TWI725414B - Heat treatment apparatus and heat treatment method - Google Patents

Abstract

The present invention provides a heat treatment device and a heat treatment method that can easily confirm whether the heat treatment is normally performed. The heat treatment unit 160 performs preliminary heating processing on the semiconductor wafer W, and irradiates a flash light to perform flash heating processing. Reflectance measuring sections 135 and 145 are provided on the forward path of the semiconductor wafer W returning from the heat treatment section 160 to the mounting section 101 to measure the reflectance of the semiconductor wafer W after the heat treatment. When the reflectance of the semiconductor wafer W after the heating process is within a predetermined specific range, it is determined that the heating process of the semiconductor wafer W is normally performed. On the other hand, when the reflectance deviates from the specific range, it is determined that the heating process of the semiconductor wafer W is not normally performed. A warning is issued when it is determined that the heating process is not proceeding normally.

Description

Heat treatment device and heat treatment method

The present invention relates to a heat treatment device and a heat treatment method for heating a thin plate-shaped precision electronic substrate such as a semiconductor wafer (hereinafter referred to as a "substrate") by flashing the substrate.

In the manufacturing process of semiconductor devices, flash annealing (FLA), which heats semiconductor wafers in a very short time, is attracting attention. Flash lamp annealing uses a xenon flash lamp (hereinafter, referred to as "flash lamp" when it is abbreviated as xenon flash lamp) to irradiate the surface of the semiconductor wafer with flash, thereby only heating the surface of the semiconductor wafer in a very short time (less than a few milliseconds) Heat treatment technology.

The Xenon flash lamp emits light from the ultraviolet region to the near-infrared region. The wavelength is shorter than that of the previous halogen lamps, which is roughly the same as the basic absorption band of silicon semiconductor wafers. Therefore, when the semiconductor wafer is irradiated with a flash light from the xenon flash lamp, the transmitted light is less, and the semiconductor wafer can be heated rapidly. In addition, it has also been found that flash irradiation for a very short time of several milliseconds or less can selectively heat up only the vicinity of the surface of the semiconductor wafer.

This flash lamp annealing is used for treatments that require a very short time of heating, such as activation of impurities implanted into semiconductor wafers. This flash lamp annealing is used for treatments that require a very short time of heating, such as activation of impurities implanted into semiconductor wafers. If the flash is irradiated from the flash lamp to the surface of the semiconductor wafer that has been implanted with impurities by ion implantation, the surface of the semiconductor wafer can be heated to the activation temperature in a very short time, so that only the impurity activation can be performed without diffusion of the impurities To the depths.

Flash lamp annealing is to irradiate a flash with a very short irradiation time to heat up the semiconductor wafer instantaneously. Therefore, it is impossible to measure the temperature of the wafer while feedback control the luminous intensity of the flash lamp. Therefore, the luminous intensity of the flash lamp must be adjusted in advance to properly heat the surface of the semiconductor wafer to a specific target temperature. Patent Document 1 discloses a technique of measuring the reflectance of a semiconductor wafer to be processed before heat treatment, and calculating the applied voltage to the flash lamp based on the measured reflectance. In the technique disclosed in Patent Document 1, the reflectance of the semiconductor wafer is measured before the semiconductor wafer is carried into the processing chamber for flash irradiation. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2011-204741

[The problem to be solved by the invention]

In addition, the reflectivity of a semiconductor wafer varies according to the properties of the surface of the wafer and the film formed on the surface of the wafer. Therefore, by measuring the reflectance of the semiconductor wafer before loading the semiconductor wafer into the processing chamber, it can be checked in advance whether there is a semiconductor wafer outside the specification that has been loaded. However, in the past, the reflectance of the semiconductor wafer was measured only before the semiconductor wafer was loaded into the processing chamber, so it was impossible to confirm whether the heating process was performed normally by the reflectance measurement.

The present invention was made in view of the above-mentioned problems, and its object is to provide a heat treatment device and a heat treatment method that can easily confirm whether the heat treatment is normally performed. [Technical means to solve the problem]

In order to solve the above-mentioned problems, the invention of claim 1 is a heat treatment device that heats the substrate by irradiating the substrate with a flash of light, which is characterized by including: a processing chamber for accommodating the substrate; The substrate is heated by irradiating a flash light; and a reflectance measuring section that measures the reflectance of the substrate after being heated by the flash irradiation from the flash lamp.

In addition, the invention of claim 2 is the heat treatment apparatus of the invention of claim 1, wherein the reflectance measuring unit also measures the reflectance of the substrate before the flash is irradiated from the flash lamp.

In addition, the invention of claim 3 is the heat treatment apparatus of the invention of claim 1 or 2, which is characterized in that it is further equipped with a loading device for loading unprocessed substrates into the device and unprocessed substrates out of the device. Section, and the reflectance measuring section is provided in a transport path of the substrate from the processing chamber to the loading section.

Furthermore, the invention of claim 4 is the heat treatment apparatus of the invention of claim 3, characterized in that a cooling chamber for cooling the heated substrate is provided in the conveying path, and the reflectance measuring unit is provided in the cooling Chamber.

In addition, the invention of claim 5 is the heat treatment apparatus of the invention of claim 2, further comprising: a determination unit that determines the heating of the substrate based on the reflectance of the substrate measured by the reflectance measurement unit Whether the processing is proceeding normally; and a warning issuing unit that issues a warning when it is determined by the determination unit that the heating processing of the substrate is not proceeding normally.

In addition, the invention of claim 6 is the heat treatment device of the invention of claim 2, and is characterized by further comprising a memory section for memorizing the reflectance of the substrate measured by the reflectance measurement section.

In addition, the invention of claim 7 is the heat treatment device of the invention of claim 6, characterized in that the luminous intensity of the flash lamp is adjusted by artificial intelligence based on the reflectivity of a plurality of substrates stored in the memory portion.

In addition, the invention of claim 8 is the heat treatment apparatus of the invention of claim 1, further comprising a continuous lighting lamp that preliminarily heats the substrate irradiated light before irradiating the flash from the flash lamp.

In addition, the invention of claim 9 is a heat treatment method characterized in that it heats the substrate by irradiating the substrate with a flash, and includes: an irradiation step of irradiating the substrate contained in the processing chamber with the flash from the flash lamp Heating; and a step of measuring reflectivity after treatment, which is to measure the reflectivity of the substrate after the above-mentioned irradiation step.

In addition, the invention of claim 10 is the heat treatment method of the invention of claim 9, characterized by further comprising a pre-treatment reflectance measurement step for measuring the reflectance of the substrate before the irradiation step.

In addition, the invention of claim 11 is the heat treatment method of the invention of claim 9 or claim 10, and is characterized by further comprising: a determination step based on the reflectance of the substrate measured in the reflectance measurement step after the treatment, It is determined whether the heating treatment of the above-mentioned substrate is normally performed; and a warning issuance step is to issue a warning when the above-mentioned determination step determines that the heating treatment of the above-mentioned substrate is not normally performed.

In addition, the invention of claim 12 is the heat treatment method of the invention of claim 10, and is characterized by further comprising a memory step of storing the reflectance of the substrate measured in the reflectance measurement step after the treatment in a memory portion.

In addition, the invention of claim 13 is the heat treatment method of the invention of claim 12, and is characterized by further comprising an adjustment step of adjusting the luminous intensity of the flash lamp based on the reflectivity of the plurality of substrates stored in the memory portion.

In addition, the invention of claim 14 is the heat treatment method of the invention of claim 13, which is characterized in that, in the adjustment step, artificial intelligence is used to adjust the luminous intensity of the flash.

Furthermore, the invention of claim 15 is the heat treatment method of the invention of claim 9, characterized by further comprising a preheating step of preheating the substrate irradiated light by self-continuous lighting before irradiating the flash from the flash lamp. [Effects of Invention]

According to the invention of claim 1 to claim 8, the reflectance of the substrate heated by the flash light from the flash lamp is measured, so it can be easily confirmed whether the heating process is proceeding normally based on the reflectance of the heated substrate.

In particular, according to the invention of claim 7, the luminous intensity of the flash lamp can be adjusted by artificial intelligence based on the reflectance of a plurality of substrates stored in the memory unit. Therefore, the luminous intensity of the flash lamp can also be considered by considering the reflectivity of the substrate after heating. Adjust to an appropriate value.

According to the inventions of claim 9 to claim 15, the reflectance of the substrate is measured after the step of heating the substrate by irradiating the flash from the flash lamp, so it is possible to easily confirm whether the heating process is proceeding normally based on the reflectance of the heated substrate .

In particular, according to the inventions of Technical Solution 13 and Technical Solution 14, the luminous intensity of the flash lamp is adjusted based on the reflectivity of a plurality of substrates stored in the memory unit. Therefore, the luminous intensity of the flash lamp can be adjusted in consideration of the reflectivity of the substrate after heating. Is an appropriate value.

