High-pressure annealing apparatus

Abstract

To provide a high-pressure annealing apparatus for performing heat treatment on a semiconductor wafer or a semiconductor device, in which overheating of a pressure vessel is suppressed and increase in size of the apparatus is suppressed.SOLUTION: A treatment device 1 includes a pressure vessel 3 including an end plate 6, and a cooling board 31 forming a cooling medium passage 33 through which a cooling medium flows. The end plate 6 has an inner surface 6a that is a concave curved surface, and an outer surface 6a on the opposite side of the inner surface 6b. The end plate 6 includes a required plate thickness region 26 sandwiched between the inner surface 6a and a curved face 25 separated from the inner surface 6a by a distance equal to the center plate thickness TA of the end plate 6, and an excess thickness region 27 sandwiched between the curved face 25 and the outer surface 6b outside the required plate thickness region 26. A cooling plate 31 is attached to the excess thickness region 27 in a state of abutting on the outer surface 6b part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a high pressure annealing apparatus. [Background technology]

[0002] Patent Document 1 discloses a processing apparatus for performing an annealing process on a semiconductor wafer or semiconductor device as a processing object. The processing apparatus includes a pressure vessel, the upper end of which is configured by a head plate. The inner surface of the head plate is a concave curved surface, the outer surface is a convex curved surface, and the plate thickness is constant. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-242785 Summary of the Invention [Problem to be solved by the invention]

[0004] During the annealing process, the pressure vessel may overheat. To prevent this, it is possible to install a cooling structure on the outer surface of the pressure vessel, for example, on the outer surface of the head plate. However, in order to fix the cooling structure to the head plate, it is necessary to increase the thickness of the head plate, which leads to an increase in the size of the processing equipment.

[0005] An object of the present invention is to provide a high-pressure annealing apparatus that can prevent the pressure vessel from overheating and can prevent the apparatus from becoming large in size. [Means for solving the problem]

[0006] One aspect of the present invention provides a high-pressure annealing treatment apparatus for heat treatment of semiconductor wafers or semiconductor devices, comprising a pressure vessel including a head plate and a cooling plate forming a cooling medium passage through which a cooling medium flows, the head plate having an inner surface which is a concave curved surface and an outer surface opposite the inner surface, the head plate including a required thickness region sandwiched between the inner surface and a curved surface spaced from the inner surface by a distance equal to the thickness of the central part of the head plate, and an excess thickness region sandwiched between the curved surface and the outer surface outside the required thickness region, the cooling plate being attached to the excess thickness region in a state where it abuts the outer surface.

[0007] According to the above-mentioned configuration, the cooling plate forming the cooling medium passage is attached in contact with the outer surface of the head plate, and heat exchange between the cooling medium and the head plate can prevent overheating of the pressure vessel.

[0008] A required thickness region and an excess thickness region are set for the head plate. The required thickness region is the region sandwiched between the inner surface and a curved surface that is equidistant from the inner surface to the thickness of the center of the head plate. The required thickness region corresponds to the overall shape of a conventional head plate with a constant thickness, and the curved surface corresponds to the outer surface of a conventional head plate. On the other hand, the outer surface of the head plate in this case is located on the opposite side of the curved surface from the inner surface. The excess thickness region is the region sandwiched between the curved surface and the outer surface and outside the required thickness region.

[0009] Here, the plate thickness can be defined as the dimension between the inner surface and the outer surface. The required plate thickness region is set based on the plate thickness at the center of the head plate, so there is no excess material region or the excess material region is very thin at the center of the head plate. The excess material region is set radially outward from the center of the head plate. The plate thickness of the head plate at the center is equivalent to that of a conventional head plate, but is greater than that of a conventional head plate at the radially outward.

[0010] The inner surface is a concave curve, i.e., it curves radially outward from the center toward the inside in the axial direction of the pressure vessel. Therefore, even if an extra pad area is provided on the radially outer side, the outer surface on the radially outer side can be positioned at the same position in the axial direction as the outer surface of the central part or further inward. In other words, the extra pad area can be provided without increasing the overall height of the pressure vessel or the size of the high-pressure annealing treatment device.

