JP7495285B2 - Heat treatment apparatus and heat treatment method - Google Patents

Description

The technology disclosed in this specification relates to a heat treatment device and a heat treatment method.

In the manufacturing process of semiconductor devices, the introduction of impurities is a necessary step for forming pn junctions and the like in thin precision electronic substrates (hereinafter sometimes simply referred to as "substrates") such as semiconductor wafers. The introduction of impurities is generally performed by ion implantation followed by annealing.

When activating the implanted impurities by annealing, if the annealing time is longer than a few seconds, the implanted impurities will diffuse too deeply due to the heat, resulting in a junction depth that is deeper than required, which may hinder the formation of a good device.

As a result, flash lamp annealing (FLA) has attracted attention as an annealing technique that heats semiconductor wafers in an extremely short time. FLA is a heat treatment technique that uses a xenon flash lamp (hereinafter, when simply referred to as "flash lamp" it means a xenon flash lamp) to irradiate the top surface of a semiconductor wafer with a flash of light, thereby raising the temperature of only the top surface of a semiconductor wafer into which impurities have been implanted in an extremely short time (for example, a few milliseconds or less).

The spectral distribution of radiation from a xenon flash lamp is from the ultraviolet to near infrared range, has a shorter wavelength than conventional halogen lamps, and is almost identical to the fundamental absorption band of silicon semiconductor wafers. Therefore, when a semiconductor wafer is irradiated with flash light from a xenon flash lamp, little light is transmitted, making it possible to rapidly heat the semiconductor wafer. It has also been found that if the flash light is irradiated for an extremely short period of time, less than a few milliseconds, it is possible to selectively heat only the area near the surface of the semiconductor wafer. For this reason, if the temperature is raised in an extremely short period of time using a xenon flash lamp, impurity activation can be performed without the impurities diffusing deeply.

For example, Patent Document 1 discloses a flash lamp annealing device that preheats a semiconductor wafer using a heating plate located below the processing chamber, and then irradiates the top surface of the semiconductor wafer with a flash of light from a flash lamp located above the processing chamber.

JP 2004-186542 A

However, because the flash light emitted from a flash lamp is high-energy light, the temperature of the top surface of a substrate, such as a semiconductor wafer, that is irradiated with the flash light rises in a short period of time. If sudden thermal expansion occurs on the top surface of the substrate that is irradiated with the flash light, this may cause the substrate to be displaced, such as by bending the top surface.

This displacement can cause the substrate supported by the support pins to wobble, which can then cause the substrate to bounce off the support pins. There is a concern that the substrate that bounces off the support pins may break when it comes into contact with the support pins again.

The technology disclosed in this specification has been developed in consideration of the problems described above, and is a technology that prevents the substrate from cracking even when the substrate is displaced by irradiation with a flash light.

A heat treatment apparatus according to a first aspect of the technology disclosed in the present specification includes a holding unit for holding a substrate, a flash lamp for heating the substrate by irradiating the substrate with a flash light, at least one detection unit for detecting the displacement of the substrate after the flash light is irradiated, a calculation unit for calculating a measured frequency distribution, which is a frequency distribution of the substrate, based on the detected displacement of the substrate, a storage unit for storing in advance a first frequency distribution, which is the frequency distribution of the substrate that has cracks after being irradiated with the flash light, and a second frequency distribution, which is the frequency distribution of the substrate that has no cracks after being irradiated with the flash light, and a classification unit for classifying the measured frequency distribution based on the similarity between the measured frequency distribution and the first frequency distribution and the similarity between the measured frequency distribution and the second frequency distribution.

The heat treatment apparatus according to a second aspect of the technology disclosed in the present specification is related to the first aspect, and the holding unit includes at least one vibration adjustment unit for adjusting vibrations generated in the substrate, and further includes a control unit for controlling the vibration adjustment unit so that the measured frequency distribution approaches the second frequency distribution.

The heat treatment device, which is a third aspect of the technology disclosed in the present specification, is related to the second aspect, and the vibration adjustment unit is a damper mechanism that contacts the underside of the substrate and supports the substrate.

The heat treatment device, which is a fourth aspect of the technology disclosed in the present specification, is related to the second or third aspect, and the holding unit includes support pins that contact the underside of the substrate and support the substrate, and a holding plate on whose upper surface the support pins are disposed, and the vibration adjustment unit is a damper mechanism that contacts the underside of the holding plate and supports the holding plate.

The heat treatment device, which is a fifth aspect of the technology disclosed in the present specification, is related to any one of the second to fourth aspects, and the vibration adjustment unit is an ultrasonic vibrator that generates ultrasonic waves toward the substrate.

A sixth aspect of the technology disclosed in the present specification, the heat treatment device, is related to any one of the first to fifth aspects, and the classification unit performs machine learning using the first frequency distribution and the second frequency distribution as training data, and classifies the measured frequency distribution using a trained model obtained by the machine learning.

A heat treatment method according to a seventh aspect of the technology disclosed in the present specification includes the steps of: holding a substrate; heating the substrate by irradiating the substrate with a flash light; detecting the displacement of the substrate after the flash light is irradiated; calculating a measured frequency distribution, which is a frequency distribution of the substrate, based on the detected displacement of the substrate; and classifying the measured frequency distribution based on the similarity between the measured frequency distribution and the first frequency distribution and the similarity between the measured frequency distribution and the second frequency distribution, taking the frequency distribution of the substrate that has cracks after the flash light is irradiated as a first frequency distribution and the frequency distribution of the substrate that has no cracks after the flash light is irradiated as a second frequency distribution.

