SUBSTRATE PROCESSING APPARATUS AND SUBSTRATE PROCESSING METHOD

Abstract

To suppress the supply amount of processing gas when processing a plurality of substrates supported in a shelf shape by supplying the processing gas.SOLUTION: A substrate processing apparatus includes a processing container containing a substrate support for supporting a plurality of substrates in a shelf-like manner in the vertical direction, and including a cylindrical portion having an axis directed in the vertical direction, a first gas supply port for supplying first gas for processing each substrate to one side in the vertical direction of a substrate support area in which each substrate is supported in the cylindrical portion, a first exhaust port for exhausting the first gas from the other side in the vertical direction of the substrate supporting area, and recesses located at the height of each of the substrates on the inside surface of the cylindrical portion so as to form a flow path in which the first gas flows from the first gas supply port toward the first exhaust port along the surface of each of the substrates so as to meander left and right, and provided alternately to the left and right when viewed along the vertical direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a substrate processing apparatus and a substrate processing method. [Background technology]

[0002] As an apparatus for processing semiconductor wafers (hereinafter referred to as "wafers"), there is known an apparatus in which a plurality of wafers are arranged in a processing vessel like a shelf and a processing gas is supplied to the surface of each wafer to process them all at once. Patent Document 1 describes, as an example of such an apparatus, a substrate processing apparatus configured to process each wafer by supplying a processing gas to each wafer from the side. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-191955 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure aims to suppress the amount of gas supplied when processing a plurality of substrates supported on a shelf. [Means for solving the problem]

[0005] The substrate processing apparatus of the present disclosure includes a processing vessel that houses a substrate support that supports a plurality of substrates in a vertical direction in a shelf-like manner and has a cylindrical portion whose axis faces the vertical direction; a first gas supply port for supplying a first gas for processing each of the substrates, the first gas supply port being disposed on one side in a longitudinal direction of a substrate support region in which each of the substrates is supported within the cylindrical portion; a first exhaust port for exhausting the first gas from the other longitudinal side of the substrate support region; recesses that are located at the height of the substrates on the inner surface of the cylindrical portion and are provided alternately left and right as viewed along the vertical direction so as to form a flow path for the first gas to flow from the first gas supply port toward the first exhaust port along the surfaces of the substrates in a serpentine manner left and right; a second gas supply port formed on an inner surface of the cylindrical portion for supplying a second gas to each of the substrates; a second exhaust port that opens in an inner surface of the cylindrical portion opposite the second gas supply port and that exhausts the second gas; Equipped with. Effect of the Invention

[0006] According to the present disclosure, when supplying a process gas to process a plurality of substrates supported on a shelf, the supply amount of the gas can be suppressed. [Brief description of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view of a film forming apparatus according to the present disclosure taken along the X-axis. [Diagram 2] 4 is a Y-axis cross-sectional view of the film forming apparatus according to the present disclosure. FIG. [Diagram 3] FIG. 2 is a perspective view of a wafer boat provided in the film forming apparatus. [Figure 4] FIG. 2 is a perspective view of a cylindrical portion provided in the film forming apparatus. [Diagram 5] FIG. [Figure 6] FIG. 2 is a perspective view of an outer cylinder portion provided in the film forming apparatus. [Figure 7] FIG. 2 is a transparent perspective view of the outer cylinder portion. [Figure 8] FIG. 4 is a plan view showing the outer cylinder portion aligned at a first position. [Figure 9] FIG. 4 is a plan view showing the outer cylinder portion aligned to a second position. [Figure 10] 5 is an operational diagram showing the gas flow when the outer tubular portion is aligned at the first position. FIG. [Figure 11] 6 is an operational diagram showing the gas flow when the outer tubular portion is aligned at the second position. FIG. [Figure 12] 11 is an X-axis cross-sectional view of another example of a film forming apparatus according to the present disclosure. FIG. [Figure 13]6 is a Y-axis cross-sectional view of another example of a film forming apparatus according to the present disclosure. FIG. [Figure 14] FIG. 13 is a plan view of another example of a film forming apparatus according to the present disclosure. [Figure 15] 4 is a pressure distribution diagram showing the gas pressure when the outer cylinder portion is aligned at a first position. FIG. [Figure 16] 6 is a pressure distribution diagram showing the gas pressure when the outer cylinder portion is aligned at the second position. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] An example will be described in which the substrate processing apparatus according to the present disclosure is applied to a film forming apparatus that forms a film on a wafer W. FIG. 1 and FIG. 2 respectively show a vertical cross-sectional view along the X-axis direction and a vertical cross-sectional view along the Y-axis direction of the film forming apparatus 1, where the X-axis and the Y-axis are orthogonal to each other. The Z-axis in the figure is a vertical axis orthogonal to the X-axis and the Y-axis, and is specifically, for example, a vertical axis. In the following description, the left hand side and the right hand side of FIG. 1 as viewed from the front are described as the left side and the right side of the film forming apparatus 1, and the left hand side and the right hand side of FIG. 2 as viewed from the front are described as the front side and the rear side of the film forming apparatus 1. Therefore, the X-axis direction is the left-right direction, and the Y-axis direction is the front-back direction.

[0009] The film forming apparatus 1 is generally configured as follows: the film forming apparatus 1 includes a low-profile, generally circular processing vessel 10. Inside the processing vessel 10, a wafer boat 2 is provided, which is a substrate support that supports a plurality of wafers W in a shelf-like manner in the Z-axis direction, i.e., vertically. Inside the processing vessel 10, a cylindrical portion 3 having a lid and an outer cylindrical portion 4 surrounding the cylindrical portion 3 are each provided upright, and the wafer boat 2 is housed within the cylindrical portion 3. A heating unit 14 is provided to surround the periphery of the processing vessel 10, and is configured to heat each wafer W placed on the wafer boat 2.

[0010] Furthermore, an exhaust port 11 is formed on the left side surface of the processing vessel 10. An exhaust unit 12 that exhausts an exhaust space 12A formed between the outer tubular portion 4, the tubular portion 3, and the side wall of the processing vessel 10 is connected to the exhaust port 11. An exhaust port (described later) provided in the tubular portion 3 is connected to the exhaust space 12A via a through hole provided in the outer tubular portion 4, and the inside of the tubular portion 3 is also exhausted by exhaust from the exhaust port 11.

