KR20180057536A - Substrate treatment apparatus - Google Patents

Abstract

A substrate processing apparatus capable of improving in-plane uniformity of substrate processing.
A substrate processing apparatus according to an embodiment of the present invention includes a processing vessel, a rotation shaft inserted in the opening of the processing vessel so as to be inserted therethrough and extending in the vertical direction, a support portion provided at an upper end of the rotation shaft, A substrate holder for holding a plurality of substrates substantially horizontally at a predetermined interval in a vertical direction, and a substrate holder for holding the substrate holder, the substrate holder holder being rotatable about the rotation axis, And a center-of-gravity position adjusting member for adjusting the center-of-gravity position of the whole body.

Description

[0001] SUBSTRATE TREATMENT APPARATUS [0002]

The present invention relates to a substrate processing apparatus.

BACKGROUND ART Conventionally, a wafer boat, which is rotatably provided around a predetermined rotation axis in a processing vessel and holds a plurality of substrates substantially horizontally at predetermined intervals in the vertical direction, And the heat treatment is carried out by the heat treatment apparatus.

As a wafer boat, for example, a plurality of support columns are provided between a top plate and a bottom plate arranged vertically and opposed to each other, a plurality of grooves are formed at substantially equal intervals on the inner surface of each support column, (See, for example, Patent Document 1). Further, for example, a structure in which a plurality of struts are provided between a top plate and a bottom plate arranged vertically and opposed to each other, a ring member having a flat support surface is provided on a plurality of struts, and a structure for supporting the wafer on the support surface of the ring member (See, for example, Patent Document 2).

Incidentally, in such a wafer boat, the support is disposed on the side opposite to the side where the wafer is inserted, and the support is not disposed on the side where the wafer is inserted. This is to prevent the wafer and the support from interfering with each other when inserting the wafer. As a result, the gravity center position of the rotating body including the wafer boat rotating around the rotating shaft is inclined from the center of the rotating shaft to the side where the stanchions are arranged. When the position of the center of gravity of the rotary body is shifted, the wafer boat rotates in a tilted state, so that the inner surface of the processing vessel and the wafer boat are likely to contact each other. Therefore, in order to avoid contact between the inner surface of the processing vessel and the wafer boat, a sufficient gap is provided between the inner surface of the processing vessel and the wafer boat so that they do not come into contact with each other.

Japanese Patent Application Laid-Open No. 2011-222653 Japanese Patent Application Laid-Open No. 2010-062446

However, when the gap between the inner surface of the processing vessel and the wafer boat is increased, the supply amount of the processing gas to the central region of the wafer is lowered, and the in-plane uniformity of the substrate processing is lowered.

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

In order to achieve the above object, a substrate processing apparatus according to one aspect of the present invention is a substrate processing apparatus including a processing vessel, a rotation shaft inserted through the opening of the processing vessel so as to be inserted therethrough and extending in the vertical direction, A substrate holder which is mounted on the support portion and holds the plurality of substrates substantially horizontally at a predetermined interval in the vertical direction; a support portion which is disposed in a predetermined region of the support portion and rotates around the rotation axis; And a center-of-gravity position adjusting member for adjusting the center-of-gravity position of the rotating body including the substrate holding support.

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

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

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Note that, in the present specification and drawings, the same reference numerals are assigned to substantially the same configurations, and redundant description is omitted.

(Substrate processing apparatus)

A substrate processing apparatus according to an embodiment of the present invention will be described. 1 is a schematic vertical 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 having an outer tube 6 having a ceiling and an inner tube 8 concentrically arranged on the inner side of the outer tube 6 and having a ceiling. The lower end of the inner cylinder 8 has a flange projecting outwardly and 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 outwardly and a flange bottom face of the outer cylinder 6 is supported by an annular bottom flange 10 formed of stainless steel or the like. The bottom flange 10 is fixed to the base plate by fastening means such as bolts.

A substantially disc-shaped cap portion 14 made of, for example, stainless steel is attached to the opening of the lower end portion of the bottom flange 10 in a hermetically sealable manner through a seal member 16 such as a O ring. A substantially central portion of the cap portion 14 is inserted with a rotation shaft 20 extending in the up-and-down direction, which is rotatable in an air-tight state by, for example, a magnetic fluid seal 18. A lower end of the rotary shaft 20 is connected to a rotary mechanism 22. A table 24 made of, for example, stainless steel is fixed to the upper end of the rotary shaft 20. [

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

2 is a schematic perspective view showing a configuration of a rotating body of the substrate processing apparatus of FIG. In Fig. 2, for convenience of explanation, the rotating body is cut in the longitudinal direction. Fig. 3 is an enlarged perspective view of the rotary body of Fig. 2 in the vicinity of a heat-insulating container. 4 is an enlarged cross-sectional view of the vicinity of the heat insulating container of the rotating body of Fig. 2;

