Heat treatment equipment

Abstract

To provide heat treatment equipment capable of easily adjusting the illuminance distribution.SOLUTION: A distribution adjustment section 90 is placed between a semiconductor wafer held in a chamber and a flash lamp. The distribution adjustment section 90 consists of a plurality of filters 35 inside an accommodation body 91. The accommodation body 91 is structured by placing a plurality of bar-shaped members 93 in grid-like fashion over the inside a cylindrical tubular body 92. The plurality of bar-shaped members 93 are assembled in a grid of equilateral triangles to form a plurality of equilateral triangular accommodation spaces 94 surrounded by a frame of the bar-shaped members 93. The filter 35 is fitted into any of the plurality of accommodation spaces 94. The filter 35 reduces light in a predetermined wavelength range from the transmitted light. The illuminance distribution can be adjusted simply by fitting the filter 35 into the required accommodation space 94, without replacing the entire distribution adjustment section 90, and the appropriate illuminance distribution can be obtained quickly.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a heat treatment apparatus for heating a substrate by irradiating the substrate with light, for example, a semiconductor wafer, a substrate for a liquid crystal display device, a substrate for a flat panel display (FPD), a substrate for an optical disk, a substrate for a magnetic disk, or a substrate for a solar cell. [Background technology]

[0002] Flash lamp annealing (FLA), which heats semiconductor wafers in an extremely short time, has been attracting attention in the semiconductor device manufacturing process. Flash lamp annealing is a heat treatment technique that uses a xenon flash lamp (hereinafter, simply "flash lamp" means a xenon flash lamp) to irradiate the surface of a semiconductor wafer with a flash of light, thereby raising the temperature of only the surface of the semiconductor wafer in an extremely short time (several milliseconds or less).

[0003] The spectral distribution of radiation from a xenon flash lamp is in the ultraviolet to near infrared range, and has a shorter wavelength than conventional halogen lamps, which almost matches the fundamental absorption band of silicon semiconductor wafers. Therefore, when a semiconductor wafer is irradiated with flash light from a xenon flash lamp, there is little transmitted light, and it is possible to rapidly heat the semiconductor wafer. It has also been found that if the flash light is irradiated for an extremely short period of time, less than a few milliseconds, it is possible to selectively heat only the vicinity of the surface of the semiconductor wafer.

[0004] Such flash lamp annealing is used in processes that require heating for an extremely short time, such as activating impurities typically implanted in semiconductor wafers. By irradiating the surface of a semiconductor wafer into which impurities have been implanted by ion implantation with a flash light from a flash lamp, the surface of the semiconductor wafer can be heated to the activation temperature for an extremely short time, and only the impurity activation can be performed without deep diffusion of the impurities.

[0005] When a semiconductor wafer is heated by flash light irradiation, the temperature distribution may vary due to non-uniformity in the illuminance distribution within the wafer surface. For this reason, for example, Patent Document 1 discloses a method for improving the uniformity of the illuminance distribution within the wafer surface by providing a distribution adjustment member in which a concave or convex lens is fitted into a quartz positioning plate. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-21828 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, when a flash light having an extremely strong intensity is irradiated, a part of the distribution adjustment member may be damaged by vibration or the like. In such a case, in the device disclosed in Patent Document 1, it is necessary to replace the entire distribution adjustment member, which leads to an increase in costs. For this reason, there is a demand for a simpler method of treating the distribution adjustment member. In addition, it is preferable to obtain an arbitrary illuminance distribution, rather than simply making the illuminance distribution uniform.

[0008] The present invention has been made in view of the above problems, and has an object to provide a heat treatment apparatus capable of easily adjusting the illuminance distribution. [Means for solving the problem]

[0009] In order to solve the above problems, a first aspect of the present invention is a heat treatment apparatus for heating a substrate by irradiating the substrate with light, the heat treatment apparatus comprising: a chamber for accommodating a substrate; a holding unit for holding the substrate in the chamber; a light irradiating unit for irradiating light onto the substrate held in the holding unit; and a distribution adjustment unit for adjusting the illuminance distribution of the light irradiated onto the substrate from the light irradiating unit, the distribution adjustment unit including a storage body having a plurality of storage spaces surrounded by a frame by combining a plurality of rod-shaped members in a lattice pattern; and an optical element fitted into one of the plurality of storage spaces and providing an optical effect to light emitted from the light irradiating unit and reaching the storage space.

[0010] In a second aspect, in the heat treatment device according to the first aspect, the accommodation space has a polygonal planar shape.

[0011] In a third aspect, in the heat treatment device according to the second aspect, the planar shape of the accommodation space is an equilateral triangle, a square, or a regular hexagon.

[0012] In addition, a fourth aspect is the heat treatment device according to any one of the first to third aspects, wherein the optical elements are accommodated in the accommodation space in a stacked manner.

[0013] In addition, a fifth aspect is a heat treatment device according to the fourth aspect, wherein the number of stacked optical elements accommodated in a central storage space facing the center of the substrate among the multiple storage spaces is greater than the number of stacked optical elements accommodated in a peripheral storage space facing the peripheral portion of the substrate.

[0014] In addition, a sixth aspect is a heat treatment device according to the fourth aspect, wherein the number of stacked optical elements accommodated in a peripheral storage space facing the peripheral portion of the substrate among the multiple storage spaces is greater than the number of stacked optical elements accommodated in a central storage space facing the central portion of the substrate.

[0015] In a seventh aspect, in the heat treatment device according to any one of the first to sixth aspects, the container is made of quartz.

[0016] In an eighth aspect, in the heat treatment device according to any one of the first to seventh aspects, the optical element is a filter that attenuates light of a predetermined wavelength from the light emitted from the light irradiation unit. Effect of the Invention

[0017] According to the heat treatment apparatus of the first to eighth aspects, a plurality of storage spaces surrounded by a frame are formed by combining a plurality of rod-shaped members in a lattice pattern, and an optical element is fitted into one of the plurality of storage spaces. Therefore, it is possible to easily adjust the illuminance distribution by simply fitting the optical element into the required storage space without replacing the entire distribution adjustment unit. [Brief description of the drawings]