[0011] This film forming apparatus 1 forms a film on a wafer W by ALD (Atomic Layer Deposition). Thus, a precursor gas containing a precursor of the film, a reactive gas that reacts with the precursor gas to generate a reaction product, and a purge gas for purging unnecessary precursor gas and reactive gas are supplied into the above-mentioned tube portion 3. When the precursor gas is supplied to the wafer boat 2 and when the purge gas and reactive gas are supplied to the wafer boat 2, through holes at different positions in the tube portion 3 are used as exhaust ports. The outer tube portion 4 is used to switch the exhaust port. In addition, the precursor gas, reactive gas, and purge gas are supplied into the tube portion 3 from openings at different positions in the tube portion 3. By switching the exhaust position and the gas supply position, the precursor gas forms a meandering flow that meanders left and right in the tube portion 3 and heads downward, and the reactive gas and purge gas flow from the front to the rear. The reason for switching the flow path according to the type of gas in this way will be described in detail later.

[0012] Each part of the film forming apparatus 1 will be described in detail below. A circular opening 13 is formed in the center of the bottom plate 10A constituting the processing vessel 10, and a circular lid 20 is provided to close the opening 13. A through hole 21 is formed in the center of the lid 20, and a rotating shaft 24 with a support table 23 installed at the upper end is inserted in the through hole 21 along the Z-axis direction, and the wafer boat 2 is placed on the support table 23 as shown in the perspective view of FIG. 3. The lower part of the rotating shaft 24 is connected to a rotating mechanism 25 provided below the lid 20, and the supporting table 23 and the wafer boat 2 are rotated clockwise in a plan view by the rotating mechanism 25 during processing. A purge gas is supplied from a purge gas supply source 63 to the gap between the rotating shaft 24 and the lid 20, and flows into the processing vessel 10 and is exhausted from the exhaust space 12A. The supply of the purge gas prevents the precursor gas and the reaction gas from being supplied to a sealing mechanism (not shown) for sealing the gap between the rotating shaft 24 and the lid 20. The rotation mechanism 25 and the lid 20 are connected to a lifting mechanism (not shown), and are raised and lowered relative to the processing vessel 10 to open and close the opening 13 and allow the wafer boat 2 to be loaded and unloaded into and from the processing vessel 10 .

[0013] The wafer boat 2 includes a circular bottom plate 26 having a diameter larger than the diameter (300 mm) of the wafers W, and the bottom plate 26 is supported on the support platform 23. In a semicircular region of the periphery of the bottom plate 26, for example, four support columns 27 extending in the Z-axis direction are provided at equal intervals in the circumferential direction of the bottom plate 26. Moreover, above the bottom plate 26, four mounting portions 200 are provided at intervals from one another in the Z-axis direction.

[0014] The placement portion 200 is a circular ring-shaped member whose outer diameter is the same as the diameter of the bottom plate 26, and its periphery is supported by each support 27. A step is formed on the upper surface of the placement portion 200 around the entire circumference, and the height of the inner peripheral edge is lower than that of the outer peripheral edge. The upper surface of this inner peripheral edge supports the peripheral edge of the wafer W as the placement surface 28, and the step prevents the wafer W from being displaced on the placement portion 200. By placing the wafer W on each of the placement portions 200, the wafer W is supported on the wafer boat 2 in a shelf-like manner in the Z-axis direction as described above. The wafer boat 2 has a substrate support region extending from the height at which the uppermost wafer W is supported to the height at which the lowermost wafer W is supported. The wafers W supported in this manner may be described in the order counted from the top hereinafter. Specifically, when the wafers W are described as the second and third wafers W, they are the second and third wafers W counted from the top. Similarly, the placement portion 200 and a recess 32 described below may also be described in order counted from the top.

[0015] Next, the cylindrical part 3 will be described with reference to the perspective views of FIG. 4 and FIG. 5. FIG. 5 shows the arrangement of each part formed on the inner wall of the cylindrical part 3, which is omitted in FIG. 4. In the following description of the device configuration, unless otherwise specified, it is assumed that the opening 13 of the processing vessel 10 is closed and the wafer boat 2 is stored in the cylindrical part 3. The cylindrical part 3 is configured in a cylindrical shape with an axis facing vertically, more specifically, in the Z-axis direction, and includes a top plate (lid part) 30. The lower end of the cylindrical part 3 is connected to the periphery of the opening 13. In order to form the meandering flow described above, the inner peripheral surface of the cylindrical part 3 is close to the outer edge of the mounting part 200 of the wafer boat 2, and the distance L1 (see FIG. 1) between the inner peripheral surface of the cylindrical part 3 and the mounting part 200 is sufficiently smaller than the depth of the recess 32, for example, 2 mm.

[0016] The upstream end of a flow path 31A for introducing a precursor gas, which is a first gas, into the cylindrical part 3 is opened on the upper surface of the edge of the top plate 30 of the cylindrical part 3. The downstream side of this flow path 31A extends downward and opens at the upper end of the inner wall of the cylindrical part 3, thereby forming a first gas supply port 31. The first gas supply port 31 opens to the right side above the uppermost wafer W and the uppermost mounting part 200. In addition, a through hole is formed in the side wall of the cylindrical part 3 below the lowermost wafer W and the lowermost mounting part 200 of the wafer boat 2 in the cylindrical part 3, forming a first exhaust port 33. This first exhaust port 33 is formed in a slit shape along the circumference of the cylindrical part 3 and is located on the right side. Since the first gas supply port 31 and the first exhaust port 33 are provided as described above, the precursor gas can be supplied to one vertical side (upper side) of the substrate support area in the cylindrical portion 3, and the precursor gas can be exhausted from the other vertical side (lower side) of the substrate support area.

[0017] Further, two recesses 32 are provided on each of the left and right sides of the inner peripheral surface of the tube portion 3, each of which is elongated horizontally along the circumferential direction of the tube portion 3. Therefore, each recess 32 is formed in an arc shape in a plan view. In a plan view, a point that equally divides the arc of the left recess 32 and a point that equally divides the arc of the right recess 32 face each other across the axis P (along the Z axis and shown in Figs. 8 and 9 described later) of the tube portion 3. The vertical width of each recess 32 is larger than the vertical width of the placement portion 200. The two recesses 32 on the left side are spaced apart from each other in the Z axis direction, and the two recesses 32 on the right side are also spaced apart from each other in the Z axis direction.