As shown in Fig. 2, the rotating body has a table 24, a thermal insulation container 26, and a wafer boat 28. Fig. The wafer boat 28 is provided with a plurality of struts 283 between the top plate 281 and the bottom plate 282 arranged vertically opposite to each other and a plurality of grooves 284 formed on the inner surface of each strut 283 , A so-called rudder boat. The wafer W is supported by inserting the peripheral portion into the groove portion 284 of the wafer boat 28. In Fig. 2, the illustration of the wafer W is omitted. Since the wafer W is inserted from the horizontal direction into the wafer boat 28, no strut 283 is disposed on the side of the wafer boat 28 where the wafer W is inserted (-Y direction in Fig. 2).

As shown in Figs. 3 and 4, the heat-insulating container 26 includes a top plate 261 and a substantially disk-shaped bottom plate 262 which are arranged substantially vertically and opposed to each other, and a top plate 262 disposed between the top plate 261 and the bottom plate 262 For example, four pillars 263 (only two pillars are shown in Figs. 3 and 4). Between the top plate 261 and the bottom plate 262 in the middle of the column 263, a plurality of quartz fins 264 in a substantially disk shape are provided substantially horizontally at predetermined intervals in the vertical direction. The heat insulating box 26 accumulates heat from the heater device 48 to be described later to insulate the temperature of the area at the lower end of the wafer boat 28 so as not to excessively lower. 2 to 4, the heat insulating container 26 and the wafer boat 28 are formed as separate members, but they may be integrally formed of quartz. Further, the heat insulating container 26 is not limited to the illustrated form, but may be formed into a cylindrical shape by quartz, for example.

A notch 261a and a notch 264a are formed in the top plate 261 and the pin 264 at positions overlapping each other when viewed from above. In the illustrated example, the notch portion 261a and the notch portion 264a are formed in an arc shape. That is, the radii Ra of the top plate 261 and the fins 264 at the positions where the notched portion 261a and the notched portion 264a are formed are set so that the notches 261a and the notches 264a are not formed Is smaller than the radius R of the top plate 261 and the pin 264 in the position.

A counterweight 90 is provided at a position corresponding to the notched portion 261a and the notched portion 264a and whose shape as seen from the upper surface is an arcuate shape along the periphery of the top plate 261 and the pin 264. [ That is, the counterweight 90 is disposed in a partial area in the circumferential direction of the heat-insulating container 26. The counterweight 90 is provided on the bottom plate 262 and rotates integrally with the bottom plate 262. The counterweight 90 has, for example, a height substantially equal to that of the heat insulating container 26. [ The counterweight 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 (the direction indicated by the arrow A in Figs. 3 and 4). The center of gravity of the rotating body rotating around the rotating shaft 20 can be moved by moving the counterweight 90 in the radial direction of the pin 264. [ For example, by moving the counterweight 90 outward in the radial direction of the pin 264 (the -Y direction in FIGS. 3 and 4), the center of gravity of the rotating body can be moved radially outward . 3 and 4), the center of gravity of the rotating body can be moved in the direction of the center of the pin 264 (for example, by moving the counterweight 90 in the center direction of the pin 264 . The operation of the counter weight 90 is controlled by the control unit 1A described later.

1, the cap portion 14, the table 24, the heat insulating container 26, the wafer boat 28, and the counterweight 90 are held by a lifting mechanism 30, for example, a boat elevator, And is integrally loaded and unloaded in the processing vessel 4. [

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

The injector 60 supplies the process 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, for example, quartz, or may be made of ceramics such as SiC. In addition to quartz and ceramics, the injector 60 can be formed using various materials that are hardly contaminated in the interior of the processing vessel 4.

A plurality of gas supply holes (not shown) for supplying a process gas in parallel with the surface to be processed of the plurality of wafers W accommodated in the processing container 4 are formed in the side surface of the injector 60 61 are provided. That is, the gas supply holes 61 are provided at predetermined intervals in the vertical direction, and the wafer W is heat-treated while supplying the process gas from the gas supply holes 61, thereby performing film formation on the wafer W. Therefore, the gas supply hole 61 is provided on the side close to the wafer W. [

1 shows a case where one gas introduction pipe 82 is provided, but the present invention is not limited to this, and a plurality of gas introduction pipes 82 may be provided in accordance with the number of gas species to be used. The gas introduced into the processing vessel 4 from the gas introduction port 75 is supplied from the gas supply source 80 and the flow rate is controlled by the flow rate control valve 81.