[0018] [Figure 1] 1 is a vertical cross-sectional view showing a configuration of a heat treatment apparatus according to the present invention. [Diagram 2] FIG. 2 is a perspective view showing the overall appearance of a holding portion. [Diagram 3] FIG. [Figure 4] FIG. 2 is a cross-sectional view of a susceptor. [Diagram 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 2 is a plan view showing an arrangement of a plurality of halogen lamps. [Figure 8] FIG. 4 is a perspective view showing the appearance of a distribution adjustment unit. [Figure 9] FIG. 4 is a plan view of the distribution adjustment section as seen from above. [Figure 10] FIG. 2 is a perspective view showing an example of a rod-shaped member. [Figure 11] FIG. 2 is a perspective view showing an example of a rod-shaped member. [Figure 12] FIG. 2 is a perspective view showing an example of a rod-shaped member. [Figure 13] FIG. 2 is a perspective view showing an example of a filter. [Figure 14] FIG. 11 is a perspective view showing another example of a filter. [Figure 15]11 is a diagram showing an example of variation in in-plane temperature distribution that occurs when a distribution adjustment section is not provided. FIG. [Figure 16] 13A and 13B are diagrams illustrating another example of the variation in the in-plane temperature distribution that occurs when no distribution adjustment section is provided. [Figure 17] FIG. 11 is a diagram showing a schematic diagram of a laminated state of a plurality of filters in the second embodiment. [Figure 18] FIG. 13 is a diagram illustrating a stacked state of a plurality of filters in a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. In the following, expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) not only strictly indicate the positional relationship, but also indicate a state in which the relative angle or distance is displaced within a range in which a tolerance or similar function is obtained, unless otherwise specified. Furthermore, expressions indicating an equal state (e.g., "same," "equal," "homogeneous," etc.) not only indicate a state in which the relative position is strictly equal quantitatively, but also indicate a state in which there is a difference in which a tolerance or similar function is obtained, unless otherwise specified. Furthermore, expressions indicating a shape (e.g., "circular," "square," "cylindrical," etc.) not only indicate a geometrically strict shape, but also indicate a shape within a range in which a similar effect is obtained, and may have, for example, unevenness or chamfering. Furthermore, each expression such as "comprises," "includes," "has," "includes," and "has" for a component is not an exclusive expression that excludes the presence of other components. In addition, the expression "at least one of A, B, and C" includes "A only," "B only," "C only," "any two of A, B, and C," and "all of A, B, and C."

[0020] First Embodiment FIG. 1 is a vertical cross-sectional view showing the configuration of a heat treatment apparatus 1 according to the present invention. The heat treatment apparatus 1 in FIG. 1 is a flash lamp annealing apparatus that heats a disk-shaped semiconductor wafer W as a substrate by irradiating the semiconductor wafer W with flash light. The size of the semiconductor wafer W to be treated is not particularly limited, but is, for example, φ300 mm or φ450 mm (φ300 mm in this embodiment). Impurities are implanted into the semiconductor wafer W before it is carried into the heat treatment apparatus 1, and activation processing of the implanted impurities is performed by the heat treatment by the heat treatment apparatus 1. Note that in FIG. 1 and the subsequent figures, the dimensions and numbers of each part are exaggerated or simplified as necessary for easy understanding.

[0021] The heat treatment apparatus 1 includes a chamber 6 that accommodates a semiconductor wafer W, a flash heating unit 5 that incorporates a plurality of flash lamps FL, and a halogen heating unit 4 that incorporates a plurality of halogen lamps HL. The flash heating unit 5 is provided on the upper side of the chamber 6, and the halogen heating unit 4 is provided on the lower side. The heat treatment apparatus 1 also includes, inside the chamber 6, a holding unit 7 that holds the semiconductor wafer W in a horizontal position, and a transfer mechanism 10 that transfers the semiconductor wafer W between the holding unit 7 and the outside of the apparatus. The heat treatment apparatus 1 also includes a control unit 3 that controls the respective operating mechanisms provided in the halogen heating unit 4, the flash heating unit 5, and the chamber 6 to perform heat treatment of the semiconductor wafer W.

[0022] The chamber 6 is configured by mounting quartz chamber windows on the top and bottom of a cylindrical chamber side portion 61. The chamber side portion 61 has a roughly cylindrical shape with openings at the top and bottom, with an upper chamber window 63 mounted and closed at the upper opening, and a lower chamber window 64 mounted and closed at the lower opening. The upper chamber window 63 constituting the ceiling of the chamber 6 is a disk-shaped member made of quartz, and functions as a quartz window that transmits the flash light emitted from the flash heating unit 5 into the chamber 6. The lower chamber window 64 constituting the floor of the chamber 6 is also a disk-shaped member made of quartz, and functions as a quartz window that transmits the light from the halogen heating unit 4 into the chamber 6.

[0023] In addition, a reflective ring 68 is attached to the upper part of the inner wall surface of the chamber side part 61, and a reflective ring 69 is attached to the lower part. Both of the reflective rings 68, 69 are formed in an annular shape. The upper reflective ring 68 is attached by fitting it from the upper side of the chamber side part 61. On the other hand, the lower reflective ring 69 is attached by fitting it from the lower side of the chamber side part 61 and fastening it with screws (not shown). In other words, both of the reflective rings 68, 69 are detachably attached to the chamber side part 61. The inner space of the chamber 6, i.e., the space surrounded by the upper chamber window 63, the lower chamber window 64, the chamber side part 61, and the reflective rings 68, 69, is defined as a heat treatment space 65.

[0024] By mounting the reflecting rings 68, 69 on the chamber side portion 61, a recess 62 is formed on the inner wall surface of the chamber 6. That is, the recess 62 is formed by a central portion of the inner wall surface of the chamber side portion 61 where the reflecting rings 68, 69 are not mounted, the lower end surface of the reflecting ring 68, and the upper end surface of the reflecting ring 69. The recess 62 is formed in an annular shape along the horizontal direction on the inner wall surface of the chamber 6, and surrounds the holder 7 that holds the semiconductor wafer W. The chamber side portion 61 and the reflecting rings 68, 69 are formed from a metal material (e.g., stainless steel) that has excellent strength and heat resistance.

[0025] Further, a transfer opening (furnace port) 66 for carrying a semiconductor wafer W into and out of the chamber 6 is formed in the chamber side portion 61. The transfer opening 66 can be opened and closed by a gate valve 185. The transfer opening 66 is connected in communication with the outer circumferential surface of the recess 62. Therefore, when the gate valve 185 opens the transfer opening 66, the semiconductor wafer W can be carried into and out of the heat treatment space 65 through the transfer opening 66 and the recess 62. Furthermore, when the gate valve 185 closes the transfer opening 66, the heat treatment space 65 in the chamber 6 becomes an airtight space.

[0026] Furthermore, a through hole 61a is formed in the chamber side 61. A radiation thermometer 20 is attached to the portion of the outer wall surface of the chamber side 61 where the through hole 61a is provided. The through hole 61a is a cylindrical hole for guiding infrared light radiated from the lower surface of a semiconductor wafer W held on a susceptor 74 (described later) to the radiation thermometer 20. The through hole 61a is provided at an incline with respect to the horizontal direction so that the axis of the through hole 61a intersects with the main surface of the semiconductor wafer W held on the susceptor 74. A transparent window 21 made of a barium fluoride material that transmits infrared light in a wavelength range that can be measured by the radiation thermometer 20 is attached to the end of the through hole 61a facing the heat treatment space 65.

