Heat treatment device and heat treatment method

Abstract

To provide a heat treatment device and a heat treatment method capable of preventing gas leakage from a treatment chamber.SOLUTION: In a processing chamber, a semiconductor wafer is irradiated with light in a reduced pressure atmosphere to perform heat treatment. When the semiconductor wafer is loaded into and unloaded from the processing chamber, the pressure in the processing chamber is set to a base pressure Pb that is a certain value lower than atmospheric pressure Pa. When the semiconductor wafer is subjected to heat treatment, the pressure in the processing chamber is less than the base pressure Pb. Since the pressure in the processing chamber is always maintained lower than atmospheric pressure Pa, even when the pressure fluctuation in the chamber slightly overshoots the base pressure Pb, the inside of the processing chamber is always at a negative pressure relative to the outside of the device, and gas leakage from the processing chamber can be prevented.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a heat treatment apparatus and a heat treatment method for heating a substrate by irradiating the substrate with light. Examples of the substrate to be processed include semiconductor wafers, substrates for liquid crystal display devices, substrates for flat panel displays (FPDs), substrates for optical disks, substrates for magnetic disks, or substrates for solar cells.

Background Art

[0002] In the manufacturing process of semiconductor devices, flash lamp annealing (FLA) for heating a semiconductor wafer in an extremely short time has attracted attention. Flash lamp annealing is a heat treatment technique that uses a xenon flash lamp (hereinafter, simply referred to as "flash lamp" when meaning a xenon flash lamp) to irradiate flash light onto the surface of a semiconductor wafer, thereby raising the temperature of only the surface of the semiconductor wafer in an extremely short time (several milliseconds or less).

[0003] The emission spectral distribution of a xenon flash lamp is from the ultraviolet region to the near-infrared region, and its wavelength is shorter than that of a conventional halogen lamp and almost coincides with the fundamental absorption band of a silicon semiconductor wafer. Therefore, when flash light is irradiated from a xenon flash lamp onto a semiconductor wafer, there is little transmitted light and it is possible to rapidly raise the temperature of the semiconductor wafer. Also, it has been found that if flash light is irradiated for an extremely short time of several milliseconds or less, only the vicinity of the surface of the semiconductor wafer can be selectively heated.

[0004] Such flash lamp annealing is used for processes that require heating in an extremely short time, for example, typically for activating impurities implanted in a semiconductor wafer. If flash light is irradiated from a flash lamp onto the surface of a semiconductor wafer into which impurities have been implanted by the ion implantation method, the temperature of the surface of the semiconductor wafer can be raised to the activation temperature in an extremely short time, and only impurity activation can be performed without deeply diffusing the impurities.

[0005] Flash lamp annealing such as impurity activation is performed in an atmospheric pressure atmosphere. However, depending on the content of the process, flash lamp annealing may be performed while supplying a specific processing gas (for example, ammonia, ozone, etc.) in a reduced pressure atmosphere in which the pressure in the processing chamber is reduced to about 5 kPa to 50 kPa, for example (for example, Patent Document 1). On the other hand, since the pressure in each chamber responsible for transporting the semiconductor wafer is always atmospheric pressure, the transfer of the semiconductor wafer to the processing chamber where flash lamp annealing is performed must be carried out at atmospheric pressure. Therefore, after the semiconductor wafer is carried into the processing chamber, the inside of the processing chamber is evacuated with a vacuum pump, and after the annealing process, it is necessary to supply nitrogen or the like to return the pressure in the processing chamber to atmospheric pressure.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] When nitrogen or the like is supplied into the processing chamber in a reduced pressure atmosphere to restore the chamber internal pressure, the pressure fluctuation may overshoot and the pressure in the processing chamber may become a positive pressure that is unintentionally higher than the external pressure. When the inside of the processing chamber becomes a positive pressure, there is a risk that harmful gases such as ammonia may leak from the processing chamber to the outside.

[0008] In addition, if the pressure reduction and restoration in the processing chamber are repeated every time the semiconductor wafer is processed, parts such as O-rings may deteriorate and break in a relatively short time, and there is also a risk that the processing gas may leak to the outside from the damaged part.

[0009] The present invention has been made in view of the above problems, and an object thereof is to provide a heat treatment apparatus and a heat treatment method capable of preventing gas leakage from a processing chamber.

Means for Solving the Problems

[0010] To solve the above problems, a first aspect of the present invention is a heat treatment apparatus that heats a substrate by irradiating the substrate with light, including a processing chamber that houses the substrate and performs heat treatment on the substrate, a holding unit that holds the substrate in the processing chamber, a light source that irradiates the substrate housed in the processing chamber with light, a gas supply unit that supplies a processing gas to the processing chamber, an exhaust unit that discharges the atmosphere in the processing chamber, and a control unit that controls the gas supply unit and the exhaust unit so that the inside of the processing chamber reaches a target pressure. The control unit always maintains the pressure in the processing chamber at or below a reference pressure that is lower than atmospheric pressure by a certain value, and controls the gas supply unit and the exhaust unit so that the pressure during heat treatment of the substrate is lower than the reference pressure.

[0011] Further, a second aspect is the heat treatment apparatus according to the first aspect, wherein the control unit controls the gas supply unit and the exhaust unit so that the pressure in the processing chamber is reduced from the reference pressure to the processing pressure after the substrate is carried into the processing chamber, and the pressure in the processing chamber is restored from the processing pressure to the reference pressure after the heat treatment.

[0012] Further, a third aspect is the heat treatment apparatus according to the first or second aspect, wherein the reference pressure is 50 kPa or more and 95 kPa or less.

[0013] Further, a fourth aspect is the heat treatment apparatus according to any one of the first to third aspects, further comprising a transfer chamber connected to the processing chamber and accommodating a transfer robot that transfers a substrate into and out of the processing chamber, wherein the pressure in the transfer chamber is constantly maintained at the reference pressure, and the transfer of the substrate between the transfer chamber and the processing chamber is performed at the reference pressure.

[0014] Further, a fifth aspect is the heat treatment apparatus according to the fourth aspect, further comprising a cooling chamber connected to the transfer chamber, temporarily holding an untreated substrate to be transferred to the transfer chamber, and temporarily holding and cooling a substrate after heat treatment transferred from the transfer chamber, wherein the volume of the cooling chamber is smaller than the volume of the transfer chamber, and the pressure in the cooling chamber is reduced from atmospheric pressure to the reference pressure after an untreated substrate is loaded into the cooling chamber and while the untreated substrate is being held in the cooling chamber, and the pressure in the cooling chamber is restored from the reference pressure to atmospheric pressure after a substrate after heat treatment is loaded into the cooling chamber and while the substrate after heat treatment is being held in the cooling chamber.

[0015] Further, a sixth aspect is the heat treatment apparatus according to any one of the first to fifth aspects, wherein the light source includes a flash lamp that irradiates flash light onto the surface of the substrate held by the holding unit.

[0016] Further, a seventh aspect is a heat treatment method for heating a substrate by irradiating light onto the substrate, comprising: a housing step of housing the substrate in a processing chamber; a pressure reduction step of reducing the pressure in the processing chamber in which the substrate is housed; a heating step of irradiating light onto the substrate; and a pressure restoration step of restoring the pressure in the processing chamber, wherein the pressure in the processing chamber is constantly maintained at a reference pressure lower than atmospheric pressure by a certain value, and the pressure in the processing chamber during the heating step is a processing pressure lower than the reference pressure.

[0017] Further, in an eighth aspect, in the heat treatment method according to the seventh aspect, in the pressure reduction step, the pressure in the processing chamber is reduced from the reference pressure to the processing pressure, and in the pressure recovery step, the pressure in the processing chamber is recovered from the processing pressure to the reference pressure.

[0018] Further, in a ninth aspect, in the heat treatment method according to the seventh or eighth aspect, the reference pressure is 50 kPa or more and 95 kPa or less.

[0019] Further, in a tenth aspect, in the heat treatment method according to any one of the seventh to ninth aspects, a transfer robot provided in a transfer chamber connected to the processing chamber performs loading and unloading of a substrate to and from the processing chamber, the pressure in the transfer chamber is constantly maintained at the reference pressure, and the transfer of the substrate between the transfer chamber and the processing chamber is performed at the reference pressure.

[0020] Further, in an eleventh aspect, in the heat treatment method according to the tenth aspect, a cooling chamber connected to the transfer chamber temporarily holds an untreated substrate to be transferred to the transfer chamber and temporarily holds and cools a substrate after heat treatment transferred from the transfer chamber. The volume of the cooling chamber is smaller than the volume of the transfer chamber. After an untreated substrate is loaded into the cooling chamber and while the untreated substrate is being held in the cooling chamber, the pressure in the cooling chamber is reduced from atmospheric pressure to the reference pressure. After a substrate after heat treatment is loaded into the cooling chamber and while the substrate after heat treatment is being held in the cooling chamber, the pressure in the cooling chamber is pressurized from the reference pressure to atmospheric pressure.

[0021] Further, in a twelfth aspect, in the heat treatment method according to any one of the seventh to eleventh aspects, in the heating step, flash light is irradiated from a flash lamp onto the surface of the substrate.

Advantages of the Invention

[0022] According to the heat treatment apparatus according to the first to sixth aspects, since the pressure in the processing chamber is constantly maintained at a reference pressure lower than the atmospheric pressure by a certain value, the inside of the processing chamber is always in a negative pressure with respect to the outside of the apparatus, and gas leakage from the processing chamber can be prevented.

[0023] In particular, according to the heat treatment apparatus according to the fifth aspect, since the volume of the cooling chamber is smaller than the volume of the transfer chamber, if the pressure is adjusted in the cooling chamber, it can be adjusted in a short time.

