JP2022186347A - Substrate processing apparatus and substrate processing method - Google Patents

Abstract

To prevent the occurrence of abnormalities in processing by storing substrates in the recesses in the rotary table.SOLUTION: An apparatus is configured so that a rotary table in the processing container, a recess on the top surface of the rotary table to contain substrates as they revolve with the rotation of the rotary table, a processing gas supply unit above the rotary table to process each of the substrates by supplying processing gas in a portion of the direction of rotation of the rotary table, and a front exhaust channel whose upstream end opens to the side wall of the recess and whose downstream end opens to the outer circumferential side or top surface of the rotary table for exhausting the inside of the recess, and a rear exhaust channel provided in the processing container and connected to an exhaust mechanism for exhausting the processing gas from the downstream end of the front exhaust channel, are provided.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a substrate processing apparatus and a substrate processing method.

2. Description of the Related Art In a manufacturing process of a semiconductor device, various kinds of processing are performed on a semiconductor wafer (hereinafter referred to as a wafer) which is a substrate. Patent Document 1 discloses a substrate processing apparatus which includes a rotary table having a plurality of concave portions for storing wafers arranged in a rotating direction, a nozzle for supplying raw material gas, and a nozzle for supplying reaction gas. is described, and ALD is performed in the film forming apparatus.

JP 2015-159248 A

The present disclosure provides a technology capable of preventing the occurrence of abnormalities in processing when substrates are stored in recesses of a rotary table and processed.

The substrate processing apparatus of the present disclosure is
a rotary table provided in the processing container;
a concave portion provided on the upper surface of the rotary table for accommodating the substrate so as to revolve with the rotation of the rotary table;
a processing gas supply unit provided above the rotary table for supplying the processing gas to a portion of the rotary table in the rotation direction to process the substrates;
a pre-stage exhaust passage whose upstream end opens to the side wall of the recess and whose downstream end opens to the outer peripheral side surface or the upper surface of the rotary table for exhausting the interior of the recess;
a post-exhaust passage provided in the processing vessel and connected to an exhaust mechanism for exhausting the processing gas from a downstream end of the pre-exhaust passage.

Advantageous Effects of Invention According to the present disclosure, it is possible to prevent the occurrence of abnormalities in processing when a substrate is stored in a concave portion of a turntable and processed.

1 is a longitudinal side view of a film forming apparatus according to a first embodiment of a substrate processing apparatus of the present disclosure; FIG. It is a cross-sectional plan view of the said film-forming apparatus. It is a cross-sectional plan view of the said film-forming apparatus. It is a top view which shows the rotary table provided in the said film-forming apparatus. It is a vertical side view for demonstrating the gas flow of the said film-forming apparatus. It is a vertical side view for demonstrating the gas flow of the said film-forming apparatus. It is a top view for demonstrating the gas flow of the said film-forming apparatus. It is a top view for showing operation of the film-forming apparatus. It is a top view for showing operation of the film-forming apparatus. It is a top view for showing operation of the film-forming apparatus. It is a top view for showing operation of the film-forming apparatus. It is a top view for showing operation of the film-forming apparatus. It is a top view for showing operation of the film-forming apparatus. It is a top view for showing operation of the film-forming apparatus. It is a top view for showing operation of the film-forming apparatus. FIG. 4 is a vertical cross-sectional side view of a film forming apparatus according to a second embodiment of the substrate processing apparatus of the present disclosure; It is a vertical side view of the said film-forming apparatus. 3 is a plan view of a rotary table of the film forming apparatus; FIG. It is a top view of the ceiling part in the said film-forming apparatus.

[First Embodiment]
A film forming apparatus 1 according to a first embodiment of the substrate processing apparatus of the present disclosure will be described with reference to the longitudinal side view of FIG. 1 and the horizontal plan view of FIG. The film forming apparatus 1 is configured to be able to collectively form films on six wafers W by ALD (Atomic Layer Deposition). The film forming apparatus 1 includes a vacuum vessel (processing vessel) 11 having a substantially circular planar shape, a flat circular vacuum vessel 11 , and a disk-shaped horizontal rotary table 2 provided in the vacuum vessel 11 . , is equipped with The vacuum container 11 is composed of a top plate 12 forming the ceiling of the container, and a container body 13 forming the bottom 18 and side walls 19 of the container. A central portion of the bottom portion 18 is open, and the opening is closed by a cover 14 from below.

A disk-shaped horizontal rotary table 2 is provided in the vacuum vessel 11 . The center P of the rotary table 2 coincides with the center of the vacuum vessel 11 in plan view, and the outer peripheral side surface of the rotary table 2 is close to the side wall of the vacuum vessel 11 . A center portion of the lower side of the rotary table 2 is connected to a rotary mechanism 15 surrounded by a cover 14 . The rotating mechanism 15 rotates the rotating table 2 around the vertical axis with the center P as the center of rotation.

On the upper surface (surface) of the turntable 2, six circular recesses 21 are formed at equal intervals along the direction of rotation (=the circumferential direction of the turntable 2) for respectively accommodating the wafers W. 2 are equidistant from the center. By being arranged in this way, the concave portion 21 revolves around the center P when the rotary table 2 rotates. The diameter of the recess 21 is slightly larger than the diameter of the wafer W. As shown in FIG. A circular pedestal 22 is provided on the bottom surface of each recess 21 , and the wafer W is placed horizontally on the upper surface of the pedestal 22 . The diameter of the upper surface of the pedestal 22 is slightly larger than the diameter of the wafer W, and a gap is formed between the peripheral portion of the wafer W placed on the pedestal 22 and the bottom surface of the recess 21 . The formation of this gap prevents the wafer W from warping when placed on the rotary table 2 and the peripheral edge of the wafer W from sliding against the concave portion 21 .