[0027] Further, a gas supply hole 81 is formed in the upper part of the inner wall of the chamber 6 to supply a processing gas to the heat treatment space 65. The gas supply hole 81 is formed at a position above the recessed portion 62, and may be provided in the reflecting ring 68. The gas supply hole 81 is connected to a gas supply pipe 83 through a buffer space 82 formed in an annular shape inside the side wall of the chamber 6. The gas supply pipe 83 is connected to a processing gas supply source 85. A valve 84 is inserted in the middle of the gas supply pipe 83. When the valve 84 is opened, the processing gas is supplied from the processing gas supply source 85 to the buffer space 82. The processing gas that has flowed into the buffer space 82 flows in a spreading manner in the buffer space 82, which has a smaller fluid resistance than the gas supply hole 81, and is supplied from the gas supply hole 81 to the heat treatment space 65. As the processing gas, for example, an inert gas such as nitrogen (N2), a reactive gas such as hydrogen (H2) or ammonia (NH3), or a mixed gas of these gases can be used (nitrogen gas in this embodiment).

[0028] On the other hand, a gas exhaust hole 86 is formed in the lower part of the inner wall of the chamber 6 to exhaust the gas in the heat treatment space 65. The gas exhaust hole 86 is formed at a position lower than the recessed portion 62, and may be provided in the reflecting ring 69. The gas exhaust hole 86 is connected to a gas exhaust pipe 88 through a buffer space 87 formed in an annular shape inside the side wall of the chamber 6. The gas exhaust pipe 88 is connected to an exhaust unit 190. A valve 89 is inserted in the middle of the gas exhaust pipe 88. When the valve 89 is opened, the gas in the heat treatment space 65 is exhausted from the gas exhaust hole 86 through the buffer space 87 to the gas exhaust pipe 88. The gas supply hole 81 and the gas exhaust hole 86 may be provided in a plurality of holes along the circumferential direction of the chamber 6, or may be slit-shaped. The process gas supply source 85 and the exhaust unit 190 may be mechanisms provided in the heat treatment apparatus 1, or may be utilities of a factory in which the heat treatment apparatus 1 is installed.

[0029] A gas exhaust pipe 191 for discharging gas from within the heat treatment space 65 is also connected to the tip of the transfer opening 66. The gas exhaust pipe 191 is connected to an exhaust unit 190 via a valve 192. By opening the valve 192, the gas from within the chamber 6 is exhausted via the transfer opening 66.

[0030] 2 is a perspective view showing the overall appearance of the holder 7. The holder 7 holds a semiconductor wafer W in the chamber 6. The holder 7 is configured to include a base ring 71, a connecting portion 72, and a susceptor 74. The base ring 71, the connecting portion 72, and the susceptor 74 are all made of quartz. That is, the entire holder 7 is made of quartz.

[0031] The base ring 71 is an arc-shaped quartz member with a portion missing from the annular shape. This missing portion is provided to prevent interference between the base ring 71 and a transfer arm 11 of the transfer mechanism 10, which will be described later. The base ring 71 is placed on the bottom surface of the recess 62, and is supported by the wall surface of the chamber 6 (see FIG. 1). A plurality of connecting portions 72 (four in this embodiment) are erected on the upper surface of the base ring 71 along the circumferential direction of the annular shape. The connecting portions 72 are also quartz members, and are fixed to the base ring 71 by welding.

[0032] The susceptor 74 is supported by four connecting portions 72 provided on the base ring 71. FIG. 3 is a plan view of the susceptor 74. FIG. 4 is a cross-sectional view of the susceptor 74. The susceptor 74 includes a holding plate 75, a guide ring 76, and a plurality of substrate support pins 77. The holding plate 75 is a substantially circular flat member made of quartz. The diameter of the holding plate 75 is larger than the diameter of the semiconductor wafer W. In other words, the holding plate 75 has a larger planar size than the semiconductor wafer W.

[0033] A guide ring 76 is installed on the periphery of the upper surface of the holding plate 75. The guide ring 76 is an annular member having an inner diameter larger than the diameter of the semiconductor wafer W. For example, when the diameter of the semiconductor wafer W is φ300 mm, the inner diameter of the guide ring 76 is φ320 mm. The inner circumference of the guide ring 76 is a tapered surface that widens from the holding plate 75 upward. The guide ring 76 is made of quartz, similar to the holding plate 75. The guide ring 76 may be fused to the upper surface of the holding plate 75, or may be fixed to the holding plate 75 by a separately processed pin or the like. Alternatively, the holding plate 75 and the guide ring 76 may be processed as an integrated member.

[0034] The area of ​​the upper surface of the holding plate 75 inside the guide ring 76 is a flat holding surface 75a that holds the semiconductor wafer W. A plurality of substrate support pins 77 are provided on the holding surface 75a of the holding plate 75. In this embodiment, a total of 12 substrate support pins 77 are provided at 30° intervals along a circumference concentric with the outer circumferential circle of the holding surface 75a (the inner circumferential circle of the guide ring 76). The diameter of the circle on which the 12 substrate support pins 77 are arranged (the distance between the opposing substrate support pins 77) is smaller than the diameter of the semiconductor wafer W, and is φ270 mm to φ280 mm (φ270 mm in this embodiment) if the diameter of the semiconductor wafer W is φ300 mm. Each substrate support pin 77 is made of quartz. The substrate support pins 77 may be provided on the upper surface of the holding plate 75 by welding, or may be processed integrally with the holding plate 75.

[0035] Returning to FIG. 2, four connecting parts 72 erected on the base ring 71 and the peripheral part of the holding plate 75 of the susceptor 74 are fixed by welding. That is, the susceptor 74 and the base ring 71 are fixedly connected by the connecting parts 72. The base ring 71 of the holding part 7 is supported on the wall surface of the chamber 6, and the holding part 7 is attached to the chamber 6. When the holding part 7 is attached to the chamber 6, the holding plate 75 of the susceptor 74 is in a horizontal position (a position in which the normal line coincides with the vertical direction). That is, the holding surface 75a of the holding plate 75 is a horizontal plane.

[0036] The semiconductor wafer W carried into the chamber 6 is placed and held in a horizontal position on the susceptor 74 of the holder 7 attached to the chamber 6. At this time, the semiconductor wafer W is supported by twelve substrate support pins 77 standing on a holding plate 75 and held on the susceptor 74. More precisely, the upper ends of the twelve substrate support pins 77 contact the lower surface of the semiconductor wafer W to support the semiconductor wafer W. The heights of the twelve substrate support pins 77 (the distance from the upper ends of the substrate support pins 77 to the holding surface 75a of the holding plate 75) are uniform, so that the twelve substrate support pins 77 can support the semiconductor wafer W in a horizontal position.

[0037] Furthermore, the semiconductor wafer W is supported by a plurality of substrate support pins 77 at a predetermined distance from the holding surface 75a of the holding plate 75. The thickness of the guide ring 76 is greater than the height of the substrate support pins 77. Therefore, the guide ring 76 prevents the semiconductor wafer W supported by the plurality of substrate support pins 77 from shifting in the horizontal direction.