Hereinafter, the embodiments of the present invention will be described in detail while referring to the drawings.

First, the overall schematic configuration of the heat treatment apparatus 100 of the present invention will be described. FIG. 1 is a top view of a heat treatment apparatus 100 of the present invention, and FIG. 2 is a front view thereof. The heat treatment device 100 is a flash lamp annealing device that irradiates a semiconductor wafer W having a disc shape as a substrate with a flash to heat the semiconductor wafer W. The size of the semiconductor wafer W to be processed is not particularly limited, and is, for example, ϕ 300 mm or ϕ 450 mm. Before being carried into the heat treatment apparatus 100, the semiconductor wafer W is implanted with impurities, and an activation process of the implanted impurities is performed by the heat treatment performed by the heat treatment apparatus 100. Furthermore, in FIG. 1 and the following figures, for ease of understanding, the size or number of each part is exaggerated or simplified as necessary. In addition, in each of FIGS. 1 to 3, in order to clarify the directional relationship, an XYZ orthogonal coordinate system with the Z-axis direction as the vertical direction and the XY plane as the horizontal plane is indicated.

As shown in FIGS. 1 and 2, the heat treatment apparatus 100 includes a loading section 101 for carrying unprocessed semiconductor wafers W into the apparatus from the outside, and unprocessed semiconductor wafers W out of the apparatus Alignment part 230, which performs the positioning of the unprocessed semiconductor wafer W; 2 cooling parts 130, 140, which cool the semiconductor wafer W after heat treatment; and the transport robot 150, which is opposite to the semiconductor wafer W The heat treatment unit 160, the cooling units 130 and 140, and the heat treatment unit 160 where the wafer W is subjected to flash heating treatment perform the transfer of the semiconductor wafer W. In addition, the heat treatment apparatus 100 includes a control unit 3 that controls the operation mechanism and the transport robot 150 provided in each of the above-mentioned processing units to perform flash heat treatment of the semiconductor wafer W.

The loading unit 101 includes: a loading port 110 for placing a plurality of carriers C (two in this embodiment) in a row; and a transfer robot 120 for taking out the unprocessed semiconductor wafer W from each carrier C and placing it on each carrier The processed semiconductor wafer W is stored in C. The carrier C containing the unprocessed semiconductor wafer W is transported by an unmanned transport vehicle (AGV, OHT) and placed on the load port 110, and the carrier C containing the processed semiconductor wafer W is transported by The unmanned transport vehicle is moved out of the load port 110.

In addition, the carrier C is configured to move up and down as shown by the arrow CU in FIG. 2, so that the transfer robot 120 in the load port 110 can pick and place any semiconductor wafer W on the carrier C. Furthermore, as the form of the carrier C, in addition to the FOUP (front opening unified pod) that stores the semiconductor wafer W in a confined space, it can also be SMIF (Standard Mechanical Inter Face). Interface) a wafer cassette or an OC (open cassette) that exposes the stored semiconductor wafer W to external air.

In addition, the handover robot 120 can perform sliding movement as shown by arrow 120S in FIG. 1, as well as turning and lifting movements as shown by arrow 120R. Thereby, the transfer robot 120 picks up and places the semiconductor wafer W on the two carriers C, and transfers the semiconductor wafer W to the alignment part 230 and the two cooling parts 130 and 140. The picking and placing of the semiconductor wafer W on the carrier C by the transfer robot 120 is performed by the sliding movement of the robot 121 and the lifting movement of the carrier C. In addition, the transfer of the semiconductor wafer W between the transfer robot 120 and the alignment part 230 or the cooling parts 130 and 140 is performed by the sliding movement of the robot 121 and the lifting motion of the transfer robot 120.

The aligning part 230 is connected to the side of the loading part 101 along the Y-axis direction. The alignment part 230 is a processing part that rotates the semiconductor wafer W in a horizontal plane to a direction suitable for flash heating. The alignment part 230 is provided inside the alignment chamber 231 which is an aluminum alloy frame, a mechanism that supports and rotates the semiconductor wafer W in a horizontal position, and optically detects the recess formed on the periphery of the semiconductor wafer W It is constituted by mechanisms such as a mouth or orientation flat (all are not shown).

The transfer of the semiconductor wafer W to the alignment part 230 is performed by the transfer robot 120. The transfer robot 120 delivers the semiconductor wafer W to the alignment chamber 231 in such a manner that the center of the wafer is located at a specific position. In the alignment section 230, the center of the semiconductor wafer W received from the loading section 101 is used as the center of rotation, the semiconductor wafer W is rotated around the vertical axis, and the notch is optically detected, thereby adjusting the semiconductor wafer W之向。 The direction. The semiconductor wafer W whose orientation has been adjusted is taken out from the alignment chamber 231 by the transfer robot 120.

As a transfer space in which the semiconductor wafer W is transferred by the transfer robot 150, a transfer chamber 170 for accommodating the transfer robot 150 is provided. The processing chamber 6 of the heat treatment part 160, the first cooling chamber 131 of the cooling part 130, and the second cooling chamber 141 of the cooling part 140 are connected to the three sides of the transfer chamber 170.

The heat treatment unit 160, which is the main part of the heat treatment apparatus 100, is a substrate processing unit that irradiates the preheated semiconductor wafer W with flash light from the xenon flash lamp FL to perform flash heat treatment. The detailed structure of the heat treatment unit 160 will be further described below.

The two cooling units 130 and 140 have substantially the same structure. The cooling parts 130 and 140 are equipped with a metal cooling plate and a quartz plate placed on the upper surface of the first cooling chamber 131 and the second cooling chamber 141, which are aluminum alloy frames, respectively (all are not shown) ). The cooling plate is adjusted to normal temperature (approximately 23°C) by Peltier elements or constant temperature water circulation. The semiconductor wafer W that has been subjected to the flash heat treatment by the heat treatment unit 160 is carried into the first cooling chamber 131 or the second cooling chamber 141, and placed on the quartz plate for cooling.

Both the first cooling chamber 131 and the second cooling chamber 141 are connected to both of the loading part 101 and the transfer chamber 170. In the first cooling chamber 131 and the second cooling chamber 141, two openings for carrying the semiconductor wafer W in and out are formed. Among the two openings of the first cooling chamber 131, the opening connected to the loading portion 101 can be opened and closed by the gate valve 181. On the other hand, the opening of the first cooling chamber 131 connected to the transfer chamber 170 can be opened and closed by the gate valve 183. That is, the first cooling chamber 131 and the loading 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.

When the semiconductor wafer W is transferred between the loading part 101 and the first cooling chamber 131, the gate valve 181 is opened. In addition, when the semiconductor wafer W is transferred 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 closed space.

In addition, the opening connected to the loading part 101 among the two openings of the second cooling chamber 141 can be opened and closed by the gate valve 182. On the other hand, the opening of the second cooling chamber 141 connected to the transfer chamber 170 can be opened and closed by the gate valve 184. That is, the second cooling chamber 141 and the loading 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.

When the semiconductor wafer W is transferred between the loading part 101 and the second cooling chamber 141, the gate valve 182 is opened. In addition, when the semiconductor wafer W is transferred 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 closed space.

In addition, the first cooling chamber 131 and the second cooling chamber 141 are respectively provided with a reflectance measuring section 135 and a reflectance measuring section for measuring the reflectance of the surface of the semiconductor wafer W placed and supported on the quartz plate. 145. The reflectance measuring units 135 and 145 both irradiate light on the surface of the semiconductor wafer W and receive the reflected light reflected by the surface, thereby determining the intensity of the semiconductor wafer W based on the intensity of the irradiated light and the intensity of the received reflected light The reflectivity of the surface. More specifically, the reflectance measuring units 135 and 145 calculate the reflectance of the semiconductor wafer W by dividing the intensity of the received reflected light by the intensity of the irradiated light.

Furthermore, the cooling units 130 and 140 respectively include a gas supply mechanism for supplying clean nitrogen to the first cooling chamber 131 and the second cooling chamber 141, and an exhaust mechanism for exhausting the gas in the chamber. The gas supply mechanism and exhaust mechanism can also switch the flow rate in two stages. In addition, the conveying chamber 170 and the alignment chamber 231 are also supplied with nitrogen gas from the gas supply part, and the gas system inside them is discharged through the exhaust part.

The transfer robot 150 installed in the transfer chamber 170 can rotate as shown by an arrow 150R centered on the axis in the vertical direction. The transfer robot 150 has two link mechanisms including a plurality of arm segments, and transfer robots 151a and 151b for holding the semiconductor wafer W are respectively provided at the front ends of the two link mechanisms. The conveying robots 151a, 151b are arranged up and down at a specific interval, and can be linearly slid and moved in the same horizontal direction independently by a link mechanism. In addition, the transport robot 150 moves up and down the base provided with two link mechanisms, so that the two transport robots 151a and 151b are kept separated by a certain distance.