A side wall 19 of the vacuum container 11 is formed with a transfer opening (not shown) for the wafer W that can be freely opened and closed. An elevating mechanism 16 is provided below the bottom portion 18 of the vacuum vessel 11, and elevates three elevating pins 17 (only two are shown in FIG. 1). Through holes vertically formed in the bottom 18 of the vacuum chamber 11 , the bottom of the recess 21 , and the pedestal 22 , the upper end of the lift pin 17 moves up and down between the upper position of the pedestal 22 and the lower position of the rotary table 2 . Then, the wafer W is transferred to and from the transfer mechanism that has entered the vacuum vessel 11 through the transfer port. The through holes in the bottom of the recess 21 and the through holes in the pedestal 22 are shown as 22A and 2A in FIG.

On the rotary table 2, rod-shaped first processing gas nozzles 31, separation gas nozzles 32, second processing gas nozzles 33, and separation gas nozzles 34 are arranged clockwise in this order. are arranged. These gas nozzles 31 to 34 are provided with discharge holes 35 below and discharge gas along the diameter of the rotary table 2, respectively. The first processing gas nozzle 31, which is a first processing gas supply unit, supplies a raw material gas serving as a film raw material as a first processing gas, and the second processing gas nozzle 33, which is a second processing gas supply unit, supplies a second processing gas. A reaction gas that reacts with the raw material gas is discharged as a processing gas for each. Separation gas nozzles 32 and 34 discharge N ₂ (nitrogen) gas. Reference numeral 31A in the drawing denotes a first processing gas supply source connected to the first processing gas nozzle 31, reference numeral 33A in the drawing denotes a second processing gas supply source connected to the second processing gas nozzle 33, and reference numeral 32A in the drawing. is a source of _N2 gas connected to the separation gas nozzles 32,34.

The top plate 12 of the vacuum container 11 has projecting portions 41 and 42 which are fan-shaped in plan view and are formed so as to project toward the rotary table 2 below. These projecting portions 41 and 42 are formed so as to widen from the center side to the outer peripheral side of the turntable 2, and the projecting portions 41 and 42 are arranged at intervals in the circumferential direction of the turntable 2. there is The separation gas nozzles 32 and 34 are embedded in the lower surfaces of the projecting portions 41 and 42, respectively, and are arranged so as to equally divide the projecting portions 41 and 42 in the circumferential direction in plan view.

Regions below the protrusions 41 and 42 are separation regions D1 and D2 to which N ₂ gas is supplied from the separation gas nozzles 32 and 34 . In the rotation direction of the rotary table 2, of the two regions between the separation regions D1 and D2, the region where the first processing gas nozzles 31 are provided is called the first processing region R1, and the region where the second processing gas nozzles 33 are arranged. Let it be the second processing region R2. Therefore, the first processing area R1 and the second processing area R2 are partial areas on the rotary table 2 in the rotation direction. The separation regions D1 and D2 separate the atmosphere (first processing gas atmosphere) of the first processing region R1 and the atmosphere (second processing gas atmosphere) of the second processing region R2 in the rotation direction of the turntable 2. , is separated by the above N ₂ gas, which is the separation gas.

A vertical flow path 43 is formed on the central portion of the top plate 12 toward the central portion of the rotary table 2 below, and _N2 gas is supplied from the gas supply source 32A. Then, this N ₂ gas passes through a gap (referred to as a central flow path 49) between the annular projecting portion 44 projecting annularly downward from the central portion of the top plate 12 and the central portion of the turntable 2. It flows radially outward of the rotary table 2 . This N ₂ gas is a purge gas that prevents mixing of process gases on the central portion of the rotary table 2 . The lower surface of the annular projecting portion 44 is formed so as to be continuous with the lower surfaces of the projecting portions 41 and 42 forming the separation regions D1 and D2.

The downstream end of a lower gas supply pipe 45 for supplying _N2 gas as a purge gas is connected to the space surrounded by the cover 14, and the upstream end of the lower gas supply pipe 45 is connected to the gas supply source 32A. be done. This purge gas is supplied to the lower side of the turntable 2 from within the cover 14 to prevent the processing gas from flowing from the upper surface to the lower surface of the turntable 2 . An annular space 46 is provided at the bottom of the vacuum container 11 along the rotation direction of the turntable 2 , and a heater 47 is arranged in the annular space 46 . The heater 47 heats the wafer W on the rotary table 2 to a desired temperature.

Next, in order to describe the configuration of the exhaust gas flow path in the film forming apparatus 1, FIG. To describe the outline of this flow path, a flow path is formed in the turntable 2 for exhausting gas from the side wall of the recess 21 toward the outer peripheral side surface of the turntable 2, and the gas is further discharged from the outer peripheral surface to the vacuum chamber. 11 is exhausted through channels formed in the sidewalls. The channel of the side wall of the vacuum vessel 11 is configured to independently exhaust the first processing gas and the second processing gas, that is, to exhaust these gases without being mixed with each other.

A specific configuration of the flow path will be described below. Suction ports 51A and 51B are opened on the left and right sides of the center P of the turntable 2, respectively, in the side walls of each recess 21 on the peripheral end side of the turntable 2. As shown in FIG. Channels 52A and 52B are formed so as to be drawn out from the suction ports 51A and 51B to the peripheral end of the rotary table 2 . Therefore, the suction ports 51A and 51B form the upstream ends of the channels 52A and 52B. The flow paths 52A and 52B are separated from each other, and their downstream sides are formed so as to separate from each other toward the outer peripheral side surface of the rotary table 2 . Of the flow paths 52A and 52B, the flow path on the downstream side in the rotation direction of the rotary table 2 that rotates clockwise in plan view is indicated as 52A in the drawing.