According to the first to seventh aspects of the technology disclosed in the present specification, the frequency distribution of a substrate irradiated with flash light can be measured and the frequency distribution can be classified into cases where the substrate is likely to crack due to the flash light and cases where the substrate is unlikely to crack. Therefore, for example, by adjusting the setting conditions such as the output energy or pulse width of the flash light to achieve a frequency distribution classified into cases where the substrate is unlikely to crack, it is possible to prevent the substrate from cracking due to irradiation with the flash light.

Furthermore, the objects, features, aspects and advantages associated with the technology disclosed in the present specification will become more apparent from the detailed description and accompanying drawings set forth below.

1 is a plan view illustrating an example of the configuration of a heat treatment apparatus according to an embodiment. FIG. 1 is a front view illustrating a schematic configuration example of a heat treatment apparatus according to an embodiment. 1 is a cross-sectional view illustrating a schematic configuration of a heat treatment section in a heat treatment apparatus according to an embodiment. FIG. 2 is a perspective view showing the overall appearance of a holding portion. FIG. FIG. 2 is a cross-sectional view of a susceptor. FIG. FIG. FIG. 2 is a plan view showing an arrangement of a plurality of halogen lamps. 4 is a diagram showing the relationship between a lower radiation thermometer, an upper radiation thermometer, a camera, and a control unit. FIG. 1 is a flowchart showing a processing procedure for a semiconductor wafer. FIG. 13 is a diagram showing changes in temperature of the upper surface of a semiconductor wafer. 11 is a diagram showing an example of the displacement of a semiconductor wafer after being irradiated with a flash light, which is obtained by analyzing image data captured by a camera in a calculation unit. FIG. FIG. 14 is a diagram showing an example of a frequency distribution of a semiconductor wafer after being irradiated with a flash light, the frequency distribution being obtained by performing a fast Fourier transform in a calculation unit on the displacement and acceleration of the semiconductor wafer shown in FIG. 13 . FIG. 13 is a diagram showing an example of the correlation between output energy and amplitude in a certain frequency component. 11A and 11B are cross-sectional views showing an example of the configuration of a holding section provided with a plurality of damper mechanisms. 11A and 11B are cross-sectional views showing an example of the configuration of a holding section provided with a plurality of damper mechanisms. 1 is a cross-sectional view showing an example of the configuration of a holding section provided with a plurality of ultrasonic transducers.

The following describes the embodiments with reference to the attached drawings. In the following embodiments, detailed features are shown to explain the technology, but these are merely examples and are not necessarily all essential features for the embodiments to be feasible.

The drawings are schematic, and for ease of explanation, configurations are omitted or simplified as appropriate in the drawings. Furthermore, the size and positional relationships of the configurations shown in different drawings are not necessarily described accurately, and may be changed as appropriate. Furthermore, hatching may be used in drawings such as plan views that are not cross-sectional views to make it easier to understand the contents of the embodiments.

In addition, in the following description, similar components are illustrated with the same reference symbols, and their names and functions are also similar. Therefore, detailed descriptions of them may be omitted to avoid duplication.

In addition, in the following description, when a certain component is described as "comprising," "including," or "having," unless otherwise specified, this is not an exclusive expression that excludes the presence of other components.

In addition, even if ordinal numbers such as "first" or "second" are used in the following description, these terms are used for convenience to facilitate understanding of the contents of the embodiments, and are not limited to the ordering that may result from these ordinal numbers.

In addition, in the following explanation, expressions indicating relative or absolute positional relationships, such as "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," unless otherwise specified, include cases where the positional relationship is strictly indicated and cases where the angle or distance is displaced within a tolerance or within a range where the same level of functionality is obtained.

In addition, in the following description, expressions indicating an equal state, such as "same," "equal," "uniform," or "homogeneous," unless otherwise specified, include cases indicating a strictly equal state, as well as cases where differences occur within the tolerance or range where the same level of functionality is obtained.

In addition, in the following description, terms that indicate specific positions or directions, such as "top," "bottom," "left," "right," "side," "bottom," "front," or "back," may be used, but these terms are used for convenience to facilitate understanding of the contents of the embodiments, and do not relate to positions or directions when actually implemented.

In addition, in the following explanation, when it is written "upper surface of ..." or "lower surface of ...", it is meant to include not only the upper surface or lower surface of the target component itself, but also a state in which another component is formed on the upper surface or lower surface of the target component. In other words, for example, when it is written "B provided on the upper surface of A", it does not prevent another component "C" from being between A and B.

<Embodiment>
The heat treatment apparatus and the heat treatment method according to the present embodiment will be described below.

<Configuration of Heat Treatment Device>
Fig. 1 is a plan view that shows a schematic example of the configuration of a heat treatment apparatus 100 according to the present embodiment. Fig. 2 is a front view that shows a schematic example of the configuration of the heat treatment apparatus 100 according to the present embodiment.

As shown in FIG. 1, 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 is, for example, a circle with a diameter of 300 mm or 450 mm.

As shown in Figures 1 and 2, the heat treatment apparatus 100 includes an indexer unit 101 for loading unprocessed semiconductor wafers W into the apparatus from outside and unloading processed semiconductor wafers W from the apparatus, an alignment unit 230 for positioning the unprocessed semiconductor wafers W, two cooling units 130 and 140 for cooling the semiconductor wafers W after heat treatment, a heat treatment unit 160 for subjecting the semiconductor wafers W to a flash heat treatment, and a transfer robot 150 for transferring the semiconductor wafers W to and from the cooling unit 130, the cooling unit 140, and the heat treatment unit 160.

