at predetermined intervals in the vertical direction. In the wafer boat 28, substrates such as 50 to 150 wafers W, for example, are accommodated in a shelf shape at predetermined intervals, for example, about 10 mm. The table 24, the thermal insulation container 26, and the wafer boat 28 constitute a rotating body that rotates around the rotating shaft 20.

FIG. 2 is a schematic perspective view showing a configuration of a rotating body of the substrate processing apparatus of FIG. 1. In Fig. 2, for convenience of explanation, a state in which the rotating body is cut in the vertical direction is shown. Fig. 3 is an enlarged perspective view of the rotating body of Fig. 2 in the vicinity of the thermal insulation container. Fig. 4 is an enlarged cross-sectional view of the rotating body of Fig. 2 in the vicinity of the thermal insulation container.

As shown in FIG. 2, the rotating body has a table 24, a heat insulating tube 26, and a wafer boat 28. The wafer boat 28 is provided with a plurality of posts 283 between the top plate 281 and the bottom plate 282 arranged vertically facing each other, and a plurality of grooves 284 are formed on the inner surface of each post 283 , The so-called rudder boat. The wafer W is supported by inserting a peripheral edge portion into the groove portion 284 of the wafer boat 28. In addition, in FIG. 2, the illustration of the wafer W is omitted. Since the wafer W is inserted in the wafer boat 28 from the horizontal direction, the post 283 is not disposed on the side of the wafer boat 28 where the wafer W is inserted (in the -Y direction in FIG. 2 ).

As shown in FIGS. 3 and 4, the thermal insulation container 26 is disposed between the substantially disk-shaped top plate 261 and the substantially disk-shaped bottom plate 262 and the top plate 261 and the bottom plate 262 disposed opposite to each other in the vertical direction. It has a plurality of provided, for example, four posts 263 (only two are shown in Figs. 3 and 4). And, between the top plate 261 and the bottom plate 262, which is the middle of the post 263, a plurality of substantially disk-shaped quartz pins 264 are provided substantially horizontally with a predetermined interval in the vertical direction. The thermal insulation tube 26 stores heat from a heater device 48 to be described later to keep the temperature of the lower end region of the wafer boat 28 from excessively lowering. In Figs. 2 to 4, the heat insulating tube 26 and the wafer boat 28 are formed as separate bodies, but both may be integrally formed of quartz. In addition, the thermal insulation tube 26 is not limited to the illustrated form, and may be formed into a cylindrical shape made of quartz, for example.

The top plate 261 and the pin 264 are provided with a notch portion 261a and a notch portion 264a, respectively, at positions overlapping each other when viewed from the top. In the illustrated example, the notch portion 261a and the notch portion 264a are formed in an arc shape. That is, the radius Ra of the top plate 261 and the pin 264 at the position where the notch portion 261a and the notch portion 264a are formed is not formed with the notch portion 261a and the notch portion 264a. It is smaller than the radius R of the top plate 261 and the pin 264 at the position.

At positions corresponding to the notch portion 261a and the notch portion 264a, a counterweight 90 having an arc shape along the periphery of the top plate 261 and the pin 264 is provided as viewed from the top. In other words, the counter weight 90 is disposed in a partial area in the circumferential direction of the thermal insulation container 26. The counter weight 90 is provided on the bottom plate 262 and rotates integrally with the bottom plate 262. The counter weight 90 has substantially the same height as the thermal insulation container 26, for example. The counter weight 90 is made of a heat-resistant material such as quartz.

The counterweight 90 is movable on the bottom plate 262 in the radial direction of the pin 264 (direction indicated by arrow A in FIGS. 3 and 4 ). By moving the counter weight 90 in the radial direction of the pin 264, the position of the center of gravity of the rotating body rotating around the rotation shaft 20 can be moved. For example, by moving the counterweight 90 outward in the radial direction of the pin 264 (in the -Y direction in FIGS. 3 and 4), the position of the center of gravity of the rotating body is moved outward in the radial direction of the pin 264 Can be moved to. In addition, for example, by moving the counterweight 90 in the center direction of the pin 264 (in the +Y direction in FIGS. 3 and 4), the position of the center of gravity of the rotating body can be moved in the center direction of the pin 264. I can. The operation of the counter weight 90 is controlled by the control unit 1A described later.

Referring again to Fig. 1, the cap 14, the table 24, the thermal insulation container 26, the wafer boat 28, and the counter weight 90 are, for example, by a lifting mechanism 30 which is a boat elevator, It is integrated into the processing container 4 and loaded and unloaded.