[0018] For the two recesses 32 on the left side, the center of the height of the first stage mounting portion 200 is located in the height range in which the upper recess 32 is formed, and the center of the height of the third stage mounting portion 200 is located in the height range in which the lower recess 32 is formed. For the two recesses 32 on the right side, the center of the height of the second stage mounting portion 200 is located in the height range in which the upper recess 32 is formed, and the center of the height of the fourth stage mounting portion 200 is located in the height range in which the lower recess 32 is formed. The recess 32 and the mounting portion 200 whose center of the height is located in the height range of the recess 32 are regarded as corresponding recesses 32 and mounting portions 200. In this way, the recesses 32 are located at the height of the mounting portions 200 of each stage (i.e., the wafers W of each stage) and are provided alternately on the left and right as viewed in the vertical direction (Z-axis direction).

[0019] Since the recess 32 has the above-mentioned vertical width, the upper end of the recess 32 is located above the upper surfaces of the mounting parts 200 corresponding to the recess 32 and the wafer W corresponding to the recess 32. The lower end of the recess 32 is located below the lower surfaces of the mounting parts 200 corresponding to the recess 32 and the wafer W corresponding to the recess 32. This is to provide a flow path that guides the gas to flow in order one stage at a time, as described later. The first stage recess 32 and the third stage recess 32 are located at a height offset from the second stage and fourth stage mounting parts 200 and wafer W, and the second stage recess 32 and the fourth stage recess 32 are located at a height offset from the first stage and third stage mounting parts 200 and wafer W. In other words, the recess 32 is provided only on one of the left and right sides of the mounting parts 200 and wafer W of each stage. The first exhaust port 33 is connected to the lower part of the fourth stage recess 32. From another perspective, the lower side of the recess 32 is further recessed outward from the tubular portion 3 and opens onto the outer circumferential surface of the tubular portion 3 , thereby forming a first exhaust port 33 .

[0020] A sufficient conductance is ensured between the placement part 200 and the portion of the cylindrical part 3 where the recess 32 described above is formed. Therefore, the recess 32 and the gaps formed between the wafers W by arranging them like shelves form a flow path that runs from the first gas supply port 31 to the first exhaust port 33 and meanders left and right. In other words, in the cylindrical part 3, the precursor gas flows from one of the left end and the right end of the wafer W to the other on the surface of the wafer W of one stage, moves downward through the recess 32, and flows from the other of the left end and the right end of the wafer W to the one on the surface of the wafer W of the next stage.

[0021] Further, through holes are formed in five stages in the Z-axis direction in the side wall on the front side of the cylindrical portion 3, forming second gas supply ports 35 each opening on the inner side surface of the cylindrical portion 3. The five second gas supply ports 35 are supply ports for supplying a reaction gas and a purge gas as the second gas, and are formed in the shape of slits extending in the circumferential direction of the cylindrical portion 3. The second gas supply ports 35 are located above the mounting parts 200 of each stage and below the mounting part 200 of the lowest stage, and supply a reaction gas and a purge gas to the front side and back side of each wafer W.

[0022] Further, through holes are formed in five stages in the Z-axis direction in the side wall on the rear side of the tube part 3, forming second exhaust ports 36 that open on the inner side surface of the tube part 3. The five second exhaust ports 36 are for exhausting the reaction gas and the purge gas, and are formed in the shape of slits extending in the circumferential direction of the tube part 3. Since they are formed in the side walls of the tube part 3 as described above, the second gas supply port 35 and the second exhaust port 36 are arc-shaped in plan view, and are formed to have, for example, the same length as each other. In plan view, the point that equally divides the arc of the second gas supply port 35 and the point that equally divides the arc of the second exhaust port 36 face each other across the axis P of the tube part 3. In addition, for example, the vertical width of the second gas supply port 35 and the second exhaust port 36 are also the same size. By supplying a reaction gas or a purge gas from the second gas supply port 35 and exhausting the gas from the second exhaust port 36, the gas flows along the front and back surfaces of each wafer W from the front to the rear.

[0023] The arrangement of the recess 32, the second gas supply port 35, and the second exhaust port 36 will be supplemented. In plan view, the left recess 32 and the right recess 32 are arranged so as to be equally divided by a line along the X-axis passing through the axis P. In addition, in plan view, the second gas supply port 35 and the second exhaust port 36 are arranged so as to be equally divided by a line along the Y-axis passing through the axis P. With such an arrangement, the second gas supply port 35 and the second exhaust port 36 are positioned far apart from each other when viewed from the precursor gas flowing as a meandering flow from one of the left and right recesses 32 to the other of the left and right recesses 32. Therefore, the flow of the precursor gas is less affected by the second gas supply port 35 and the second exhaust port 36 being provided on the circumferential surface of the cylindrical portion 3. In other words, stagnation and retention near the second gas supply port 35 and the second exhaust port 36 are prevented, and the in-plane uniformity of the processing of the wafer W can be improved.

[0024] In addition, in the side wall of the cylindrical portion 3, for example, nine through holes are drilled below the second gas supply port 35 and the second exhaust port 36 to form exhaust holes 34. These exhaust holes 34 are arranged at equal intervals along the circumference of the cylindrical portion 3 and are configured as flow paths for discharging the purge gas that is supplied around the above-mentioned rotating shaft 24 and flows into the cylindrical portion 3 to the outside of the cylindrical portion 3.