The heat treatment apparatus 100 also includes a control unit 3 that controls the operating mechanisms and the transport robot 150 provided in each of the above-mentioned processing units to advance the flash heat treatment of the semiconductor wafer W.

The indexer section 101 includes a load port 110 on which multiple carriers C (two in this embodiment) are arranged and placed, and a transfer robot 120 that removes unprocessed semiconductor wafers W from each carrier C and stores processed semiconductor wafers W in each carrier C.

The carrier C containing the unprocessed semiconductor wafer W is transported by an automated guided vehicle (AGV, OHT) or the like and placed on the load port 110, while the carrier C containing the processed semiconductor wafer W is removed from the load port 110 by the automated guided vehicle.

In addition, in the load port 110, the carrier C is configured to be movable up and down as shown by the arrow CU in FIG. 2 so that the transfer robot 120 can insert and remove any semiconductor wafer W into and from the carrier C.

The carrier C may take the form of a front opening unified pod (FOUP) that stores the semiconductor wafers W in an enclosed space, a standard mechanical interface (SMIF) pod, or an open cassette (OC) that exposes the stored semiconductor wafers W to the outside air.

The transfer robot 120 is also capable of sliding as indicated by the arrow 120S in FIG. 1, and rotating and ascending/descending motions as indicated by the arrow 120R. This allows the transfer robot 120 to take in and out the semiconductor wafers W from the two carriers C, and to transfer the semiconductor wafers W to the alignment section 230 and the two cooling sections 130 and 140.

The transfer robot 120 transfers the semiconductor wafer W into and out of the carrier C by sliding the hand 121 and raising and lowering the carrier C. The transfer robot 120 transfers the semiconductor wafer W between the alignment unit 230 or the cooling unit 130 (cooling unit 140) by sliding the hand 121 and raising and lowering the transfer robot 120.

The alignment unit 230 is 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 a horizontal plane to orient it in an appropriate direction for flash heating. The alignment unit 230 is configured by providing, inside an alignment chamber 231, which is an aluminum alloy housing, a mechanism for supporting and rotating the semiconductor wafer W in a horizontal position, and a mechanism for optically detecting notches or orientation flats formed on the peripheral edge of the semiconductor wafer W.

The semiconductor wafer W is delivered to the alignment section 230 by the delivery robot 120. The semiconductor wafer W is delivered from the delivery robot 120 to the alignment chamber 231 so that the center of the wafer is positioned at a predetermined position.

In the alignment section 230, the semiconductor wafer W received from the indexer section 101 is rotated around a vertical axis with the center of the semiconductor wafer W as the center of rotation, and the orientation of the semiconductor wafer W is adjusted by optically detecting a notch or the like. After the orientation adjustment is completed, the semiconductor wafer W is removed from the alignment chamber 231 by the transfer robot 120.

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

The heat treatment section 160, which is the main part of the heat treatment apparatus 100, is a substrate treatment section that performs flash heating by irradiating a semiconductor wafer W that has been preheated (assisted heating) with a flash of light (flash light) from a xenon flash lamp FL. The configuration of this heat treatment section 160 will be described in further detail below.

The two cooling units 130 and 140 have roughly the same configuration. Inside the first cool chamber 131 or the second cool chamber 141, which is an aluminum alloy housing, the cooling unit 130 and the cooling unit 140 each have a metal cooling plate and a quartz plate placed on the upper surface of the metal cooling plate (both not shown). The temperature of the cooling plate is regulated to room temperature (approximately 23°C) by a Peltier element or constant temperature water circulation.

The semiconductor wafer W that has been subjected to the flash heating process in the heat treatment section 160 is loaded into the first cool chamber 131 or the second cool chamber 141, placed on the quartz plate, and cooled.

The first cool chamber 131 and the second cool chamber 141 are both connected to the indexer section 101 and the transport chamber 170 between them.

The first cool chamber 131 and the second cool chamber 141 are provided with two openings for loading and unloading the semiconductor wafer W. Of the two openings in the first cool chamber 131, the opening connected to the indexer section 101 can be opened and closed by a gate valve 181.

On the other hand, the opening of the first cool chamber 131 connected to the transport chamber 170 can be opened and closed by a gate valve 183. That is, the first cool chamber 131 and the indexer unit 101 are connected via the gate valve 181, and the first cool chamber 131 and the transport chamber 170 are connected via the gate valve 183.

When the semiconductor wafer W is transferred between the indexer unit 101 and the first cool chamber 131, the gate valve 181 is opened. When the semiconductor wafer W is transferred between the first cool chamber 131 and the transfer chamber 170, the gate valve 183 is opened. When the gate valves 181 and 183 are closed, the inside of the first cool chamber 131 becomes an airtight space.

Of the two openings of the second cool 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 of the second cool chamber 141 connected to the transport chamber 170 can be opened and closed by a gate valve 184. That is, the second cool chamber 141 and the indexer unit 101 are connected via the gate valve 182, and the second cool chamber 141 and the transport chamber 170 are connected via the gate valve 184.

When the semiconductor wafer W is transferred between the indexer unit 101 and the second cool chamber 141, the gate valve 182 is opened. When the semiconductor wafer W is transferred between the second cool chamber 141 and the transfer chamber 170, the gate valve 184 is opened. When the gate valves 182 and 184 are closed, the inside of the second cool chamber 141 becomes an airtight space.