A downstream end of the flow path 52A and a downstream end of the flow path 52B are opened as an opening 53A and an opening 53B on the outer peripheral side surface of the rotary table 2, respectively. The channels 52A and 52B are flat, and the suction ports 51A and 51B and the openings 53A and 53B are formed in slits extending in the horizontal direction. Further, the flow paths 52A and 52B are formed so as to be symmetrical to each other with respect to a straight line connecting the center P of the rotary table 2 and the center of the recess 21 . As seen from the center P, the flow paths 52A and 52B provided on the right side and the left side respectively form the front exhaust passages, and the openings 53A and 53B form the downstream ends of the front exhaust passages.

Flow paths 61A and 61B are formed in the side wall 19 of the vacuum container 11 and are formed in a circular arc shape in plan view along the rotation direction of the turntable 2 and extend downward through the side wall 19 . A portion of the lower arc of the flow path 61A is drawn downward to form an exhaust port 62A that opens to the bottom of the vacuum container 11, and an exhaust mechanism 63A is connected to the exhaust port 62A. A part of the lower arc of the flow path 61B is drawn downward to form an exhaust port 62B that opens to the bottom of the vacuum vessel 11, and an exhaust mechanism 63B is connected to the exhaust port 62B. The exhaust mechanisms 63A and 63B each include, for example, a valve and a vacuum pump.

A portion of each of the flow paths 61A and 61B in the height direction is formed so as to be pulled out toward the turntable 2 side, and is opened as side wall suction ports 64A and 64B on the inner peripheral surface of the side wall 19 of the vacuum vessel 11. . Therefore, the side wall suction ports 64A and 64B are formed in the shape of slits formed along the rotation direction of the rotary table 2. As shown in FIG. The side wall suction ports 64A, 64B are formed at a height facing the openings 53A, 53B of the rotary table. Side wall suction port 64A is a first side wall suction port, and side wall suction port 64B is a second side wall suction port. The inside of the vacuum vessel 11 is evacuated through the side wall suction ports 64A and 64B by the exhaust mechanisms 63A and 63B, respectively, so that the inside of the vacuum vessel 11 becomes a vacuum atmosphere with a desired pressure.

Hereinafter, the side wall suction port 64A and the flow path 61A are collectively described as an exhaust path 65A, and the side wall suction port 64B and the flow path 61B are collectively described as an exhaust path 65B. The exhaust passages 65A and 65B are rear-stage exhaust passages, the exhaust passage 65A corresponds to a first rear-stage exhaust passage, and the exhaust passage 65B corresponds to a second rear-stage exhaust passage. The exhaust paths 65A and 65B are channels independent (partitioned) from each other, and partition walls 66A and 66B, which are partition members, are provided in order to partition the exhaust paths 65A and 65B in the circumferential direction of the vacuum vessel 11. It is More specifically, the partition wall 66A is provided on an extension of a straight line that connects the center P of the rotary table 2 and the circumferential center of the separation area D2, and the partition wall 66B is provided on the line that connects the center P and the separation area D1 in the circumferential direction. It is provided on an extension of a straight line connecting the center.

By being partitioned by the partition walls 66A and 66B as described above, one end and the other end in the lengthwise direction of the exhaust passages 65A and 65B are located near the center of the separation region D1 in the circumferential direction and in the circumferential direction of the separation region D2. Each located near the center. More specifically, the exhaust path 65A faces the first processing region R1 and positions near the first processing region R1 in each of the separation regions D1 and D2. The exhaust path 65B faces the second processing region R2 and positions near the second processing region R2 in each of the separation regions D1 and D2. Therefore, the side wall suction port 64A that constitutes the exhaust path 65A opens only to the first processing region R1 of the first processing region R1 and the second processing region R2, and the first processing gas and the second processing gas are supplied. It is configured to be able to selectively exhaust the first processing gas out of the gases. The side wall suction port 64B forming the exhaust path 65B opens only to the second processing region R2 out of the first processing region R1 and the second processing region R2, and is used for the first processing gas and the second processing gas. Among them, the second processing gas is configured to be selectively exhaustable.

Due to the configuration as described above, the partition walls 66A and 66B are dividing members that divide the annular exhaust passage formed in the side wall 19 of the vacuum vessel 11 along the rotation direction of the rotary table 2 in the rotation direction. be. Hereinafter, in order to show the width relationship between the partition wall 66A and the flow paths 52A and 52B connected to the recess 21 of the rotary table 2, a description will be given with reference to FIG. 4, which is a plan view. However, in this example, the partition walls 66A and 66B are constructed similarly to each other. Therefore, the following description also describes the width relationship between the partition wall 66B and the flow paths 52A and 52B. The width referred to here is the length perpendicular to the radial direction of the rotary table 2 in plan view. The width L1 of the partition wall 66A is smaller than the width L2 of each of the openings 53A and 53B, which are the downstream ends of the flow paths 52A and 52B of the rotary table 2 described above. Also, the width L2 of the partition walls 66A and 66B is smaller than the width (gap) L3 between the openings 53A and 53B connected to the same recess 21 . The advantage of setting each width in such a relationship will be described later.

Now, the reason why the gas is exhausted from the suction ports 51A and 51B provided on the side wall of the recess 21 as described above will be explained. As the rotary table 2 rotates, the recess 21 containing the wafer W repeatedly passes through the first processing region R1, the separation region D1, the second processing region R2, and the separation region D2 in order. Consider a case where the suction ports 51A and 51B are not provided in the recess 21 and the exhaust is not directly performed.

In the film forming apparatus 1, the first processing gas is supplied to the concave portion 21 in the first processing region R1. Most of the first processing gas in the recess 21 is removed when passing through the separation region D1, but remains in a relatively narrow gap between the peripheral edge of the wafer W and the corner of the recess 21. It is conceivable that the recess 21 moves to the second processing region R2. Similarly, the second processing gas supplied in the second processing region R2 remains in the recess 21 without being completely removed in the separation region D2, and the recess 21 moves to the first processing region R1. is also conceivable. In these cases, one of the first processing gas and the second processing gas remaining in the recess 21 reacts with the other gas newly supplied to the recess 21, resulting in wafer An unnecessary film is formed on the W peripheral edge. Due to this, there is a possibility that the in-plane uniformity of the film thickness of the wafer W cannot be sufficiently improved.