A gas introduction pipe 82 is provided on the side of the bottom flange 10 for introducing a processing gas into the processing container 4. The gas introduction pipe 82 is connected to the gas introduction port 75 by fixing means such as a joint 83. A through hole is formed in the flange of the outer cylinder 6 at a position corresponding to the gas introduction port 75. While the horizontal portion of the injector 60 is inserted into the through hole from the inside of the processing container 4, the gas introduction pipe 82 and the injector 60 are connected and fixed by a joint 83.

The injector 60 supplies the processing gas supplied to the gas introduction port 75 to the wafer W via the gas introduction pipe 82. The injector 60 may be made of quartz, for example, or may be made of ceramics such as SiC. In addition, the injector 60 can be constructed using a variety of materials in which the interior of the processing container 4 is difficult to be contaminated in addition to quartz and ceramics.

The upper end of the injector 60 is sealed, and at the side of the injector 60, a plurality of gas supply holes for supplying processing gas in parallel to the processing target surfaces of the plurality of wafers W accommodated in the processing container 4 ( 61) is provided. That is, the gas supply holes 61 are provided at predetermined intervals in the vertical direction, the wafer W is heat-treated while supplying the processing gas from the gas supply holes 61, and film formation is performed on the wafer W. Therefore, the gas supply hole 61 is provided on the side close to the wafer W.

In addition, although FIG. 1 shows a case in which one gas introduction pipe 82 is provided, the present invention is not limited thereto, and a plurality of gas introduction pipes 82 may be provided depending on the number of gas types used and the like. Further, the gas introduced into the processing container 4 from the gas introduction port 75 is supplied from the gas supply source 80, and the flow rate is controlled by the flow control valve 81.

Further, the substrate processing apparatus 1 may be provided with an activating means for activating the processing gas supplied from the gas supply hole 61 by plasma generated by high frequency power.

A gas outlet 36 is provided in the lower portion of the outer cylinder 6, and an exhaust system 38 is connected to the gas outlet 36. The exhaust system 38 includes an exhaust passage 40 connected to the gas outlet 36, a pressure regulating valve 42 and a vacuum pump 44 sequentially connected in the middle of the exhaust passage 40. The gas can be exhausted while adjusting the pressure in the processing container 4 by the exhaust system 38.

On the outer circumferential side of the processing container 4, a heater device 48 that surrounds the processing container 4 and heats a substrate such as a wafer W is provided.

In addition, a slit 101 is formed along a vertical direction on the side wall of the inner cylinder 8 on the side opposite to the injector 60 through the wafer boat 28, so that the gas in the inner cylinder 8 can be exhausted. Has been. That is, the processing gas supplied from the gas supply hole 61 of the injector 60 toward the wafer W flows from the inner cylinder 8 to the space between the inner cylinder 8 and the outer cylinder 6 through the slit 101, It is exhausted from the gas outlet 36 to the outside of the processing container 4.

The slit 101 is formed so that the position of the upper end is higher than the position of the wafer W held at the uppermost end of the wafers W held by the wafer boat 28. Further, the slit 101 is formed so that the lower end position is lower than the position of the lowermost wafer W held by the wafer boat 28.

In addition, although the slit 101 is shown in FIG. 1, the slit 101 is not limited to this, and a plurality of openings formed along the vertical direction of the processing container 4 may be used.

In addition, as shown in FIG. 1, the substrate processing apparatus 1 is provided with a control unit 1A made of, for example, a computer that controls the operation of each unit of the substrate processing apparatus 1. The control unit 1A includes a program, a memory, a data processing unit composed of a CPU, and the like. In the program, a command (each step) is incorporated to send a control signal from the control unit 1A to each unit of the substrate processing apparatus 1 and execute various processes. The program is stored in a medium 1C such as, for example, a flexible disk, a compact disk, a hard disk, a magneto-optical disk, and a memory card, and is read into the storage unit 1B by a predetermined reading device, and the control unit 1A It is installed in.

Further, the control unit 1A controls the operation of the counter weight 90 in the radial direction of the wafer W. The control unit 1A may control the operation of the counter weight 90 based on, for example, the number of wafers W held by the wafer boat 28. 5 is a table showing the relationship between the number of wafers held by the wafer boat and the position of the counter weight. The control unit 1A determines the number of wafers W held by the wafer boat 28, the number of wafers W held by the wafer boat 28 stored in the storage unit 1B in advance, and the counter weight 90. Based on the positional relationship (see Fig. 5), the operation of the counter weight 90 is controlled.

Further, the control unit 1A may control the operation of the counter weight 90 based on the amount of eccentricity detected by the detection unit 91 that detects the amount of eccentricity of the rotating body. The detection unit 91 just needs to be able to detect the amount of eccentricity of the rotating body, and may be, for example, a dial gauge.