[0011] As described above, the cooling plate is attached to the excess thickness region where the plate thickness is relatively large, and therefore the cooling plate can be firmly fixed to the pressure vessel.

[0012] As described above, with the above configuration, in the high-pressure annealing apparatus, it is possible to both prevent the pressure vessel from overheating and prevent the apparatus from becoming large.

[0013] The cooling plate may be fixed to the excess pad area with bolts.

[0014] According to the above configuration, it is easy to ensure the axial dimensions of the bolts and holes, and the cooling plate can be firmly fixed to the pressure vessel.

[0015] The high-pressure annealing treatment apparatus may further include a seal interposed between the outer surface and the cooling plate and surrounding the area in which the cooling medium passage is formed, and the cooling plate may be fixed to the excess material area outside the seal with the bolts.

[0016] According to the above configuration, the seal can prevent leakage of the cooling medium. Since the fastening point is set outside the seal, the cooling medium can be prevented from entering the fastening point.

[0017] The excess pad region may be provided with a recess recessed from the outer surface side to the inner surface side, and the cooling plate may have a protrusion that fits into the recess.

[0018] According to the above configuration, the cooling plate can be easily positioned on the end plate by utilizing the fitting of the recessed portion and the protruding portion. Since the cooling plate has high rigidity, the cooling plate and therefore the cooling medium passages are less likely to deform, and leakage of the cooling medium can be suppressed.

[0019] The outer surface may include a flat surface.

[0020] According to the above configuration, it is easy to keep the cooling plate in contact with the outer surface of the end plate. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a high-pressure annealing apparatus that can prevent the pressure vessel from overheating and can prevent the apparatus from becoming large in size. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a cross-sectional view of a high-pressure annealing apparatus according to an embodiment. [Figure 2] Enlarged view of Figure 1. [Figure 3] FIG. [Figure 4] FIG. 10 is a partial cross-sectional view of a high-pressure annealing apparatus according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments will be described with reference to the drawings. Note that the same or corresponding elements are designated by the same reference numerals throughout the drawings, and detailed descriptions thereof will be omitted.

[0024] Referring to FIG. 1, a high-pressure annealing apparatus according to an embodiment (hereinafter simply referred to as "processing apparatus 1") is installed in a clean room (not shown) of a semiconductor manufacturing facility. The processing apparatus 1 performs a heat treatment (annealing treatment) on a semiconductor wafer or semiconductor device as a workpiece 90. The heat treatment is performed at high temperature and high pressure in a processing space filled with a processing gas. Examples of heat treatment include solid-phase diffusion, crystal recovery, silicide formation, and gettering. The processing gas is flammable or toxic, and is, for example, hydrogen gas, deuterium gas, fluorine gas, chlorine gas, ammonia gas, or a combination thereof.

[0025] The processing device 1 is cylindrical overall with a central axis A. Unless otherwise specified, the "axial direction," "radial direction," and "circumferential direction" are based on this central axis A. In this embodiment, the central axis A is oriented vertically, for example. Hereinafter, for ease of explanation, one side of the axial direction may be referred to as "upper" and the other side as "lower." However, this direction is merely an example and may be changed as appropriate depending on the installation posture of the processing device 1.

[0026] The processing apparatus 1 includes a frame 2 , a pressure vessel 3 , an inner chamber 11 , a product table 12 , a heater 13 , a jacket 15 , a control device 16 , and a temperature sensor 17 .

[0027] The frame 2 is placed on the floor of a clean room (not shown). The pressure vessel 3 is supported by the frame 2. The pressure vessel 3 includes an outer chamber 4 and a closure 8, which form an internal space 20. A sealant (not shown) is installed between these components (the outer chamber 4 and the closure 8), keeping the internal space 20 airtight.