[0024] According to the heat treatment method according to the seventh to twelfth aspects, since the pressure in the processing chamber is constantly maintained at a reference pressure lower than the atmospheric pressure by a certain value, the inside of the processing chamber is always in a negative pressure with respect to the outside of the apparatus, and gas leakage from the processing chamber can be prevented.

[0025] In particular, according to the heat treatment method according to the eleventh aspect, since the volume of the cooling chamber is smaller than the volume of the transfer chamber, if the pressure is adjusted in the cooling chamber, it can be adjusted in a short time.

Brief Description of the Drawings

[0026]

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Figure 12

Embodiments for Carrying Out the Invention

[0027] Hereinafter, 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 (for example, "in one direction", "along one direction", "parallel", "orthogonal", "center", "concentric", "coaxial", etc.) represent not only strictly representing the positional relationship, but also a state where the angle or distance is displaced within the range where the same degree of function can be obtained with respect to the tolerance, unless otherwise specified. Also, expressions indicating an equal state (for example, "identical", "equal", "homogeneous", etc.) represent not only strictly quantitatively equal states, but also a state where there is a difference within the range where the same degree of function can be obtained with respect to the tolerance, unless otherwise specified. Further, expressions indicating a shape (for example, "circular shape", "square shape", "cylindrical shape", etc.) represent not only geometrically strictly representing the shape, but also a shape within the range where the same degree of effect can be obtained, and may have, for example, unevenness or chamfers. Also, each expression such as "comprising", "having", "including", "containing", "possessing" a component is not an exclusive expression excluding the existence of other components. Also, the expression "at least one of A, B, and C" includes "only A", "only B", "only C", "any two of A, B, and C", and "all of A, B, and C".

[0028] First, a configuration example of the heat treatment apparatus according to the present invention will be described. FIG. 1 is a plan view showing the heat treatment apparatus 100, and FIG. 2 is a front view thereof. The heat treatment apparatus 100 is a flash lamp annealing apparatus that irradiates a disk-shaped semiconductor wafer W as a substrate with flash light to heat the semiconductor wafer W. The size of the semiconductor wafer W to be processed is not particularly limited, but for example, it is φ300 mm or φ450 mm. In FIGS. 1 and subsequent figures, for ease of understanding, the dimensions and numbers of each part are exaggerated or simplified as necessary. Also, in each of FIGS. 1 to 3, an XYZ orthogonal coordinate system is attached with the Z-axis direction as the vertical direction and the XY plane as the horizontal plane to clarify their directional relationships.

[0029] As shown in FIGS. 1 and 2, the heat treatment apparatus 100 includes an indexer unit 101 for loading an untreated semiconductor wafer W into the apparatus from the outside and unloading the processed semiconductor wafer W out of the apparatus, an alignment unit 230 for positioning the untreated semiconductor wafer W, a first cooling unit 130 and a second cooling unit 140 for cooling the semiconductor wafer W after the heat treatment, a heat treatment unit 160 for performing flash heat treatment on the semiconductor wafer W, and a transfer robot 150 for transferring the semiconductor wafer W to and from the first cooling unit 130, the second cooling unit 140, and the heat treatment unit 160. Further, the heat treatment apparatus 100 includes a control unit 3 that controls the operating mechanisms provided in each of the above-described processing units and the transfer robot 150 to advance the flash heat treatment of the semiconductor wafer W.

[0030] The indexer unit 101 includes a load port 110 for arranging and placing a plurality of carriers C, and a transfer robot 120 that takes out the unprocessed semiconductor wafer W from each carrier C and stores the processed semiconductor wafer W in each carrier C. Specifically, three load ports are provided in the indexer unit 101, and the load port 110 is a general term including the first load port 110a, the second load port 110b, and the third load port 110c (when the three load ports are not particularly distinguished, it is simply referred to as the load port 110). Carriers C containing semiconductor wafers W (product wafers) to be products are placed on the first load port 110a and the second load port 110b among the three load ports. On the other hand, the third load port 110c is a load port dedicated to the dummy carrier DC containing the dummy wafer DW. That is, only the dummy carrier DC is placed on the third load port 110c. Note that the dummy wafer DW has the same shape and material as the product wafer, but is a wafer that is not processed as a product.

[0031] The carrier C containing the unprocessed semiconductor wafer W and the dummy carrier DC are transported by an automated guided vehicle (AGV, OHT, etc.) and placed on the load port 110. Tags for identification are attached to the carrier C and the dummy carrier DC, and the tags of the carrier C and the dummy carrier DC placed on the load port 110 are read by a tag reader (not shown). Also, the carrier C and the dummy carrier DC containing the processed semiconductor wafer W are also taken away from the load port 110 by an automated guided vehicle.

[0032] Also, at the load port 110, the transfer robot 120 can take in and out any semiconductor wafer W (or dummy wafer DW) with respect to the carrier C and the dummy carrier DC. Thus, the carrier C and the dummy carrier DC are configured to be movable up and down as indicated by the arrow CU in FIG. 2. Note that, as forms of the carrier C and the dummy carrier DC, in addition to a FOUP (front opening unified pod) that houses the semiconductor wafer W in a sealed space, a SMIF (Standard Mechanical Inter Face) pod or an OC (open cassette) that exposes the housed semiconductor wafer W to the outside air may be used.

[0033] Also, the transfer robot 120 is capable of slide movement as indicated by the arrow 120S in FIG. 1, turning operation as indicated by the arrow 120R, and lifting and lowering operation. Thereby, the transfer robot 120 takes in and out the semiconductor wafer W with respect to the carrier C and the dummy carrier DC, and transfers the semiconductor wafer W to the alignment unit 230 and the two cooling units (the first cooling unit 130 and the second cooling unit 140). The transfer of the semiconductor wafer W to and from the carrier C (or the dummy carrier DC) by the transfer robot 120 is performed by the slide movement of the hand 121 and the lifting and lowering movement of the carrier C. Also, the transfer of the semiconductor wafer W between the transfer robot 120 and the alignment unit 230, the first cooling unit 130, or the second cooling unit 140 is performed by the slide movement of the hand 121 and the lifting and lowering operation of the transfer robot 120.

[0034] The alignment unit 230 is provided connected to the side of the indexer unit 101 along the Y-axis direction. The alignment unit 230 is a processing unit that rotates the semiconductor wafer W in the horizontal plane to direct it in an appropriate orientation for flash heating. The alignment unit 230 is configured by providing, inside an alignment chamber 231 that is a housing made of an aluminum alloy, a mechanism that supports and rotates the semiconductor wafer W in a horizontal posture, and a mechanism that optically detects notches, orifices, etc. formed at the peripheral edge of the semiconductor wafer W.

[0035] The transfer of the semiconductor wafer W to the alignment unit 230 is performed by the transfer robot 120. The semiconductor wafer W is transferred from the transfer robot 120 to the alignment chamber 231 so that the center of the wafer is positioned at a predetermined position. In the alignment unit 230, the semiconductor wafer W is rotated around a vertical axis with the center of the semiconductor wafer W received from the indexer unit 101 as the rotation center, and the orientation of the semiconductor wafer W is adjusted by optically detecting a notch or the like. The semiconductor wafer W whose orientation adjustment has been completed is taken out from the alignment chamber 231 by the transfer robot 120.

[0036] A transfer chamber 170 that houses the transfer robot 150 is provided as a transfer space for the semiconductor wafer W by the transfer robot 150. Processing chambers 6 of the heat treatment unit 160, a first cool chamber 131 of the first cooling unit 130, and a second cool chamber 141 of the second cooling unit 140 are connected to three sides of the transfer chamber 170.

[0037] The heat treatment unit 160, which is the main part of the heat treatment apparatus 100, is a substrate processing unit that performs flash heat treatment by irradiating the semiconductor wafer W that has been preheated with a flash (flash light) from a xenon flash lamp FL. The configuration of this heat treatment unit 160 will be described in more detail later.

[0038] The first cooling unit 130 and the second cooling unit 140 have substantially the same configuration. The first cooling unit 130 and the second cooling unit 140 each include a metal cooling plate and a quartz plate placed on the upper surface thereof inside a first cool chamber 131 and a second cool chamber 141, which are housings made of an aluminum alloy (both are not shown). The cooling plate is temperature-controlled to room temperature (about 23°C) by a Peltier element or constant temperature water circulation. The semiconductor wafer W that has been subjected to flash heat treatment in the heat treatment unit 160 is carried into the first cool chamber 131 or the second cool chamber 141, placed on the quartz plate, and cooled.

[0039] Both the first cooling chamber 131 and the second cooling chamber 141 are connected to both the indexer unit 101 and the transfer chamber 170 between them. Two openings are formed in the first cooling chamber 131 and the second cooling chamber 141 for loading and unloading the semiconductor wafer W. Of the two openings in the first cooling chamber 131, the opening connected to the indexer unit 101 can be opened and closed by a gate valve 181. On the other hand, the opening connected to the transfer chamber 170 of the first cooling chamber 131 can be opened and closed by a gate valve 183. That is, the first cooling chamber 131 and the indexer unit 101 are connected via the gate valve 181, and the first cooling chamber 131 and the transfer chamber 170 are connected via the gate valve 183.

[0040] When transferring the semiconductor wafer W between the indexer unit 101 and the first cooling chamber 131, the gate valve 181 is opened. Also, when transferring the semiconductor wafer W between the first cooling chamber 131 and the transfer chamber 170, the gate valve 183 is opened. When the gate valve 181 and the gate valve 183 are closed, the inside of the first cooling chamber 131 becomes a sealed space.