[0038] 2 and 3, an opening 78 is formed in the holding plate 75 of the susceptor 74, penetrating vertically. The opening 78 is provided so that the radiation thermometer 20 can receive radiation light (infrared light) emitted from the underside of the semiconductor wafer W. That is, the radiation thermometer 20 receives the light emitted from the underside of the semiconductor wafer W through the opening 78 and a transparent window 21 attached to the through hole 61a of the chamber side part 61, and measures the temperature of the semiconductor wafer W. Furthermore, the holding plate 75 of the susceptor 74 is provided with four through holes 79 through which the lift pins 12 of the transfer mechanism 10, which will be described later, pass to transfer the semiconductor wafer W.

[0039] FIG. 5 is a plan view of the transfer mechanism 10. FIG. 6 is a side view of the transfer mechanism 10. The transfer mechanism 10 includes two transfer arms 11. The transfer arms 11 are formed in an arc shape that is aligned with the generally annular recess 62. Two lift pins 12 are provided upright on each of the transfer arms 11. The transfer arms 11 and the lift pins 12 are made of quartz. Each transfer arm 11 is rotatable by a horizontal movement mechanism 13. The horizontal movement mechanism 13 horizontally moves the pair of transfer arms 11 between a transfer operation position (solid line position in FIG. 5) where the semiconductor wafer W is transferred to the holder 7 and a retracted position (double-dashed line position in FIG. 5) where the pair of transfer arms 11 do not overlap the semiconductor wafer W held by the holder 7 in a plan view. The horizontal movement mechanism 13 may be a mechanism that rotates each transfer arm 11 using an individual motor, or a mechanism that uses a link mechanism to rotate a pair of transfer arms 11 in unison using a single motor.

[0040] The pair of transfer arms 11 are raised and lowered together with the horizontal movement mechanism 13 by the lifting mechanism 14. When the lifting mechanism 14 raises the pair of transfer arms 11 to the transfer operation position, the total of four lift pins 12 pass through the through holes 79 (see FIGS. 2 and 3) formed in the susceptor 74, and the upper ends of the lift pins 12 protrude from the upper surface of the susceptor 74. On the other hand, when the lifting mechanism 14 lowers the pair of transfer arms 11 to the transfer operation position to remove the lift pins 12 from the through holes 79, and the horizontal movement mechanism 13 moves the pair of transfer arms 11 to open them, each transfer arm 11 moves to a retracted position. The retracted position of the pair of transfer arms 11 is directly above the base ring 71 of the holder 7. Since the base ring 71 is placed on the bottom surface of the recess 62, the retracted position of the transfer arms 11 is inside the recess 62. In addition, an exhaust mechanism (not shown) is provided near the location where the drive part of the transfer mechanism 10 (horizontal movement mechanism 13 and lifting mechanism 14) is located, and is configured to exhaust the atmosphere around the drive part of the transfer mechanism 10 to the outside of the chamber 6.

[0041] Returning to FIG. 1, the flash heating unit 5 provided above the chamber 6 is configured to include a light source consisting of multiple (30 in this embodiment) xenon flash lamps FL inside a housing 51, and a reflector 52 provided to cover the light source from above. A lamp light emission window 53 is attached to the bottom of the housing 51 of the flash heating unit 5. The lamp light emission window 53 forming the floor of the flash heating unit 5 is a plate-shaped quartz window made of quartz. By installing the flash heating unit 5 above the chamber 6, the lamp light emission window 53 faces the upper chamber window 63. The flash lamps FL irradiate flash light from above the chamber 6 through the lamp light emission window 53 and the upper chamber window 63 into the heat treatment space 65.

[0042] The multiple flash lamps FL are each a rod-shaped lamp having a long cylindrical shape, and are arranged in a plane such that their respective longitudinal directions are parallel to each other along the main surface of the semiconductor wafer W held by the holder 7 (i.e., along the horizontal direction). Therefore, the plane formed by the arrangement of the flash lamps FL is also a horizontal plane. The area in which the multiple flash lamps FL are arranged is larger than the planar size of the semiconductor wafer W.

[0043] The xenon flash lamp FL comprises a rod-shaped glass tube (discharge tube) filled with xenon gas and having an anode and a cathode connected to a capacitor at both ends, and a trigger electrode attached to the outer periphery of the glass tube. Since xenon gas is an electrical insulator, electricity does not flow through the glass tube under normal conditions even if an electric charge is stored in the capacitor. However, when a high voltage is applied to the trigger electrode to break down the insulation, the electricity stored in the capacitor flows instantly through the glass tube, and light is emitted by the excitation of the xenon atoms or molecules at that time. In such a xenon flash lamp FL, the electrostatic energy stored in the capacitor in advance is converted into an extremely short light pulse of 0.1 to 100 milliseconds, so that it has the characteristic of being able to irradiate extremely strong light compared to a light source that is continuously lit such as a halogen lamp HL. In other words, the flash lamp FL is a pulsed light-emitting lamp that emits light instantaneously for an extremely short time of less than one second. The light emission time of the flash lamps FL can be adjusted by the coil constant of the lamp power supply that supplies power to the flash lamps FL.

[0044] Moreover, the reflector 52 is provided above the multiple flash lamps FL so as to cover them entirely. The basic function of the reflector 52 is to reflect the flash light emitted from the multiple flash lamps FL toward the heat treatment space 65. The reflector 52 is made of an aluminum alloy plate, and its surface (the surface facing the flash lamps FL) is roughened by blasting.

[0045] The halogen heating unit 4 provided below the chamber 6 has a plurality of halogen lamps HL (40 in this embodiment) built inside the housing 41. The halogen heating unit 4 heats the semiconductor wafer W by irradiating light from the plurality of halogen lamps HL into a heat treatment space 65 from below the chamber 6 through a lower chamber window 64.

[0046] FIG. 7 is a plan view showing the arrangement of a plurality of halogen lamps HL. 40 halogen lamps HL are arranged in two tiers, upper and lower. 20 halogen lamps HL are arranged in the upper tier close to the holder 7, and 20 halogen lamps HL are also arranged in the lower tier farther from the holder 7 than the upper tier. Each halogen lamp HL is a rod-shaped lamp having a long cylindrical shape. The 20 halogen lamps HL in both the upper and lower tiers are arranged so that their longitudinal directions are parallel to each other along the main surface of the semiconductor wafer W held by the holder 7 (i.e., along the horizontal direction). Therefore, the plane formed by the arrangement of the halogen lamps HL in both the upper and lower tiers is a horizontal plane.

[0047] 7, the halogen lamps HL are arranged at a higher density in the region facing the periphery of the semiconductor wafer W held by the holder 7 in both the upper and lower tiers than in the region facing the center of the semiconductor wafer W. That is, in both the upper and lower tiers, the arrangement pitch of the halogen lamps HL is shorter in the periphery of the lamp arrangement than in the center. This makes it possible to irradiate a greater amount of light to the periphery of the semiconductor wafer W, which is prone to temperature drop during heating by light irradiation from the halogen heating unit 4.

[0048] The lamp group consisting of the halogen lamps HL in the upper row and the lamp group consisting of the halogen lamps HL in the lower row are arranged to intersect in a lattice pattern. That is, a total of 40 halogen lamps HL are arranged so that the longitudinal direction of the 20 halogen lamps HL arranged in the upper row and the longitudinal direction of the 20 halogen lamps HL arranged in the lower row are perpendicular to each other.