[0028] The outer chamber 4 has a cylindrical body 5 and a head 6 provided at one end of the body 5. The head 6 forms one end of the pressure vessel 3 as a whole. The other end of the body 5 is open.

[0029] The inner chamber 11 is housed in the pressure vessel 3. In other words, the pressure vessel 3 surrounds the inner chamber 11. The inner chamber 11 is cylindrical with one end closed and the other end open, with a bottom. The inner chamber 11 divides the internal space 20 of the pressure vessel 3 into a processing space 21 and a container space 22. The processing space 21 is formed inside the inner chamber 11. The container space 22 is formed outside the inner chamber 11 and inside the pressure vessel 3.

[0030] The closure 8 is disk-shaped and releasably closes the processing space 21. The closure 8 is axially displaceable between a closed position where the closure 8 closes the processing space 21 and an open position where the closure 8 is separated from the outer chamber 4 and opens the processing space 21.

[0031] A product stage 12 is fixed to the inner surface of the closure 8, and the product stage 12 removably supports the workpiece 90. When the closure 8 is in the open position, the workpiece 90 before heat treatment is transferred to the product stage 12. When the closure 8 is shifted to the closed position, the product stage 12 and the workpiece 90 are housed in the treatment space 21. In this state, the heat treatment is performed. During the heat treatment, a high-pressure treatment gas is filled into the treatment space 21. When the heat treatment is completed, the closure 8 is shifted to the open position, and the workpiece 90 after heat treatment is transferred from the product stage 12.

[0032] The heater 13 operates during heat treatment. The heater 13 is housed in the vessel space 22 and is arranged along the outer surface of the inner chamber 11. The heat generated by the heater 13 is transferred to the processing space 21 via the inner chamber 11, thereby heating the workpiece 90. Because the heater 13 is arranged outside the processing space 21, particles that may be generated in the heater 13, etc., can be prevented from entering the processing space 21.

[0033] During the heat treatment, the pressure vessel 3 is heated. The jacket 15 is cylindrical and is attached to the outer periphery of the barrel 5. A cooling medium (e.g., water) flows through the space between the inner periphery of the jacket 15 and the outer periphery of the barrel 5, thereby cooling the pressure vessel 3, particularly the barrel 5. Note that sealing materials are provided at both axial ends of the jacket 15 to prevent leakage of the cooling medium.

[0034] The control device 16 controls the operation of the closure 8. The control device 16 also controls the internal temperature and pressure of the processing space 21 during heat treatment. The temperature sensor 17 is an example of a sensor that acquires information necessary for performing such control, and detects the internal temperature of the processing space 21.

[0035] A contact point 51 (temperature measuring contact point) of the temperature sensor 17 is installed inside the pressure vessel 3, for example, on the outer periphery of the product stage 12. The contact point 51 is connected to the control device 16 via a wiring 52. The control device 16 is installed outside the pressure vessel 3. The wiring 52 passes through the pressure vessel 3.

[0036] The processing apparatus 1 further includes a cooling mechanism 30 and a sealing mechanism 60. The sealing mechanism 60 prevents the processing gas from leaking from the processing space 21 to the outside of the pressure vessel 3 through the hole through which the wiring 52 passes. Note that the sealing mechanism 60 can also be applied to sensors other than the temperature sensor 17.

[0037] The cooling mechanism 30 will be described below with reference to Figures 1 to 3. Note that in Figure 2, the contents of the pressure vessel 3 are not shown.

[0038] 1, the cooling mechanism 30 has a cooling plate 31 that forms a cooling medium passage 33 through which a cooling medium flows. The cooling plate 31 is a metal plate having a first surface 31a that faces the end plate 6 and abuts against the outer surface 6b, and a second surface 31b opposite to the first surface 31a.