[0041] Of the two openings in the second cooling chamber 141, the opening connected to the indexer unit 101 can be opened and closed by a gate valve 182. On the other hand, the opening connected to the transfer chamber 170 of the second cooling chamber 141 can be opened and closed by a gate valve 184. That is, the second cooling chamber 141 and the indexer unit 101 are connected via the gate valve 182, and the second cooling chamber 141 and the transfer chamber 170 are connected via the gate valve 184.

[0042] When transferring the semiconductor wafer W between the indexer unit 101 and the second cooling chamber 141, the gate valve 182 is opened. Also, when transferring the semiconductor wafer W between the second cooling chamber 141 and the transfer chamber 170, the gate valve 184 is opened. When the gate valve 182 and the gate valve 184 are closed, the inside of the second cooling chamber 141 becomes a sealed space. The volumes of the first cooling chamber 131 and the second cooling chamber 141 are smaller than the volume of the transfer chamber 170 and are about 1 / 10 of it.

[0043] The transfer robot 150 provided in the transfer chamber 170 is rotatable about an axis along the vertical direction as indicated by the arrow 150R. The transfer robot 150 has two link mechanisms composed of a plurality of arm segments, and transfer hands 151a and 151b for holding the semiconductor wafer W are provided at the tips of these two link mechanisms, respectively. These transfer hands 151a and 151b are arranged at a predetermined pitch vertically and are linearly slidable independently in the same horizontal direction by the link mechanism. Also, the transfer robot 150 moves the two transfer hands 151a and 151b up and down while keeping them separated by a predetermined pitch by moving up and down the base on which the two link mechanisms are provided.

[0044] When the transfer robot 150 transfers (takes in and out) the semiconductor wafer W to or from the first cooling chamber 131, the second cooling chamber 141, or the processing chamber 6 of the heat treatment unit 160 as a transfer partner, first, both transfer hands 151a and 151b rotate so as to face the transfer partner, and then (or while rotating) move up and down until one of the transfer hands is positioned at the height at which the semiconductor wafer W is transferred to or from the transfer partner. Then, the transfer hand 151a (151b) is linearly slid in the horizontal direction to transfer the semiconductor wafer W to or from the transfer partner.

[0045] The transfer of the semiconductor wafer W between the transfer robot 150 and the transfer robot 120 can be performed via the first cooling unit 130 or the second cooling unit 140. That is, the first cooling chamber 131 of the first cooling unit 130 and the second cooling chamber 141 of the second cooling unit 140 also function as paths for transferring the semiconductor wafer W between the transfer robot 150 and the transfer robot 120. Specifically, the transfer of the semiconductor wafer W is performed by one of the transfer robot 150 or the transfer robot 120 delivering the semiconductor wafer W to the first cooling chamber 131 or the second cooling chamber 141 and the other receiving it. A transfer mechanism is configured by the transfer robot 150 and the transfer robot 120 to transfer the semiconductor wafer W from the carrier C to the heat treatment unit 160.

[0046] As described above, gate valves 181 and 182 are provided between the first cooling chamber 131 and the second cooling chamber 141 and the indexer unit 101, respectively. Also, gate valves 183 and 184 are provided between the transfer chamber 170 and the first cooling chamber 131 and the second cooling chamber 141, respectively. Further, a gate valve 185 is provided between the transfer chamber 170 and the processing chamber 6 of the heat treatment unit 160. When the semiconductor wafer W is transferred within the heat treatment apparatus 100, these gate valves are opened and closed as appropriate.

[0047] Next, the configuration of the heat treatment unit 160 will be described. FIG. 3 is a longitudinal sectional view showing the configuration of the heat treatment unit 160. The heat treatment unit 160 includes a processing chamber 6 that houses the semiconductor wafer W and performs heat treatment, a flash lamp house 5 that incorporates a plurality of flash lamps FL, and a halogen lamp house 4 that incorporates a plurality of halogen lamps HL. The flash lamp house 5 is provided above the processing chamber 6, and the halogen lamp house 4 is provided below it. Further, the heat treatment unit 160 includes a holding unit 7 that holds the semiconductor wafer W in a horizontal posture inside the processing chamber 6, and a transfer mechanism 10 that transfers the semiconductor wafer W between the holding unit 7 and the transfer robot 150.

[0048] The processing chamber 6 is configured by attaching quartz chamber windows above and below the cylindrical chamber side portion 61. The chamber side portion 61 has a generally cylindrical shape with openings at the top and bottom. An upper chamber window 63 is attached to and closes the upper opening, and a lower chamber window 64 is attached to and closes the lower opening. The upper chamber window 63 that constitutes the ceiling portion of the processing chamber 6 is a disc-shaped member formed of quartz and functions as a quartz window that transmits the flash light emitted from the flash lamp FL into the processing chamber 6. Also, the lower chamber window 64 that constitutes the floor portion of the processing chamber 6 is a disc-shaped member formed of quartz and functions as a quartz window that transmits the light from the halogen lamp HL into the processing chamber 6.

[0049] Also, a reflection ring 68 is attached to the upper part of the inner wall surface of the chamber side portion 61, and a reflection ring 69 is attached to the lower part. Both the reflection rings 68 and 69 are formed in an annular shape. The upper reflection ring 68 is attached by fitting it from the upper side of the chamber side portion 61. On the other hand, the lower reflection ring 69 is attached by fitting it from the lower side of the chamber side portion 61 and fastening it with screws (not shown). That is, both the reflection rings 68 and 69 are detachably attached to the chamber side portion 61. The inner space of the processing chamber 6, that is, the space surrounded by the upper chamber window 63, the lower chamber window 64, the chamber side portion 61, and the reflection rings 68 and 69 is defined as the heat treatment space 65.

[0050] By mounting reflection rings 68 and 69 on the side portion 61 of the chamber, a recess 62 is formed on the inner wall surface of the processing chamber 6. That is, a recess 62 is formed which is surrounded by the central portion of the inner wall surface of the chamber side portion 61 where the reflection rings 68 and 69 are not mounted, the lower end surface of the reflection ring 68, and the upper end surface of the reflection ring 69. The recess 62 is formed in an annular shape along the horizontal direction on the inner wall surface of the processing chamber 6 and surrounds the holding portion 7 that holds the semiconductor wafer W. The chamber side portion 61 and the reflection rings 68 and 69 are formed of a metal material (for example, stainless steel) excellent in strength and heat resistance.

[0051] Further, a transfer opening (furnace port) 66 for carrying the semiconductor wafer W into and out of the processing 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 communicatively connected to the outer peripheral surface of the recess 62. Therefore, when the gate valve 185 opens the transfer opening 66, the semiconductor wafer W can be carried into the heat treatment space 65 through the recess 62 from the transfer opening 66 and carried out from the heat treatment space 65. Also, when the gate valve 185 closes the transfer opening 66, the heat treatment space 65 in the processing chamber 6 becomes a sealed space.

[0052] In addition, a gas supply hole 81 for supplying a processing gas to the heat treatment space 65 is formed at the upper part of the inner wall of the processing chamber 6. The gas supply hole 81 is formed at a position above the recess 62 and may be provided on the reflection ring 68. The gas supply hole 81 is connected in communication with a gas supply pipe 83 through a buffer space 82 formed in an annular shape inside the side wall of the processing chamber 6. The gas supply pipe 83 is connected to a processing gas supply source 85. Further, an air supply valve 84 is inserted in the middle of the path of the gas supply pipe 83. When the air supply valve 84 is opened, the processing gas is fed from the processing gas supply source 85 to the buffer space 82. The processing gas flowing into the buffer space 82 flows so as to spread in the buffer space 82 where the fluid resistance is smaller than that of the gas supply hole 81 and is supplied from the gas supply hole 81 into the heat treatment space 65. As the processing gas, an inert gas such as nitrogen (N2), or a reactive gas such as ozone (O3), hydrogen (H2), ammonia (NH3), etc. can be used.

[0053] On the other hand, a gas exhaust hole 86 for exhausting the gas in the heat treatment space 65 is formed at the lower part of the inner wall of the processing chamber 6. The gas exhaust hole 86 is formed at a position below the recess 62 and may be provided on the reflection ring 69. The gas exhaust hole 86 is connected in communication with a gas exhaust pipe 88 through a buffer space 87 formed in an annular shape inside the side wall of the processing chamber 6. The gas exhaust pipe 88 is connected to an exhaust mechanism 190. Further, an exhaust valve 89 is inserted in the middle of the path of the gas exhaust pipe 88. When the exhaust valve 89 is opened, the gas in the heat treatment space 65 is discharged from the gas exhaust hole 86 through the buffer space 87 to the gas exhaust pipe 88. Note that a plurality of gas supply holes 81 and gas exhaust holes 86 may be provided along the circumferential direction of the processing chamber 6, or they may be slit-shaped. Also, the processing gas supply source 85 and the exhaust mechanism 190 may be mechanisms provided in the heat treatment apparatus 100, or may be utilities of the factory where the heat treatment apparatus 100 is installed.

[0054] Also, a gas exhaust pipe 191 for discharging the gas in the heat treatment space 65 is connected to the tip of the transfer opening 66. The gas exhaust pipe 191 is connected to an exhaust mechanism 190 via a valve 192. By opening the valve 192, the gas in the processing chamber 6 is exhausted through the transfer opening 66.

[0055] The exhaust mechanism 190 has a vacuum pump. By closing the air supply valve 84 and opening the exhaust valve 89 to exhaust the atmosphere in the processing chamber 6 by the vacuum pump, the pressure in the processing chamber 6 can be reduced to less than atmospheric pressure. A pressure gauge 95 is provided in the processing chamber 6, and the pressure in the processing chamber 6 can be measured by the pressure gauge 95.