[0049] The halogen lamp HL is a filament type light source that emits light by passing electricity through a filament disposed inside a glass tube, which becomes incandescent. A gas consisting of an inert gas such as nitrogen or argon with a small amount of halogen elements (iodine, bromine, etc.) is sealed inside the glass tube. By introducing halogen elements, it is possible to set the temperature of the filament at a high temperature while suppressing filament breakage. Therefore, the halogen lamp HL has the characteristics of having a longer life than a normal incandescent light bulb and being able to continuously irradiate strong light. In other words, the halogen lamp HL is a continuous lighting lamp that emits light continuously for at least one second or more. In addition, since the halogen lamp HL is a rod-shaped lamp, it has a long life, and by arranging the halogen lamp HL along the horizontal direction, the radiation efficiency to the semiconductor wafer W above is excellent.

[0050] Also, a reflector 43 is provided below the two-tiered halogen lamps HL within the housing 41 of the halogen heating unit 4 (FIG. 1). The reflector 43 reflects the light emitted from the multiple halogen lamps HL toward the heat treatment space 65.

[0051] As shown in Fig. 1, a distribution adjustment unit 90 is provided on the top surface of the upper chamber window 63. The distribution adjustment unit 90 adjusts the illuminance distribution of the flash light irradiated from the flash lamps FL onto the top surface of the semiconductor wafer W. Fig. 8 is a perspective view showing the appearance of the distribution adjustment unit 90. Fig. 9 is a plan view of the distribution adjustment unit 90 as viewed from above. The distribution adjustment unit 90 is configured by housing a plurality of filters 35 inside a housing body 91.

[0052] The storage body 91 of the first embodiment is configured by suspending a plurality of rod-shaped members 93 in a lattice pattern on the inside of a cylindrical body 92. The cylindrical body 92 and the plurality of rod-shaped members 93 are both formed of quartz. The cylindrical body 92 has a cylindrical shape with an open upper end and lower end (a bottomless cylindrical shape). The diameter of the cylindrical body 92 is equal to or smaller than the diameter of the semiconductor wafer W, and when the diameter of the semiconductor wafer W is φ300 mm, the diameter of the cylindrical body 92 is 100 mm or more and 300 mm or less. The height of the cylindrical body 92 is approximately 10 mm.

[0053] A plurality of rod-shaped members 93 are hung horizontally on the inner wall of the cylindrical body 92. Figs. 10, 11 and 12 are perspective views showing examples of the rod-shaped members 93. All the rod-shaped members 93 are made of quartz and have a width of about several mm. As shown in Figs. 10 to 12, recesses 93a are formed on the upper and / or lower surfaces of the rod-shaped members 93. The recesses 93a formed on the plurality of rod-shaped members 93 are fitted together, whereby the plurality of rod-shaped members 93 are combined in a lattice pattern.

[0054] In the first embodiment, the rod-shaped members 93 are divided into three groups: a first group arranged along a first direction, a second group arranged along a second direction, and a third group arranged along a third direction. The first direction, the second direction, and the third direction are all horizontal directions and intersect with each other at an angle of 60°. That is, the rod-shaped members 93 in the first embodiment are combined in a triangular lattice shape of equilateral triangles. As a result, as shown in FIG. 9, a plurality of equilateral triangular storage spaces 94 are formed surrounded by the frames of the rod-shaped members 93.

[0055] Filters 35 are fitted into any of the multiple equilateral triangular storage spaces 94 formed by the rod-shaped members 93. The filters 35 attenuate light of a predetermined wavelength range from the light that passes through them. The filters 35 are made, for example, by adding metal ions to quartz glass. The wavelength range of light to be cut is determined by the type of metal ion added.

[0056] The shape of the filter 35 may be any shape that corresponds to the shape of the accommodation space 94. FIG. 13 is a perspective view showing an example of the filter 35. In the first embodiment, the accommodation space 94 is an equilateral triangle, so the filter 35 is shaped like a triangular prism. The shape of the filter 35 when viewed from above is an equilateral triangle, and the length of one side of the triangle is slightly shorter than the length of one side of the accommodation space 94. Therefore, the filter 35 can be fitted into the accommodation space 94. Although the lower end of the housing 91 is open, the distribution adjustment unit 90 is placed on the upper chamber window 63, so that the filter 35 fitted into the accommodation space 94 is supported by the upper chamber window 63.

[0057] 14 is a perspective view showing another example of the filter 35. The filter 35 in FIG. 14 has a flange 36 provided on the upper surface of the triangular prism shown in FIG. 13. The flange 36 has an equilateral triangular shape when viewed from above, and one side of the triangle is slightly longer than one side of the accommodation space 94. Therefore, when the filter 35 in FIG. 14 is fitted into the accommodation space 94, the flange 36 engages with the frame of the rod-shaped member 93, thereby supporting the filter 35. Which of the multiple accommodation spaces 94 the filter 35 is to be fitted into will be described later.

[0058] Returning to Fig. 1, the control unit 3 controls the various operating mechanisms provided in the heat treatment device 1. The hardware configuration of the control unit 3 is similar to that of a general computer. That is, the control unit 3 includes a CPU, which is a circuit that performs various arithmetic processing, a ROM, which is a read-only memory that stores basic programs, a RAM, which is a readable and writable memory that stores various information, and a magnetic disk that stores control software, data, and the like. The CPU of the control unit 3 executes a predetermined processing program, and thereby the processing in the heat treatment device 1 proceeds.

[0059] In addition to the above configuration, the heat treatment apparatus 1 is provided with various cooling structures to prevent an excessive temperature rise in the halogen heating unit 4, the flash heating unit 5, and the chamber 6 due to the thermal energy generated from the halogen lamps HL and the flash lamps FL during the heat treatment of the semiconductor wafer W. For example, a water-cooling pipe (not shown) is provided in the wall of the chamber 6. The halogen heating unit 4 and the flash heating unit 5 are also of an air-cooled structure that forms a gas flow inside to remove heat. Air is also supplied to the gap between the upper chamber window 63 and the lamp light emission window 53 to cool the flash heating unit 5 and the upper chamber window 63.

[0060] Next, the processing procedure of the semiconductor wafer W in the heat treatment apparatus 1 will be described. The semiconductor wafer W to be processed here is a semiconductor substrate to which impurities (ions) have been added by ion implantation. The impurities are activated by a flash light irradiation heat treatment (annealing) performed by the heat treatment apparatus 1. The processing procedure of the heat treatment apparatus 1 described below progresses as the control unit 3 controls each operating mechanism of the heat treatment apparatus 1.

[0061] First, the valve 84 for supplying air is opened, and the exhaust valves 89, 192 are also opened to start supplying and exhausting air to and from the chamber 6. When the valve 84 is opened, nitrogen gas is supplied to the heat treatment space 65 from the gas supply hole 81. When the valve 89 is opened, the gas in the chamber 6 is exhausted from the gas exhaust hole 86. As a result, the nitrogen gas supplied from the upper part of the heat treatment space 65 in the chamber 6 flows downward and is exhausted from the lower part of the heat treatment space 65.