[0025] Next, the outer cylindrical part 4 surrounding the cylindrical part 3 will be described with reference to the perspective views of FIG. 6 and FIG. 7. FIG. 7 shows the arrangement of each part formed on the inner wall of the cylindrical part 3, which is omitted in FIG. 6. The outer cylindrical part 4 is configured as a cylinder coaxial with the cylindrical part 3. Therefore, the axis P of the cylindrical part 3 is also the axis of the outer cylindrical part 4. The inner peripheral surface of the outer cylindrical part 4 is close to the outer peripheral surface of the cylindrical part 3. As shown in FIG. 1 and FIG. 2, the lower end side of the outer cylindrical part 4 protrudes below the processing vessel 10 through an annular opening 19 formed in the bottom plate 10A, and is supported by, for example, supports 45 provided at intervals in the circumferential direction of the outer cylindrical part 4. The supports 45 are connected to a rotation mechanism 46 that rotates around a vertical axis via an arm 45A. The support 45 is formed to be sufficiently long so that the arm 45A does not interfere with the lowering of the wafer boat 2 when the lid part 20 is lowered. A purge gas is supplied from a purge gas supply source 63 to the gap between the edge of the opening 19 and the outer tubular portion 4, flows into the processing vessel 10, and is exhausted from the exhaust space 12A. The supply of the purge gas prevents the precursor gas and the reaction gas from being supplied to a sealing mechanism (not shown) for sealing the gap between the edge of the opening 19 and the outer tubular portion 4.

[0026] The rotation mechanism 46 rotates the outer tube portion 4 relatively to the tube portion 3 around the axis P. More specifically, the rotation mechanism 46 rotates the outer tube portion 4 clockwise and counterclockwise in a plan view, thereby switching the position of the outer tube portion 4 relative to the tube portion 3.

[0027] A first through hole 41, a second through hole 42, and a third through hole 43 are formed in the side wall of the outer tubular portion 4. These through holes 41, 42, and 43 overlap with the first exhaust port 33, the second gas supply port 35, and the second exhaust port 36 in the tubular portion 3, respectively, and serve to open the first exhaust port 33, the second gas supply port 35, and the second exhaust port 36 to the outside of the outer tubular portion 4.

[0028] The first through hole 41 is formed in a slit shape along the circumference of the outer cylinder 4 in correspondence with the shape of the first exhaust port 33. The second through hole 42 and the third through hole 43 are formed vertically long in correspondence with the second gas supply port 35 provided in the fifth stage and the second exhaust port 36 provided in the fifth stage as described above. That is, the upper ends of the second through hole 42 and the third through hole 43 are located at the height of the second gas supply port 35 and the second exhaust port 36 in the uppermost stage. The lower ends of the second through hole 42 and the third through hole 43 are located at the height of the second gas supply port 35 and the second exhaust port 36 in the lowermost stage. Since they correspond to the second gas supply port 35 and the second exhaust port 36, respectively, the second through hole 42 and the third through hole 43 are arranged opposite each other. The first through hole 41 opens at a position shifted in the circumferential direction of the outer tubular portion 4 with respect to the second through hole 42 and the third through hole 43 .

[0029] 8 and 9 showing the positional relationship between the cylindrical portion 3 and the outer cylindrical portion 4 will be also referred to for explanation. When the outer cylindrical portion 4 is placed at the first position (the position shown in FIG. 8) so that the first through-hole 41 overlaps with the first exhaust port 33 (first state), the second through-hole 42 and the third through-hole 43 are out of the second gas supply port 35 and the second exhaust port 36, respectively. That is, in the first position, the first exhaust port 33 is open to the outside of the outer cylindrical portion 4, while the second gas supply port 35 and the second exhaust port 36 are closed to the outside of the outer cylindrical portion 4 by the side wall of the outer cylindrical portion 4. When the outer cylinder part 4 is placed at the second position (position shown in FIG. 9 ) so that the second through hole 42 and the third through hole 43 overlap with the second gas supply port 35 and the second exhaust port 36, respectively (when the outer cylinder part 4 is placed in the second state), the first through hole 41 is removed from the first exhaust port 33. That is, in the second position, the second gas supply port 35 and the second exhaust port 36 are opened to the outside of the outer cylinder part 4, while the first exhaust port 33 is closed to the outside of the outer cylinder part 4 by the side wall of the outer cylinder part 4. The second position is a position where the outer cylinder part 4 is rotated 40° counterclockwise in a plan view with the axis P as the rotation axis from the first position.

[0030] Further, nine through holes 44, for example, are formed at equal intervals in the circumferential direction in a lower position of the outer tubular portion 4. The through holes 44 overlap the exhaust holes 34 of the tubular portion 3 when the outer tubular portion 4 is aligned in either the first position or the second position.

[0031] A first gas supply unit 5 is provided on the right side of the outer tubular part 4 in the exhaust space 12A. The first gas supply unit 5 is configured as a pipe provided upright with respect to the bottom plate 10A of the processing vessel 10, and its tip side is folded back toward the inner side of the outer tubular part 4 so as to face downward above the upper end of the outer tubular part 4. A gas supply port formed at the tip of the first gas supply unit 5 opens close to the flow path 31A of the top plate 30 of the tubular part 3, and can supply a first gas to the flow path 31A. The base end side of the first gas supply unit 5 passes through the bottom plate 10A and faces downward, and is connected to a first gas supply source 52 outside the processing vessel 10. In this example, it is assumed that DCS (Dichlorosilane) gas is supplied from the first gas supply source 52 as a precursor gas, which is the first gas.

[0032] A second gas supply unit 6 is provided in the exhaust space 12A on the front side of the outer cylinder 4. The second gas supply unit 6 is configured as a pipe that is wide on the left and right sides and is provided upright with respect to the bottom plate 10A of the processing vessel 10. On the side surface of the second gas supply unit 6 facing the outer cylinder 4, five stages of slits 61 are formed in the Z-axis direction close to the outer cylinder 4. The height of the slits 61 in each stage is aligned with the height of the second gas supply ports 35 in each stage of the cylinder 3, and when the outer cylinder 4 is located at the second position as described in FIG. 9, gas can be supplied from each slit 61 to each second gas supply port 35. The base end side of the second gas supply unit 6 passes through the bottom plate 10A downward and is connected to a second gas supply source 62 and a purge gas supply source 63 outside the processing vessel 10. In this example, for example, ozone (O3) gas is supplied from a second gas supply source 62 as a reactive gas, which is the second gas, and for example, nitrogen (N2) gas is supplied from a purge gas supply source 63 as a purge gas.

[0033] The film forming apparatus 1 is also provided with a control unit 90, which is, for example, a computer. The control unit 90 includes a program, a memory, a data processing unit including a CPU, and the program includes commands (each step) for sending control signals from the control unit 90 to each part of the film forming apparatus 1 and for progressing each step of the film forming process. The program is stored in a storage medium, for example, a storage unit such as a compact disc, a hard disk, a DVD, or a memory card, and installed in the control unit 90.