In the film forming apparatus 1 , film formation is performed not only on the wafer W but also on the rotary table 2 by supplying the first processing gas and the second processing gas. Therefore, the film formed inside the concave portion 21 slides on the wafer W due to the thermal expansion of the rotary table 2 and the wafer W during the film forming process. , there is a risk that the sliding will break it into particles and stay in the recess 21 . When the lifting pins 17 lift the wafer W to remove it from the recess 21 , there is a risk that the particles will be lifted up and adhere to the surface of the wafer W. FIG. In addition, it is conceivable that the pressure on the back side of the wafer W becomes higher than the pressure on the front side during the film formation process, causing the wafer W to detach from the concave portion 21 .

In order to prevent these problems from occurring, it is conceivable to employ a configuration in which the interior of the recess 21 is evacuated, the retained processing gas and generated particles are removed, and the pressure on the lower surface side of the wafer W is reduced. be done. For the exhaust, a through hole is formed in the bottom of the recess 21, and the gas in the recess 21 is exhausted through the bottom of the rotary table 2 through the through hole.

However, when configured in such a manner, the first processing gas and the second processing gas are respectively supplied from the through-hole of the recess 21 located in the first processing region R1 and the through-hole of the recess 21 located in the second processing region R2. flows below the rotary table 2 and reacts with each other to generate particles, which may adhere to the wafer W. Further, since the lower area of the rotary table 2 is relatively close to the heater 47, the temperature is high. Therefore, it is conceivable that the first processing gas is thermally decomposed, and the decomposition product forms a film on the bottom portion 18 of the vacuum vessel 11 . In that case, it is conceivable that particles may be generated from the film of the decomposition products, or that film formation is performed in areas where film formation should not be performed, resulting in an increase in maintenance work.

In order to prevent the problems described above, the film forming apparatus 1 is provided with suction ports 51A and 51B on the side walls of the recess 21 so that the air is exhausted from the outer periphery of the rotary table 2 toward the side wall 19 of the vacuum vessel 11. ing. In order to prevent the generation of particles due to mixing of the first processing gas and the second processing gas by the time they are exhausted from the vacuum chamber 11, the first processing gas and the second processing gas are used as described above. The gases are individually exhausted to exhaust paths 65A and 65B, respectively.

By the way, as shown in FIG. 1, the film forming apparatus 1 is provided with a control section 10 comprising a computer for controlling the operation of each section of the apparatus. This control unit 10 has a program. The program controls each operation such as the elevation of the lifting pin 17 by the lifting mechanism 16, the number of rotations of the rotary table 2 by the rotating mechanism 15, and the gas supply/cutoff from the gas supply sources 31A, 32A, and 33A to each part of the apparatus. A control signal is sent to each part of the apparatus so that the This program is installed in the computer while being stored in a storage medium such as a hard disk, compact disk, memory card, or DVD.

Next, the operation of the film forming apparatus 1 will be described with reference to longitudinal side views of the apparatus in FIGS. 5 and 6 and schematic cross-sectional plan views of the apparatus in FIGS. 7 to 12. FIG. In this example, a BTBAS (Bistertial Butyl Aminosilane) gas is used as the first processing gas, and an O ₃ gas is used as the second processing gas, and a SiO ₂ film is formed on the wafer W. FIG. In FIG. 7, arrows indicate the flow of each gas supplied onto the turntable 2 . Since the wafers W accommodated in the six recesses 21 are treated in the same manner, one of the six recesses 21 is assumed to be 21A in the following description. The description will focus on the flow paths 52A and 52B connected to the recess 21A. In FIGS. 8 to 12, arrows indicate gas flows only in the flow paths 52A and 52B connected to the recess 21A, and gas flows in the flow paths 52A and 52B connected to the other recesses 21 are omitted.

5 and 6 show the gas flow in the radial direction of the turntable 2. The processing gas supplied onto the turntable 2 is indicated by solid arrows, and the purge gas supplied below the turntable 2 is indicated by solid arrows. The flows are indicated by dotted arrows, respectively. 5 and 6 representatively show the gas flow in the first processing region R1. It is the same. In the separation regions D1 and D2, the radial gas flow is the same as the radial gas flow in the processing regions R1 and R2, except that the _N2 gas flows as the separation gas instead of the processing gas on the turntable 2. It is the same. FIG. 5 is a cross section taken along the line AA' in FIG. 6 is a cross section taken along the line BB' of FIG. 2, showing a cross section along the diameter of the recess 21. FIG.

First, in a state where the turntable 2 is heated by the heater 47, the intermittent rotation of the turntable 2 and the lifting and lowering of the lifting pins 17 work together to successively place the wafers W in the recesses 21. is heated to the desired temperature. On the other hand, the inside of the vacuum container 11 is evacuated from the exhaust paths 65A and 65B by the exhaust mechanisms 63A and 63B, and the vacuum atmosphere at a desired pressure is created. N ₂ gas is supplied from each of the separation gas nozzles 32 and 34 , the central flow path 49 and the lower gas supply pipe 45 .

The N ₂ gas supplied from the separation gas nozzles 32 and 34 spreads in the separation regions D1 and D2 in the circumferential direction and then flows to the outer circumference of the turntable 2 as separation gas. Part of the separated gas that flows toward the outer periphery flows along the upper surface of the rotary table 2 toward the outer periphery, and the other portion enters the recess 21 and is connected to the recess 21. By passing through the paths 52A and 52B, it goes to the perimeter. Then, the separated gas that has flowed toward the outer circumference flows into the exhaust passages 65A and 65B and is removed. Since the exhaust passages 65A and 65B are arranged as described above, the separation gas that has flowed toward the first processing region R1 in the circumferential direction of the separation regions D1 and D2 is exhausted from the exhaust passage 65A and is discharged from the first processing region R1. 2 is removed from the exhaust path 65B. On the other hand, the N ₂ gas supplied to the center portion of the turntable 2 from the central flow path 49 and the N ₂ gas supplied to the center portion below the turntable 2 from the lower side gas supply pipe 45 are each used as a purge gas. It flows to the outer circumference of the rotary table 2 and into the exhaust passages 65A and 65B to be removed. A portion of the purge gas supplied onto the rotary table 2 circulates through the flow paths 52A and 52B and goes to the exhaust paths 65A and 65B, like the separation gas.