Transfer robot 150, which is provided in transfer chamber 170 installed adjacent to chamber 6, can rotate around a vertical axis as shown by arrow 150R. Transfer robot 150 has two link mechanisms consisting of multiple arm segments, and transfer hands 151a and 151b that hold semiconductor wafers W are provided at the tips of these two link mechanisms. These transfer hands 151a and 151b are arranged vertically at a predetermined pitch apart, and are capable of independently sliding linearly in the same horizontal direction by the link mechanisms.

The transport robot 150 also raises and lowers the base on which the two link mechanisms are mounted, thereby raising and lowering the two transport hands 151a and 151b while keeping them spaced apart by a predetermined pitch.

When the transport robot 150 transfers (takes in and out) a semiconductor wafer W to the first cool chamber 131, the second cool chamber 141, or the chamber 6 of the heat treatment unit 160, first, both transport hands 151a and 151b rotate to face the transfer partner, and then (or while rotating) move up and down until one of the transport hands is at a height where it can transfer the semiconductor wafer W to the transfer partner. Then, the transport hand 151a (151b) slides linearly horizontally to transfer the semiconductor wafer W to the transfer partner.

The transfer of the semiconductor wafer W between the transport robot 150 and the delivery robot 120 can be performed via the cooling section 130 and the cooling section 140. That is, the first cool chamber 131 of the cooling section 130 and the second cool chamber 141 of the cooling section 140 also function as a path for transferring the semiconductor wafer W between the transport robot 150 and the delivery robot 120. Specifically, the transfer of the semiconductor wafer W is performed by one of the transport robot 150 and the delivery robot 120 receiving the semiconductor wafer W transferred to the first cool chamber 131 or the second cool chamber 141 by the other robot. The transport robot 150 and the delivery robot 120 constitute a transfer mechanism that transfers the semiconductor wafer W from the carrier C to the heat treatment section 160.

As described above, a gate valve 181 or a gate valve 182 is provided between the first cool chamber 131 and the indexer unit 101, and between the second cool chamber 141 and the indexer unit 101. A gate valve 183 or a gate valve 184 is provided between the transfer chamber 170 and the first cool chamber 131 or between the second cool chamber 141 and the transfer chamber 170. A gate valve 185 is provided between the transfer chamber 170 and chamber 6 of the heat treatment unit 160. When a semiconductor wafer W is transferred in the heat treatment unit 100, these gate valves are opened and closed as appropriate.

Figure 3 is a cross-sectional view that shows a schematic configuration of the heat treatment section 160 in the heat treatment apparatus 100 according to this embodiment.

As shown in FIG. 3, the heat treatment section 160 is a flash lamp annealing device that heats a disk-shaped semiconductor wafer W as a substrate by irradiating the semiconductor wafer W with flash light.

The size of the semiconductor wafer W to be processed is not particularly limited, but is, for example, φ300 mm or φ450 mm (φ300 mm in this embodiment).

The heat treatment section 160 includes a chamber 6 that houses a semiconductor wafer W, a flash heating section 5 that incorporates multiple flash lamps FL, and a halogen heating section 4 that incorporates multiple halogen lamps HL. The flash heating section 5 is provided above the chamber 6, and the halogen heating section 4 is provided below it.

The heat treatment section 160 also includes a holding section 7 inside the chamber 6 that holds the semiconductor wafer W in a horizontal position, and a transfer mechanism 10 that transfers the semiconductor wafer W between the holding section 7 and the outside of the apparatus.

The heat treatment unit 160 further includes a control unit 3 that controls the halogen heating unit 4, the flash heating unit 5, and each of the operating mechanisms provided in the chamber 6 to perform heat treatment on the semiconductor wafer W.

The chamber 6 is constructed by attaching quartz chamber windows to the top and bottom of a cylindrical chamber side portion 61. The chamber side portion 61 has a roughly cylindrical shape with openings at the top and bottom, with the upper opening being attached and closed by an upper chamber window 63, and the lower opening being attached and closed by a lower chamber window 64.

The upper chamber window 63, which constitutes the ceiling of the chamber 6, is a disk-shaped member made of quartz and functions as a quartz window that transmits the flash light emitted from the flash heating unit 5 into the chamber 6.

The lower chamber window 64, which constitutes the floor of the chamber 6, is also a disk-shaped member made of quartz, and functions as a quartz window that transmits light from the halogen heating unit 4 into the chamber 6.

A reflective ring 68 is attached to the upper part of the inner wall surface of the chamber side portion 61, and a reflective ring 69 is attached to the lower part. Both the reflective ring 68 and the reflective ring 69 are formed in a circular ring shape.

The upper reflective ring 68 is attached by fitting it from the top of the chamber side 61. On the other hand, the lower reflective ring 69 is attached by fitting it from the bottom of the chamber side 61 and fastening it with screws (not shown). In other words, both the reflective ring 68 and the reflective ring 69 are attached to the chamber side 61 in a removable manner.

The inner space of the chamber 6, i.e., the space surrounded by the upper chamber window 63, the lower chamber window 64, the chamber side 61, the reflecting ring 68 and the reflecting ring 69, is defined as the heat treatment space 65.