[0056] FIG. 4 is a perspective view showing the overall external appearance of the holding part 7. The holding part 7 is configured to include a base ring 71, a connecting part 72, and a susceptor 74. The base ring 71, the connecting part 72, and the susceptor 74 are all formed of quartz. That is, the entire holding part 7 is formed of quartz.

[0057] The base ring 71 is an arc-shaped quartz member with a part missing from an annular shape. This missing part is provided to prevent interference between the transfer arm 11 of the transfer mechanism 10, which will be described later, and the base ring 71. The base ring 71 is placed on the bottom surface of the recess 62, and thus is supported by the wall surface of the processing chamber 6 (see FIG. 3). A plurality of connecting parts 72 (four in this embodiment) are erected along the circumferential direction of the annular shape on the upper surface of the base ring 71. The connecting part 72 is also a quartz member and is fixed to the base ring 71 by welding.

[0058] The susceptor 74 is supported by four connecting parts 72 provided on the base ring 71. FIG. 5 is a plan view of the susceptor 74. Further, FIG. 6 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 plate member formed of quartz. The diameter of the holding plate 75 is larger than the diameter of the semiconductor wafer W. That is, the holding plate 75 has a larger planar size than the semiconductor wafer W.

[0059] The guide ring 76 is installed at the upper surface peripheral edge 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 upward from the holding plate 75. The guide ring 76 is formed of the same quartz as the holding plate 75. The guide ring 76 may be welded to the upper surface of the holding plate 75, or may be fixed to the holding plate 75 by separately processed pins or the like. Alternatively, the holding plate 75 and the guide ring 76 may be processed as an integral member.

[0060] The region inside the guide ring 76 on the upper surface of the holding plate 75 is a planar holding surface 75a for holding the semiconductor wafer W. A plurality of substrate support pins 77 are erected on the holding surface 75a of the holding plate 75. In the present embodiment, a total of 12 substrate support pins 77 are erected at intervals of 30° along the circumference concentric with the outer peripheral circle (inner peripheral circle of the guide ring 76) of the holding surface 75a. 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 the present embodiment) when the diameter of the semiconductor wafer W is φ300 mm. Each substrate support pin 77 is formed of quartz. The plurality of 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.

[0061] Returning to FIG. 4, four connecting portions 72 erected on the base ring 71 and the peripheral edge 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 portions 72. By supporting the base ring 71 of such a holding portion 7 on the wall surface of the processing chamber 6, the holding portion 7 is mounted on the processing chamber 6. In a state where the holding portion 7 is mounted on the processing chamber 6, the holding plate 75 of the susceptor 74 assumes a horizontal posture (a posture in which the normal line coincides with the vertical direction). That is, the holding surface 75a of the holding plate 75 becomes a horizontal plane.

[0062] The semiconductor wafer W carried into the processing chamber 6 is placed and held in a horizontal posture on the susceptor 74 of the holding portion 7 mounted on the processing chamber 6. At this time, the semiconductor wafer W is supported by twelve substrate support pins 77 erected on the holding plate 75 and held by 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. Since 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, the semiconductor wafer W can be supported in a horizontal posture by the twelve substrate support pins 77.

[0063] Also, the semiconductor wafer W will be supported at a predetermined interval from the holding surface 75a of the holding plate 75 by a plurality of substrate support pins 77. The thickness of the guide ring 76 is larger than the height of the substrate support pins 77. Therefore, the horizontal displacement of the semiconductor wafer W supported by the plurality of substrate support pins 77 is prevented by the guide ring 76.

[0064] Also, as shown in FIGS. 4 and 5, the holding plate 75 of the susceptor 74 has an opening 78 formed therethrough vertically. The opening 78 is provided for receiving the radiant light (infrared light) radiated from the lower surface of the semiconductor wafer W held by the susceptor 74 by the radiation thermometer 20 (see FIG. 3). That is, the radiation thermometer 20 receives the light radiated from the lower surface of the semiconductor wafer W held by the susceptor 74 through the opening 78 and measures the temperature of the semiconductor wafer W. Further, four through-holes 79 through which the lift pins 12 of the transfer mechanism 10 described later penetrate are formed in the holding plate 75 of the susceptor 74 for the transfer of the semiconductor wafer W.

[0065] FIG. 7 is a plan view of the transfer mechanism 10. FIG. 8 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 along the generally annular recess 62. Two lift pins 12 are erected on each transfer arm 11. 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 (the solid line position in FIG. 7) where the semiconductor wafer W is transferred with respect to the holding portion 7 and a retracted position (the two-dot chain line position in FIG. 7) where the semiconductor wafer W held by the holding portion 7 does not overlap in plan view. The transfer operation position is below the susceptor 74, and the retracted position is outside the susceptor 74. As the horizontal movement mechanism 13, each transfer arm 11 may be rotated by an individual motor, or a pair of transfer arms 11 may be rotated in conjunction with each other by one motor using a link mechanism.

[0066] Further, the pair of transfer arms 11 are moved up and down together with the horizontal movement mechanism 13 by the lifting mechanism 14. When the lifting mechanism 14 raises the pair of transfer arms 11 at the transfer operation position, a total of four lift pins 12 pass through the through holes 79 (see FIGS. 4 and 5) 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 at the transfer operation position to extract the lift pins 12 from the through holes 79 and the horizontal movement mechanism 13 moves the pair of transfer arms 11 to open, each transfer arm 11 moves to the retracted position. The retracted position of the pair of transfer arms 11 is directly above the base ring 71 of the holding portion 7. Since the base ring 71 is placed on the bottom surface of the recess 62, the retracted position of the transfer arm 11 is inside the recess 62. In addition, an exhaust mechanism (not shown) is provided in the vicinity of the portion where the drive units (the horizontal movement mechanism 13 and the lifting mechanism 14) of the transfer mechanism 10 are provided, and the atmosphere around the drive units of the transfer mechanism 10 is configured to be discharged to the outside of the processing chamber 6.

[0067] Returning to FIG. 3, the heat treatment unit 160 includes a radiation thermometer 20 and a pressure gauge 95 as measuring devices. The radiation thermometer 20 is provided obliquely below the semiconductor wafer W held by the susceptor 74. The radiation thermometer 20 is a wafer thermometer that receives the infrared light radiated from the lower surface of the semiconductor wafer W through the opening 78 of the susceptor 74 and measures the temperature of the semiconductor wafer W from the intensity of the infrared light. The pressure gauge 95 measures the pressure inside the processing chamber 6. For the sake of illustration, in FIG. 3, the radiation thermometer 20 and the pressure gauge 95 are shown inside the processing chamber 6, but these are all attached to the wall surface of the processing chamber 6.

[0068] The flash lamp house 5 provided above the processing chamber 6 is configured to include, inside the housing 51, a light source composed of a plurality (30 in this embodiment) of xenon flash lamps FL, and a reflector 52 provided so as to cover above the light source. Further, a lamp light emission window 53 is attached to the bottom of the housing 51 of the flash lamp house 5. The lamp light emission window 53 constituting the floor portion of the flash lamp house 5 is a plate-shaped quartz window formed of quartz. By installing the flash lamp house 5 above the processing chamber 6, the lamp light emission window 53 faces the upper chamber window 63. The flash lamp FL irradiates the heat treatment space 65 with flash light from above the processing chamber 6 through the lamp light emission window 53 and the upper chamber window 63.

[0069] The plurality of flash lamps FL are each rod-shaped lamps having a long cylindrical shape, and are arranged in a plane so that their longitudinal directions are parallel to each other along the main surface of the semiconductor wafer W held by the holding portion 7 (that is, along the horizontal direction). Therefore, the plane formed by the arrangement of the flash lamps FL is also a horizontal plane.

[0070] The xenon flash lamp FL includes a rod-shaped glass tube (discharge tube) with xenon gas sealed inside and an anode and a cathode connected to a capacitor disposed at both ends thereof, and a trigger electrode attached to the outer peripheral surface of the glass tube. Since xenon gas is an electrical insulator, even if charge is accumulated in the capacitor, electricity does not flow through the glass tube under normal conditions. However, when a high voltage is applied to the trigger electrode to break down the insulation, the electricity stored in the capacitor instantaneously flows through the glass tube, and light is emitted by the excitation of xenon atoms or molecules at that time. In such a xenon flash lamp FL, since the electrostatic energy previously stored in the capacitor is converted into an extremely short light pulse of 0.1 milliseconds to 100 milliseconds, it has the characteristic of being able to irradiate extremely strong light compared to a light source with continuous lighting such as a halogen lamp HL. That is, the flash lamp FL is a pulse emission lamp that emits light instantaneously in an extremely short time of less than 1 second.

[0071] The flash power supply that supplies power to the flash lamp FL includes an IGBT (insulated gate bipolar transistor) in addition to the above capacitor. By adjusting the waveform of the pulse applied to the gate of the IGBT, the emission time of the flash lamp FL can be specified between 0.1 milliseconds and 100 milliseconds.

[0072] Also, the reflector 52 is provided above a plurality of flash lamps FL so as to cover them all. The basic function of the reflector 52 is to reflect the flash light emitted from the plurality of flash lamps FL toward the heat treatment space 65. The reflector 52 is formed of an aluminum alloy plate, and its surface (the surface facing the flash lamp FL) is roughened by blasting.

[0073] The halogen lamp house 4 provided below the processing chamber 6 houses a plurality of (40 in this embodiment) halogen lamps HL inside the housing 41. The plurality of halogen lamps HL perform light irradiation into the heat treatment space 65 from below the processing chamber 6 through the lower chamber window 64.