For example, the entire recess 21A is located in the separation area D2 as shown in FIG. , exhaust paths 65B and 65A. From this state, the turntable 2 starts to rotate and the concave portion 21A revolves, and the BTBAS gas and the O3 gas are supplied onto the turntable ₂ from the first process gas nozzle 31 and the second process gas nozzle 33, respectively. Some of these BTBAS gas and O ₃ gas flow along the upper surface of the rotary table 2 to the outer circumference of the rotary table 2 and are exhausted, and the other part flows into the recess 21, like the separation gas described above. , through channels 52A and 52B. As described above, the BTBAS gas flows to the exhaust path 65A _, and the O3 gas flows to the exhaust path 65B to be exhausted.

As the rotary table 2 rotates, the downstream side of the recess 21A in the rotation direction enters the first processing region R1, and both the openings 53A and 53B face the exhaust path 65A. Then, the BTBAS gas is supplied to the downstream side of the recess 21A in the rotational direction, flows into the flow path 52A, and is exhausted from the exhaust path 65A (FIG. 9). Further, the rotary table 2 rotates so that the entire concave portion 21A is positioned in the first processing region R1, and the entire surface of the wafer W is adsorbed with the BTBAS gas. The surplus BTBAS gas that has flowed into the recess 21A flows from the flow paths 52A and 52B into the exhaust path 65A (FIG. 10). 5 and 6 show the gas flow around the recess 21A in this state.

As the rotary table 2 continues to rotate, the downstream side of the recess 21A in the rotational direction enters the separation area D1, and the separation gas flowing into the recess 21A flows from the flow path 52A to the exhaust path 65A and is exhausted (FIG. 11). Then, the rotary table 2 is further rotated to position the entire recess 21A in the separation area D1, and the opening 53A faces the exhaust path 65B (FIG. 12). In this state, the separation gas that has flowed into the recess 21A flows toward the exhaust paths 65A and 65B via the flow paths 52A and 52B, respectively. The flow of the separation gas purges the BTBAS gas supplied to the recess 21A in the first processing region R1, and the gas in the recess 21A is replaced with the separation gas from the BTBAS gas.

Subsequently, the downstream side of the recess 21A in the rotational direction enters the second processing region R2, and both the openings 53A and 53B face the exhaust path 65B. Then _, the O ₃ gas is supplied to the downstream side of the recess 21A in the rotational direction, flows into the flow path 52A, and is exhausted from the exhaust path 65B (FIG. 13). Further, the rotary table 2 rotates so that the entire concave portion 21A is positioned in the second processing region R2, and the O ₃ gas is supplied to the entire surface of the wafer W and reacts with the adsorbed BTBAS gas to form a SiO ₂ layer. It is formed. Then, the surplus O ₃ gas that has flowed into the recess 21A flows from the flow paths 52A and 52B into the exhaust path 65B (FIG. 14).

Then, as the rotary table 2 continues to rotate, the downstream side of the recess 21A in the rotational direction enters the separation area D2, and the separation gas flowing into the recess 21A flows from the flow path 52A to the exhaust path 65B and is exhausted (FIG. 15). Then, the rotary table 2 is further rotated so that the entire recess 21A is positioned in the separation area D2, and the opening 53A faces the exhaust path 65A. That is, it returns to the state shown in FIG. In this state, the separation gas that has flowed into the recess 21A flows toward the exhaust paths 65B and 65A through the flow paths 52A and 52B, respectively. Due to the flow of the separation gas, the O ₃ gas supplied to the recess 21A in the second processing region R2 is purged, and the gas in the recess 21A is replaced with the separation gas from the O ₃ gas.

The rotation of the turntable 2 is continued thereafter, and the concave portion 21A repeatedly passes through the first processing region R1, the separation region D1, the second processing region R2, and the separation region D2 in this order. As a result, a SiO ₂ layer is deposited on the wafer W in the recess 21A to form a SiO ₂ film. The wafers W inside the recesses 21 other than the recesses 21A are also processed in the same manner as the wafers W inside the recesses 21A except for the difference in the position where the revolution starts, and the SiO ₂ film is formed. When the film thickness of the SiO ₂ film of each wafer W reaches a desired size, the supply of each gas is stopped, and the wafer W is unloaded from the concave portion 21 by intermittent rotation of the rotary table 2 and elevation of the lifting pins 17 . be.

As described above, in the film forming apparatus 1, the wafer W is accommodated in the concave portion 21 formed on the turntable 2, and the concave portion 21 is repeatedly passed through the first processing region R1 and the second processing region R2. Then, ALD is used to form a film. At this time, the interior of the recess 21 is evacuated from the exhaust paths 65A and 65B formed on the side walls of the vacuum chamber 11 via the channels 52A and 52B that open to the side walls of the recess 21 . By evacuating the inside of the concave portion 21 in this way, the film is formed on the peripheral edge portion of the wafer W due to the remaining processing gas in the concave portion 21, and particles are generated by sliding between the wafer W and the concave portion 21. adhesion to the wafer W and detachment of the wafer W from the concave portion 21 are suppressed. The inside of the recessed portion 21 is exhausted from the suction ports 51A and 51B opened in the side walls of the recessed portion 21 . Therefore, compared to the case of exhausting from the bottom of the recess 21 to the lower part of the turntable 2, particles are generated due to the reaction between the first process gas and the second process gas below the turntable 2, and the first process gas is discharged. Film formation due to thermal decomposition of the film and generation of particles from the film generated by the thermal decomposition are prevented.