By attaching the reflecting ring 68 and reflecting ring 69 to the chamber side 61, a recess 62 is formed on the inner wall surface of the chamber 6. That is, the recess 62 is formed surrounded by the central portion of the inner wall surface of the chamber side 61 where the reflecting ring 68 and reflecting ring 69 are not attached, the lower end surface of the reflecting ring 68, and the upper end surface of the reflecting ring 69.

The recess 62 is formed in a circular ring shape along the horizontal direction on the inner wall surface of the chamber 6, and surrounds the holder 7 that holds the semiconductor wafer W. The chamber side 61 and the reflecting ring 68 and reflecting ring 69 are formed from a metal material (e.g., stainless steel) that has excellent strength and heat resistance.

The chamber side 61 is also provided with a transport opening (furnace port) 66 for loading and unloading the semiconductor wafer W into and from the chamber 6. The transport opening 66 can be opened and closed by a gate valve 185. The transport opening 66 is connected to the outer circumferential surface of the recess 62.

Therefore, when the gate valve 185 opens the transport opening 66, the semiconductor wafer W can be transported from the transport opening 66 through the recess 62 into the heat treatment space 65 and out of the heat treatment space 65. When the gate valve 185 closes the transport opening 66, the heat treatment space 65 in the chamber 6 becomes an airtight space.

Furthermore, through holes 61a, 61b, and 61c are drilled in the chamber side 61. The through hole 61a is a cylindrical hole for guiding infrared light radiated from the upper surface of the semiconductor wafer W held by the susceptor 74 to the infrared sensor 29 of the upper radiation thermometer 25, which will be described later. The through hole 61b is a cylindrical hole for guiding infrared light radiated from the lower surface of the semiconductor wafer W to the infrared sensor 24 of the lower radiation thermometer 20. The through hole 61c is a cylindrical hole for capturing an image of the semiconductor wafer W, which may be displaced when irradiated with flash light, by at least one camera 142. The through holes 61a, 61b, and 61c are inclined with respect to the horizontal direction so that their axes in the penetration direction intersect with the main surface of the semiconductor wafer W held by the susceptor 74.

The infrared sensor 29 is, for example, a quantum infrared sensor. The infrared sensor 24 is, for example, a pyroelectric sensor that uses the pyroelectric effect, a thermopile that uses the Seebeck effect, or a thermal infrared sensor such as a bolometer that uses changes in the resistance of a semiconductor due to heat. The camera 142 is, for example, a CCD camera.

A transparent window 26 made of calcium fluoride material that transmits infrared light in the wavelength range measurable by the upper radiation thermometer 25 is attached to the end of the through hole 61a facing the heat treatment space 65. A transparent window 21 made of barium fluoride material that transmits infrared light in the wavelength range measurable by the lower radiation thermometer 20 is attached to the end of the through hole 61b facing the heat treatment space 65. A transparent window 26a made of calcium fluoride material that transmits light is attached to the end of the through hole 61c facing the heat treatment space 65.

A gas supply hole 81 is formed in the upper part of the inner wall of the chamber 6 to supply processing gas to the heat treatment space 65. The gas supply hole 81 is formed in a position above the recess 62, and may be provided in the reflecting ring 68. The gas supply hole 81 is connected to a gas supply pipe 83 via a buffer space 82 formed in an annular shape inside the side wall of the chamber 6.

The gas supply pipe 83 is connected to a processing gas supply source 85. A valve 84 is inserted in the gas supply pipe 83. When the valve 84 is opened, processing gas is supplied from the processing gas supply source 85 to the buffer space 82.

The processing gas that has flowed into the buffer space 82 spreads within the buffer space 82, which has a smaller fluid resistance than the gas supply hole 81, and is supplied from the gas supply hole 81 into the heat treatment space 65. As the processing gas, for example, an inert gas such as nitrogen (N ₂ ), a reactive gas such as hydrogen (H ₂ ) or ammonia (NH ₃ ), or a mixed gas of these gases can be used (nitrogen gas in this embodiment).

On the other hand, a gas exhaust hole 86 is provided in the lower part of the inner wall of the chamber 6 to exhaust the gas in the heat treatment space 65. The gas exhaust hole 86 is formed at a position lower than the recess 62, and may be provided in the reflecting ring 69. The gas exhaust hole 86 is connected to a gas exhaust pipe 88 via a buffer space 87 formed in an annular shape inside the side wall of the chamber 6. The gas exhaust pipe 88 is connected to an exhaust section 190. 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 exhausted from the gas exhaust hole 86 through the buffer space 87 to the gas exhaust pipe 88.

The gas supply holes 81 and the gas exhaust holes 86 may be provided in multiple locations along the circumferential direction of the chamber 6, or may be slit-shaped. The process gas supply source 85 and the exhaust unit 190 may be mechanisms provided in the heat treatment unit 160, or may be utilities of the factory in which the heat treatment unit 160 is installed.

A gas exhaust pipe 191 that exhausts gas from within the heat treatment space 65 is also connected to the tip of the transport opening 66. The gas exhaust pipe 191 is connected to the exhaust section 190 via a valve 192. By opening the valve 192, the gas in the chamber 6 is exhausted via the transport opening 66.

Figure 4 is a perspective view showing the overall appearance of the holding unit 7. The holding unit 7 is configured with a base ring 71, a connecting portion 72, and a susceptor 74. The base ring 71, the connecting portion 72, and the susceptor 74 are all made of quartz. In other words, the entire holding unit 7 is made of quartz.