[0074] FIG. 9 is a plan view showing the arrangement of the plurality of halogen lamps HL. In this embodiment, 20 halogen lamps HL are arranged in each of the upper and lower two stages. Each halogen lamp HL is a rod-shaped lamp having a long cylindrical shape. In both the upper and lower stages, the 20 halogen lamps HL are arranged so as to be parallel to each other along the main surface of the semiconductor wafer W held by the holding portion 7 (that is, along the horizontal direction). Therefore, in both the upper and lower stages, the plane formed by the arrangement of the halogen lamps HL is a horizontal plane.

[0075] Also, as shown in FIG. 9, the arrangement density of the halogen lamps HL is higher in the region facing the peripheral portion of the semiconductor wafer W than in the region facing the central portion of the semiconductor wafer W held by the holding portion 7 in both the upper and lower stages. That is, in both the upper and lower stages, the arrangement pitch of the halogen lamps HL is shorter at the peripheral portion than at the central portion of the lamp arrangement. For this reason, it is possible to irradiate a larger amount of light to the peripheral portion of the semiconductor wafer W where a temperature drop is likely to occur during heating by light irradiation from the halogen lamp HL.

[0076] Also, the lamp group composed of the upper-stage halogen lamps HL and the lamp group composed of the lower-stage halogen lamps HL are arranged so as to cross each other in a lattice pattern. That is, a total of 40 halogen lamps HL are arranged so that the longitudinal directions of the upper-stage halogen lamps HL and the longitudinal directions of the lower-stage halogen lamps HL are orthogonal to each other.

[0077] The halogen lamp HL is a filament-type light source that emits light by heating a filament to incandescence by energizing the filament disposed inside a glass tube. Inside the glass tube, a gas in which a trace amount of a halogen element (such as iodine or bromine) is introduced into an inert gas such as nitrogen or argon is enclosed. By introducing the halogen element, it becomes possible to set the temperature of the filament to a high temperature while suppressing breakage of the filament. Therefore, the halogen lamp HL has the characteristics of having a longer lifespan and being able to continuously irradiate strong light compared to a normal incandescent light bulb. That is, the halogen lamp HL is a continuous lighting lamp that emits light continuously for at least 1 second or more. Further, since the halogen lamp HL is a rod-shaped lamp, it has a long lifespan, and by arranging the halogen lamp HL along the horizontal direction, the radiation efficiency to the upper semiconductor wafer W becomes excellent.

[0078] Also, a reflector 43 is provided below the two-stage halogen lamp HL in the housing 41 of the halogen lamp house 4 (FIG. 3). The reflector 43 reflects the light emitted from the plurality of halogen lamps HL toward the heat treatment space 65.

[0079] In addition to the above configuration, the heat treatment unit 160 is provided with various cooling structures in order to prevent excessive temperature rise of the halogen lamp house 4, the flash lamp house 5, and the processing chamber 6 due to the heat energy generated from the halogen lamp HL and the flash lamp FL during the heat treatment of the semiconductor wafer W. For example, a water cooling pipe (not shown) is provided on the wall of the processing chamber 6. Further, the halogen lamp house 4 and the flash lamp house 5 have an air cooling structure in which a gas flow is formed inside to exhaust heat. Also, air is supplied to the gap between the upper chamber window 63 and the lamp light emission window 53 to cool the flash lamp house 5 and the upper chamber window 63.

[0080] The control unit 3 controls the various operating mechanisms provided in the heat treatment apparatus 100. The hardware configuration of the control unit 3 is the same as that of a general computer. That is, the control unit 3 includes a CPU which is a circuit that performs various arithmetic processes, a ROM which is a read-only memory that stores a basic program, a RAM which is a readable and writable memory that stores various information, and a storage unit (for example, a magnetic disk or an SSD) that stores control software, data, etc. The processing in the heat treatment apparatus 100 proceeds when the CPU of the control unit 3 executes a predetermined processing program. The control unit 3 also controls the operations of the air supply valve 84 and the exhaust valve 89 to adjust the air supply and exhaust to the processing chamber 6. In FIG. 1, the control unit 3 is shown inside the indexer unit 101, but it is not limited thereto, and the control unit 3 can be arranged at any position within the heat treatment apparatus 100.

[0081] FIG. 10 is a diagram schematically showing the air supply and exhaust system for the heat treatment apparatus 100. The vacuum pump 195 provided in the exhaust mechanism 190 (FIG. 3) is connected to each of the processing chamber 6, the transfer chamber 170, the first cooling chamber 131, and the second cooling chamber 141 via a pipe (exhaust line). On the other hand, the nitrogen supply source 201 is connected to each of the transfer chamber 170, the first cooling chamber 131, and the second cooling chamber 141 via a pipe (air supply line). Also, as described above, the processing gas supply source 85 that supplies various processing gases is connected to the processing chamber 6 via the gas supply pipe 83.

[0082] An exhaust valve 89 is provided in a pipe (gas exhaust pipe 88) connecting a vacuum pump 195 and a processing chamber 6, and an air supply valve 84 is provided in a gas supply pipe 83. When the air supply valve 84 is opened, a processing gas is supplied to the processing chamber 6. When the exhaust valve 89 is opened, the atmosphere in the processing chamber 6 is exhausted. A pressure gauge 95 is provided in the processing chamber 6, and the pressure in the processing chamber 6 is measured by the pressure gauge 95. By appropriately controlling the opening and closing of the air supply valve 84 and the exhaust valve 89, the pressure in the processing chamber 6 can be adjusted. If the exhaust flow rate is larger than the air supply flow rate of the processing gas to the processing chamber 6, the inside of the processing chamber 6 can be depressurized, and conversely, if the exhaust flow rate is smaller than the air supply flow rate, the inside of the processing chamber 6 can be pressurized.

[0083] A transfer chamber 170 for accommodating a transfer robot 150 that carries in and out a semiconductor wafer W with respect to the processing chamber 6 is connected to the processing chamber 6. An exhaust valve 172 is provided in a pipe connecting the transfer chamber 170 and the vacuum pump 195, and when the exhaust valve 172 is opened, the atmosphere in the transfer chamber 170 is exhausted. An APC (Automatic Pressure Control) valve 171 is also provided in the pipe. In addition, an air supply valve 173 is provided in a pipe connecting a nitrogen supply source 201 and the transfer chamber 170, and when the air supply valve 173 is opened, nitrogen gas is supplied into the transfer chamber 170. A pressure gauge 175 is provided in the transfer chamber 170, and the pressure in the transfer chamber 170 is measured by the pressure gauge 175. By appropriately controlling the opening and closing of the air supply valve 173 and the exhaust valve 172, the pressure in the transfer chamber 170 can be adjusted. In addition, an APC valve 171 is provided in a pipe for exhausting the transfer chamber 170, and by setting a target pressure in the APC valve 171, the inside of the transfer chamber 170 is maintained at the target pressure.

[0084] The transfer chamber 170 has a first cooling chamber 131 and a second cooling chamber 141 connected in parallel. An exhaust valve 133 is provided in the pipe connecting the first cooling chamber 131 and the vacuum pump 195. When the exhaust valve 133 is opened, the atmosphere in the first cooling chamber 131 is discharged. Also, an air supply valve 134 is provided in the pipe connecting the nitrogen supply source 201 and the first cooling chamber 131. When the air supply valve 134 is opened, nitrogen gas is supplied into the first cooling chamber 131. A pressure gauge 135 is provided in the first cooling chamber 131, and the pressure in the first cooling chamber 131 is measured by the pressure gauge 135. By appropriately controlling the opening and closing of the air supply valve 134 and the exhaust valve 133, the pressure in the first cooling chamber 131 can be adjusted.

[0085] Similarly, an exhaust valve 143 is provided in the pipe connecting the second cooling chamber 141 and the vacuum pump 195. When the exhaust valve 143 is opened, the atmosphere in the second cooling chamber 141 is discharged. Also, an air supply valve 144 is provided in the pipe connecting the nitrogen supply source 201 and the second cooling chamber 141. When the air supply valve 144 is opened, nitrogen gas is supplied into the second cooling chamber 141. A pressure gauge 145 is provided in the second cooling chamber 141, and the pressure in the second cooling chamber 141 is measured by the pressure gauge 145. By appropriately controlling the opening and closing of the air supply valve 144 and the exhaust valve 143, the pressure in the second cooling chamber 141 can be adjusted.

[0086] Thus, in this embodiment, for each of the transfer chamber 170, the first cooling chamber 131, and the second cooling chamber 141, independent air supply and exhaust separated from the processing chamber 6 can be performed to adjust the pressure. Note that no special air supply and exhaust is performed for the indexer unit 101. The indexer unit 101 is exposed to the external atmosphere of the heat treatment apparatus 100 (typically, the atmosphere in the clean room where the heat treatment apparatus 100 is installed). Therefore, the pressure in the indexer unit 101 is generally always approximately atmospheric pressure.

[0087] Next, the processing operation of the heat treatment apparatus 100 according to the present invention will be described. In this embodiment, the base pressure (reference pressure) in the processing chamber 6 of the heat treatment unit 160 is set. The base pressure of the processing chamber 6 is a reduced pressure that is lower than atmospheric pressure (about 101 kPa) by a certain value, specifically, a predetermined value of 50 kPa or more and 95 kPa or less. In this embodiment, the base pressure is, for example, 80 kPa. The processing procedure of the heat treatment apparatus 100 described below proceeds by the control unit 3 controlling each operation mechanism of the heat treatment apparatus 100.

[0088] First, unprocessed semiconductor wafers (product wafers) W are placed on the first load port 110a or the second load port 110b of the indexer unit 101 in a state where a plurality of them are accommodated in the carrier C. Then, the transfer robot 120 takes out the unprocessed semiconductor wafers W one by one from the carrier C and carries them into the alignment chamber 231 of the alignment unit 230. In the alignment chamber 231, the semiconductor wafer W is rotated around a vertical axis in a horizontal plane with its center as the rotation center, and the orientation of the semiconductor wafer W is adjusted by optically detecting notches and the like.