[0039] The cooling plate 31 has an abutment portion 32 that abuts against the outer surface 6b of the head plate 6 and is attached to the head plate 6, and a frame fixing portion 39 that is fixed to the frame 2. The abutment portion 32 is circular when viewed in the axial direction and has a diameter that is approximately equal to the outer diameter of the pressure vessel 3. The frame fixing portion 39 protrudes radially outward from the outer peripheral edge of the abutment portion 32 and is fastened to the frame 2. The pressure vessel 3 is suspended from the abutment portion 32 and is supported by the frame 2 via the cooling plate 31.

[0040] Referring to FIG. 2, the inner surface 6a of the head plate 6 is a concave curved surface and defines an internal space 20. The type of concave curved surface is not particularly limited and may be a sphere, an ellipsoid, a paraboloid, a hyperboloid, or any other curved surface. The outer surface 6b of the head plate 6 is opposite the inner surface 6a. The head plate 6 includes a required thickness region 26 and an excess thickness region 27. The required thickness region 26 is a region sandwiched between the inner surface 6a and the curved surface 25. The excess thickness region 27 is a region sandwiched between the curved surface 25 and the outer surface 6b and is located outside the required thickness region 26. The curved surface 25 is virtually imagined inside the head plate 6 and forms a boundary between the required thickness region 26 and the excess thickness region 27. The curved surface 25 is spaced from the inner surface 6a by a distance equal to the thickness of the center of the head plate 6 (hereinafter referred to as the "center thickness TA").

[0041] The thickness of the head plate 6 is the dimension between the inner surface 6a and the outer surface 6b. At the center of the head plate 6, the dimension between the inner surface 6a and the outer surface 6b is the central thickness TA, which defines the required thickness region 26. In other words, there is no or almost no excess material region 27. The central thickness TA is the value required for pressure resistance.

[0042] The inner surface 6a is a concave curved surface, and therefore curves inward (the other side, the lower side) in the axial direction from the center toward the radially outward direction. The outer surface 6b extends from the center toward the radially outward direction, further outward (one side, the upper side) in the axial direction than the curved surface 25. This provides an excess pad region 27. In this embodiment, the outer surface 6b is a flat surface perpendicular to the central axis A. The axial dimension of the excess pad region 27 increases as it moves away from the center of the end plate 6 toward the radially outward direction.

[0043] On the other hand, the first surface 31a of the cooling plate 31 has a shape that matches the outer surface 6b. In this embodiment, the first surface 31a is a flat surface like the outer surface 6b, and is in surface contact with the outer surface 6b.

[0044] The cooling medium passages 33 are provided in the abutment portion 32. Specifically, non-penetrating grooves are formed in the first surface 31a. When the cooling plate 31 is attached to the end plate 6, these grooves are closed by the outer surface 6b of the end plate 6, thereby forming the cooling medium passages 33.

[0045] 3 is a bottom view showing the first surface 31a of the abutment portion 32. In FIG. 3, the frame fixing portion 39 (see FIG. 1) is not shown, and the coolant passage 33 is indicated by a cross-hatched area. As a mere example, the coolant passage 33 includes a circular center portion 33a, a first annular ring portion 33b surrounding the outer periphery of the center portion 33a, a second annular ring portion 33c surrounding the outer periphery of the first ring portion 33b, a first connecting portion 33d radially connecting the center portion 33a and the first ring portion 33b, and a second connecting portion 33e radially connecting the first ring portion 33b and the second ring portion 33c.

[0046] The center portion 33a, the first ring portion 33b, and the second ring portion 33c are concentric, and their centers coincide with the central axis A when the cooling plate 31 is assembled to the end plate 6. The central axis A passes through the center of the cooling plate 31, the center portion 33a of the cooling medium passage 33, and the center of the end plate 6. The center portion of the cooling plate 31, the center portion 33a of the cooling medium passage 33, and the center portion of the end plate 6 are all located near the central axis A. The excess pad region 27 is located outside the center portion 33a of the cooling medium passage 33.