(Eccentricity of the rotating body)

Next, the amount of eccentricity of the rotating body will be described. 6 is a diagram illustrating the amount of eccentricity from the center of the axis of the rotating body. In Fig. 6, the radial direction represents the amount of eccentricity (mm), and the circumferential direction represents the angle (degree). In addition, in Fig. 6, the curve M is a state loaded on the axis of the rotating body, and represents the eccentricity of the rotating body when the rotating body is rotated, and the curve N is loaded at a position 10 mm inclined from the axis of the rotating body. State, and shows the amount of eccentricity of the rotating body when the rotating body is rotated.

As shown in Fig. 6, when the load is biased from the axial center of the rotating body, the amount of eccentricity increases as compared with the case of the load on the axial center of the rotating body. When the amount of eccentricity of the rotating body increases in this way, since the wafer boat 28 rotates in an inclined state, the inner surface of the processing container 4 (inner cylinder 8) and the wafer boat 28 become easier to contact. Therefore, in order to avoid contact between the inner surface of the processing vessel 4 (inner cylinder 8) and the wafer boat 28, between the inner surface of the processing vessel 4 (inner cylinder 8) and the wafer boat 28, A sufficient gap S (refer to FIG. 1) is provided so that both do not contact.

However, when the gap S between the inner surface of the processing vessel 4 (inner cylinder 8) and the wafer boat 28 increases, the amount of processing gas supplied to the central region of the wafer W decreases, and the in-plane uniformity of the substrate processing decreases. do.

As described above, the substrate processing apparatus according to the embodiment of the present invention has a counter weight 90 for adjusting the position of the center of gravity of the rotating body rotating around the rotating shaft 20. Accordingly, the position of the center of gravity of the rotating body rotating around the rotating shaft 20 can be moved to the center of the rotating shaft 20. For this reason, since the rotating body rotates almost without eccentricity, the gap S between the inner surface of the processing container 4 (inner cylinder 8) and the wafer boat 28 can be made small. As a result, the amount of processing gas supplied to the central region of the wafer W can be increased, and the in-plane uniformity of the substrate processing is improved.

In addition, since the rotating body rotates without being almost eccentric, the distance between the inner surface of the processing container 4 (inner cylinder 8) and the wafer boat 28 becomes substantially constant at any position in the height direction of the wafer boat 28. . As a result, the inter-plane uniformity is improved. Further, since the teaching time of the moving mounting mechanism for adjusting the moving mounting position of the wafer W in the horizontal direction can be shortened, the number of steps at the time of starting the device can be reduced. Further, since the load applied to the magnetic fluid seal 18 is small, the life of the magnetic fluid seal 18 can be lengthened.

( Example )

In the examples, by changing the position of the wafer W held by the wafer boat 28 in the horizontal direction, the effect on the in-plane uniformity of the film thickness of the film formed on the surface of the wafer W was evaluated. Further, in Examples, a silicon nitride film was formed on the surface of the wafer W by an atomic layer deposition (ALD) method using plasma, and the in-plane uniformity of the film thickness was measured.

7 shows the evaluation results of the in-plane uniformity of the film thickness of the silicon nitride film formed on the surface of the wafer W when the position of the wafer W held by the wafer boat 28 in the horizontal direction is changed. In FIG. 7, for each area of the upper portion (hereinafter referred to as “TOP”), the central portion (hereinafter referred to as “CTR”) and the lower portion (hereinafter referred to as “BTM”) of the wafer boat 28, the wafer boat 28 The in-plane uniformity of the film thickness of the silicon nitride film formed on the surface of the wafer W when the position of the wafer W held in the horizontal direction is changed.

The position of the wafer W held by the wafer boat 28 in the horizontal direction is as follows.

·reference

TOP: RT=0㎜, FB=0㎜

CTR: RT=0㎜, FB=0㎜

BTM: RT=0㎜, FB=0㎜

·Teaching 1

TOP: RT=-0.15㎜, FB=-1.0㎜

CTR: RT=-0.10mm, FB=-1.0mm

BTM: RT=-0.15mm, FB=-1.0mm

·Teaching 2

TOP: RT=-0.15㎜, FB=-1.0㎜

CTR: RT=-0.25mm, FB=-1.0mm

BTM: RT=-0.10mm, FB=-1.0mm

In addition, "RT" is the distance that the moving mounting mechanism for inserting the wafer W into the wafer boat 28 moves in a clockwise rotation direction from the reference position, as shown in FIG. 8, and the clockwise direction is defined. Direction, counterclockwise direction is negative direction. In addition, "FB" is a distance that the moving mounting mechanism moves in the direction in which the wafer W is inserted (+Y direction in FIG. 8) from the reference position as shown in FIG. 8, and the direction in which the wafer W is inserted is defined. The direction and the direction in which the wafer W is taken out are negative directions. The reference position is a position where the wafer W is held before teaching is performed on the moving mounting mechanism.