The substrate processing apparatus 1 may also be provided with an activating means for activating the process gas supplied from the gas supply hole 61 by the plasma generated by the 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 and a pressure regulating valve 42 and a vacuum pump 44 sequentially connected in the middle of the exhaust passage 40. The exhaust system 38 can exhaust the gas while adjusting the pressure in the processing vessel 4. [

On the outer peripheral side of the processing container 4, there is provided a heater device 48 for heating the substrate such as the wafer W so as to surround the processing container 4. [

A slit 101 is formed in the side wall of the inner tube 8 on the side opposite to the injector 60 through the wafer boat 28 along the vertical direction so as to exhaust gas in the inner tube 8 . 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, And is exhausted from the gas outlet 36 to the outside of the processing vessel 4. [

The slit 101 is formed such that the position of the upper end is located above the position of the wafer W held by the uppermost one of the wafers W held by the wafer boat 28. The position of the lower end of the slit 101 is formed to be lower than the position of the wafer W held at the lowermost end of the wafer W held by the wafer boat 28. [

1 shows the slit 101, the present invention is not limited to this, and a plurality of openings formed along the vertical direction of the processing container 4 may be provided.

1, the substrate processing apparatus 1 is provided with a control unit 1A such as a computer that controls the operation of each part of the substrate processing apparatus 1. [ The control unit 1A includes a program, a memory, and a data processing unit including a CPU. The program includes instructions (each step) for sending control signals from the control unit 1A to the respective units of the substrate processing apparatus 1 and executing various processes. The program is stored in the medium 1C such as a flexible disk, a compact disk, a hard disk, a magneto-optical disk and a memory card, read by the predetermined reading device into the storage unit 1B, .

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

The control section 1A may also control the operation of the counterweight 90 based on the amount of eccentricity detected by the detecting section 91 for detecting the amount of eccentricity of the rotating body. The detecting unit 91 can detect the amount of eccentricity of the rotating body. For example, it may be a dial gauge.

(Eccentricity of the rotating body)

Next, the eccentricity of the rotating body will be described. 6 is a view for explaining the amount of eccentricity from the axis center of the rotating body. In Fig. 6, the radial direction indicates the amount of eccentricity (mm), and the circumferential direction indicates the angle (degrees). 6, the curve M indicates the amount of eccentricity of the rotating body when the rotating body is rotated, and the curve N is loaded at a position shifted by 10 mm from the axis center of the rotating body 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 applied to a position offset from the axis center of the rotating body, the amount of eccentricity is increased as compared with the case where the load is applied to the center of the rotating body. As the amount of eccentricity of the rotating body increases in this way, the wafer boat 28 is rotated in a tilted state, so that the inner surface of the processing container 4 (inner tube 8) and the wafer boat 28 are easily contacted. Between the inner surface of the processing container 4 (inner tube 8) and the wafer boat 28, there is a gap between the inner surface of the processing container 4 (inner tube 8) and the wafer boat 28, A sufficient gap S (see Fig. 1) is provided so as not to cause the two to contact each other.

However, when the gap S between the inner surface of the processing container 4 (inner tube 8) and the wafer boat 28 is increased, the supply amount of the processing gas to the central region of the wafer W is lowered, do.

The substrate processing apparatus according to the embodiment of the present invention has the counter weight 90 for adjusting the center of gravity position of the rotating body rotating around the rotary shaft 20 as described above. Accordingly, the center-of-gravity position of the rotating body rotating around the rotating shaft 20 can be moved to the center of the rotating shaft 20. This makes it possible to reduce the clearance S between the inner surface of the processing container 4 (inner tube 8) and the wafer boat 28 because the rotating body rotates without being eccentric. As a result, the supply amount of the processing gas to the central region of the wafer W can be increased, and the in-plane uniformity of the substrate processing can be improved.

The distance between the inner surface of the processing container 4 (inner tube 8) and the wafer boat 28 is substantially constant at any position in the height direction of the wafer boat 28 because the rotating body rotates without being eccentric . As a result, the interplanar uniformity is improved. In addition, it is possible to shorten the teaching time of the mobile mounting mechanism for adjusting the moving-placing position of the wafer W in the horizontal direction, thereby reducing the number of steps at the time of starting the apparatus. Further, since the load applied to the magnetic fluid seal 18 is reduced, the life of the magnetic fluid seal 18 can be prolonged.