When the transfer robot 150 uses the first cooling chamber 131, the second cooling chamber 141, or the processing chamber 6 of the heat treatment unit 160 as the transfer target to transfer (pick and place) the semiconductor wafer W, first, the two transfer robots 151a , 151b rotates to the opposite side of the transfer object, and then (or during the rotation) moves up and down so that any transfer robot is located at the height of the semiconductor wafer W that is transferred to the transfer object. Then, the transfer robot 151a (151b) is linearly slid and moved in the horizontal direction to transfer the semiconductor wafer W to the transfer target.

The transfer of the semiconductor wafer W between the transfer robot 150 and the transfer robot 120 can be performed via the cooling units 130 and 140. That is, the first cooling chamber 131 of the cooling part 130 and the second cooling chamber 141 of the cooling part 140 also function as a passage for transferring the semiconductor wafer W between the transfer robot 150 and the transfer robot 120. Specifically, one of the transfer robot 150 or the transfer robot 120 delivers the semiconductor wafer W to the first cooling chamber 131 or the second cooling chamber 141, and the other receives the semiconductor wafer W therefrom, by Here, the semiconductor wafer W is transferred.

As described above, the gate valves 181 and 182 are provided between the first cooling chamber 131 and the second cooling chamber 141 and the loading part 101, respectively. In addition, 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. Furthermore, 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 transported in the heat treatment apparatus 100, the gate valves are appropriately opened and closed.

Next, the structure of the heat treatment unit 160 will be described. FIG. 3 is a longitudinal cross-sectional view showing the structure of the heat treatment unit 160. The heat treatment unit 160 includes a processing chamber 6 that houses the semiconductor wafer W and heat-processes it, a flash lamp cover 5 with a plurality of flash lamps FL, and a halogen lamp cover 4 with a plurality of halogen lamps HL. A flashlight cover 5 is provided on the upper side of the processing chamber 6 and a halogen lamp cover 4 is provided on the lower side. In addition, the heat treatment unit 160 is provided inside the processing chamber 6: a holding unit 7 that holds the semiconductor wafer W in a horizontal position; and a transfer mechanism 10 that carries the semiconductor wafer W between the holding unit 7 and the transfer robot 150 The handover.

The processing chamber 6 is configured by installing a quartz chamber window above and below a cylindrical chamber side 61. The chamber side portion 61 has a substantially cylindrical shape with upper and lower openings. An upper chamber window 63 is attached to the upper opening to be closed, and a lower chamber window 64 is attached to the lower opening to be closed. The upper chamber window 63 on the top plate constituting the processing chamber 6 is a circular plate-shaped member formed of quartz, and functions as a quartz window through which flash light emitted from the flash lamp FL penetrates into the processing chamber 6. In addition, the lower chamber window 64 of the bottom plate constituting the processing chamber 6 is also a disc-shaped member formed of quartz, and functions as a quartz window through which light from the halogen lamp HL is transmitted into the processing chamber 6.

In addition, a reflection ring 68 is attached to the upper part of the inner wall surface of the chamber side part 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 reflection ring 68 on the upper side is installed by being inserted from the upper side of the chamber side portion 61. On the other hand, the reflection ring 69 on the lower side is inserted from the lower side of the chamber side portion 61 and fixed with screws (not shown) to be installed. 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 61, and the reflection rings 68 and 69 is defined as the heat treatment space 65.

By installing the reflection rings 68 and 69 on the side 61 of the chamber, a recess 62 is formed on the inner wall surface of the processing chamber 6. That is, a recess 62 surrounded by 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 are formed. The concave portion 62 is formed in a circular ring shape in 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 61 and the reflection rings 68 and 69 are formed of a metal material (for example, stainless steel) excellent in strength and heat resistance.

In addition, a transfer opening (furnace opening) 66 for carrying in and out of the semiconductor wafer W with respect to the processing chamber 6 is formed on the chamber side 61. The conveyance opening 66 can be opened and closed by the gate valve 185. The conveyance opening 66 is connected to the outer peripheral surface of the recess 62 in communication. Therefore, when the gate valve 185 opens the transfer opening 66, the semiconductor wafer W can be carried in from the transfer opening 66 through the recess 62 to the heat treatment space 65 and the semiconductor wafer W can be carried out from the heat treatment space 65. In addition, when the gate valve 185 closes the conveyance opening 66, the heat treatment space 65 in the processing chamber 6 becomes a closed space.

In addition, a gas supply hole 81 for supplying processing gas to the heat treatment space 65 is formed in the upper part of the inner wall of the processing chamber 6. The gas supply hole 81 is formed at a position higher than the concave portion 62, and may also be provided at the reflection ring 68. The gas supply hole 81 is connected to the gas supply pipe 83 via 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. In addition, a valve 84 is inserted in the middle of the path of the gas supply pipe 83. When the valve 84 is opened, the processing gas is delivered 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 diffuse in the buffer space 82 whose fluid resistance is smaller than that of the gas supply hole 81, and is supplied into the heat treatment space 65 from the gas supply hole 81. As the processing gas, _{an inert gas such as nitrogen (N 2} ), or a reactive gas such as hydrogen (H ₂ ) or ammonia (NH ₃ ) (nitrogen in this embodiment) can be used.

On the other hand, a gas exhaust hole 86 is formed in the lower part of the inner wall of the processing chamber 6 to discharge the gas in the heat treatment space 65. The gas exhaust hole 86 is formed at a position lower than the concave portion 62, and may also be provided at the reflection ring 69. The gas exhaust hole 86 is connected to the gas exhaust pipe 88 via 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 the exhaust mechanism 190. In addition, a valve 89 is inserted in the middle of the path of the gas exhaust pipe 88. When the valve 89 is opened, the gas in the heat treatment space 65 is discharged from the gas exhaust hole 86 to the gas exhaust pipe 88 through the buffer space 87. Furthermore, the gas supply holes 81 and the gas exhaust holes 86 may be provided in plural along the circumferential direction of the processing chamber 6, or may be slit-shaped. In addition, the processing gas supply source 85 and the exhaust mechanism 190 may be a mechanism installed in the heat treatment device 100, or may be a facility in a factory where the heat treatment device 100 is installed.

In addition, a gas exhaust pipe 191 for exhausting the gas in the heat treatment space 65 is also connected to the front end of the conveying opening 66. The gas exhaust pipe 191 is connected to the exhaust mechanism 190 via a valve 192. By opening the valve 192, the gas in the processing chamber 6 is discharged through the conveying opening 66.

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

The abutment ring 71 is an arc-shaped quartz member with a part of the ring shape missing. This missing part is provided in order to prevent the transfer arm 11 and the base ring 71 of the transfer mechanism 10 described below from interfering with each other. The abutment ring 71 is supported by the wall surface of the chamber 6 by being placed on the bottom surface of the recess 62 (refer to FIG. 3). On the upper surface of the abutment ring 71, a plurality of connecting portions 72 (four in this embodiment) are erected along the circumferential direction of the ring shape. The connecting portion 72 is also a quartz member, and is fixed to the abutment ring 71 by welding.

The base 74 is supported by the four connecting parts 72 provided on the abutment ring 71. FIG. 5 is a top view of the base 74. 6 is a cross-sectional view of the base 74. The base 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 plate-shaped 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 plane size than the semiconductor wafer W.

A guide ring 76 is provided on the peripheral edge of the upper surface of the holding plate 75. The guide ring 76 is a ring-shaped 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 ϕ 300 mm, the inner diameter of the guide ring 76 is ϕ 320 mm. The inner circumference of the guide ring 76 becomes an inclined surface extending 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.

The region on the upper surface of the holding plate 75 that is more inside than the guide ring 76 becomes a planar holding surface 75a for holding the semiconductor wafer W. A plurality of substrate support pins 77 are erected on the holding surface 75 a of the holding plate 75. In this embodiment, a total of 12 substrate support pins 77 are erected on a circumference that is concentric with the outer circumference of the holding surface 75a (the inner circumference of the guide ring 76) every 30°. The diameter of the circle equipped with 12 substrate support pins 77 (the distance between the opposed substrate support pins 77) is smaller than the diameter of the semiconductor wafer W. If the diameter of the semiconductor wafer W is ϕ 300 mm, it is ϕ 270 mm～ ϕ 280 mm ( ϕ 270 mm in this embodiment). Each substrate support pin 77 is formed of quartz. The plurality of substrate support pins 77 can be welded and arranged on the upper surface of the holding plate 75, or can be processed as a whole with the holding plate 75.

Returning to FIG. 4, the four connecting portions 72 erected on the abutment ring 71 and the peripheral edge portions of the retaining plate 75 of the base 74 are fixed by welding. That is, the base 74 and the abutment ring 71 are fixedly connected by the connecting portion 72. The abutment ring 71 of the holding portion 7 is supported on the wall surface of the processing chamber 6 so that the holding portion 7 is installed in the processing chamber 6. In the state where the holding portion 7 is installed in the processing chamber 6, the holding plate 75 of the base 74 is in a horizontal posture (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 surface.