As shown in Fig. 7, in teaching (1) and teaching (2), the in-plane uniformity of the film thickness of the silicon nitride film formed on the wafer W was improved at any position of TOP, CTR, and BTM compared to the reference. From this result, by moving the position of the wafer W held by the wafer boat 28 to the side where the wafer W of the wafer boat 28 is inserted, the in-plane uniformity of the film thickness of the silicon nitride film formed on the surface of the wafer W Was found to be able to improve.

In addition, it can be considered that changing the position of the wafer W held by the wafer boat 28 in the horizontal direction is artificially changing the position of the center of gravity of the rotating body to adjust the amount of eccentricity. Taking this into consideration, it is considered that by adjusting the amount of eccentricity of the rotating body, the in-plane uniformity of the film thickness of the silicon nitride film formed on the surface of the wafer W can be controlled. In particular, by reducing the amount of eccentricity of the rotating body, it is considered that the in-plane uniformity of the film thickness of the silicon nitride film formed on the surface of the wafer W can be improved.

In addition, in the above-described embodiment, the table 24 and the thermal insulation container 26 are examples of the support. The wafer boat 28 is an example of a substrate holding tool. The injector 60 is an example of a gas supply means. The counter weight 90 is an example of a center of gravity position adjustment member.

As described above, the embodiments for carrying out the present invention have been described, but the above contents do not limit the contents of the invention, and various modifications and improvements are possible within the scope of the present invention.

In the above-described embodiment, a plurality of posts are provided between the top plate and the bottom plate arranged upward and downward, and a plurality of grooves are formed on the inner surface of each of the posts, and the peripheral edge of the wafer W is inserted and supported in the grooves. Although the so-called rudder boat has been described as an example, the present invention is not limited thereto. For example, a plurality of struts are provided between the top plate and the bottom plate arranged vertically opposite to each other, and a ring member having a flat support surface is provided on the plurality of struts to support the wafer W on the supporting surface of the ring member. , The present invention can also be applied to a so-called ring boat.

1: substrate processing device
1A: control unit
4: processing vessel
8: inner barrel
26: thermos
28: wafer boat
60: injector
90: counter weight
W: wafer

Claims (12)

A processing container,
A rotation shaft that is installed to be inserted into the opening of the processing container and extends in the vertical direction;
A support installed on the upper end of the rotation shaft
A substrate holding tool mounted on the support and horizontally holding a plurality of substrates at predetermined intervals in the vertical direction;
A center-of-gravity position adjusting member disposed in a predetermined area of the support portion and rotating around the rotation axis, adjusting the position of the center of gravity of the rotating body including the support portion and the substrate holding device
Have,
The support portion has a thermal insulation container including a top plate and a bottom plate arranged opposite to each other in the vertical direction, and a plurality of quartz pins provided between the top plate and the bottom plate,
The center of gravity position adjustment member is disposed on the bottom plate,
Substrate processing apparatus. The method according to claim 1, wherein the predetermined region is a partial region in a circumferential direction of the support part,
Substrate processing apparatus. The method according to claim 2, wherein the center of gravity position adjustment member has an arc shape along the periphery of the support part as viewed from an upper surface.
Substrate processing apparatus. The method according to any one of claims 1 to 3, wherein the center of gravity position adjustment member is movable in the radial direction of the substrate,
Substrate processing apparatus. According to claim 4, Having a control unit for controlling the operation of the center of gravity position adjustment member
Substrate processing apparatus. The method according to claim 5, wherein the control unit controls an operation of the center of gravity position adjusting member based on the number of sheets of the substrate held by the substrate holder,
Substrate processing apparatus. The method of claim 5, wherein the control unit controls the operation of the center of gravity position adjustment member based on the amount of eccentricity of the rotating body,
Substrate processing apparatus. The method according to any one of claims 1 to 3, wherein the center of gravity position adjustment member is formed of quartz,
Substrate processing apparatus. The method according to any one of claims 1 to 3, comprising a gas supply means for supplying a processing gas in parallel to the processing target surfaces of the plurality of substrates.
Substrate processing apparatus. The method according to any one of claims 1 to 3, wherein the substrate holding tool is a rudder boat,
Substrate processing apparatus. The method according to any one of claims 1 to 3, wherein the substrate holding tool is a ring boat,
Substrate processing apparatus. delete

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