[0062] Furthermore, by opening the valve 192, the gas in the chamber 6 is also exhausted from the transfer opening 66. Furthermore, the atmosphere around the drive unit of the transfer mechanism 10 is also exhausted by an exhaust mechanism (not shown). Note that, during the heat treatment of the semiconductor wafer W in the heat treatment apparatus 1, nitrogen gas is continuously supplied to the heat treatment space 65, and the supply amount is appropriately changed depending on the treatment process.

[0063] Next, the gate valve 185 is opened to open the transfer opening 66, and the semiconductor wafer W after ion implantation is transferred into the heat treatment space 65 in the chamber 6 through the transfer opening 66 by a transfer robot outside the apparatus. The semiconductor wafer W transferred by the transfer robot advances to a position directly above the holder 7 and stops there. Then, the pair of transfer arms 11 of the transfer mechanism 10 move horizontally from the retreated position to the transfer operation position and rise, whereby the lift pins 12 pass through the through holes 79 and protrude from the upper surface of the holding plate 75 of the susceptor 74 to receive the semiconductor wafer W. At this time, the lift pins 12 rise to a position above the upper ends of the substrate support pins 77.

[0064] After the semiconductor wafer W is placed on the lift pins 12, the transport robot leaves the heat treatment space 65, and the transport opening 66 is closed by the gate valve 185. Then, the pair of transfer arms 11 descend, and the semiconductor wafer W is transferred from the transfer mechanism 10 to the susceptor 74 of the holder 7, where it is held from below in a horizontal position. The semiconductor wafer W is supported by a plurality of substrate support pins 77 erected on the holding plate 75 and held by the susceptor 74. The semiconductor wafer W is held by the holder 7 with the surface on which the pattern has been formed and the impurities have been implanted as the upper surface. A predetermined gap is formed between the back surface (the main surface opposite to the front surface) of the semiconductor wafer W supported by the plurality of substrate support pins 77 and the holding surface 75a of the holding plate 75. The pair of transfer arms 11 that descend to below the susceptor 74 are retreated to a retreat position, that is, inside the recess 62, by the horizontal movement mechanism 13.

[0065] After the semiconductor wafer W is held from below in a horizontal position by the susceptor 74 of the holder 7 made of quartz, the 40 halogen lamps HL of the halogen heating unit 4 are turned on all at once to start preheating (assisted heating). Halogen light emitted from the halogen lamps HL passes through the lower chamber window 64 and the susceptor 74, both made of quartz, and is irradiated onto the underside of the semiconductor wafer W. The semiconductor wafer W is preheated by being irradiated with light from the halogen lamps HL, and its temperature rises. Note that the transfer arm 11 of the transfer mechanism 10 is retracted inside the recess 62, and does not interfere with heating by the halogen lamps HL.

[0066] When preheating is performed by the halogen lamps HL, the temperature of the semiconductor wafer W is measured by the radiation thermometer 20. That is, the radiation thermometer 20 receives infrared light radiated from the lower surface of the semiconductor wafer W held on the susceptor 74 through the opening 78 through the transparent window 21 to measure the wafer temperature during heating. The measured temperature of the semiconductor wafer W is transmitted to the control unit 3. The control unit 3 controls the output of the halogen lamps HL while monitoring whether the temperature of the semiconductor wafer W, which is heated by the light irradiation from the halogen lamps HL, has reached a predetermined preheating temperature T1. That is, the control unit 3 feedback-controls the output of the halogen lamps HL based on the measured value by the radiation thermometer 20 so that the temperature of the semiconductor wafer W becomes the preheating temperature T1. The preheating temperature T1 is set to about 200° C. to 800° C., preferably about 350° C. to 600° C. (600° C. in this embodiment) at which there is no risk of impurities added to the semiconductor wafer W being diffused by heat.

[0067] After the temperature of the semiconductor wafer W reaches the preheating temperature T1, the control unit 3 temporarily maintains the semiconductor wafer W at the preheating temperature T1. Specifically, when the temperature of the semiconductor wafer W measured by the radiation thermometer 20 reaches the preheating temperature T1, the control unit 3 adjusts the output of the halogen lamps HL to maintain the temperature of the semiconductor wafer W at approximately the preheating temperature T1.

[0068] By performing such preheating with the halogen lamps HL, the temperature of the entire semiconductor wafer W is uniformly raised to the preheating temperature T1. During the preheating stage with the halogen lamps HL, the temperature of the peripheral portion of the semiconductor wafer W, where heat dissipation is more likely to occur, tends to be lower than that of the central portion, but the arrangement density of the halogen lamps HL in the halogen heating unit 4 is higher in the region facing the peripheral portion than in the region facing the central portion of the semiconductor wafer W. As a result, a greater amount of light is irradiated to the peripheral portion of the semiconductor wafer W, where heat dissipation is more likely to occur, and the in-plane temperature distribution of the semiconductor wafer W during the preheating stage can be made uniform.

[0069] When a predetermined time has elapsed since the temperature of the semiconductor wafer W reached the preheating temperature T1, the flash lamps FL of the flash heating unit 5 irradiate the surface of the semiconductor wafer W held on the susceptor 74 with flash light. At this time, part of the flash light emitted from the flash lamps FL heads directly into the chamber 6, and the other part heads into the chamber 6 after being reflected by the reflector 52, and the semiconductor wafer W is flash-heated by the irradiation of these flash lights.

[0070] Since flash heating is performed by irradiating a flash light (light flash) from the flash lamp FL, the surface temperature of the semiconductor wafer W can be raised in a short time. That is, the flash light irradiated from the flash lamp FL is an extremely short and strong flash with an irradiation time of about 0.1 milliseconds to 100 milliseconds, in which electrostatic energy previously stored in a capacitor is converted into an extremely short light pulse. The surface temperature of the semiconductor wafer W flash-heated by the irradiation of the flash light from the flash lamp FL instantaneously rises to a processing temperature T2 of 1000°C or more, and the impurities implanted in the semiconductor wafer W are activated, and then the surface temperature drops rapidly. In this way, the heat treatment device 1 can raise and lower the surface temperature of the semiconductor wafer W in an extremely short time, so that the impurities can be activated while suppressing the diffusion of the impurities implanted in the semiconductor wafer W due to heat. The time required for activating the impurities is extremely short compared to the time required for their thermal diffusion, so that the activation is completed even in a short time of about 0.1 milliseconds to 100 milliseconds in which diffusion does not occur.