The base ring 71 is an arc-shaped quartz member with a portion missing from the annular shape. This missing portion is provided to prevent interference between the base ring 71 and the transfer arm 11 of the transfer mechanism 10 (described below). The base ring 71 is placed on the bottom surface of the recess 62, and is supported by the wall surface of the chamber 6 (see FIG. 3). A number of connecting portions 72 (four in this embodiment) are erected on the upper surface of the base ring 71 along the circumferential direction of the annular shape. The connecting portions 72 are also quartz members, and are fixed to the base ring 71 by welding.

The susceptor 74 is supported by four connecting parts 72 provided on the base ring 71. Figure 5 is a plan view of the susceptor 74. Figure 6 is a cross-sectional view of the susceptor 74.

The susceptor 74 includes a holding plate 75, a guide ring 76, and a number of support pins 77. The holding plate 75 is a generally circular, flat member made of quartz. The diameter of the holding plate 75 is larger than the diameter of the semiconductor wafer W. In other words, the holding plate 75 has a planar size larger than the semiconductor wafer W.

A guide ring 76 is installed on the peripheral portion of the upper surface of the holding plate 75. The guide ring 76 is a circular ring-shaped member having an inner diameter larger than the diameter of the semiconductor wafer W. For example, if 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 made of quartz, the same material 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 a separately processed pin or the like. Alternatively, the holding plate 75 and the guide ring 76 may be processed as an integrated member.

The area of the upper surface of the holding plate 75 that is inside the guide ring 76 is a planar holding surface 75a that holds the semiconductor wafer W. A plurality of support pins 77 are provided on the holding surface 75a of the holding plate 75. In this embodiment, a total of 12 support pins 77 are erected in a ring shape at 30° intervals along a circumference concentric with the outer circumferential circle of the holding surface 75a (the inner circumferential circle of the guide ring 76).

The diameter of the circle on which the 12 support pins 77 are arranged (the distance between opposing support pins 77) is smaller than the diameter of the semiconductor wafer W, and if the diameter of the semiconductor wafer W is φ300 mm, then the diameter is φ210 mm to φ280 mm. Three or more support pins 77 are provided. Each support pin 77 is made of quartz.

The multiple support pins 77 may be attached to the upper surface of the holding plate 75 by welding, or may be machined integrally with the holding plate 75.

Returning to FIG. 4, the four connecting parts 72 erected on the base ring 71 are fixed to the peripheral part of the holding plate 75 of the susceptor 74 by welding. That is, the susceptor 74 and the base ring 71 are fixedly connected by the connecting parts 72. The base ring 71 of the holding part 7 is supported on the wall surface of the chamber 6, and the holding part 7 is attached to the chamber 6. When the holding part 7 is attached to the chamber 6, the holding plate 75 of the susceptor 74 is in a horizontal position (a position in which the normal line coincides with the vertical direction). That is, the holding surface 75a of the holding plate 75 is a horizontal plane.

The semiconductor wafer W that has been carried into the chamber 6 is placed and held in a horizontal position on the susceptor 74 of the holder 7 that is attached to the chamber 6. At this time, the semiconductor wafer W is supported by 12 support pins 77 that are erected on the holding plate 75 and held on the susceptor 74. More precisely, the upper ends of the 12 support pins 77 contact the underside of the semiconductor wafer W to support the semiconductor wafer W.

The height of the 12 support pins 77 (the distance from the upper end of the support pin 77 to the holding surface 75a of the holding plate 75) is uniform, so that the semiconductor wafer W can be supported in a horizontal position by the 12 support pins 77.

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

As shown in Figs. 4 and 5, an opening 78 is formed in the holding plate 75 of the susceptor 74, penetrating vertically. The opening 78 is provided so that the lower radiation thermometer 20 can receive radiation light (infrared light) emitted from the underside of the semiconductor wafer W. That is, the lower radiation thermometer 20 receives the light emitted from the underside of the semiconductor wafer W through the opening 78 and a transparent window 21 attached to the through hole 61b of the chamber side 61, and measures the temperature of the semiconductor wafer W.

Furthermore, the holding plate 75 of the susceptor 74 has four through holes 79 through which the lift pins 12 of the transfer mechanism 10 described later pass to transfer the semiconductor wafer W.

Figure 7 is a plan view of the transfer mechanism 10. Figure 8 is a side view of the transfer mechanism 10. The transfer mechanism 10 has two transfer arms 11. The transfer arms 11 are formed in an arc shape that fits roughly along the annular recess 62.

Each transfer arm 11 has two lift pins 12 standing upright. The transfer arms 11 and the lift pins 12 are made of quartz. Each transfer arm 11 can be rotated by a horizontal movement mechanism 13. The horizontal movement mechanism 13 moves the pair of transfer arms 11 horizontally between a transfer operation position (solid line position in FIG. 7) where the semiconductor wafer W is transferred to the holder 7 and a retracted position (double-dashed line position in FIG. 7) where the pair of transfer arms 11 do not overlap the semiconductor wafer W held by the holder 7 in a plan view.

The horizontal movement mechanism 13 may be one that rotates each transfer arm 11 using an individual motor, or one that uses a link mechanism to rotate a pair of transfer arms 11 in unison using a single motor.

The pair of transfer arms 11 are raised and lowered together with the horizontal movement mechanism 13 by the lifting mechanism 14. When the lifting mechanism 14 raises the pair of transfer arms 11 to the transfer operation position, a total of four lift pins 12 pass through through holes 79 (see Figures 4 and 5) drilled in the susceptor 74, and the upper ends of the lift pins 12 protrude from the upper surface of the susceptor 74. On the other hand, when the lifting mechanism 14 lowers the pair of transfer arms 11 to the transfer operation position to remove the lift pins 12 from the through holes 79, and the horizontal movement mechanism 13 moves the pair of transfer arms 11 to open them, each transfer arm 11 moves to a retracted position.