[0034] The operation of the film forming apparatus 1 will be described. When the wafer boat 2 with the wafers W placed on each placement portion 200 is stored in the processing vessel 10 and the opening 13 of the processing vessel 10 is closed by the lid portion 20, the inside of the processing vessel 10 is heated by the heating portion 14. Meanwhile, the exhaust portion 12 evacuates the exhaust space 12A in the processing vessel 10, and the rotating mechanism 25 rotates the wafer boat 2. Furthermore, the rotating mechanism 46 positions the outer cylinder portion 4 at the first position shown in FIG. 8, closes the second gas supply port 35 and the second exhaust port 36, and opens the first exhaust port 33. Then, DCS gas is supplied from the first gas supply portion 5 (step S1).

[0035] As shown in FIG. 10, this DCS gas is supplied from the right side of the top wafer W and flows on the surface of the wafer W toward the left side. Then, it descends to the left side of the second wafer W through the recess 32 of the top wafer W and flows toward the right side of the second wafer W. Thereafter, the DCS gas flows from one wafer W to the surface of another wafer W located one below the first wafer W through the recess 32, and flows from one side to the other side on the surface of the other wafer W. The gas flow on the surface of the other wafer W is in the opposite direction to the gas flow on the surface of the first wafer W. Therefore, the DCS gas flows from the top wafer W to the wafer W below, alternately repeating a flow from right to left and a flow from left to right. That is, as described above, a meandering flow is formed, and DCS contained in the gas is adsorbed on the surface of each wafer W. The DCS gas flows in sequence over the surfaces of the four wafers W, flows from the surface of the bottommost wafer W toward the right, enters the first exhaust port 33 located on the right side of that wafer W, is released into the exhaust space 12A through the first through hole 41, and is exhausted from the exhaust port 11.

[0036] Next, the supply of DCS gas is stopped, and the outer cylinder 4 is rotated 40° counterclockwise as viewed from above to the second position shown in Fig. 9. As a result, the first exhaust port 33 is closed, and the second gas supply port 35 and the second exhaust port 36 are opened.

[0037] Then, a purge gas is supplied from the second gas supply unit 6 (step S2), and the purge gas is supplied to the front and back surfaces of each wafer W in the cylindrical portion 3 through the third through hole 43 and the second gas supply port 35 in this order. Since exhaust is being performed from the second exhaust port 36 facing each second gas supply port 35, the purge gas flows from the front to the rear along the front and back surfaces of each wafer W and flows into the second exhaust port 36 (FIG. 11). Then, the purge gas is released through the second through hole 42 into the exhaust space 12A and exhausted. As a result, the DCS gas remaining in the cylindrical portion 3 is purged and removed.

[0038] Next, O3 gas is supplied from the second gas supply unit 6 instead of the purge gas (step S3). Like the purge gas, O3 gas also flows from the front side to the rear side along the front and back surfaces of each wafer W, and is discharged into the exhaust space 12A through the second exhaust port 36 and the second through hole 42 in this order and exhausted. By supplying O3 gas in this manner, DCS adsorbed on the wafer W reacts with the O3 gas, generating SiO2 as a reaction product. Next, purge gas is supplied from the second gas supply unit 6 instead of O3 gas (step S4). This step S4 is the same operation as step S2, except that the target of purging is O3 gas instead of DCS gas.

[0039] Then, the supply of purge gas is stopped, the outer cylinder 4 is rotated 40° clockwise as viewed from above, returned to the first position, and DCS gas is supplied. That is, the above step S1 is performed again. Thereafter, steps S2 to S4 are performed, and then steps S1 to S4 are performed. By repeating steps S1 to S4 in this manner, SiO2 is repeatedly deposited on the wafers W as a reaction product, and a SiO2 film is formed. When the SiO2 film reaches a desired thickness by repeating steps S1 to S4 a predetermined number of times, exhaust of the processing vessel 10 is stopped, and the lid 20 is lowered to unload the wafer boat 2 from the processing vessel 10.

[0040] Although DCS has been used as the precursor gas, which is the first gas, in the above-mentioned example, various gases can be used depending on the type of film to be formed. In some cases, a precursor gas having a low adsorption efficiency to the surface of the wafer W is used as the precursor gas. If such a precursor gas is supplied from one end side of each wafer W and exhausted from the other end side of each wafer W, as with the above-mentioned reaction gas and purge gas, most of the precursor gas will be removed from the periphery of the wafer W without being adsorbed to the wafer W. Therefore, in order to adsorb the amount of precursor gas required for film formation to the wafer W, the amount of the precursor gas supplied into the cylindrical portion 3 will be relatively large, and there is a risk that the cost required for processing will be high.

[0041] In the film forming apparatus 1, as described above, the precursor gas meanders inside the cylindrical portion 3 and flows in order over the surfaces of the wafers W. Therefore, even if a component in the gas is not adsorbed when the precursor gas passes over the surface of one wafer W, it can be adsorbed when the gas passes over the surface of another wafer W below the one wafer W. This can increase the utilization efficiency of the precursor gas, allowing each wafer W to be processed with a relatively small supply of precursor gas, thereby reducing the cost required for processing.

[0042] In addition, although O3 gas has been used as an example of the reactive gas in the above example, various gases can be used depending on the type of film to be formed. However, depending on the type of precursor gas and reactive gas used, by-products other than the reaction products for forming a film on the wafer W may be generated, and the by-products may be mixed into the film, which may deteriorate the film quality. In other words, the reactive gas that has passed through the surface of the wafer W may contain the above-mentioned by-products, and it is desirable to quickly exhaust the by-products so that they are not supplied to other wafers W. Therefore, in the film forming apparatus 1, as described above, the reactive gas is supplied from the second gas supply port 35 on the front side of each wafer W, and exhaust is performed from the second exhaust port 36 facing the second gas supply port 35 on the rear side of the wafer W. As a result, the reactive gas that flows from the front to the rear on the surface of one wafer W is quickly removed from the inside of the tube part 3 and is prevented from being supplied to other wafers W. As a result, the by-products are prevented from being mixed into the film of each wafer W, and a decrease in the yield of semiconductor products manufactured from the wafers W can be prevented.