[0089] Next, the transfer robot 120 of the indexer unit 101 takes out the semiconductor wafer W with its orientation adjusted from the alignment chamber 231 and carries it into the first cool chamber 131 of the first cooling unit 130 or the second cool chamber 141 of the second cooling unit 140. In this embodiment, it is described that the semiconductor wafer W is carried into the first cool chamber 131, but the same applies when it is carried into the second cool chamber 141. The first cool chamber 131 temporarily holds the unprocessed semiconductor wafer W to be conveyed to the transfer chamber 170.

[0090] When the semiconductor wafer W is carried into the first cool chamber 131, the gate valve 181 is opened and the gate valve 183 is closed. Therefore, the atmosphere inside the first cool chamber 131 becomes the atmospheric atmosphere, and the pressure inside the first cool chamber 131 also becomes the atmospheric pressure.

[0091] After the semiconductor wafer W is carried into the first cool chamber 131, the gate valve 181 is closed and the inside of the first cool chamber 131 becomes a sealed space. Then, the air supply valve 134 is opened and the exhaust valve 133 is also opened. As a result, nitrogen gas is supplied into the first cool chamber 131 while the atmosphere containing oxygen inside the first cool chamber 131 is discharged, and the inside of the first cool chamber 131 is gradually replaced with a nitrogen atmosphere and the oxygen concentration decreases. Also, since the exhaust flow rate is larger than the supply flow rate of the nitrogen gas, the pressure inside the first cool chamber 131 gradually decreases from the atmospheric pressure. The pressure inside the first cool chamber 131 is measured by the pressure gauge 135. The control unit 3 controls the air supply valve 134 and the exhaust valve 133 so that the pressure inside the first cool chamber 131 becomes equal to the above base pressure (80 kPa) based on the measurement result of the pressure gauge 135.

[0092] When the pressure in the first cooling chamber 131 is reduced from atmospheric pressure to reach the base pressure, the control unit 3 controls the air supply valve 134 and the exhaust valve 133 to maintain the pressure in the first cooling chamber 131 at a constant base pressure. Then, the gate valve 183 is opened, and the semiconductor wafer W in the first cooling chamber 131 is carried out to the transfer chamber 170 by the transfer robot 150. Note that the gate valve 181 remains closed.

[0093] When the unprocessed semiconductor wafer W is transferred from the indexer unit 101 to the transfer chamber 170 via the first cooling chamber 131 or the second cooling chamber 141, the first cooling chamber 131 and the second cooling chamber 141 function as a path for the transfer of the semiconductor wafer W. Also, in the present embodiment, the first cooling chamber 131 and the second cooling chamber 141 also function as load lock chambers for adjusting the pressure from atmospheric pressure to the base pressure of the processing chamber 6.

[0094] While the air supply valve 173 in the transfer chamber 170 is opened to supply nitrogen gas, the exhaust valve 172 is opened to exhaust from the transfer chamber 170. The inside of the transfer chamber 170 is set to a nitrogen atmosphere with a low oxygen concentration, and the pressure inside the transfer chamber 170 is constantly maintained at the base pressure by the APC valve 171. Therefore, after the pressure in the first cooling chamber 131 is reduced to the base pressure, the gate valve 183 is opened.

[0095] The transfer robot 150 that has taken out the semiconductor wafer W from the first cool chamber 131 turns so as to face the heat treatment unit 160. Subsequently, the gate valve 185 opens between the processing chamber 6 and the transfer chamber 170. At this time, the pressure in the processing chamber 6 is also the base pressure. Then, the transfer robot 150 carries the unprocessed semiconductor wafer W into the processing chamber 6. At this time, if there is a previously heat-treated semiconductor wafer W in the processing chamber 6, the heat-treated semiconductor wafer W is taken out by one of the transfer hands 151a and 151b, and then the unprocessed semiconductor wafer W is carried into the processing chamber 6 for wafer replacement. After that, the gate valve 185 closes between the processing chamber 6 and the transfer chamber 170.

[0096] The semiconductor wafer W carried into the processing chamber 6 is preheated by the halogen lamp HL and then flash-heat-treated by irradiation with flash light from the flash lamp FL. Also, the flash heat treatment of this embodiment is performed, for example, in an ammonia atmosphere under reduced pressure.

[0097] After the flash heat treatment is completed, the gate valve 185 opens again between the processing chamber 6 and the transfer chamber 170. At this time, too, the pressure in the processing chamber 6 is the base pressure. Then, the transfer robot 150 carries the semiconductor wafer W after the flash heat treatment out of the processing chamber 6 into the transfer chamber 170. The transfer robot 150 that has taken out the semiconductor wafer W turns so as to face the first cool chamber 131 or the second cool chamber 141 from the processing chamber 6. Also, the gate valve 185 closes between the processing chamber 6 and the transfer chamber 170.

[0098] Thereafter, the transfer robot 150 carries the semiconductor wafer W after heat treatment into the first cool chamber 131 of the first cooling unit 130 or the second cool chamber 141 of the second cooling unit 140. In this embodiment, it is described that the semiconductor wafer W after heat treatment is carried into the second cool chamber 141, but the same applies when it is carried into the first cool chamber 131. The second cool chamber 141 temporarily holds and cools the semiconductor wafer W after heat treatment transferred from the transfer chamber 170.

[0099] When the semiconductor wafer W is carried into the second cool chamber 141, the air supply valve 144 and the exhaust valve 143 are opened so that the inside of the second cool chamber 141 is in a nitrogen atmosphere, and the control unit 3 controls the air supply valve 144 and the exhaust valve 143 so that the pressure inside the second cool chamber 141 maintains the base pressure. In this state, the gate valve 184 is opened, while the gate valve 182 is closed.

[0100] After the semiconductor wafer W after heat treatment is carried into the second cool chamber 141, the gate valve 184 is closed so that the inside of the second cool chamber 141 becomes a sealed space. In the second cool chamber 141, the cooling process of the semiconductor wafer W after flash heat treatment is performed. Since the temperature of the entire semiconductor wafer W at the time of being carried out from the processing chamber 6 of the heat treatment unit 160 is relatively high, it is cooled to near room temperature in a nitrogen atmosphere in the second cool chamber 141.

[0101] While executing the cooling process of the semiconductor wafer W, the supply flow rate of nitrogen gas is made larger than the exhaust flow rate to repressurize the pressure inside the second cool chamber 141 from the base pressure to atmospheric pressure. Specifically, based on the measurement result of the pressure gauge 145, the control unit 3 controls the air supply valve 134 and the exhaust valve 133 so that the pressure inside the second cool chamber 141 becomes equal to atmospheric pressure.

[0102] After the pressure in the second cooling chamber 141 returns to atmospheric pressure and a predetermined cooling treatment time has elapsed, the gate valve 182 is opened. Then, the transfer robot 120 carries out the cooled semiconductor wafer W from the second cooling chamber 141 and returns it to the carrier C. When a predetermined number of processed semiconductor wafers W are accommodated in the carrier C, the carrier C is carried out from the first load port 110a or the second load port 110b of the indexer unit 101.

[0103] Continue to explain the heat treatment in the heat treatment unit 160. FIG. 11 is a diagram showing the pressure fluctuation in the processing chamber 6. Before the semiconductor wafer W is carried into the processing chamber 6, the pressure in the processing chamber 6 is maintained at a base pressure Pb which is lower than the atmospheric pressure Pa by a certain value. Specifically, when the air supply valve 84 is opened and nitrogen gas is supplied into the processing chamber 6, the exhaust valve 89 is opened and the atmosphere in the processing chamber 6 is discharged. The pressure in the processing chamber 6 is measured by the pressure gauge 95. Then, the control unit 3 controls the air supply valve 84 and the exhaust valve 89 so that the pressure in the processing chamber 6 maintains the base pressure Pb based on the measurement result of the pressure gauge 95. Note that the control unit 3 controls, in the same manner as the exhaust valve 89, the mechanism for discharging the atmosphere around the driving part of the valve 192 and the transfer mechanism 10 so that the pressure in the processing chamber 6 maintains the base pressure Pb.

[0104] Since the pressure in the transfer chamber 170 is constantly maintained at the base pressure by the APC valve 171, the gate valve 185 can be opened to open the transfer opening 66 in a state where the pressure in the processing chamber 6 is set to the base pressure Pb. The transfer opening 66 is opened by the gate valve 185, and the semiconductor wafer W to be processed is carried into the heat treatment space 65 in the processing chamber 6 through the transfer opening 66 by the transfer robot 150. That is, the transfer of the semiconductor wafer W between the transfer chamber 170 and the processing chamber 6 is carried out at the base pressure Pb.

[0105] The transfer robot 150 advances the transfer hand 151a (or transfer hand 151b) that holds the unprocessed semiconductor wafer W to a position directly above the holding unit 7 and stops. Then, when the pair of transfer arms 11 of the transfer mechanism 10 horizontally move from the retracted position to the transfer operation position and rise, the lift pins 12 protrude from the upper surface of the holding plate 75 of the susceptor 74 through the through holes 79 to receive the semiconductor wafer W. At this time, the lift pins 12 rise above the upper ends of the substrate support pins 77.