Further, by evacuating the recess 21, even if the depth of the recess 21 is relatively large, the first processing gas and the second processing gas are prevented from remaining. In some cases, the wafer W is warped to a relatively large extent by heat immediately after it is placed on the rotary table 2, and the warpage is alleviated as time elapses. If the wafer W protrudes from the concave portion 21 due to warping, the wafer W may be separated from the concave portion 21 by the air flow exposed during the rotation of the rotary table 2. This will delay the start of processing. However, by making the depth of the concave portion 21 relatively large, the wafer W can be accommodated in the concave portion 21 even if the warp is relatively large. Therefore, according to the film forming apparatus 1 which exhausts the concave portion 21, there is also an advantage that the processing efficiency of the wafer W can be improved.

Further, when exhausting from the side wall of the concave portion 21 of the rotary table 2 as described above, the side wall 19 of the vacuum chamber 11 forms exhaust paths 65A and 65B that are separated from each other by the partition walls 66A and 66B. Of the first processing region R1 and the second processing region R2, the exhaust passage 65A faces only the first processing region R1, and the exhaust passage 65B faces the first processing region R1 and the second processing region R2. facing only the second processing region R2. Via the channels 52A and 52B connected to the recess 21, the first processing gas flows from the first processing region R1 to the exhaust passage 65A, and the second processing gas flows from the second processing region R2 to the exhaust passage 65B. , respectively. Therefore, since the first processing gas and the second processing gas are exhausted without coming into contact with each other, the generation of particles due to mixing of these processing gases and the adhesion of the particles to the wafer W can be suppressed more reliably.

By the way, only one of the flow paths 52A and 52B may be provided as the flow path connected to the concave portion 21 in the turntable 2 . In providing only one channel 52 (52A or 52B), the width L2 of the opening 53 (53A or 53B) at the downstream end of the channel 52 as described in FIG. or 66B) is greater than the width L1. Therefore, even when the opening 53 overlaps with the partition wall 66 during rotation of the rotary table 2, the opening 53 is not blocked by the partition wall 66, and the exhaust passage 65A or 65B exhausts air through the opening 53. It can be performed. That is, since the interior of the recess 21 is always exhausted while the rotary table 2 is rotating, fluctuations in the exhaust pressure in the recess 21 and reverse flow of gas from the flow path 52 to the recess 21 are prevented. Therefore, uneven distribution of the processing gas in the plane of the wafer W and residual processing gas in the concave portion 21 are suppressed. Adhesion of particles is more reliably suppressed.

In addition, in the film forming apparatus 1 described above, a plurality of flow paths (two 52A and 52B) connected to the concave portion 21 are provided. By providing a plurality of flow paths in this way, the replacement of the gas in the concave portion 21 can be performed more quickly, which is preferable. Further, as described above, the width L3 between the flow paths 52A and the flow paths 52B>the width L1 of the partition walls 66A and 66B. Therefore, when the partition wall 66A or 66B is aligned between the exhaust ports 62A and 62B as viewed from the center P of the turntable 2 while the rotary table 2 is rotating, the air is exhausted from both the exhaust ports 62A and 62B. . That is, when viewed from the center P of the rotary table 2, the period in which the exhaust ports 62A and 62B overlap the partition walls 66A and 66B is shortened, and the interior of the recess 21 is efficiently exhausted.

[Second embodiment]
Next, a film forming apparatus 7 according to the second embodiment will be described, focusing on differences from the film forming apparatus 1. FIG. This film forming apparatus 7 is different from the film forming apparatus 1 in the gas exhaust path in the concave portion 21 . Briefly speaking, the downstream end of the flow path connected to the side wall of the recess 21 is open to the upper surface of the rotary table, and the gas in the recess 21 passes through the exhaust path provided on the top plate 12 of the vacuum vessel 11. The air is exhausted to the outside of the vacuum vessel 11 through the air.

FIG. 16 is a longitudinal perspective view of the film forming apparatus 7. As shown in FIG. 17 is a longitudinal side view of the turntable 20 and the top plate 12 of the vacuum vessel 11, and FIG. 18 is a plan view of the turntable 20. As shown in FIG. 19 is a cross-sectional plan view of the top plate 12. FIG. Like the rotary table 2, the rotary table 20 has recesses 21, and the channels 52A and 52B are connected to the recesses 21, respectively. The downstream sides of the flow paths 52A and 52B are bent upward, and openings 53A and 53B, which are the downstream ends of the flow paths 52A and 52B, open to the upper surface of the turntable 20. As shown in FIG. In this second embodiment, the openings 53A and 53B are referred to as peripheral end side openings 53A and 53B. These peripheral end side openings 53A and 53B are each formed as a slit extending along the circumference of the turntable 20 and positioned equidistant from the center P of the turntable 20. As shown in FIG.

In addition, suction ports are opened on the left and right sides of the center P of the rotary table 20 in the side walls of the recess 21 . Channels 55A and 55B are formed from these suction ports toward the center P, and the downstream sides of the channels 55A and 55B are bent upward. Downstream ends of the flow paths 55A and 55B are opened to the upper surface of the rotary table 20 as center side openings 56A and 56B, respectively. The center-side openings 56A and 56B are formed as slits extending along the circumference of the turntable 2 and are positioned equidistant from the center P of the turntable 2 . The channels 52A, 52B, 55A, and 55B formed in the rotary table 20 described above correspond to the front-stage channel. In FIG. 18 , the flow of gas in each flow path connected to one of the six recesses 21 is indicated by dashed-line arrows. Flow paths 52A and 52B are front-stage peripheral exhaust paths, and peripheral edge side openings 53A and 53B forming the downstream ends thereof are first openings. Further, the flow paths 55A and 55B are the front-stage center-side exhaust paths, and the center-side openings 56A and 56B forming the downstream ends thereof are the second openings.