The semiconductor wafer W carried into the processing chamber 6 is placed and held in a horizontal posture on the susceptor 74 mounted on the holding portion 7 of the processing chamber 6. At this time, the semiconductor wafer W is supported and held by the base 74 by the 12 substrate support pins 77 erected on the holding plate 75. More precisely, the upper ends of the 12 substrate support pins 77 are in contact with the lower surface of the semiconductor wafer W to support the semiconductor wafer W. The heights of the 12 substrate support pins 77 (the distance from the upper end of the substrate support pins 77 to the holding surface 75a of the holding plate 75) are equal, so the semiconductor wafer W can be supported in a horizontal posture by the 12 substrate support pins 77.

In addition, the semiconductor wafer W is supported by a plurality of substrate support pins 77 at a certain interval from the holding surface 75 a of the holding plate 75. The thickness of the guide ring 76 is greater than the height of the substrate support pin 77. Therefore, the guide ring 76 is used to prevent the semiconductor wafer W supported by the plurality of substrate supporting pins 77 from being misaligned in the horizontal direction.

In addition, as shown in FIGS. 4 and 5, the holding plate 75 of the base 74 has an opening 78 penetrating vertically. The opening 78 is provided in order for the radiation thermometer 20 (refer to FIG. 3) to receive radiation light (infrared light) emitted from the lower surface of the semiconductor wafer W held on the susceptor 74. That is, the radiation thermometer 20 receives the light radiated from the lower surface of the semiconductor wafer W held on the susceptor 74 through the opening 78, and measures the temperature of the semiconductor wafer W by a detector provided separately. Furthermore, the holding plate 75 of the susceptor 74 is provided with four through holes 79 through which the jacking pins 12 of the transfer mechanism 10 described below penetrate for the transfer of the semiconductor wafer W.

FIG. 7 is a top view of the transfer mechanism 10. In addition, FIG. 8 is a side view of the transfer mechanism 10. The transfer mechanism 10 includes two transfer arms 11. The transfer arm 11 is shaped like an arc along a substantially circular recess 62. Two jacking pins 12 are erected on each transfer arm 11. Each transfer arm 11 can be rotated by the horizontal movement mechanism 13. The horizontal movement mechanism 13 moves the pair of transfer arms 11 at the transfer operation position (the solid line position in FIG. 7) for transferring the semiconductor wafer W to the holding portion 7 and the semiconductor wafer held by the holding portion 7 in a plan view. W moves horizontally between the retreat positions that do not overlap (the two-dot chain line position in Figure 7). The horizontal movement mechanism 13 may be one that rotates each transfer arm 11 by a separate motor, or one that uses a link mechanism to rotate the pair of transfer arms 11 in conjunction with one motor.

In addition, the pair of transfer arms 11 are moved up and down together by the lifting mechanism 14 and the horizontal moving mechanism 13. When the lifting mechanism 14 raises the pair of transfer arms 11 to the transfer action position, a total of four jacking pins 12 pass through the through holes 79 (see Figures 4 and 5) provided in the base 74, and the jacking pins 12 The upper end protrudes from the upper surface of the base 74. On the other hand, when the lifting mechanism 14 lowers the pair of transfer arms 11 to the transfer operation position, the jacking pin 12 is drawn out from the through hole 79, and the horizontal movement mechanism 13 moves the pair of transfer arms 11 in an open manner At this time, each transfer arm 11 moves to the retracted position. The retreat position of the pair of transfer arms 11 is directly above the abutment ring 71 of the holding portion 7. The abutment ring 71 is placed on the bottom surface of the recess 62, so the retracted position of the transfer arm 11 is the inside of the recess 62. Furthermore, an exhaust mechanism (not shown) is also installed near the portion of the transfer mechanism 10 where the driving part (horizontal movement mechanism 13 and the elevating mechanism 14) is installed, and is configured to remove the gas around the driving part of the transfer mechanism 10 Discharge to the outside of the chamber 6.

Returning to FIG. 3, the flash cover 5 arranged above the processing chamber 6 is provided with a light source including a plurality of xenon flash lamps FL (30 in this embodiment) on the inside of the frame 51, and to cover the top of the light source The reflector 52 is arranged in this way. In addition, a light emission window 53 is installed at the bottom of the frame 51 of the flash cover 5. The light emission window 53 constituting the bottom plate of the flash cover 5 is a plate-shaped quartz window formed of quartz. By disposing the strobe cover 5 above the processing chamber 6, the light emission window 53 becomes opposite to the upper chamber window 63. The flash lamp FL irradiates a flash light to the heat treatment space 65 from above the processing chamber 6 through the lamp radiation window 53 and the upper chamber window 63.

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

The xenon flash lamp FL is equipped with: a rod-shaped glass tube (discharge tube) in which xenon gas is enclosed and the anode and cathode connected to the capacitor are arranged at both ends of the rod-shaped glass tube; the trigger electrode is attached to the outer circumference of the glass tube on. Xenon gas is an electrical insulator, so even if there is charge stored in the capacitor, there is no electrical flow in the glass tube under normal conditions. However, when a high voltage is applied to the trigger electrode to destroy the insulation, the electricity stored in the capacitor flows into the glass tube instantaneously, and light is released by the excitation of xenon atoms or molecules at this time. This xenon flash lamp FL has the following characteristics: the electrostatic energy pre-stored in the capacitor is converted into an extremely short light pulse of 0.1 millisecond to 100 milliseconds, so it can illuminate extremely strongly compared to a light source that is continuously lit like a halogen lamp HL Light. That is, the flash lamp FL is a pulsed light that emits instantaneously in a very short time of less than 1 second. Furthermore, the light-emitting time of the flash lamp FL can be adjusted by the coil constant of the lamp power supply for power supply to the flash lamp FL.

In addition, the reflector 52 is arranged to cover the whole of the plurality of flash lamps FL. The basic function of the reflector 52 is to reflect the flashes emitted from the plurality of flash lamps FL to the side of the heat treatment space 65. The reflector 52 is formed of an aluminum alloy plate, and its surface (the surface facing the side of the flash lamp FL) is roughened by spray processing.

The halogen lamp cover 4 arranged under the processing chamber 6 has a plurality of (40 in this embodiment) halogen lamps HL built in the inside of the frame 41. The plurality of halogen lamps HL irradiate light to the heat treatment space 65 through the lower chamber window 64 from below the treatment chamber 6.

Fig. 9 is a plan view showing the arrangement of a plurality of halogen lamps HL. In this embodiment, 20 halogen lamps HL are arranged in each of the upper and lower stages. Each halogen lamp HL is a rod-shaped lamp with a long cylindrical shape. In the upper and lower stages, the 20 halogen lamps HL are all arranged in such a way that the length direction of each of them is parallel to each other along the main surface of the semiconductor wafer W held by the holding portion 7 (ie, in the horizontal direction). Therefore, in the upper and lower sections, the planes formed by the arrangement of the halogen lamps HL are all horizontal planes.

In addition, as shown in FIG. 9, the upper and lower stages are the arrangement of the halogen lamp HL in the area opposed to the central portion of the semiconductor wafer W held by the holding portion 7, and the area opposed to the peripheral edge portion The density is higher. That is, the arrangement pitch of the halogen lamp HL is shorter than the center part of the peripheral part where the lamps are arranged in the upper and lower stages. Therefore, it is possible to irradiate the peripheral portion of the semiconductor wafer W, which is likely to cause a temperature drop when heated by the light irradiation from the halogen lamp HL, to irradiate a larger amount of light.

In addition, the lamp group including the halogen lamp HL of the upper stage and the lamp group including the halogen lamp HL of the lower stage are arranged in a grid-like cross. That is, a total of 40 halogen lamps HL are arranged so that the longitudinal direction of each halogen lamp HL in the upper stage is orthogonal to the longitudinal direction of each halogen lamp HL in the lower stage.

The halogen lamp HL is a filament light source in which the filament is incandescent and emits light by energizing the filament arranged inside the glass tube. Inside the glass tube, there is a gas that introduces a trace amount of halogen elements (iodine, bromine, etc.) into an inert gas such as nitrogen or argon. By introducing halogen elements, the breakage of the filament can be suppressed and the temperature of the filament can be set to a high temperature. Therefore, the halogen lamp HL has the characteristics of a longer life span and the ability to continuously irradiate strong light compared with ordinary incandescent bulbs. That is, the halogen lamp HL is a continuous lighting lamp that continuously emits light for at least 1 second or longer. In addition, since the halogen lamp HL is a rod-shaped lamp, it has a long life. By arranging the halogen lamp HL in the horizontal direction, the radiation efficiency of the semiconductor wafer W upward becomes excellent.