[0071] After the flash heating process is completed, the halogen lamps HL are turned off after a predetermined time has elapsed. This causes the temperature of the semiconductor wafer W to rapidly drop from the preheating temperature T1. The temperature of the semiconductor wafer W during the temperature drop is measured by the radiation thermometer 20, and the measurement result is transmitted to the control unit 3. The control unit 3 monitors whether the temperature of the semiconductor wafer W has dropped to a predetermined temperature based on the measurement result of the radiation thermometer 20. Then, after the temperature of the semiconductor wafer W has dropped to a predetermined temperature or lower, the pair of transfer arms 11 of the transfer mechanism 10 again move horizontally from the retreat position to the transfer operation position and rise, so that the lift pins 12 protrude from the upper surface of the susceptor 74 and receive the semiconductor wafer W after the heat treatment from the susceptor 74. Next, the transfer opening 66 that was closed by the gate valve 185 is opened, and the semiconductor wafer W placed on the lift pins 12 is carried out by a transfer robot outside the apparatus, and the heat treatment of the semiconductor wafer W in the heat treatment apparatus 1 is completed.

[0072] If the distribution adjustment unit 90 is not provided, the in-plane temperature distribution of the semiconductor wafer W may become non-uniform due to the illuminance distribution of the light irradiated from the halogen lamps HL and the illuminance distribution of the flash light irradiated from the flash lamps FL. FIG. 15 is a diagram showing an example of the in-plane temperature distribution variation that occurs when the distribution adjustment unit 90 is not provided. The horizontal axis of FIG. 15 linearly arranges positions in the plane of the semiconductor wafer W. The vertical axis of FIG. 15 indicates the temperature during flash heating. As shown in FIG. 15, if the distribution adjustment unit 90 is not provided, the temperature distribution varies such that a part of the plane of the semiconductor wafer W is relatively higher in temperature than other regions during flash light irradiation.

[0073] In the first embodiment, a distribution adjustment unit 90 in which a filter 35 is fitted is provided in a storage space 94 facing an in-plane position (hot spot) of the semiconductor wafer W where the temperature becomes relatively high during flash heating. The distribution adjustment unit 90 adjusts the illuminance distribution in the plane of the semiconductor wafer W during flash light irradiation to eliminate variations. Specifically, light components in a specific wavelength range are attenuated from the light emitted from the flash lamp FL and incident on the distribution adjustment unit 90 that has passed through the filter 35. This reduces the illuminance at the position where the temperature becomes relatively high, and as a result, the in-plane temperature distribution of the semiconductor wafer W during flash heating becomes uniform. Note that the entire storage body 91 including the cylindrical body 92 and the multiple rod-shaped members 93 is made of quartz, so the storage body 91 itself does not affect the transmitted light.

[0074] Depending on the light emission conditions of the halogen lamps HL and the flash lamps FL, the in-plane temperature distribution occurring on the semiconductor wafer W may change from that shown in FIG. 15. In such a case, the operator leaves the housing 91 on the upper chamber window 63 as it is, removes the filter 35 that has already been fitted there, and then fits the filter 35 into a housing space 94 different from the above. This makes it possible to quickly and easily obtain an illuminance distribution corresponding to the changed in-plane temperature distribution even when the in-plane temperature distribution occurring on the semiconductor wafer W changes, and to make the in-plane temperature distribution uniform. In other words, the illuminance distribution can be easily adjusted by simply fitting the filter 35 into the required housing space 94 according to the in-plane temperature distribution appearing on the semiconductor wafer W, without replacing the entire distribution adjustment unit 90, and an appropriate illuminance distribution can be quickly obtained.

[0075] In addition, there are cases where it is desired to obtain a desired in-plane temperature distribution, not just to make the in-plane temperature distribution uniform. In such cases, the illuminance distribution can be easily adjusted by simply fitting the filter 35 into the necessary accommodation space 94 formed in the distribution adjustment unit 90, and an appropriate illuminance distribution can be obtained immediately, making it possible to achieve the desired in-plane temperature distribution without delay.

[0076] Furthermore, when a flash light with an extremely strong intensity is irradiated, a part of the distribution adjustment unit 90 may be damaged by vibration, etc. Even in such a case, since in this embodiment, a plurality of rod-shaped members 93 are combined to form the housing 91, it is not necessary to replace the entire distribution adjustment unit 90, and the distribution adjustment unit 90 can be repaired by simply replacing the rod-shaped members 93 in the necessary places.

[0077] <Second embodiment> Next, a second embodiment of the present invention will be described. The configuration of the heat treatment apparatus and the processing procedure of the semiconductor wafer W in the second embodiment are generally the same as those in the first embodiment. In the second embodiment, a plurality of filters 35 are fitted in one accommodation space 94 in a stacked manner.

[0078] FIG. 16 is a diagram showing another example of the variation in the in-plane temperature distribution that occurs when the distribution adjustment unit 90 is not provided. The horizontal axis of FIG. 16 indicates the position along the radial direction of the semiconductor wafer W. The vertical axis of FIG. 16 indicates the temperature during flash heating. As shown in FIG. 16, when the semiconductor wafer W is heated, the temperature of the peripheral portion of the semiconductor wafer W, where heat dissipation is likely to occur, may become lower than the temperature of the central portion. In order to eliminate such non-uniformity in the temperature distribution, in the second embodiment, the number of layers of the filters 35 is changed for each storage space 94.

[0079] FIG. 17 is a diagram showing a schematic stacking state of a plurality of filters 35 in the second embodiment. FIG. 17 shows a simplified stacking state of the filters 35 accommodated in a plurality of accommodation spaces 94 arranged along the radial direction of the semiconductor wafer W. As shown in the figure, in the second embodiment, the number of stacked filters 35 is greater in the center than in the peripheral portion in the arrangement of the plurality of accommodation spaces 94. That is, the number of stacked filters 35 accommodated in the accommodation space (central accommodation space) 94 facing the center of the semiconductor wafer W among the plurality of accommodation spaces 94 provided in the distribution adjustment unit 90 is greater than the number of stacked filters 35 accommodated in the accommodation space (peripheral accommodation space) 94 facing the peripheral portion of the semiconductor wafer W. The remaining configuration of the second embodiment except for the stacking of the filters 35 is the same as that of the first embodiment.

[0080] The light blocking rate increases as the number of layers of the filters 35 increases. Therefore, the light blocking rate is higher in the central portion of the distribution adjustment portion 90 than in the peripheral portion. As a result, when a flash light is applied, the intensity of the flash light applied to the central portion is weaker than the intensity of the flash light applied to the peripheral portion of the semiconductor wafer W, and the variation in the in-plane temperature distribution as shown in FIG. 16 can be eliminated.

[0081] <Third embodiment> Next, a third embodiment of the present invention will be described. The configuration of the heat treatment apparatus and the processing procedure of the semiconductor wafer W in the third embodiment are generally the same as those in the first embodiment. In the third embodiment, a plurality of filters 35 are stacked and fitted in one accommodation space 94.