Peripheral edge side ceiling suction ports 71A and 71B are opened at the peripheral end portions of the bottom surface of the top plate 12, and center side ceiling suction ports 72A and 72B are opened at the center portion of the bottom surface of the top plate 12. The peripheral end side ceiling suction ports 71A and 71B are each formed in a slit shape along the peripheral direction of the rotary table 20, are separated from each other, and face the peripheral end side openings 53A and 53B of the rotary table 20. do. One end and the other end of the peripheral ceiling suction ports 71A and 71B are located at the center of the separation area D1 and the center of the separation area D2 in the circumferential direction, respectively. Because of the configuration as described above, it can be said that the peripheral edge side ceiling suction ports 71A and 71B are formed by dividing the annular suction port into two. The center-side ceiling suction ports 72A and 72B are each formed in a slit shape along the circumferential direction of the turntable 20, are separated from each other, and face the center-side openings 56A and 56B of the turntable 20. As shown in FIG. One end and the other end of the central ceiling suction ports 72A and 72B are positioned at the circumferential center of the separation area D1 and the circumferential center of the separation area D2, respectively. Because of the configuration as described above, it can be said that the center-side ceiling suction ports 72A and 72B are formed by dividing the annular suction port into two.

Since each suction port is formed in the top plate 12 as described above, the peripheral edge side ceiling suction port 71A and the central side ceiling suction port 72A are the first processing region R1 and the second processing region R2. It opens only in the first processing region R1. The peripheral edge side ceiling suction port 71B and the central side ceiling suction port 72B open only in the second processing region R2 out of the first processing region R1 and the second processing region R2.

A plurality of connecting paths 73A and 73B are formed on the top plate 12 and extend in the radial direction of the top plate 12 and are separated from each other. The connection paths 73A and 73B are embedded in the top plate 12 and therefore do not open on the lower surface of the top plate 12. As shown in FIG. The connection path 73A connects the peripheral side ceiling suction port 71A and the center side ceiling suction port 72A, and the connection path 73B connects the peripheral side ceiling suction port 71B and the center side ceiling suction port 72B. In the film forming apparatus 7, an exhaust port 62A connected to the exhaust mechanism 63A and an exhaust port 62B connected to the exhaust mechanism 63B are provided in the top plate 12, respectively. It overlaps part of the length direction of the side ceiling suction port 71A, and the exhaust port 62B overlaps part of the length direction of the peripheral end side ceiling suction port 71B in plan view. Since the flow paths are formed in the rotary table 2 and the top plate 12 in this manner, the first processing gas and the second processing gas are independently exhausted through the exhaust ports 62A and 62B, respectively.

FIG. 17 shows the gas flow in the first processing region R1. The first process gas is indicated by a solid line, and the flow of purge gas supplied above the center portion of the turntable 20 and the flow of purge gas supplied to the lower side of the turntable 20 are indicated by dotted lines. As described above, the first processing gas supplied into the concave portion 21 is exhausted from the peripheral end side openings 53A and 53B of the turntable 20 to the peripheral end side ceiling suction port 71A, and the center of the turntable 20 is discharged. The air is sucked from the side openings 56A and 56B to the center side ceiling suction port 72A. The first processing gas sucked into the center-side ceiling suction port 72A flows through the connection path 73A to the peripheral-end-side ceiling suction port 71A.

Further, the purge gas supplied to the lower part of the rotary table 2 flows around the upper surface of the rotary table 20 via the outer peripheral side surface, and is sucked into the peripheral edge side ceiling suction port 71A. The purge gas supplied onto the central portion of the rotary table 2 is sucked by the central side ceiling suction port 72A and flows to the peripheral side ceiling suction port 71A through the connection path 73A, like the first processing gas. Each gas that has flowed to the peripheral edge side ceiling suction port 71A in this way is removed from the exhaust port 62A.

As for the second processing gas supplied to the second processing region R2, instead of the peripheral edge side ceiling suction port 71A and the central side ceiling suction port 72A that open to the first processing region R1, It flows to the peripheral edge side ceiling suction port 71B and the center side ceiling suction port 72B that open in the processing region R2 and is exhausted. Except for such differences, the gas flow in the second processing region R2 is similar to the gas flow in the first processing region R1. Regarding the gas flow in the separation regions D1 and D2, except that the separation gas is exhausted to the peripheral edge side ceiling suction ports 71A and 71B and the center side ceiling suction ports 72A and 72B that open to the separation regions D1 and D2, This is the same as the gas flow in the first processing region R1 already described.

In the film forming apparatus 7 as well, the first processing gas and the second processing gas are not mixed with each other and are exhausted from the side walls of the concave portion 21 toward the exhaust ports 62A and 62B. effect. Further, in the film forming apparatus 7, the flow paths 52 (52A and 52B) and the flow paths 55 (55A and 55B) are arranged so that the atmosphere in the concave portion 21 can be exhausted from both the peripheral end portion side and the central portion side of the rotary table 2. ) are provided. With such a configuration, the replacement efficiency of the gas in the concave portion 21 is increased, and film formation on the edge portion of the wafer W due to the process gas remaining in the concave portion 21 can be more reliably suppressed. However, only one of the flow paths 52 and 55 may be provided, and the concave portion 21 may be exhausted through the flow path. In this case, as for the suction port of the top plate 12, only the peripheral side ceiling suction ports 71A and 71B and the center side ceiling suction ports 72A and 72B are provided corresponding to the flow passages and positioned above. Just do it.