[0106] After the unprocessed semiconductor wafer W is placed on the lift pins 12, the transfer robot 150 withdraws the transfer hand 151a from the heat treatment space 65, and the transfer opening 66 is closed by the gate valve 185. Then, when the pair of transfer arms 11 descend, the semiconductor wafer W is delivered from the transfer mechanism 10 to the susceptor 74 of the holding unit 7 and held from below in a horizontal posture. 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. Also, the semiconductor wafer W is held by the holding unit 7 with the surface to be subjected to flash heat treatment as the upper surface. A predetermined interval is formed between the back surface (the main surface on the side opposite to the 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 have descended below the susceptor 74 are retracted to the retracted position, that is, inside the recess 62, by the horizontal movement mechanism 13.

[0107] After the semiconductor wafer W is carried into the processing chamber 6 and the transfer opening 66 is closed by the gate valve 185 to make the heat treatment space 65 an airtight space, the pressure inside the processing chamber 6 is further reduced from the base pressure Pb. Specifically, the control unit 3 controls the air supply valve 84 and the exhaust valve 89 so that the pressure inside the processing chamber 6 is reduced from the base pressure Pb to the target processing pressure Ps. The processing pressure Ps is lower than the base pressure Pb and is, for example, a predetermined value of 5 kPa or more and 10 kPa or less.

[0108] While reducing the pressure inside the processing chamber 6, a mixed gas of ammonia and nitrogen is supplied from the processing gas supply source 85 into the processing chamber 6. Thereby, a reduced-pressure ammonia atmosphere is formed in the heat treatment space 65 inside the processing chamber 6. If the exhaust flow rate is larger than the supply flow rate of the mixed gas of ammonia and nitrogen, it is possible to form an ammonia atmosphere in the processing chamber 6 while reducing the pressure inside the processing chamber 6.

[0109] While an ammonia atmosphere is formed inside the processing chamber 6 and the pressure inside the processing chamber 6 is reduced to the processing pressure Ps, 40 halogen lamps HL are simultaneously lit and preheating (assist heating) is started. The halogen light emitted from the halogen lamp HL passes through the lower chamber window 64 and the susceptor 74 formed of quartz and is irradiated from the lower surface of the semiconductor wafer W. By receiving the light irradiation from the halogen lamp HL, the semiconductor wafer W is preheated and its temperature rises. Since the transfer arm 11 of the transfer mechanism 10 is retracted inside the recess 62, it does not interfere with the heating by the halogen lamp HL.

[0110] When performing preheating by the halogen lamp HL, the temperature of the semiconductor wafer W is measured by the radiation thermometer 20. That is, the radiation thermometer 20 receives the infrared light radiated from the lower surface of the semiconductor wafer W held by the susceptor 74 through the opening 78 and measures the temperature of the wafer being heated. 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 lamp HL while monitoring whether the temperature of the semiconductor wafer W that is heated up by the light irradiation from the halogen lamp HL has reached a predetermined preheating temperature T1. That is, the control unit 3 performs feedback control on the output of the halogen lamp HL based on the measurement value by the radiation thermometer 20 so that the temperature of the semiconductor wafer W becomes the preheating temperature T1.

[0111] 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 lamp HL to maintain the temperature of the semiconductor wafer W at approximately the preheating temperature T1.

[0112] By performing such preheating with the halogen lamp HL, the entire semiconductor wafer W is uniformly heated to the preheating temperature T1. In the stage of preheating with the halogen lamp HL, the temperature of the peripheral portion of the semiconductor wafer W, where more heat dissipation occurs, tends to be lower than that of the central portion. However, the arrangement density of the halogen lamp HL in the halogen lamp house 4 is higher in the region facing the peripheral portion of the semiconductor wafer W than in the region facing the central portion. Therefore, the amount of light irradiated to the peripheral portion of the semiconductor wafer W where heat dissipation is likely to occur increases, and the in-plane temperature distribution of the semiconductor wafer W in the preheating stage can be made uniform.

[0113] When the temperature of the semiconductor wafer W reaches the preheating temperature T1 and a predetermined time has elapsed, the flash lamp FL irradiates the surface of the semiconductor wafer W with flash light. At this time, a part of the flash light emitted from the flash lamp FL directly goes into the processing chamber 6, and the other part is once reflected by the reflector 52 and then goes into the processing chamber 6. The semiconductor wafer W is flash-heated by the irradiation of these flash lights.

[0114] Flash heating is performed by irradiating flash light (flashes) from a flash lamp FL, so that the surface temperature of the semiconductor wafer W can be increased in a short time. That is, the flash light irradiated from the flash lamp FL is an extremely short and intense flash with an irradiation time of about 0.1 milliseconds or more and 100 milliseconds or less, in which the electrostatic energy previously stored in the capacitor is converted into an extremely short light pulse. By irradiating the surface of the semiconductor wafer W with such a flash light having an extremely short irradiation time and high intensity, the temperature of its surface instantaneously rises to the processing temperature T2. The processing temperature T2 is higher than the preheating temperature T1. Then, the surface temperature of the semiconductor wafer W rapidly decreases simultaneously with reaching the processing temperature T2. By performing flash heating of the semiconductor wafer W in an ammonia atmosphere, surface treatment (for example, nitriding treatment) of the semiconductor wafer W is to be executed.

[0115] After the flash heat treatment is completed, the halogen lamp HL is turned off after a predetermined time has elapsed. Thereby, the semiconductor wafer W rapidly cools down from the preheating temperature T1. The temperature of the semiconductor wafer W during cooling is measured by the radiation thermometer 20, and the measurement result is transmitted to the control unit 3. Also, after the flash heat treatment is completed, the supply valve 84 is once closed with the exhaust valve 89 open to discharge ammonia from the processing chamber 6 under the control of the control unit 3. Then, the supply valve 84 is opened again, and nitrogen gas is supplied from the processing gas supply source 85 into the processing chamber 6 to repressurize the pressure in the processing chamber 6 to the base pressure Pb. More precisely, the control unit 3 controls the supply valve 84 and the exhaust valve 89 so that the pressure in the processing chamber 6 is repressurized to the base pressure Pb based on the measurement result of the pressure gauge 95.

[0116] After the pressure in the processing chamber 6 is restored to the base pressure Pb, 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 horizontally move and rise again from the retracted position to the transfer operation position, so that the lift pins 12 protrude from the upper surface of the susceptor 74 to receive the heat-treated semiconductor wafer W from the susceptor 74. Subsequently, the transfer opening 66 that has been closed by the gate valve 185 is opened, and the heat-treated semiconductor wafer W placed on the lift pins 12 is carried out into the transfer chamber 170 by the transfer hand 151b (or transfer hand 151a) of the transfer robot 150. Also at this time, since the pressure in the transfer chamber 170 and the pressure in the processing chamber 6 are both the base pressure Pb, the gate valve 185 can be opened. Then, the transfer of the semiconductor wafer W from the processing chamber 6 to the transfer chamber 170 is also executed at the base pressure Pb.

[0117] FIG. 12 is a diagram showing the pressure relationships in the indexer unit 101, the first cool chamber 131 and the second cool chamber 141, the transfer chamber 170, and the processing chamber 6. Since the first cool chamber 131 and the second cool chamber 141 perform similar processes and are equivalent, they are collectively referred to as cool chambers in the figure. The pressure in the indexer unit 101 that is open to the atmosphere is always the atmospheric pressure Pa. The pressure in the transfer chamber 170 is always maintained at the base pressure Pb. The pressures in the first cool chamber 131 and the second cool chamber 141 that connect the transfer chamber 170 and the indexer unit 101 vary between the atmospheric pressure Pa and the base pressure Pb. On the other hand, the pressure in the processing chamber 6 of the heat treatment unit 160 varies between the base pressure Pb and the processing pressure Ps.

[0118] In this embodiment, as shown in FIGS. 11 and 12, the pressure in the processing chamber 6 is constantly maintained at a base pressure Pb which is lower than the atmospheric pressure Pa by a certain value under the control of the control unit 3. That is, when the semiconductor wafer W is carried in and out of the processing chamber 6, the pressure in the processing chamber 6 is set to the base pressure Pb, and when the heat treatment is performed on the semiconductor wafer W, the pressure in the processing chamber 6 is less than the base pressure Pb. In short, typically the reference pressure in the processing chamber 6 for performing flash heat treatment is the atmospheric pressure Pa, but in this embodiment, the reference pressure in the processing chamber 6 is set lower than the atmospheric pressure Pa.

[0119] Since the pressure in the processing chamber 6 is constantly lower than the atmospheric pressure Pa, as shown in FIG. 11, even if the pressure fluctuates somewhat overshoots from the reference base pressure Pb when the pressure in the processing chamber 6 is repressurized after the flash heat treatment, the pressure in the processing chamber 6 does not exceed the atmospheric pressure Pa. As a result, even if the pressure fluctuation in the processing chamber 6 overshoots, it is prevented that the inside of the processing chamber 6 becomes a positive pressure with respect to the outside of the apparatus. Therefore, the inside of the processing chamber 6 is always a negative pressure with respect to the outside of the apparatus, and leakage of harmful gases such as ammonia from the processing chamber 6 to the outside of the apparatus is prevented.

[0120] Also, even in the case of this embodiment, since the pressure in the processing chamber 6 repeats the pressure reduction to the processing pressure Ps and the pressure restoration to the base pressure Pb every time one semiconductor wafer W is processed, for example, an O-ring or the like that seals between the upper chamber window 63 and the lower chamber window 64 and the chamber side portion 61 may deteriorate in a relatively short time. In this embodiment, since the pressure in the processing chamber 6 is constantly lower than the atmospheric pressure Pa and the inside of the processing chamber 6 is always a negative pressure with respect to the outside of the apparatus, even if parts such as an O-ring deteriorate and break, leakage of the gas in the processing chamber 6 from the damaged portion to the outside is prevented.