In addition, in the frame 41 of the halogen lampshade 4, a reflector 43 is also provided under the two-stage halogen lamp HL (FIG. 3). The reflector 43 reflects the light emitted from the plurality of halogen lamps HL to the side of the heat treatment space 65.

In addition to the above-mentioned configuration, the heat treatment unit 160 also has various functions in order to prevent the heat generated from the halogen lamp HL and flash lamp FL during the heat treatment of the semiconductor wafer W from excessively increasing the temperature of the halogen lamp cover 4, the flash lamp cover 5, and the processing chamber 6. Cooling structure. For example, a water cooling pipe (not shown) is provided on the wall of the processing chamber 6. In addition, the halogen lamp cover 4 and the flash lamp cover 5 are provided with an air-cooled structure that forms a gas flow inside to perform heat dissipation. In addition, air is also supplied to the gap between the upper chamber window 63 and the light emission window 53 to cool the flashlight cover 5 and the upper chamber window 63.

In addition, the control unit 3 controls the above-mentioned various operating mechanisms provided in the heat treatment apparatus 100. FIG. 10 is a functional block diagram of the control unit 3 of the heat treatment apparatus 100. The structure of the control unit 3 as a hardware is the same as that of a general computer. That is, the control unit 3 includes: a CPU (Central Processing Unit), which is a circuit for performing various arithmetic processing; ROM (Read Only Memory), which is a dedicated memory for reading basic programs ; RAM (Random Access Memory, random access memory), which is a freely read and write memory for storing various information; and a magnetic disk, which has control software and data in its memory. The processing in the heat treatment apparatus 100 is performed by causing the CPU of the control unit 3 to execute a specific processing program. Furthermore, in FIG. 1, the control unit 3 is shown in the loading unit 101, but it is not limited to this, and the control unit 3 can be arranged at any position in the heat treatment apparatus 100.

In addition, the reflectance measuring sections 135, 145 provided in the first cooling chamber 131 and the second cooling chamber 141 are electrically connected to the control section 3, and the semiconductor wafer W measured by the reflectance measuring sections 135, 145 The reflectivity of the surface is transmitted to the control unit 3. The control unit 3 includes a determination unit 31 and a warning issuing unit 32. The judging unit 31 and the warning issuing unit 32 are functional processing units realized by causing the CPU of the control unit 3 to execute a specific processing program. The processing content of the judging unit 31 and the warning issuing unit 32 will be further described below.

The input unit 33 and the display unit 34 are connected to the control unit 3. The input unit 33 is a device for allowing the operator of the heat treatment apparatus 100 to input various commands and parameters to the control unit 3. The control unit 3 displays various information on the display unit 34. The operator can also confirm the display content of the display unit 34, and set the condition setting of the processing recipe describing the processing procedure and processing conditions of the semiconductor wafer W from the input unit 33. As the input unit 33 and the display unit 34, a touch panel having both functions can also be used. In this embodiment, a liquid crystal touch panel provided on the outer wall of the heat treatment device 100 is used.

Furthermore, in this embodiment, the control unit 3 of the heat treatment apparatus 100 is further connected to the host computer 90 at a higher level via a LAN (Local Area Network) line or the like. The main computer 90 also has the same hardware configuration as a general computer. The reflectance of the surface of the semiconductor wafer W measured by the reflectance measurement units 135 and 145 is transmitted from the control unit 3 to the host computer 90 and stored in the memory unit 91 of the host computer 90. It is also possible to connect the control unit 3 of a plurality of heat treatment apparatuses 100 to the host computer 90, and store the reflectance of the semiconductor wafer W measured by the plurality of heat treatment apparatuses 100 in the memory unit 91.

Next, the processing operation of the semiconductor wafer W by the heat treatment apparatus 100 of the present invention will be described. The semiconductor wafer W to be processed is a semiconductor substrate to which impurities (ions) have been added by an ion implantation method. The activation of the impurity is performed by flash irradiation heat treatment (annealing) using the heat treatment device 100. Here, after a general description of the transportation procedure of the semiconductor wafer W in the heat treatment apparatus 100, the heat treatment of the semiconductor wafer W in the heat treatment unit 160 will be described.

First, the unprocessed semiconductor wafer W into which impurities have been injected is placed in the load port 110 of the load portion 101 in a state where a plurality of wafers are contained in the carrier C. Then, the transfer robot 120 takes out the unprocessed semiconductor wafers W from the carrier C one by one, and carries them into the alignment chamber 231 of the alignment part 230. In the alignment chamber 231, the semiconductor wafer W is rotated about the vertical axis in the horizontal plane with its center as the center of rotation, and the notch is optically detected, thereby adjusting the orientation of the semiconductor wafer W.

Next, the transfer robot 120 of the loading part 101 takes out the semiconductor wafer W whose orientation has been adjusted from the alignment chamber 231 and carries it into the first cooling chamber 131 of the cooling part 130 or the second cooling chamber 141 of the cooling part 140. When the unprocessed semiconductor wafer W is carried into the first cooling chamber 131, the reflectance measuring unit 135 measures the reflectance of the surface of the semiconductor wafer W. On the other hand, when the unprocessed semiconductor wafer W is carried into the second cooling chamber 141, the reflectance measuring unit 145 measures the reflectance of the surface of the semiconductor wafer W. At this time, the reflectance measuring units 135 and 145 measure the reflectance of the semiconductor wafer W before the heat treatment. The reflectance of the semiconductor wafer W measured by the reflectance measuring units 135 and 145 is transmitted from the control unit 3 to the host computer 90 and stored in the memory unit 91 as the reflectance before heating.

The semiconductor wafer W carried in the first cooling chamber 131 or the second cooling chamber 141 is carried out to the transfer chamber 170 by the transfer robot 150. When the semiconductor wafer W before the heat treatment is transferred from the loading part 101 to the transfer chamber 170 through the first cooling chamber 131 or the second cooling chamber 141, the first cooling chamber 131 and the second cooling chamber 141 serve as The path for transferring the semiconductor wafer W functions.

The transfer robot 150 that takes out the semiconductor wafer W rotates toward the heat treatment unit 160. Then, the gate valve 185 opens the space between the processing chamber 6 and the transfer chamber 170, and the transfer robot 150 transfers the unprocessed semiconductor wafer W into the processing chamber 6. At this time, when there is a semiconductor wafer W that has been heat-processed first in the processing chamber 6, one of the transport robots 151a and 151b takes out the heat-processed semiconductor wafer W and then takes out the unprocessed semiconductor wafer W. The semiconductor wafer W is carried into the processing chamber 6 and wafer replacement is performed. After that, the gate valve 185 closes the space between the processing chamber 6 and the transfer chamber 170.

After preheating the semiconductor wafer W carried into the processing chamber 6 by the halogen lamp HL, flash heating treatment is performed by flash irradiation from the flash lamp FL. The activation of the impurity injected into the semiconductor wafer W is performed by the flash heating process.

After the flash heating process is completed, the gate valve 185 opens the processing chamber 6 and the transfer chamber 170 again, and the transfer robot 150 transports the semiconductor wafer W after the flash heating process from the process chamber 6 to the transfer chamber 170. The transfer robot 150 that takes out the semiconductor wafer W rotates from the processing chamber 6 toward the first cooling chamber 131 or the second cooling chamber 141. In addition, the gate valve 185 closes the space between the processing chamber 6 and the transfer chamber 170.

After that, the transfer robot 150 transfers the heat-processed semiconductor wafer W into the first cooling chamber 131 of the cooling part 130 or the second cooling chamber 141 of the cooling part 140. At this time, when the semiconductor wafer W passes through the first cooling chamber 131 before the heat treatment, it is also carried into the first cooling chamber 131 after the heat treatment, and passes through the second cooling chamber 141 before the heat treatment At this time, it is also carried into the second cooling chamber 141 after the heat treatment. In the first cooling chamber 131 or the second cooling chamber 141, a cooling process of the semiconductor wafer W after the flash heating process is performed. At the time when the processing chamber 6 of the thermal processing unit 160 is carried out, the temperature of the entire semiconductor wafer W is relatively high, so it is cooled in the first cooling chamber 131 or the second cooling chamber 141 to near normal temperature.

In addition, the reflectance of the semiconductor wafer W after the heating process is measured simultaneously with the cooling process of the semiconductor wafer W. When the semiconductor wafer W after the heat treatment is carried into the first cooling chamber 131, the reflectance measuring unit 135 measures the reflectance of the surface of the semiconductor wafer W. On the other hand, when the semiconductor wafer W after the heat treatment is carried into the second cooling chamber 141, the reflectance measuring unit 145 measures the reflectance of the surface of the semiconductor wafer W. At this time, the reflectance measuring units 135 and 145 measure the reflectance of the semiconductor wafer W after the heat treatment. The reflectance of the semiconductor wafer W measured by the reflectance measuring units 135 and 145 is transmitted from the control unit 3 to the host computer 90 and stored in the memory unit 91 as the reflectance after heating.