[0047] The cooling plate 31 is provided with an inlet 34a through which the cooling medium flows into the cooling medium passage 33 and an outlet 34b through which the cooling medium flows out of the cooling medium passage 33. In the illustrated example, the inlet 34a opens to the second ring portion 33c, and the outlet 34b opens to the center portion 33a. The second connecting portion 33e is disposed at a position radially opposite the inlet 34a, and the first connecting portion 33d is disposed at a position radially opposite the second connecting portion 33e. This allows the cooling medium to be distributed evenly throughout the entire cooling medium passage 33 from the time it flows into the second ring portion 33c until it flows out from the center portion 33a.

[0048] 2, the cooling mechanism 30 includes a seal 41 interposed between the outer surface 6b and the cooling plate 31. The seal 41 is, for example, an O-ring, and surrounds the area where the coolant passage 33 is formed. A closed-ring groove 32a is provided in the first surface 31a of the abutment portion 32 outside the coolant passage 33 (specifically, on the outer circumferential side of the second ring portion 33c) (see also FIG. 3). The seal 41 is housed in this groove 32a.

[0049] The abutment portion 32 is provided with a plurality of insertion holes 32b that open to the first surface 31a and the second surface 31b. The plurality of insertion holes 32b are arranged at intervals in the circumferential direction, radially outward of the groove 32a and the seal 41 (see also FIG. 3). On the other hand, a plurality of female threaded holes 6c are provided in the excess pad region 27 of the end plate 6. The female threaded holes 6c open to the outer surface 6b and do not penetrate through. In this embodiment, the female threaded holes 6c do not reach the required plate thickness region 26, but terminate within the excess pad region 27.

[0050] The abutment portion 32 is positioned circumferentially and radially relative to the end plate 6 so that the multiple insertion holes 32b are axially aligned with the multiple female threaded holes 6c. Bolts 42 are inserted into the corresponding insertion holes 32b from the second surface 31b side and screwed into the corresponding female threaded holes 6c. This fixes the cooling plate 31 to the excess material region 27 on the outside of the seal 41 with the bolts 42. Tightening the bolts 42 crushes the seal 41, sealing the cooling medium passage 33.

[0051] The processing apparatus 1 according to this embodiment comprises a pressure vessel 3 including a head plate 6 and a cooling plate 31 forming a cooling medium passage 33 through which a cooling medium flows. The head plate 6 has an inner surface 6a, which is a concave curved surface, and an outer surface 6b opposite the inner surface 6a. The head plate 6 includes a required thickness region 26 sandwiched between the inner surface 6a and a curved surface 25 spaced from the inner surface 6a by a distance equal to the thickness of the center of the head plate 6 (central thickness TA), and an excess thickness region 27 sandwiched between the curved surface 25 and the outer surface 6b outside the required thickness region 26. The cooling plate 31 is attached to the excess thickness region 27 in a state of contact with the outer surface 6b.

[0052] In this way, the cooling plate 31 forming the cooling medium passage 33 is attached in contact with the outer surface 6b of the head plate 6. Heat exchange between the cooling medium and the head plate 6 can prevent the pressure vessel 3 from overheating.

[0053] When the outer surface 6b is a flat surface extending perpendicular to the axis, the axial position of the outer surface 6b remains the same between the center and the radially outer side. The inner surface 6a curves inward in the axial direction from the center toward the radially outer side. In this way, an excess pad area 27 can be provided on the radially outer side of the head plate 6 without increasing the overall axial dimension of the pressure vessel 3. The cooling plate 31 is attached to this excess pad area 27. Therefore, the cooling plate 31 can be firmly attached to the head plate 6 without increasing the size of the processing apparatus 1.

[0054] The cooling plate 31 is fixed to the excess material region 27 outside the seal 41 with bolts 42. This prevents leakage of the cooling medium with the seal 41. Because the fastening point is set outside the seal 41, it is possible to prevent the cooling medium from entering the fastening point.

[0055] The outer surface 6b is a flat surface. Since the cooling plate 31 can be easily brought into surface contact with the end plate 6, the work of assembling the cooling plate 31 to the end plate 6 can be easily performed. In addition, the sealing performance of the cooling medium passage 33 is improved.