[0043] Similarly to the reaction gas, the purge gas is supplied from the second gas supply port 35 and exhausted from the second exhaust port 36. This allows the precursor gas and reaction gas swept away by the purge gas to be quickly removed from the inside of the cylindrical portion 3, and prevents them from remaining in the cylindrical portion 3 for a long time. This is therefore preferable because the purging can be quickly completed.

[0044] Incidentally, the second gas supply port 35 and the second exhaust port 36 may be provided near the recesses 32 in the circumferential direction of the tube portion 3, that is, provided in the left-right direction, respectively, so that the reaction gas and the purge gas flow in the left-right direction instead of the front-rear direction. However, it is preferable that the second gas supply port 35 and the second exhaust port 36 are provided farther away from the precursor gas that flows between the recesses 32 forming a serpentine flow as described above. Therefore, it is preferable that the second gas supply port 35 and the second exhaust port 36 are disposed in the front-rear direction, respectively, as described above, so that the reaction gas and the purge gas form a front-rear airflow.

[0045] Furthermore, according to the film forming apparatus 1, by rotating the outer tubular portion 4, one of the first exhaust port 33 and the second exhaust port 36 is opened in the tubular portion 3, but the outer tubular portion 4 is configured so that the second gas supply port 35 is also closed when the second exhaust port 36 is closed. Since the second gas supply port 35 and the second exhaust port 36 are opened and closed together in this manner, the configuration of the apparatus is simplified.

[0046] When the serpentine flow is formed, both the second gas supply port 35 and the second exhaust port 36 are closed as described above, thereby preventing gas from entering the gas supply port 35 and the second exhaust port 36 and disturbing the airflow. This makes it possible to improve the uniformity of processing between the wafers W and within the surface of the wafer W. Alternatively, the tube portion 3 may be connected to a rotation mechanism 46 instead of the outer tube portion 4 and rotated relative to the outer tube portion 4, thereby opening and closing the first exhaust port 33, the second gas supply port 35, and the second exhaust port 36.

[0047] Furthermore, the mounting part 200 on which the wafer W is mounted has an outer diameter larger than the diameter of the wafer W, and the inner peripheral surface of the tube part 3 is close to the peripheral end of the mounting part 200 except for the portion where the recess 32 is formed. In other words, the mounting part 200 is configured so that the gas pressure loss is high between the mounting part 200 and the inner peripheral surface of the tube part 3, and the precursor gas is prevented from flowing out from between the tube part 3 and the mounting part 200. Therefore, it is possible to more reliably reduce the amount of precursor gas used.

[0048] In the above-described film forming apparatus 1, the second gas supply port 35 and the second exhaust port 36 in the cylindrical portion 3 are provided for each wafer W in each stage, but the present invention is not limited to such a configuration. Specifically, for example, the second through hole 42 and the third through hole 43 in the outer cylindrical portion 4 may be configured to be vertically elongated so as to open from the height of the uppermost wafer W to the height of the lowermost wafer W. Even in such a configuration, the placement portion 200 is close to the inner peripheral surface of the cylindrical portion 3, so that the reaction gas or purge gas supplied onto one wafer W is exhausted while being suppressed from being supplied to the surface of the other wafer W.

[0049] In the film forming apparatus 1, the first gas supply port 31 opens on the inner circumferential surface of the cylindrical portion 3, and the precursor gas is supplied toward the first-stage recessed portion 32 located on the left. That is, the recessed portion 32 closest to one end (closest to the upper end) in the vertical direction among the multiple recessed portions 32 is provided on one of the left and right sides (left side), and the first gas supply port 31 opens on the other of the left and right sides (right side) of the inner surface of the cylindrical portion 3. However, the first gas supply port 31 is not limited to such an opening position as long as it is opened so that the precursor gas can be supplied to the surface of the first-stage wafer W. For example, the first gas supply port 31 may be provided on the top plate 30 of the cylindrical portion 3, and the precursor gas may be discharged downward toward the left end of the first-stage wafer W. However, by configuring the first gas supply port 31 to open on the inner circumferential surface of the cylindrical portion 3 as described above, the flow state of the precursor gas is uniform between the surface of the first-stage wafer W and the surface of the other wafer W. That is, a similar airflow is formed on the surface of each wafer W, and the occurrence of processing variations among the wafers W is prevented.

[0050] Furthermore, the first exhaust port 33 only needs to be able to exhaust the precursor gas after passing through the surface of the fourth-stage wafer W. Therefore, it is not limited to being provided at a height below the already-described fourth-stage wafer W, and may be open at a height between the third-stage wafer W and the fourth-stage wafer W.

[0051] Incidentally, the above-mentioned film forming apparatus 1 may be configured to supply a cleaning gas from the first gas supply port 31 after the film forming process. Specifically, in addition to the first gas supply source 52, which is a precursor gas supply source, a cleaning gas supply source is also connected to the first gas supply unit 5, and the precursor gas and the cleaning gas are switched between each other and supplied to the first gas supply unit 5. Even when the cleaning gas is supplied, the outer cylindrical part 4 is set to the first position, so that the gas is exhausted from the first exhaust port 33, forming a meandering flow. The cleaning gas removes the film formed in the cylindrical part 3 and on the wafer boat 2. However, during this cleaning, the wafer boat 2 is made to support, for example, a dummy wafer that is not intended for the manufacture of semiconductor products, instead of the wafer W. In the cleaning performed as described above, the cleaning gas meanders and remains relatively long from when it is supplied into the cylindrical part 3 until it is exhausted from the cylindrical part 3. Therefore, the inside of the cylindrical part 3 and the wafer boat 2 can be cleaned with a relatively small supply amount of cleaning gas.

[0052] Furthermore, the substrate processing apparatus is not limited to film formation processing, and may be, for example, an etching apparatus for etching a wafer W, in which case an etching gas is supplied as the first gas. Also, it may be configured as an annealing apparatus for heating the wafer W while supplying an inert gas as the first gas to the wafer W. Even in these cases, it is possible to reduce the supply amount of the etching gas or inert gas, thereby reducing the cost required for processing. Note that the film formation apparatus is not limited to performing ALD, and may also perform CVD (Chemical Vapor Deposition). In that case, a gas for film formation may be supplied as the first gas.