After a specific cooling process time has elapsed, the transfer robot 120 unloads the cooled semiconductor wafer W from the first cooling chamber 131 or the second cooling chamber 141 and returns to the carrier C. When the number of processed semiconductor wafers W contained in the carrier C reaches a certain number, the carrier C is carried out from the load port 110 of the loading part 101.

The description of the flash heat treatment in the heat treatment unit 160 is continued. Before carrying the semiconductor wafer W into the processing chamber 6, the valve 84 for air supply is opened, and the exhaust valves 89 and 192 are opened, and the air supply and exhaust of the processing chamber 6 are started. When the valve 84 is opened, nitrogen gas is supplied to the heat treatment space 65 from the gas supply hole 81. In addition, when the valve 89 is opened, the gas in the processing chamber 6 is discharged from the gas exhaust hole 86. Thereby, the nitrogen gas supplied from the upper part of the heat treatment space 65 in the processing chamber 6 flows downward and is discharged from the lower part of the heat treatment space 65.

Furthermore, by opening the valve 192, the gas in the processing chamber 6 is also discharged from the conveyance opening 66. Furthermore, the gas around the driving part of the transfer mechanism 10 is also exhausted by the exhaust mechanism (not shown). Furthermore, during the heat treatment of the semiconductor wafer W in the heat treatment section 160, the nitrogen gas is continuously supplied to the heat treatment space 65, and the supply amount thereof is appropriately changed according to the processing steps.

Then, the gate valve 185 is opened to open the transfer opening 66, and the semiconductor wafer W to be processed is transferred into the heat treatment space 65 in the processing chamber 6 by the transfer robot 150 through the transfer opening 66. The transfer robot 150 advances the transfer robot 151a (or the transfer robot 151b) holding the unprocessed semiconductor wafer W to a position directly above the holding portion 7 and stops. Then, a pair of the transfer arm 11 of the transfer mechanism 10 moves horizontally from the retreat position and rises to the transfer operation position, whereby the jacking pin 12 passes through the through hole 79 and protrudes from the upper surface of the holding plate 75 of the base 74 Thus, the semiconductor wafer W is received. At this time, the jack-up pin 12 rises above the upper end of the board support pin 77.

After the unprocessed semiconductor wafer W is placed on the jacking pin 12, the transfer robot 150 causes the transfer robot 151a to withdraw from the heat treatment space 65, and the transfer opening 66 is closed by the gate valve 185. Then, the pair of transfer arms 11 are lowered, whereby the semiconductor wafer W is transferred from the transfer mechanism 10 to the base 74 of the holding portion 7 and held in a horizontal posture from below. The semiconductor wafer W is supported and held on the base 74 by a plurality of substrate support pins 77 erected on the holding plate 75. In addition, the semiconductor wafer W is held by the holding portion 7 with the surface on which the pattern is formed and injected with impurities is used as the upper surface. A certain interval is formed between the back surface (the main surface on the opposite side to the front surface) of the semiconductor wafer W supported by the plurality of substrate supporting pins 77 and the holding surface 75 a of the holding plate 75. The pair of transfer arms 11 that have fallen below the base 74 is retracted to the retracted position, that is, inside the recess 62 by the horizontal movement mechanism 13.

After the semiconductor wafer W is held in a horizontal posture from below by the susceptor 74 of the holding portion 7, the 40 halogen lamps HL are all lit to start preliminary heating (auxiliary heating). The halogen light emitted from the halogen lamp HL is irradiated from the lower surface of the semiconductor wafer W through the lower chamber window 64 and the susceptor 74 formed of quartz. By receiving light from the halogen lamp HL, the semiconductor wafer W is preheated and the temperature rises. Furthermore, since the transfer arm 11 of the transfer mechanism 10 has retracted to the inside of the recess 62, the heating by the halogen lamp HL will not be hindered.

When preliminary heating is performed 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 infrared light radiated through the opening 78 from the lower surface of the semiconductor wafer W held on the susceptor 74, and measures the temperature of the wafer during temperature rise. The measured temperature of the semiconductor wafer W is sent to the control unit 3. The control unit 3 monitors whether the temperature of the semiconductor wafer W raised by the light from the halogen lamp HL reaches the specific pre-heating temperature T1, and controls the output of the halogen lamp HL. That is, the control unit 3 feedback-controls the output of the halogen lamp HL based on the measurement value obtained by the radiation thermometer 20 so that the temperature of the semiconductor wafer W becomes the preliminary heating temperature T1. The pre-heating temperature T1 is set to be about 600° C. to 800° C. (700° C. in this embodiment) that does not cause the impurities added to the semiconductor wafer W to diffuse due to heat.

When the temperature of the semiconductor wafer W reaches the pre-heating temperature T1, the control unit 3 makes the semiconductor wafer W temporarily maintain the pre-heating temperature T1. Specifically, when the temperature of the semiconductor wafer W measured by the radiation thermometer 20 reaches the preliminary heating temperature T1, the control unit 3 adjusts the output of the halogen lamp HL to maintain the temperature of the semiconductor wafer W approximately at the preliminary heating temperature T1.

By using such a halogen lamp HL for preliminary heating, the entire semiconductor wafer W is uniformly heated to the preliminary heating temperature T1. In the stage of pre-heating by the halogen lamp HL, the temperature of the peripheral part of the semiconductor wafer W, which is more likely to generate heat, tends to drop lower than the central part. However, the arrangement density of the halogen lamp HL in the halogen lamp shade 4 Compared with the area opposed to the center portion of the semiconductor wafer W, the area opposed to the peripheral portion is higher. Therefore, the amount of light irradiated to the peripheral portion of the semiconductor wafer W that easily generates heat is increased, and the in-plane temperature distribution of the semiconductor wafer W in the preliminary heating stage can be made uniform.

When the temperature of the semiconductor wafer W reaches the pre-heating temperature T1 and a certain 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 radiated from the flash lamp FL directly faces the processing chamber 6, and the other part is reflected by the reflector 52 toward the processing chamber 6, and the semiconductor wafer W is flash heated by the irradiation of the flash lights.

The flash heating is performed by flash light irradiation from the flash lamp FL, so 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 converts the electrostatic energy previously stored in the capacitor into an extremely short light pulse. The irradiation time is about 0.1 millisecond or more and 100 milliseconds or less. Then, the surface temperature of the semiconductor wafer W heated by the flash light from the flash light of the flash lamp FL instantly rises to the processing temperature T2 of 1000° C. or more. After the impurity injected into the semiconductor wafer W is activated, the surface temperature drops rapidly. In this way, the surface temperature of the semiconductor wafer W can be raised and lowered in a very short time, so that the activation of impurities can be performed while suppressing the thermal diffusion of the impurities injected into the semiconductor wafer W. Furthermore, the time required for the activation of the impurities is extremely short compared to the time required for thermal diffusion, so even a short time of about 0.1 milliseconds to 100 milliseconds where diffusion does not occur allows the activation to be completed.

After the flash heating treatment is completed, the halogen lamp HL is extinguished after a certain time has elapsed. Thereby, the temperature of the semiconductor wafer W is rapidly lowered from the preliminary heating 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. The control unit 3 monitors whether the temperature of the semiconductor wafer W is lowered to a specific temperature based on the measurement result of the radiation thermometer 20. Then, when the temperature of the semiconductor wafer W falls below a certain level, the transfer arm 11 of one of the transfer mechanisms 10 moves horizontally from the retreat position and rises to the transfer operation position, thereby causing the jacking pin 12 to move from the base The upper surface of 74 protrudes, and the heat-treated semiconductor wafer W is received from the base 74. Then, the transfer opening 66 closed by the gate valve 185 is opened, and the processed semiconductor wafer W placed on the jacking pin 12 is carried out by the transfer robot 151b (or the transfer robot 151a) of the transfer robot 150 . The transfer robot 150 advances the transfer robot 151b to a position directly below the semiconductor wafer W lifted by the lift pins 12 and stops. Then, the pair of transfer arms 11 are lowered to deliver the semiconductor wafer W heated by the flash light and place it on the transfer robot 151b. Thereafter, the transfer robot 150 causes the transfer robot 151b to withdraw from the processing chamber 6 to carry out the processed semiconductor wafer W.

In this embodiment, the first cooling chamber 131 and the second cooling chamber 141 are provided with reflectance measuring parts 135 and 145 for measuring the reflectance of the surface of the semiconductor wafer W. As described above, the semiconductor wafer W before the heat treatment must be transferred from the loading part 101 to the processing chamber 6 through the first cooling chamber 131 or the second cooling chamber 141. In addition, the semiconductor wafer W after the heat treatment must be returned to the loading unit 101 from the processing chamber 6 through the first cooling chamber 131 or the second cooling chamber 141. That is, the first cooling chamber 131 and the second cooling chamber 141 are provided on the transfer path of the semiconductor wafer W connecting the loading part 101 and the processing chamber 6, and the reflectance measuring parts 135, 145 are provided on the transfer path. . More precisely, it can be regarded that the reflectance measuring parts 135 and 145 are provided in the forward path of the transfer path of the semiconductor wafer W from the loading part 101 to the processing chamber 6, and the semiconductor wafer from the processing chamber 6 to the loading part 101 Two of the return paths of the round W transport path.