( Example )

In the embodiment, the influence on the in-plane uniformity of the film thickness of the film formed on the surface of the wafer W was evaluated by changing the position of the wafer W held by the wafer boat 28 in the horizontal direction. In the embodiment, a silicon nitride film is 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 is 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 is changed in the horizontal direction. 7 shows a wafer boat 28 for each region of an upper portion (hereinafter referred to as "TOP"), a central portion (hereinafter referred to as "CTR") and a lower portion (hereinafter referred to as "BTM") of a wafer boat 28, 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 W 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 mm, FB = 0 mm

CTR: RT = 0 mm, FB = 0 mm

BTM: RT = 0 mm, FB = 0 mm

· Teaching 1

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

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

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

· Teaching 2

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

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

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

8, the " RT " is a distance at which the moving mounting mechanism for inserting the wafer W into the wafer boat 28 moves in the clockwise direction at the reference position, and the clockwise direction is defined Direction, and the counterclockwise direction is the negative direction. 8, the " FB " is a distance at which the moving mounting mechanism moves in the direction (the + Y direction in FIG. 8) in which the wafer W is inserted from the reference position, and the direction in which the wafer W is inserted is defined Direction, and the direction in which the wafer W is carried out is the negative direction. The reference position is a position at which the wafer W is held before the moving mechanism is taught.

As shown in Fig. 7, in the teaching (1) and the teaching (2), in-plane uniformity of the film thickness of the silicon nitride film formed on the wafer W was improved at every position of TOP, CTR and BTM. From this result, the position of the wafer W held by the wafer boat 28 is moved to the side of the wafer boat 28 where the wafer W is inserted, whereby the in-plane uniformity of the film thickness of the silicon nitride film formed on the surface of the wafer W Can be improved.

It can be considered that the position of the wafer W held by the wafer boat 28 is changed in the horizontal direction by changing the center of gravity position of the rotating body in a pseudo order. Considering this, 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 controlled by adjusting the eccentricity amount of the rotating body. In particular, it is considered that by reducing the 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 improved.

In the above embodiment, the table 24 and the heat-insulating container 26 are examples of the supporting portions. The wafer boat 28 is an example of a substrate holder. The injector 60 is an example of the gas supply means. The counterweight 90 is an example of the center-of-gravity position adjusting member.

Although the embodiments for carrying out the present invention have been described above, the present invention is not limited to the contents of the present invention, and various modifications and improvements are possible within the scope of the present invention.

In the above embodiment, a plurality of support columns are provided between the top plate and the bottom plate which are vertically opposed to each other, a plurality of grooves are formed on the inner surface of each support column, and the periphery of the wafer W is inserted into the groove, The so-called rudder boat has been described as an example, but the present invention is not limited thereto. For example, a plurality of pillars are provided between a top plate and a bottom plate arranged so as to face each other, and a plurality of pillars are provided with a ring member having a flat support surface. , The present invention can be applied to a so-called ring boat.

1: substrate processing apparatus
1A:
4: Processing vessel
8: My heart
26: Insulation
28: wafer boat
60: injector
90: Counterweight
W: Wafer

Claims (12)

A processing vessel,
A rotation shaft which is inserted through the opening of the processing container so as to be inserted therethrough and which extends in the vertical direction,
A support portion provided at an upper end of the rotary shaft,
A substrate holder which is mounted on the support portion and holds the plurality of substrates substantially horizontally at a predetermined interval in the vertical direction,
A center-of-gravity position adjusting member for adjusting a center-of-gravity position of the rotating body including the support portion and the substrate holding support portion, which is disposed in a predetermined region of the support portion and rotates about the rotation axis,
. The apparatus according to claim 1, wherein the predetermined region is a region of a part in the circumferential direction of the support portion,
/ RTI > 3. The apparatus according to claim 2, wherein the center-of-gravity position adjusting member has an arc-shaped shape as viewed from an upper surface thereof,
/ RTI > The heat exchanger according to any one of claims 1 to 3, wherein the support portion comprises a top plate and a bottom plate arranged to face each other in the vertical direction, and a plurality of quartz fins provided between the top plate and the bottom plate,
Wherein the center-of-gravity position adjusting member is disposed on the bottom plate,
/ RTI > 5. The apparatus according to claim 4, wherein the center-of-gravity position adjustment member is movable in a radial direction of the substrate,
/ RTI > 6. The apparatus according to claim 5, further comprising a control unit for controlling an operation of the center-of-gravity position adjusting member
/ RTI > 7. The apparatus according to claim 6, wherein the control unit controls the operation of the center-of-gravity position adjusting member based on the number of the substrates held by the substrate holding member,
/ RTI > The apparatus according to claim 6, wherein the control unit controls the operation of the center-of-gravity position adjusting member based on the eccentric amount of the rotating body,
/ RTI > 4. The apparatus according to any one of claims 1 to 3, wherein the center-of-gravity position adjustment member is formed of quartz,
/ RTI > 4. The plasma processing apparatus according to any one of claims 1 to 3, further comprising gas supply means for supplying a process gas in parallel with a surface to be processed of the plurality of substrates
/ RTI > 4. The apparatus according to any one of claims 1 to 3, wherein the substrate holder is a rudder boat,
/ RTI > 4. The apparatus according to any one of claims 1 to 3, wherein the substrate holder is a ring boat,
/ RTI >

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