[0053] Next, a modified example of the film forming apparatus 1 will be described with reference to Figs. 12 to 14, focusing on the differences from the film forming apparatus 1. Figs. 12 and 13 show longitudinal sections along the X-axis and Y-axis of the apparatus, respectively, and Fig. 14 shows a transverse plane of the apparatus. In the film forming apparatus of this modified example, the outer cylindrical part 4 is not provided, and exhaust pipes 110 and 111 are connected to the first exhaust port 33 and the second exhaust port 36 of the cylindrical part 3, respectively. The other ends of the exhaust pipes 110 and 111 are connected to, for example, a common exhaust part 12. Valves V1 and V2 are provided in the exhaust pipes 110 and 111, respectively. First, the valve V1 is opened so as to exhaust from the first exhaust port 33, and the valve V2 is closed. Then, the precursor gas is supplied from the first gas supply part 5, and the process of step S1 described above is performed. Next, when the supply of the precursor gas is completed, the valve V1 is closed and the valve V2 is opened. This switches to exhaust from the second exhaust port 36. Further, purge gas, O3 gas, and purge gas are supplied in this order from the second gas supply unit 6, and the processes of steps S2 to S4 described above are performed. As in the film formation apparatus 1, the processes of steps S1 to S4 are repeated in the apparatus of this modified example to perform ALD.

[0054] In this way, the position of the exhaust port to be used may be switched by opening and closing the valve instead of rotating the outer cylinder portion 4, thereby switching the form of the airflow formed inside the cylinder portion 3. In the device of this modified example, a state in which valve V1 is opened so that air is exhausted from the first exhaust port 33 and valve V2 is closed corresponds to a first state, and a state in which valve V1 is closed so that air is exhausted from the second exhaust port 33 and valve V2 is open corresponds to a second state. Valves V1 and V2 correspond to a switching mechanism.

[0055] In the apparatus of this modified example, the processing vessel 10 does not have to be provided outside the cylindrical part 3. That is, the cylindrical part 3 may be configured as a processing vessel, so that the side wall of the cylindrical part 3 becomes the side wall of the processing vessel, and each exhaust port and gas supply port may open to the processing vessel. That is, the apparatus is not limited to the configuration in which the side wall of the cylindrical part 3 and the side wall of the processing vessel 10 are separate bodies as in the film forming apparatus 1, and each exhaust port and gas supply port are provided in the cylindrical part 3.

[0056] Incidentally, in the apparatus of this modified example, the location of the first exhaust port 33 may be the first gas supply port, and the location of the first gas supply port 31 may be the first exhaust port. That is, the apparatus may be configured so that the precursor gas flows in a serpentine flow from below to above. In the case where the precursor gas flows upward in this manner, the first gas supply port is not limited to opening at a height below the fourth wafer W shown in the figure, and may open at a height between the third wafer W and the fourth wafer W, since it is only necessary for the first gas to be supplied to the surface of the fourth wafer W.

[0057] Here, the arrangement of the first gas supply port 31 and the first exhaust port 33 will be summarized. The first gas supply port 31 supplies the first gas to one side in the vertical direction of the substrate support area, and the first exhaust port 33 exhausts the first gas from the other side of the substrate support area. When the one side in the vertical direction is the upper side and the other side in the vertical direction is the lower side (i.e., when the gas flows downward), the first gas supply port 31 opens above the substrate support area so that the first gas can be supplied to the surface of the uppermost wafer W. The first exhaust port 33 may open below the height between the lowermost wafer W and the wafer W one level above the lowermost wafer W so that the first gas that has passed through the surface of the lowermost wafer W can be exhausted.

[0058] On the other hand, when one side in the vertical direction is the downward side and the other side in the vertical direction is the upward side (i.e., when the gas is flowed upward), the first gas supply port 31 only needs to open below the height between the lowermost wafer W and the wafer W one level above the lowermost wafer W so that the first gas can be supplied to the surface of the lowermost wafer W. And the first exhaust port 33 only needs to open above the uppermost wafer W so that the first gas that has passed through the surface of the uppermost wafer W can be exhausted.

[0059] The number of wafers W held in the wafer boat 2 is not limited to five, and may be more or less than five. In addition, in the film forming apparatus 1, the wafer boat 2 is rotated by the rotation mechanism 25 during processing, but rotation is not necessary if the sizes and arrangements of the recesses 32, exhaust ports, and gas supply ports can be appropriately adjusted to perform processing with high uniformity within the surface of each wafer W.

[0060] As discussed above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

[0061] [Verification test] Using the film forming apparatus 1 shown in the embodiment of the present disclosure, the pressure distribution inside the tube portion 3 and the state of airflow formation by the gas when the outer tube portion 4 is aligned to the first position and gas is supplied from the first gas supply portion 5 were obtained by simulation. The pressure distribution inside the tube portion 3 and the state of airflow formation by the gas when the outer tube portion 4 is aligned to the second position and gas is supplied from the second gas supply portion 6 were also obtained by simulation. Note that oxygen gas of 1.0×10 -5 kg / sec., and Ar gas was supplied from the second gas supply unit 6 at a flow rate of 1.0×10 -6 The purge gas flowing around the rotating shaft 24 and the outer cylinder 4 was N2 gas at a flow rate of 1.0×10 -6 In this test, the temperature of the wafer W was set to 300K, and the pressure at the exhaust port 11 of the processing chamber 10 was set to 266 Pa.

[0062] 15 and 16 are pressure distribution diagrams in the processing vessel 10 when the outer cylinder 4 is aligned to the first position and gas is supplied from the first gas supply unit 5, and when the outer cylinder 4 is aligned to the second position and gas is supplied from the second gas supply unit 6, respectively. More specifically, Figs. 15 and 16 show the pressure difference based on the pressure (266 Pa) at the exhaust port 11. In Figs. 15 and 16, the airflow obtained by the simulation is shown by arrows in a simplified manner compared to the actual one.