Therefore, the reflectance measuring units 135 and 145 can measure the reflectance of the semiconductor wafer W before heat treatment before being carried into the processing chamber 6, and can also measure the heat treatment of the semiconductor wafer W after being carried out from the processing chamber 6.的Reflectivity. In addition, the reflectance measurement units 135 and 145 measure the reflectance of the semiconductor wafer W before the heat treatment by flash irradiation and send it to the control unit 3. The reflectance of the semiconductor wafer W before the heating process is sent from the control unit 3 to the host computer 90, and is stored in the memory unit 91 as the reflectance before heating (FIG. 10). In addition, the reflectance measuring units 135 and 145 measure the reflectance of the semiconductor wafer W after the heat treatment by flash irradiation and send it to the control unit 3. The reflectance of the semiconductor wafer W after the heat treatment is sent from the control unit 3 to the host computer 90, and is stored in the memory unit 91 as the reflectance after heating.

The reflectance of the semiconductor wafer W after the heat treatment is within a substantially fixed range depending on the type of film formed on the semiconductor wafer W and the processing content. For example, if it is a process of forming nickel silicide by irradiating a thin film of nickel (Ni) on a silicon semiconductor wafer W with a thin film of nickel (Ni) and heating it to form nickel silicide, if the process proceeds normally, the reflection of the semiconductor wafer W after the heating process The rate will become a roughly fixed value. Therefore, based on the reflectance of the semiconductor wafer W after the heat treatment, it can be confirmed whether the heat treatment of the semiconductor wafer W is normally performed. Specifically, the determination unit 31 of the control unit 3 determines whether the reflectance of the semiconductor wafer W after the heating process is within a predetermined range depending on the type of the semiconductor wafer W and the processing content. When the reflectance of the semiconductor wafer W after the heating process is within this range, the determining unit 31 determines that the heating process of the semiconductor wafer W is normally performed. On the other hand, when the reflectance of the semiconductor wafer W after the heating process deviates from this range, the determination unit 31 determines that the heating process of the semiconductor wafer W is not normally performed.

In this way, the determining unit 31 determines whether the heating process of the semiconductor wafer W is normally performed based on the reflectance of the semiconductor wafer W after the heating process. When it is determined by the determining unit 31 that the heating process of the semiconductor wafer W is not normally performed, the warning issuing unit 32 issues a warning to the display unit 34 that a processing abnormality has occurred. In this way, only by measuring the reflectance of the semiconductor wafer W heated by the flash light irradiation, it can be easily confirmed whether the semiconductor wafer W has been heated normally.

Also, typically, it is preferable to adjust the luminous intensity of the flash lamp FL during flash illumination according to the reflectance of the surface of the semiconductor wafer W. When the flash light is irradiated, the surface of the semiconductor wafer W needs to be heated to a specific temperature. If the reflectivity of the semiconductor wafer W is low (ie, the absorptivity is high), then the luminous intensity of the flash FL is small. Conversely, if the reflectivity of the semiconductor wafer W is high (that is, the absorptivity is low), the luminous intensity of the flash lamp FL must also be increased. When considering performing this operation, the luminous intensity of the flash lamp FL (specifically, the voltage applied to the flash lamp FL) is adjusted based on the reflectance of the semiconductor wafer W before the heating process measured by the reflectance measuring sections 135 and 145.

However, in the processing chamber 6, the halogen lamp HL performs preliminary heating of the semiconductor wafer W before the flash light is irradiated from the flash lamp FL. Therefore, it was found that the reflectance of the surface of the semiconductor wafer W during preheating changes depending on the content of the heating process. For example, if a semiconductor wafer W whose surface has been ion-implanted into an amorphous layer is irradiated with light from a halogen lamp HL to preheat the amorphous layer, the amorphous layer will be crystallized and the reflectance of the semiconductor wafer W will change. If the reflectivity of the semiconductor wafer W changes during the pre-heating stage, even if the reflectivity of the semiconductor wafer W before the heat treatment before being moved into the processing chamber 6 is measured, if only the reflectivity before the heating is used to adjust the light emission of the flash lamp FL The intensity will also cause the flash FL to emit light with improper luminous intensity. As a result, the surface of the semiconductor wafer W cannot be heated to an appropriate target temperature during flash irradiation.

Therefore, in this embodiment, the flash FL is determined based on both the reflectance of the semiconductor wafer W before heat treatment (the reflectance before heating) and the reflectance of the semiconductor wafer W after the heat treatment (the reflectance after heating). The luminous intensity. For example, this operation may be executed when heating conditions are set before batch processing. In addition, the term "lot" refers to a group of semiconductor wafers W that are subjected to processing of the same content under the same conditions.

Specifically, according to the degree of change in the reflectance of the semiconductor wafer W during the preliminary heating stage, weighted calculation is performed on the reflectance before heating and the reflectance after heating, and the reflectance used to determine the luminous intensity is calculated (for example, a weighted average is calculated). value). For example, in the case of performing the heating treatment of the semiconductor wafer W whose surface has been transformed into an amorphous layer by ion implantation, as described above, the reflectance of the semiconductor wafer W changes greatly during the preliminary heating stage. In this case, the reflectivity of the semiconductor wafer W at the point when the flash lamp FL emits light is close to the reflectivity after heating, so the weight of the reflectivity after heating is increased to obtain the reflectivity used to determine the luminous intensity. On the other hand, for example, in the case of heating a semiconductor wafer W with a thin film of nickel formed on the surface, the reflectance of the semiconductor wafer W does not change significantly during the preliminary heating stage, but is formed during flash irradiation. Nickel silicide changes reflectivity. In this case, the reflectance of the semiconductor wafer W at the time when the flash lamp FL emits light is close to the reflectance before heating, so the weight of the reflectance before heating is increased to obtain the reflectance used to determine the luminous intensity.

In this way, if the luminous intensity of the flash lamp FL is adjusted not only based on the reflectance before heating but also based on the reflectance after heating, even if the reflectance of the surface of the semiconductor wafer W changes during pre-heating or flash irradiation, the flash lamp FL can be illuminated. The strength is determined to be an appropriate value. As a result, the surface of the semiconductor wafer W can be heated to a desired target temperature during flash irradiation.

The more the data of the reflectance before heating and the reflectance after heating as the basis, the higher the adjustment accuracy of the luminous intensity of the flash lamp FL. Therefore, in this embodiment, the reflectance before heating and the reflectance after heating of a plurality of semiconductor wafers W processed in the past are stored in the memory 91. In addition, when a plurality of heat treatment apparatuses 100 are connected to the host computer 90, if the reflectance before heating and the reflectance after heating obtained by the plurality of heat treatment apparatuses 100 are stored in the memory portion 91, it is possible to achieve higher accuracy Adjust the luminous intensity of flash FL.

Of course, as the number of data stored in the memory 91 increases, it becomes more difficult to manually calculate the reflectivity and adjust the luminous intensity of the flash FL. Therefore, it is better to install an artificial intelligence (AI) function in the main computer 90, and use artificial intelligence to analyze the large amount of data of the reflectance before heating and the reflectance after heating stored in the memory 91 to find the appropriate reflectance for adjustment. The luminous intensity of flash FL.

The embodiments of the present invention have been described above, but the present invention can be modified in various ways other than the above without departing from the gist of the present invention. For example, in the above-mentioned embodiment, the reflectance measuring parts 135 and 145 are provided in the first cooling chamber 131 and the second cooling chamber 141. Either one is provided with a reflectance measuring part. For example, the reflectance measurement unit may be installed in the transport chamber 170 or may be installed in the loading unit 101. Alternatively, the reflectance measurement unit may be provided in the alignment chamber 231. When the reflectance measuring unit is installed in the alignment chamber 231, the heat-processed semiconductor wafer W is transported to the alignment chamber 231 to measure the reflectance after heating. Furthermore, in order to measure the reflectance, a dedicated reflectance measurement chamber may be provided in the heat treatment apparatus 100. In this case, the semiconductor wafer W before the heat treatment and the semiconductor wafer W after the heat treatment are respectively transported to the reflectance measurement chamber to measure the reflectance before heating and the reflectance after heating. In short, the reflectance can be set in such a way that the reflectance of the semiconductor wafer W before the heat treatment can be measured before the processing chamber 6 is transported, and the reflectance of the semiconductor wafer W after the heat treatment can be measured after the processing chamber 6 is moved out The measuring part is sufficient.