[0121] The base pressure Pb, which is the reference pressure in the processing chamber 6, is 50 kPa or more and 95 kPa or less. Therefore, even if the atmospheric pressure outside the heat treatment apparatus 100 slightly decreases due to the influence of a typhoon or the like, the inside of the processing chamber 6 is always in a negative pressure with respect to the outside of the apparatus, and leakage of gas from the processing chamber 6 to the outside of the apparatus can be prevented.

[0122] Also, after the unprocessed semiconductor wafer W is carried into the first cool chamber 131 and while the unprocessed semiconductor wafer W is held in the first cool chamber 131, the pressure in the first cool chamber 131 is reduced from the atmospheric pressure Pa to the base pressure Pb. On the other hand, after the heat-treated semiconductor wafer W is carried into the second cool chamber 141 and while the heat-treated semiconductor wafer W is held in the second cool chamber 141, the pressure in the second cool chamber 141 is restored from the base pressure Pb to the atmospheric pressure Pa. That is, the reference pressure in the processing chamber 6 is the base pressure Pb which is lower than the atmospheric pressure Pa, while the pressure in the indexer unit 101 which is open to the atmosphere is the atmospheric pressure Pa, and the differential pressure is adjusted in both the first cool chamber 131 and the second cool chamber 141 (FIG. 12). Here, it is also possible to adjust the differential pressure in the transfer chamber 170. However, the volumes of the first cool chamber 131 and the second cool chamber 141 are about 1 / 10 of the volume of the transfer chamber 170. Therefore, if the differential pressure is adjusted in the first cool chamber 131 and the second cool chamber 141, it is possible to adjust the pressure in a short time with a smaller amount of nitrogen gas than when executed in the transfer chamber 170.

[0123] Furthermore, in the present embodiment, when performing heat treatment on the semiconductor wafer W in the processing chamber 6 of the heat treatment unit 160, the pressure is reduced from the base pressure Pb lower than the atmospheric pressure Pa to the processing pressure Ps, and after the heat treatment, the pressure is restored to the base pressure Pb. Therefore, compared with the process of reducing the pressure from the atmospheric pressure Pa to the processing pressure Ps and then restoring the pressure to the atmospheric pressure Pa after the heat treatment, the time required for pressure adjustment can be shortened in the present embodiment, and as a result, the throughput can be improved.

[0124] As described above, the embodiments of the present invention have been described. However, the present invention can be variously modified without departing from the gist thereof. For example, in the above embodiment, the pressure in the transfer chamber 170 is always equal to the base pressure Pb of the processing chamber 6, but the pressure in the transfer chamber 170 may be slightly higher than the base pressure Pb of the processing chamber 6. Specifically, for example, if the base pressure Pb of the processing chamber 6 is 79 kPa, the pressure in the transfer chamber 170 may be 81 kPa. In this way, the transfer chamber 170 is always under a positive pressure with respect to the processing chamber 6, and gas leakage from the processing chamber 6 to the transfer chamber 170 can also be prevented. Although it is not as strict as gas leakage to the outside of the apparatus, it is preferable to prevent gas leakage from the processing chamber 6 to the transfer chamber 170 as much as possible.

[0125] Also, in the layout of the heat treatment apparatus 100 shown in FIG. 1, a chamber of a defect detection unit for detecting defects on the back surface of the semiconductor wafer W, for example, may be connected to the side of the indexer unit 101 on the side opposite to the alignment unit 230 ((-Y) side). Even with such a configuration, if the reference pressure in the processing chamber 6 is lower than the atmospheric pressure Pa, the same effects as in the above embodiment can be obtained.

[0126] In the above-described embodiment, ammonia was supplied as a processing gas into the processing chamber 6, but the present invention is not limited thereto, and the processing gas to be supplied may be ozone, oxygen, nitrogen oxide, or the like. Even when using these processing gases, since the inside of the processing chamber 6 is always at a negative pressure with respect to the outside of the apparatus, leakage of harmful gases from the processing chamber can be prevented.

[0127] In the above-described embodiment, the flash lamp house 5 is provided with 30 flash lamps FL, but the present invention is not limited thereto, and the number of flash lamps FL can be any number. Further, the flash lamp FL is not limited to a xenon flash lamp, and may be a krypton flash lamp. Also, the number of halogen lamps HL provided in the halogen lamp house 4 is not limited to 40, and can be any number.

[0128] In the above-described embodiment, a filament-type halogen lamp HL is used as a continuous lighting lamp that emits light continuously for 1 second or more to preheat the semiconductor wafer W, but the present invention is not limited thereto, and instead of the halogen lamp HL, a discharge-type arc lamp (for example, a xenon arc lamp) or an LED lamp may be used as the continuous lighting lamp to perform preheating.

Explanation of Reference Numerals

[0129] 3 Control unit 4 Halogen lamp house 5 Flash lamp house 6 Processing chamber 7 Holding unit 10 Transfer mechanism 65 Heat treatment space 74 Susceptor 84, 134, 144, 173 Air supply valve 89, 133, 143, 172 Exhaust valve 95, 135, 145, 175 Pressure gauge 100 Heat treatment apparatus 101 Indexer section 110 Load port 120 Delivery robot 131 First cooling chamber 141 Second cooling chamber 150 Transfer robot 160 Heat treatment section 170 Transfer chamber 171 APC valve 195 Vacuum pump C Carrier 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 processing chamber for accommodating the substrate and performing heat treatment on the substrate; a holding unit for holding the substrate in the processing chamber; a light source for irradiating the substrate accommodated in the processing chamber with light; a gas supply unit for supplying a processing gas to the processing chamber; an exhaust unit for exhausting the atmosphere in the processing chamber; a control unit for controlling the gas supply unit and the exhaust unit so that the atmosphere in the processing chamber reaches a target pressure; wherein the control unit controls the gas supply unit and the exhaust unit such that the pressure in the processing chamber is constantly maintained at or below a reference pressure that is lower than atmospheric pressure by a certain value, and such that the pressure in the processing chamber becomes a processing pressure lower than the reference pressure during the heat treatment of the substrate.

2. The heat treatment apparatus according to claim 1, wherein the control unit controls the gas supply unit and the exhaust unit such that after the substrate is loaded into the processing chamber, the pressure in the processing chamber is reduced from the reference pressure to the processing pressure, and after the heat treatment, the pressure in the processing chamber is restored from the processing pressure to the reference pressure.

3. The heat treatment apparatus according to claim 1, wherein the reference pressure is 50 kPa or more and 95 kPa or less.

4. The heat treatment apparatus according to claim 1, further comprising a transfer chamber connected to the processing chamber and accommodating a transfer robot for loading and unloading the substrate with respect to the processing chamber, wherein the pressure in the transfer chamber is constantly maintained at the reference pressure, and the transfer of the substrate between the transfer chamber and the processing chamber is performed at the reference pressure.

5. The heat treatment apparatus according to claim 4, further comprising a cooling chamber connected to the transfer chamber, temporarily holding an untreated substrate to be transferred to the transfer chamber, and temporarily holding and cooling the heat-treated substrate transferred from the transfer chamber, wherein the volume of the cooling chamber is smaller than the volume of the transfer chamber. A heat treatment apparatus that reduces the pressure in the cooling chamber from atmospheric pressure to the reference pressure after an untreated substrate is carried into the cooling chamber and while the untreated substrate is held in the cooling chamber, and that restores the pressure in the cooling chamber from the reference pressure to atmospheric pressure after a substrate after heat treatment is carried into the cooling chamber and while the substrate after heat treatment is held in the cooling chamber.

6. In the heat treatment apparatus according to Claim 1, The light source includes a flash lamp that irradiates flash light onto the surface of a substrate held by the holding unit. A heat treatment apparatus.

7. A heat treatment method for heating a substrate by irradiating the substrate with light, comprising: A housing step of housing a substrate in a processing chamber; A pressure reduction step of reducing the pressure in the processing chamber in which the substrate is housed; A heating step of irradiating the substrate with light; A pressure restoration step of restoring the pressure in the processing chamber; Comprising: The pressure in the processing chamber is constantly maintained at a reference pressure lower than atmospheric pressure, The pressure in the processing chamber in the heating step is a processing pressure lower than the reference pressure. A heat treatment method.

8. In the heat treatment method according to Claim 7, In the pressure reduction step, the pressure in the processing chamber is reduced from the reference pressure to the processing pressure, In the pressure restoration step, the pressure in the processing chamber is restored from the processing pressure to the reference pressure. A heat treatment method.

9. In the heat treatment method according to Claim 7, The reference pressure is 50 kPa or more and 95 kPa or less. A heat treatment method.

10. In the heat treatment method according to Claim 7, A transfer robot provided in a transfer chamber connected to the processing chamber transfers a substrate into and out of the processing chamber, The pressure in the transfer chamber is constantly maintained at the reference pressure, and the transfer of the substrate between the transfer chamber and the processing chamber is performed at the reference pressure. A heat treatment method.

11. In the heat treatment method according to Claim 10, A cooling chamber connected to the transfer chamber temporarily holds an untreated substrate transferred to the transfer chamber, and temporarily holds and cools a substrate after heat treatment transferred from the transfer chamber, The volume of the cooling chamber is smaller than the volume of the transfer chamber. A heat treatment method in which, after an untreated substrate is carried into the cooling chamber and while the untreated substrate is held in the cooling chamber, the pressure in the cooling chamber is reduced from atmospheric pressure to the reference pressure, and after a substrate after heat treatment is carried into the cooling chamber and while the substrate after heat treatment is held in the cooling chamber, the pressure in the cooling chamber is pressurized from the reference pressure to atmospheric pressure.

12. In the heat treatment method according to Claim 7, in the heating step, a heat treatment method in which flash light is irradiated from a flash lamp onto the surface of the substrate.

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