In the first and second embodiments, the first processing gas and the second processing gas are shown as being discharged by the first processing gas nozzle 31 and the second processing gas nozzle 33, which are gas supply units. However, it is not limited to such a configuration. For example, shower heads having lower surfaces facing the rotary tables 2 and 20 are provided as gas supply units in the first processing region R1 and the second processing region R2, respectively, and gas is discharged from each shower head. may be processed. Various gases for film formation by ALD can be used as the first processing gas and the second processing gas, and the gas is not limited to the examples described above. Therefore, the film formed on the wafer W is not limited to the _SiO2 film. For example, a silicon nitride film may be formed on the wafer W using a gas containing silicon as the first processing gas and a gas containing nitrogen as the second processing gas.

Although an example in which the substrate processing apparatus is configured as a film formation apparatus has been shown, the configuration is not limited to such a film formation apparatus. The present technology may be applied to an apparatus that transforms a processing gas into plasma and modifies or etches a film formed on a wafer W by the plasma. However, by applying the present technology to a film forming apparatus that forms films using a first processing gas and a second processing gas, it is possible to prevent unnecessary mixing of these processing gases as described above, which is advantageous. be. In the above example, the wafer W is placed on the pedestal 22 inside the recess 21 , but the wafer W may be placed directly on the bottom surface of the recess 21 .

In addition, the embodiment disclosed this time should be considered as an example and not restrictive in all respects. The above embodiments may be omitted, substituted, changed or combined in various ways without departing from the scope and spirit of the appended claims.

R1 First processing region W Wafer 1 Film formation device 11 Vacuum chamber 2 Rotating table 21 Concave portions 31 and 33 Processing gas nozzles 52A and 52B Flow paths 63A and 63B Exhaust mechanisms 65A and 65B Exhaust paths

Claims (9)

a rotary table provided in the processing container;
a concave portion provided on the upper surface of the rotary table for accommodating the substrate so as to revolve with the rotation of the rotary table;
a processing gas supply unit provided above the turntable for processing the substrates by supplying a processing gas to a partial area in the rotation direction of the turntable;
a pre-stage exhaust passage whose upstream end opens to the side wall of the recess and whose downstream end opens to the outer peripheral side surface or the upper surface of the rotary table for exhausting the interior of the recess;
a post-stage exhaust path provided in the processing container and connected to an exhaust mechanism for exhausting the processing gas from a downstream end of the pre-stage exhaust path. The processing gas supply unit
a first processing gas supply unit that supplies a first processing gas to a first processing region in the rotation direction of the rotary table;
a second processing gas supply unit that supplies a second processing gas to a second processing region remote from the first processing region in the direction of rotation;
In order to separate the atmosphere of the first processing region and the atmosphere of the second processing region, atmospheres are separated from each other in a separation region between the first processing region and the second processing region in the rotation direction. 2. The substrate processing apparatus according to claim 1, further comprising a separation gas supply unit for supplying a separation gas for separation. the downstream side of the pre-stage exhaust passage is open to the outer peripheral side surface of the rotary table;
3. The substrate processing apparatus according to claim 2, wherein said post-stage exhaust path is provided on a side wall of said processing container and includes a side wall suction port provided along the rotation direction of said turntable. In a plan view, the post-exhaust passage is formed by dividing an annular flow passage along the rotation direction in the side wall of the processing container by a dividing member in the rotation direction. Equipped with a post-stage exhaust path of
the first post-stage exhaust path and the second post-stage exhaust path are provided with a first side wall suction port and a second side wall suction port, respectively, as the side wall suction port;
In order to selectively exhaust the first processing gas out of the first processing gas and the second processing gas through the first post-exhaust passage, the first side wall suction port is provided in the first processing gas. opening only in the first processing region of the processing region and the second processing region;
In order to selectively exhaust the second processing gas out of the first processing gas and the second processing gas through the second post-exhaust passage, the second side wall suction port is provided in the first processing gas. opening only in the second processing region of the processing region and the second processing region;
4. The substrate processing apparatus according to claim 3, wherein said partitioning member is positioned in an extending direction of said separation areas when viewed from the center of rotation of said rotary table. 5. The substrate processing apparatus according to claim 4, wherein the width of the partitioning member in plan view is smaller than the width of the downstream end of the front-stage exhaust passage. 6. The substrate processing apparatus according to claim 5, wherein said pre-stage exhaust passages are located on the left side and the right side, respectively, and are separated from each other when viewed from the center of said rotary table toward said recess. The post-stage exhaust path includes a ceiling suction port provided in the ceiling of the processing container,
3. The substrate processing apparatus according to claim 2, wherein a downstream end of said front-stage exhaust path faces said ceiling suction port. the front-stage-side exhaust path includes a front-stage center-side exhaust path and a front-stage peripheral-end-side exhaust path provided respectively on the center side and the peripheral end side of the rotary table with respect to the recess;
The downstream end of the front-stage center-side exhaust passage and the downstream end of the front-stage peripheral-end-side exhaust passage are
A first opening and a second opening are formed on the center side and the peripheral end side of the rotary table, respectively;
the rear-stage exhaust path of the ceiling portion includes a first ceiling suction port and a second ceiling suction port that are partitioned from each other as the ceiling suction port,
the first ceiling suction port is open only to the first processing area for selectively exhausting a first processing gas out of the first processing gas and the second processing gas;
8. The second ceiling suction port opens only to the second processing area for selectively exhausting the second processing gas out of the first processing gas and the second processing gas. A substrate processing apparatus as described. a step of rotating a rotary table provided in the processing vessel;
a step of storing a substrate in a recess provided on the upper surface of the rotary table and revolving the substrate by rotating the rotary table;
a step of supplying a processing gas to a partial region in the rotation direction of the turntable from a processing gas supply unit provided above the turntable to process each of the substrates;
a step of exhausting the interior of the recess through a pre-stage exhaust passage whose upstream end opens to the side wall of the recess and whose downstream end opens to the outer peripheral side surface or the upper surface of the rotary table;
a step of exhausting a post-stage exhaust passage provided in the processing container by an exhaust mechanism to exhaust the processing gas from a downstream end of the pre-stage exhaust passage;
A substrate processing method comprising:

Images