[0082] FIG. 18 is a diagram showing a schematic stacking state of a plurality of filters 35 in the third embodiment. As in FIG. 17, FIG. 18 also shows a simplified stacking state of the filters 35 accommodated in a plurality of accommodation spaces 94 arranged along the radial direction of the semiconductor wafer W. As shown in the figure, in the third embodiment, the number of stacked filters 35 is smaller in the center part than in the peripheral part in the arrangement of the plurality of accommodation spaces 94. That is, the number of stacked filters 35 accommodated in the accommodation spaces 94 facing the peripheral part of the semiconductor wafer W among the plurality of accommodation spaces 94 provided in the distribution adjustment unit 90 is greater than the number of stacked filters 35 accommodated in the accommodation spaces 94 facing the central part of the semiconductor wafer W. The remaining configuration of the third embodiment except for the stacking of the filters 35 is the same as that of the first embodiment.

[0083] The more the number of layers of the filters 35, the higher the light blocking rate. Therefore, in the third embodiment, the light blocking rate is higher in the peripheral portion of the distribution adjustment unit 90 than in the central portion. When preheating is performed using the halogen lamps HL, the intensity of the light irradiated to the peripheral portion of the semiconductor wafer W, where heat dissipation is likely to occur, may be significantly increased to intentionally form a temperature distribution in which the temperature of the peripheral portion of the semiconductor wafer W is higher than that of the central portion. In such a case, if the distribution adjustment unit 90 of the third embodiment is used, the intensity of the flash light irradiated to the central portion of the semiconductor wafer W becomes stronger than the intensity of the flash light irradiated to the peripheral portion of the semiconductor wafer W, and as a result, the in-plane temperature distribution during flash light irradiation can be made uniform.

[0084] <Modification> Although the embodiments of the present invention have been described above, this invention can be modified in various ways without departing from the spirit of the invention. For example, in each of the above embodiments, the shape of the storage space 94 is an equilateral triangle, but this is not limited thereto, and the planar shape of the storage space 94 may be any polygon, such as a rectangle, a hexagon, or an octagon. In particular, the planar shape of the storage space 94 is preferably an equilateral triangle, a square, or a regular hexagon.

[0085] The shape of the filter 35 is also preferably made to correspond to the shape of the storage space 94. For example, if the shape of the storage space 94 is quadrangular, the shape of the filter 35 is also preferably rectangular. Note that the shape of the filter 35 does not necessarily have to match the shape of the storage space 94, and the shape of the filter 35 may be any shape that can be accommodated in the storage space 94. For example, a circular filter 35 may be fitted into the equilateral triangular storage space 94 similar to the above embodiment.

[0086] Moreover, the surface of the filter 35 may be roughened, which further increases the light attenuation rate of the filter 35.

[0087] Also, instead of the filter 35, for example, a convex lens that condenses light, a concave lens that diffuses light, or an opaque quartz plate that blocks light may be fitted into the accommodation space 94. In other words, any form may be used as long as an optical element that imparts some optical effect to light that reaches the accommodation space 94 is fitted into the accommodation space 94.

[0088] Furthermore, the form in which the filters 35 are stacked is not limited to the contents of the second embodiment (FIG. 17) and the third embodiment (FIG. 18), and may be any appropriate form. Typically, the number of stacked filters 35 housed in the housing space 94 facing the region in the surface of the semiconductor wafer W where the intensity of the irradiated light is to be weakened may be increased according to the degree of the desired weakening.

[0089] Furthermore, in each of the above embodiments, the distribution adjustment unit 90 is provided on the upper surface of the upper chamber window 63, but instead of or in addition to this, the distribution adjustment unit 90 may be provided on the upper surface of the lower chamber window 64. When the distribution adjustment unit 90 is provided on the upper surface of the lower chamber window 64, it adjusts the illuminance distribution of the light irradiated from the halogen lamps HL to the underside of the semiconductor wafer W. Alternatively, the function of the distribution adjustment unit 90 may be imparted to the quartz susceptor 74 that supports the semiconductor wafer W.

[0090] In the above embodiment, the flash heating unit 5 is provided with 63 flash lamps FL, but the number of flash lamps FL is not limited to this and may be any number. The flash lamps FL are not limited to xenon flash lamps and may be krypton flash lamps. The number of halogen lamps HL provided in the halogen heating unit 4 is not limited to 40 and may be any number.

[0091] In the above embodiment, the semiconductor wafer W is preheated using a filament-type halogen lamp HL as a continuously lit lamp that emits light continuously for one second or more. However, this is not limited to this, and preheating may be performed using a discharge-type arc lamp (e.g., a xenon arc lamp) or an LED lamp as a continuously lit lamp instead of the halogen lamp HL.

[0092] Furthermore, the heat treatment apparatus 1 is not limited to heat treatment for activating impurities, and may also perform heat treatment of a high dielectric constant gate insulating film (High-k film), bonding of metal and silicon, or crystallization of polysilicon. [Explanation of symbols]

[0093] 1 Heat treatment equipment 3. Control Unit 4 Halogen heating section 5 Flash heating section 6 Chambers 7 Holding part 10 Transfer mechanism 35 Filters 65 Heat Treatment Space 74 Susceptor 75 Retaining Plate 77 Board support pin 90 Distribution adjustment section 91 Storage unit 93 Rod-shaped members 94 Containment Space FL Flash lamp HL Halogen Lamp W Semiconductor wafer

Claims

1. A heat treatment apparatus for heating a substrate by irradiating the substrate with light, comprising: a chamber for housing a substrate; a holder that holds the substrate in the chamber; a light irradiation unit that irradiates light onto the substrate held by the holding unit; a distribution adjustment unit that adjusts an illuminance distribution of light irradiated from the light irradiation unit onto the substrate; Equipped with The distribution adjustment unit is a storage body in which a plurality of storage spaces are formed by combining a plurality of rod-shaped members in a lattice shape and surrounded by a frame; an optical element that is fitted in any one of the plurality of storage spaces and that exerts an optical effect on the light that is emitted from the light irradiation unit and reaches the storage space; 2. A heat treatment device comprising:

2. 2. The heat treatment apparatus according to claim 1, The planar shape of the accommodation space is a polygon.

3. 3. The heat treatment apparatus according to claim 2, The planar shape of the accommodation space is an equilateral triangle, a square, or a regular hexagon.

4. 2. The heat treatment apparatus according to claim 1, The heat treatment device in which the optical elements are accommodated in a stacked manner in the accommodation space.

5. 5. The heat treatment apparatus according to claim 4, A heat treatment apparatus in which the number of layers of the optical elements accommodated in a central accommodation space facing the center of the substrate among the multiple accommodation spaces is greater than the number of layers of the optical elements accommodated in a peripheral accommodation space facing the peripheral portion of the substrate.

6. 5. The heat treatment apparatus according to claim 4, A heat treatment apparatus in which the number of layers of the optical elements accommodated in a peripheral accommodation space facing the peripheral portion of the substrate among the plurality of accommodation spaces is greater than the number of layers of the optical elements accommodated in a central accommodation space facing the central portion of the substrate.

7. 2. The heat treatment apparatus according to claim 1, The container is made of quartz.

8. 8. The heat treatment apparatus according to claim 1, The optical element is a filter that attenuates light of a predetermined wavelength from the light emitted from the light irradiation unit.

Images