The retracted position of the pair of transfer arms 11 is directly above the base ring 71 of the holding unit 7. Since the base ring 71 is placed on the bottom surface of the recess 62, the retracted position of the transfer arms 11 is inside the recess 62. An exhaust mechanism (not shown) is also provided near the location where the drive unit (horizontal movement mechanism 13 and lifting mechanism 14) of the transfer mechanism 10 is provided, and is configured to exhaust the atmosphere around the drive unit of the transfer mechanism 10 to the outside of the chamber 6.

Returning to FIG. 3, the flash heating unit 5 provided above the chamber 6 is configured with a light source consisting of multiple flash lamps FL (30 in this embodiment) inside a housing 51, and a reflector 52 provided to cover the light source from above.

A lamp light emission window 53 is attached to the bottom of the housing 51 of the flash heating unit 5. The lamp light emission window 53, which constitutes the floor of the flash heating unit 5, is a plate-shaped quartz window made of quartz. By installing the flash heating unit 5 above the chamber 6, the lamp light emission window 53 faces the upper chamber window 63.

The flash lamp FL irradiates flash light from above the chamber 6 through the lamp light emission window 53 and the upper chamber window 63 into the heat treatment space 65.

The multiple flash lamps FL are rod-shaped lamps each 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 holder 7 (i.e., along the horizontal direction). Therefore, the plane formed by the arrangement of the flash lamps FL is also a horizontal plane.

The flash lamp FL is equipped with a rod-shaped glass tube (discharge tube) that contains xenon gas and has an anode and cathode connected to a capacitor at both ends, and a trigger electrode attached to the outer surface of the glass tube.

Xenon gas is an electrical insulator, so under normal conditions electricity does not flow through the glass tube even if a charge is stored in the capacitor. However, when a high voltage is applied to the trigger electrode and the insulation is broken down, the electricity stored in the capacitor flows instantly through the glass tube, and light is emitted due to the excitation of the xenon atoms or molecules at that moment.

In such flash lamps FL, electrostatic energy previously stored in a capacitor is converted into an extremely short light pulse of 0.1 to 100 milliseconds, and so they have the advantage of being able to emit extremely strong light compared to a light source that lights continuously, such as a halogen lamp HL. In other words, the flash lamp FL is a pulsed light-emitting lamp that emits light instantaneously for an extremely short period of time, less than one second.

The light emission time of the flash lamp FL can be adjusted by the coil constant of the lamp power supply that supplies power to the flash lamp FL.

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

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

Figure 9 is a plan view showing the arrangement of multiple halogen lamps HL. The 40 halogen lamps HL are arranged in two rows, upper and lower. 20 halogen lamps HL are arranged in the upper row, which is closer to the holder 7, and 20 halogen lamps HL are also arranged in the lower row, which is farther from the holder 7 than the upper row.

Each halogen lamp HL is a rod-shaped lamp having a long cylindrical shape. In both the upper and lower rows, the 20 halogen lamps HL are arranged so that their longitudinal directions are parallel to each other along the main surface of the semiconductor wafer W held by the holder 7 (i.e., along the horizontal direction). Therefore, the plane formed by the arrangement of the halogen lamps HL in both the upper and lower rows is a horizontal plane.

Also, as shown in FIG. 9, in both the upper and lower tiers, the halogen lamps HL are arranged at a higher density in the area facing the periphery of the semiconductor wafer W held by the holder 7 than in the area facing the center of the semiconductor wafer W. In other words, in both the upper and lower tiers, the arrangement pitch of the halogen lamps HL is shorter in the periphery of the lamp arrangement than in the center. This allows a greater amount of light to be irradiated to the periphery of the semiconductor wafer W, which is prone to temperature drops when heated by light irradiation from the halogen heating unit 4.

The lamp group consisting of the halogen lamps HL in the upper row and the lamp group consisting of the halogen lamps HL in the lower row are arranged so that they intersect in a grid pattern. In other words, a total of 40 halogen lamps HL are arranged so that the longitudinal direction of the 20 halogen lamps HL arranged in the upper row and the longitudinal direction of the 20 halogen lamps HL arranged in the lower row are mutually perpendicular.

Halogen lamps HL are filament-type light sources that emit light by passing electricity through a filament placed inside a glass tube, causing the filament to become incandescent. Inside the glass tube is sealed a gas consisting of an inert gas such as nitrogen or argon with a small amount of a halogen element (iodine, bromine, etc.). By introducing a halogen element, it is possible to set the filament temperature to a high temperature while preventing filament breakage.

Halogen lamps HL therefore have the characteristic that they have a longer life span than normal incandescent light bulbs and can continuously irradiate strong light. In other words, halogen lamps HL are continuous lighting lamps that emit light for at least one second or more. In addition, because halogen lamps HL are rod-shaped lamps, they have a long life span, and arranging halogen lamps HL in a horizontal direction provides excellent radiation efficiency to the semiconductor wafer W above.

In addition, a reflector 43 is provided below the two rows of halogen lamps HL inside the housing 41 of the halogen heating unit 4 (Figure 3). The reflector 43 reflects the light emitted from the multiple halogen lamps HL toward the heat treatment space 65.