[0063] As shown in FIG. 15, when gas was supplied from the first gas supply unit 5, a pressure gradient was formed in the height region partitioned by the wafers W in the cylindrical portion 3 such that the pressure was lower in the lower region. According to this pressure gradient, it was confirmed that the gas formed a serpentine flow and flowed over the surface of each wafer W, as described in the embodiment, and was exhausted to the exhaust space 12A. In addition, the pressure difference between the surface of the uppermost wafer W and the surface of the lowermost wafer W was about 0.3 Pa, which is about 0.1% of the pressure of the exhaust port 11. Therefore, it is estimated that the pressure environment in which each wafer W is placed is approximately the same, and each wafer W is processed with high uniformity. Also, as shown in FIG. 16, when gas was supplied from the second gas supply unit 6, it was confirmed that an air flow from the front to the rear was formed, as described in the embodiment. The pressure in the cylindrical portion 3 was approximately uniform. Therefore, it is estimated that each wafer W is processed with high uniformity. [Explanation of symbols]

[0064] 1 Film deposition equipment 2 Wafer Boat 3 Cylinder part 10 Processing vessel 31 First gas supply port 33 First exhaust port 32 Recess W wafer

Claims

1. a processing vessel housing a substrate support that supports a plurality of substrates in a vertical direction in a shelf-like manner and including a cylindrical portion whose axis faces the vertical direction; a first gas supply port for supplying a first gas for processing each of the substrates, the first gas supply port being disposed on one side in a longitudinal direction of a substrate support region in which each of the substrates is supported within the cylindrical portion; a first exhaust port for exhausting the first gas from the other longitudinal side of the substrate support region; recesses that are located at the height of the substrates on the inner surface of the cylindrical portion and are provided alternately left and right as viewed along the vertical direction so as to form a flow path for the first gas to flow from the first gas supply port toward the first exhaust port along the surfaces of the substrates in a serpentine manner left and right; a second gas supply port formed on an inner surface of the cylindrical portion for supplying a second gas to each of the substrates; a second exhaust port that opens in an inner surface of the cylindrical portion opposite the second gas supply port and that exhausts the second gas; A substrate processing apparatus comprising:

2. 2. The substrate processing apparatus according to claim 1, wherein the second gas supply port and the second exhaust port are formed at one of the front and rear ends of the cylindrical portion, respectively.

3. a first state in which the first gas is supplied from the first gas supply port and the first gas is exhausted from the first exhaust port; a second state in which the second gas is supplied from the second gas supply port and the second gas is exhausted from the second exhaust port; 3. The substrate processing apparatus according to claim 1, further comprising a switching mechanism for switching between the above.

4. the cylindrical portion is separate from a side wall of the processing vessel, an exhaust section that exhausts an exhaust space formed between the cylindrical section and a side wall of the processing vessel; the first exhaust port and the second exhaust port are provided in the cylindrical portion, 4. The substrate processing apparatus according to claim 3, wherein the switching mechanism includes an opening / closing mechanism for opening and closing each of the first exhaust port and the second exhaust port with respect to the exhaust space.

5. The tube portion is a cylinder, The opening and closing mechanism includes an outer cylindrical portion that is provided in the processing vessel so as to surround the cylindrical portion and has an outer peripheral surface that faces the exhaust space, and that forms a cylinder coaxial with the cylindrical portion; a rotation mechanism that rotates the outer cylinder portion relative to the cylinder portion around an axis to position the outer cylinder portion at a first position and a second position, The side wall of the outer cylinder portion is provided with a first through hole that overlaps with the first exhaust port at the first position and is out of alignment with the first exhaust port at the second position; The substrate processing apparatus according to claim 4 , further comprising: a second through hole that is offset from the second exhaust port at the first position and overlaps with the second exhaust port at the second position.

6. a second gas supply unit that supplies the second gas is provided facing a side wall of the outer tubular portion in the exhaust space, The substrate processing apparatus according to claim 5 , wherein a third through hole is provided in a side wall of the outer cylindrical portion, the third through hole being out of alignment with the second gas supply portion at the first position and overlapping with the second gas supply portion at the second position.

7. Among the recesses provided alternately on the left and right, a recess located closest to one end in the vertical direction is provided on one of the left and right sides, 7. The substrate processing apparatus according to claim 5, wherein the first gas supply port opens to the other of the left and right sides of the inner surface of the cylindrical portion.

8. The one end side in the vertical direction is an upper side, the cylindrical portion includes a lid having a supply passage connected to the first gas supply port; 8. The substrate processing apparatus according to claim 4, wherein a first gas supply unit that supplies the first gas to an upstream side of the supply path is provided in the exhaust space.

9. the second gas includes a reaction gas that reacts with the first gas adsorbed on the substrate to generate a reaction product; 9. The substrate processing apparatus according to claim 3, wherein the first state and the second state are alternately repeated so that the reaction product is repeatedly deposited to form a film of the reaction product on each of the substrates.

10. The second gas is supplied in such a manner that the first gas and the reaction gas are alternately and repeatedly supplied.

10. The substrate processing apparatus of claim 9, further comprising a purge gas supplied between the supply of the first gas and the supply of the reaction gas to purge an atmosphere in the processing vessel.

11. 11. A substrate processing apparatus as described in any one of claims 1 to 10, wherein the substrate support has a support portion provided in multiple stages to support a peripheral portion of the substrate from below, and the outer peripheral edge of the support portion is closer to the inner surface of the cylindrical portion than the outer peripheral edge of the substrate.

12. an upper end of the recess is higher than an upper surface of the substrate corresponding to the recess and an upper surface of the support portion supporting the substrate; The substrate processing apparatus according to claim 11 , wherein a lower end of the recess is lower than a lower surface of the support portion.

13. supporting a plurality of substrates on a substrate support in a vertically oriented shelf-like manner; housing the substrate support in a process vessel having a cylindrical portion whose axis faces the vertical direction; supplying a first gas for processing each of the substrates from a first gas supply port to one side in a vertical direction of a substrate support region in the cylindrical portion where the substrates are supported; exhausting the first gas from another longitudinal side of the substrate support region through a first exhaust port; a step of flowing the first gas in a serpentine manner from the first gas supply port to the first exhaust port along the surfaces of the substrates, using recesses that are located on the inner surface of the cylindrical portion at the height of the substrates and that are provided alternately on the left and right as viewed in the vertical direction as flow paths; supplying a second gas to each of the substrates through a second gas supply port formed on an inner surface of the cylindrical portion; exhausting the second gas from a second exhaust port formed on an inner surface of the cylindrical portion opposite the second gas supply port; A substrate processing method comprising:

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