[0056] FIG. 4 is a partial cross-sectional view of a processing device 1 according to a modified example. A recess 6d may be provided in the excess pad region 27. In this case, a protrusion 38 that fits into the recess 6d is provided in the abutting portion 32. The recess 6d is recessed from the outer surface 6b side toward the inner surface 6a side. The recess 6d does not reach the required plate thickness region 26, and the bottom surface of the recess 6d is within the excess pad region 27. The protrusion 38 is provided on the outer peripheral edge of the abutting portion 32. The surface of the protrusion 38 forms part of the first surface 31a that abuts against the end plate. Both the bottom surface of the recess 6d and the surface of the protrusion 38 are flat.

[0057] According to this modification, the fitting of the recessed portion 6d and the protruding portion 38 is utilized to easily position the cooling plate 31 on the end plate 6. Furthermore, the provision of the protruding portion 38 increases the rigidity of the cooling plate 31. As a result, the cooling plate 31 and therefore the cooling medium passage 33 are less likely to deform, and leakage of the cooling medium can be suppressed.

[0058] The seal 41 and the bolt 42 may be provided on the protrusion 38. Also, a part of the cooling medium passage 33 may be provided on the protrusion 38. This allows the outer peripheral part of the cooling medium passage 33 to be positioned further inward, which can improve cooling performance.

[0059] Although the embodiment has been described above, the above configuration can be modified as appropriate within the scope of the spirit of the present invention.

[0060] The outer surface 6b of the end plate 6 is not limited to a flat surface and may be a curved surface. When the outer surface 6b is a curved surface, the curvature of the outer surface 6b is gentler than the curvature of the curved surface 25 due to the formation of the excess pad region 27. [Explanation of symbols]

[0061] 1 Processing equipment 2 frames 3. Pressure vessels 4 outer chamber 5. Torso 6 Headboard 6a Inner surface 6b Outer surface 6c female thread hole 6d recess 8 Closures 11 Inner chamber 12 Product stand 13 Heater 15 Jacket 16 Control device 17 Temperature Sensor 20 Interior Space 21 Processing Space 22 Container space 25 Curved surface 26 Required plate thickness area 27 Extra meat area 30 Cooling mechanism 31 Cooling board 31a 1st surface 31b 2nd surface 32 Contact part 32a groove 32b Insertion hole 33 Cooling medium passage 33a center 33b First Ring 33c Second Ring 33d First connection part 33e Second connection part 34a Inlet 34b Outlet 38 Convex part 39 Frame fixing part 41 Seal 42 volts 51 Contact point 52 Wiring 60 Sealing mechanism 90 Processing object A center axis TA center thickness

Claims

1. A high-pressure annealing apparatus for performing heat treatment on a semiconductor wafer or a semiconductor device, comprising: a pressure vessel including a head; a cooling plate forming a cooling medium passage through which a cooling medium flows; Equipped with The end plate has an inner surface that is a concave curved surface and an outer surface opposite to the inner surface, The end plate includes a required thickness region sandwiched between the inner surface and a curved surface spaced from the inner surface by a distance equal to the thickness of the central portion of the end plate, and an excess thickness region sandwiched between the curved surface and the outer surface outside the required thickness region, The cooling plate is attached to the excess pad area in a state of contact with the outer surface. High pressure annealing treatment equipment.

2. The cooling plate is fixed to the excess material area with bolts. The high pressure annealing apparatus according to claim 1 .

3. a seal interposed between the outer surface and the cooling plate and surrounding an area in which the cooling medium passage is formed; The cooling platen is fixed to the excess material area outside the seal by the bolts. The high pressure annealing apparatus according to claim 2 .

4. The excess pad region is provided with a recess recessed from the outer surface side to the inner surface side, The cooling plate has a protrusion that fits into the recess. The high pressure annealing apparatus according to claim 1 .

5. the outer surface includes a flat surface; 5. The high-pressure annealing apparatus according to claim 1.

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