In addition, it is also possible to determine whether the heating process of the semiconductor wafer W is normally performed based on both the reflectance before heating and the reflectance after heating. In this case, if the difference between the reflectance before heating and the reflectance after heating is within a specific range, the determining unit 31 determines that the heating process of the semiconductor wafer W is normally performed, and when it deviates from this range, it determines whether the semiconductor wafer W is The heat treatment did not proceed normally.

Moreover, when adjusting the luminous intensity of the flash lamp FL, in addition to the reflectance before heating and the reflectance after heating, various temperatures measured by a radiation thermometer and the intensity of light measured by a photometer can also be considered. In this way, the luminous intensity of the flash FL can be adjusted with higher precision.

In addition, in the above-described embodiment, the flash cover 5 includes 30 flashes FL, but it is not limited to this, and the number of flashes FL can be any number. In addition, the flash lamp FL is not limited to a xenon flash lamp, and may be a krypton flash lamp. In addition, the number of halogen lamps HL included in the halogen lampshade 4 is not limited to 40, and can be any number.

In addition, in the above-mentioned embodiment, the halogen lamp HL of the filament method is used as a continuous lighting lamp that emits light continuously for 1 second or longer to perform preliminary heating of the semiconductor wafer W. However, it is not limited to this, and a discharge may be used instead of the halogen lamp HL. A type arc lamp (such as a xenon arc lamp) is used as a continuous lighting lamp for preliminary heating.

In addition, the substrate to be processed by the heat treatment apparatus 100 is not limited to a semiconductor wafer, and may be a glass substrate and a substrate for solar cells used in flat panel displays such as liquid crystal display devices.

3‧‧‧Control Department 4‧‧‧Halogen lampshade 5‧‧‧Flash cover 6‧‧‧Processing chamber 7‧‧‧Retention Department 10‧‧‧Transfer agency 11‧‧‧Transfer arm 12‧‧‧Ejector pin 13‧‧‧Horizontal movement mechanism 31‧‧‧Judgment Department 32‧‧‧Warning Issuing Department 33‧‧‧Input part 34‧‧‧Display 41‧‧‧Frame 43‧‧‧Reflector 51‧‧‧Frame 52‧‧‧Reflector 53‧‧‧Light emission window 61‧‧‧The side of the chamber 62‧‧‧Concave 63‧‧‧Upper chamber window 64‧‧‧Lower chamber window 65‧‧‧Heat treatment space 66‧‧‧Transport opening 68‧‧‧Reflective ring 69‧‧‧Reflective ring 71‧‧‧Abutment Ring 72‧‧‧Connecting part 74‧‧‧Pedestal 75‧‧‧Holding plate 75a‧‧‧Keep the surface 76‧‧‧Guide Ring 77‧‧‧Substrate support pin 78‧‧‧Opening 79‧‧‧Through hole 81‧‧‧Gas supply hole 82‧‧‧Buffer space 83‧‧‧Gas supply pipe 84‧‧‧Valve 85‧‧‧Processing gas supply source 86‧‧‧Gas vent 87‧‧‧Buffer space 88‧‧‧Gas exhaust pipe 89‧‧‧Valve 90‧‧‧Main computer 91‧‧‧Memory Department 100‧‧‧Heat treatment device 101‧‧‧Loading Department 110‧‧‧Load port 120‧‧‧Handover Robot 120S‧‧‧Arrow 120R‧‧‧Arrow 121‧‧‧Robot 130‧‧‧Cooling Department 131‧‧‧The first cooling chamber 135‧‧‧Reflectance Measurement Department 140‧‧‧Cooling Department 141‧‧‧Second cooling chamber 145‧‧‧Reflectance Measurement Department 150‧‧‧Transfer robot 150R‧‧‧Arrow 151a‧‧‧Transfer robot 151b‧‧‧Transfer robot 160‧‧‧Heat Treatment Department 170‧‧‧Transportation Chamber 181‧‧‧Gate Valve 182‧‧‧Gate valve 183‧‧‧Gate valve 184‧‧‧Gate valve 185‧‧‧Gate valve 190‧‧‧Exhaust mechanism 191‧‧‧Gas exhaust pipe 192‧‧‧valve 230‧‧‧Alignment Department 231‧‧‧Aim the chamber C‧‧‧Carrier CU‧‧‧Arrow FL‧‧‧Flash HL‧‧‧Halogen lamp W‧‧‧Semiconductor Wafer X‧‧‧direction Y‧‧‧ direction Z‧‧‧ direction

Fig. 1 is a plan view showing the heat treatment device of the present invention. Fig. 2 is a front view of the heat treatment device of Fig. 1; Fig. 3 is a longitudinal sectional view showing the structure of the heat treatment section. Fig. 4 is a perspective view showing the overall appearance of the holding portion. Figure 5 is a top view of the base. Figure 6 is a cross-sectional view of the base. Figure 7 is a top view of the transfer mechanism. Figure 8 is a side view of the transfer mechanism. Fig. 9 is a plan view showing the arrangement of a plurality of halogen lamps. Figure 10 is a functional block diagram of the control unit of the heat treatment device.

3‧‧‧Control Department

5‧‧‧Flash cover

100‧‧‧Heat treatment device

101‧‧‧Loading Department

110‧‧‧Load port

120‧‧‧Handover Robot

120S‧‧‧Arrow

120R‧‧‧Arrow

121‧‧‧Robot

130‧‧‧Cooling Department

131‧‧‧The first cooling chamber

135‧‧‧Reflectance Measurement Department

140‧‧‧Cooling Department

141‧‧‧Second cooling chamber

145‧‧‧Reflectance Measurement Department

150‧‧‧Transfer robot

150R‧‧‧Arrow

151a‧‧‧Transfer robot

160‧‧‧Heat Treatment Department

170‧‧‧Transportation Chamber

181‧‧‧Gate Valve

182‧‧‧Gate valve

183‧‧‧Gate valve

184‧‧‧Gate valve

185‧‧‧Gate valve

230‧‧‧Alignment Department

231‧‧‧Aim the chamber

C‧‧‧Carrier

FL‧‧‧Flash

W‧‧‧Semiconductor Wafer

X‧‧‧direction

Y‧‧‧ direction

Z‧‧‧ direction

Claims (10)

A heat treatment device, characterized in that it heats the substrate by irradiating the substrate with a flash, and is provided with: a processing chamber for accommodating the substrate; and a flash lamp for heating the substrate accommodated in the processing chamber by irradiating the flash Reflectance measuring section, which measures the reflectance of the substrate after being heated by the flash from the flash lamp; and a memory section, which memorizes the reflectance of the substrate measured by the reflectance measuring section, the The reflectance measuring part also measures the reflectance of the substrate before the flash is irradiated from the flash lamp, and the heat treatment device adjusts the luminous intensity of the flash lamp based on the reflectance of the plurality of substrates stored in the memory part. Such as the heat treatment apparatus of claim 1, which further includes a loading section for carrying unprocessed substrates into the apparatus and carrying the processed substrates out of the apparatus, and the reflectance measuring section is provided from the processing chamber to the above The transport path of the substrate in the loading section. The heat treatment device of claim 2, wherein a cooling chamber for cooling the heated substrate is provided in the conveying path, and The reflectance measuring unit is provided in the cooling chamber. The heat treatment device of claim 1, further comprising: a determination section that determines whether the heating treatment of the substrate is normally performed based on the reflectance of the substrate measured by the reflectance measurement section; and a warning issuing section, which is A warning is issued when it is determined by the determination unit that the heating process of the substrate is not normally performed. Such as the heat treatment device of claim 1, which adjusts the luminous intensity of the flash lamp by artificial intelligence. The heat treatment device according to claim 1, further comprising a continuous lighting lamp that preliminarily heats the substrate irradiated light before the flash is irradiated from the flash lamp. A heat treatment method, characterized in that it heats the substrate by irradiating the substrate with a flash, and includes: an irradiation step of heating the substrate contained in a processing chamber by irradiating the flash from a flash lamp; and measuring the reflectance after processing The step of measuring the reflectance of the substrate after the irradiation step; the step of measuring the reflectance of the substrate before the irradiation step; the memory step of measuring the reflectance of the substrate before the step of processing And reflectivity after the above treatment The reflectance of the substrate measured in the measuring step is stored in a memory part; and the adjustment step is to adjust the luminous intensity of the flash lamp based on the reflectance of the plurality of substrates stored in the memory part. The heat treatment method of claim 7, further comprising: a determination step of determining whether the heating treatment of the substrate is normally performed based on the reflectance of the substrate measured in the reflectance measurement step after the treatment; and a warning issuing step, which When the above determination step determines that the heating process of the substrate is not normally performed, a warning is issued. According to the heat treatment method of claim 7, wherein in the adjustment step, artificial intelligence is used to adjust the luminous intensity of the flash. The heat treatment method of claim 7, further comprising a preliminary heating step of preheating the substrate irradiated light by continuously lighting the lamp before irradiating the flash from the flash lamp.

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