As shown in FIG. 3, the chamber 6 is provided with two radiation thermometers (pyrometers in this embodiment), an upper radiation thermometer 25 and a lower radiation thermometer 20. The upper radiation thermometer 25 is installed diagonally above the semiconductor wafer W held by the susceptor 74, and the lower radiation thermometer 20 is installed diagonally below the semiconductor wafer W held by the susceptor 74.

Figure 10 is a diagram showing the relationship between the lower radiation thermometer 20, the upper radiation thermometer 25, the camera 142, and the control unit 3.

The lower radiation thermometer 20, which is disposed diagonally below the semiconductor wafer W and measures the temperature of the underside of the semiconductor wafer W, is equipped with an infrared sensor 24 and a temperature measurement unit 22.

The infrared sensor 24 receives infrared light radiated through the opening 78 from the underside of the semiconductor wafer W held on the susceptor 74. The infrared sensor 24 is electrically connected to the temperature measurement unit 22 and transmits a signal generated in response to the received light to the temperature measurement unit 22.

The temperature measurement unit 22 includes an amplifier circuit, an A/D converter, a temperature conversion circuit, and the like (not shown), and converts the signal indicating the intensity of the infrared light output from the infrared sensor 24 into a temperature. The temperature obtained by the temperature measurement unit 22 is the temperature of the underside of the semiconductor wafer W.

On the other hand, the upper radiation thermometer 25, which is provided diagonally above the semiconductor wafer W and measures the temperature of the upper surface of the semiconductor wafer W, includes an infrared sensor 29 and a temperature measurement unit 27. The infrared sensor 29 receives infrared light emitted from the upper surface of the semiconductor wafer W held on the susceptor 74. The infrared sensor 29 includes an InSb (indium antimonide) optical element so that it can respond to a sudden change in temperature of the upper surface of the semiconductor wafer W at the moment when the flash light is irradiated. The infrared sensor 29 is electrically connected to the temperature measurement unit 27 and transmits a signal generated in response to the received light to the temperature measurement unit 27.

The temperature measurement unit 27 converts the signal indicating the intensity of the infrared light output from the infrared sensor 29 into a temperature. The temperature obtained by the temperature measurement unit 27 is the temperature of the top surface of the semiconductor wafer W.

The lower radiation thermometer 20 and the upper radiation thermometer 25 are electrically connected to the control unit 3, which is the controller for the entire heat treatment unit 160, and the temperatures of the lower and upper surfaces of the semiconductor wafer W measured by the lower radiation thermometer 20 and the upper radiation thermometer 25, respectively, are transmitted to the control unit 3.

The camera 142 also captures images of the semiconductor wafer W that may be displaced (e.g., bounced off the susceptor 74) when irradiated with the flash light. Preferably, the camera 142 capable of a high-speed shutter captures images of the semiconductor wafer W continuously. The camera 142 is connected to the calculation unit 143, and image data obtained by imaging with the camera 142 is input to the calculation unit 143. Note that only one camera 142 may be provided, or multiple cameras 142 may be provided.

The calculation unit 143 calculates a measured frequency distribution, which is a frequency distribution of the semiconductor wafer W, by further performing a fast Fourier transform (FFT) on the displacement and acceleration of the semiconductor wafer W after the flash light is irradiated, which is obtained by analyzing the image data input from the camera 142. The data on the measured frequency distribution is input to the classification unit 144.

The classification unit 144 classifies the measured frequency distribution based on the similarity between the measured frequency distribution input from the calculation unit 143 and the first and second frequency distributions pre-stored in the storage unit 145. The measured frequency distribution, the similarity between the measured frequency distribution and the first frequency distribution, the similarity between the measured frequency distribution and the second frequency distribution, and data related to the classification of the measured frequency distribution are input to the control unit 3.

Here, the storage unit 145 may be, for example, a hard disk drive (HDD), a random access memory (RAM), a read only memory (ROM), a flash memory, an erasable programmable read only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or other volatile or non-volatile semiconductor memory, a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, a DVD, or any other memory medium to be used in the future.

The control unit 3 controls the various operating mechanisms provided in the thermal processing unit 160. Based on the classification of the measured frequency distribution input from the classification unit 144, for example, if the measured frequency distribution is classified as a setting condition that is unlikely to cause cracks in the semiconductor wafer W, the control unit 3 stores the setting condition in the memory unit 145 as a setting condition that can be used in subsequent substrate processing. The control unit 3 also performs control for vibration adjustment to bring the measured frequency distribution closer to the second frequency distribution, as described below.

The control unit 3 is also connected to a display unit 33 and an input unit 34. The control unit 3 displays various information on the display unit 33. The input unit 34 is a device that allows the operator of the heat treatment apparatus 100 to input various commands or parameters to the control unit 3. While checking the contents displayed on the display unit 33, the operator can also set the conditions of a processing recipe that describes the processing procedure and processing conditions for the semiconductor wafer W from the input unit 34.

The hardware configuration of the control unit 3, the calculation unit 143, and the classification unit 144 is similar to that of a general computer. That is, the control unit 3, the calculation unit 143, and the classification unit 144 each include a CPU, which is a circuit that performs various arithmetic processing, a ROM, which is a read-only memory that stores basic programs, a RAM, which is a readable and writable memory that stores various information, and a magnetic disk that stores control software, data, and the like. The CPU of the control unit 3 executes a predetermined processing program, causing the processing in the heat processing unit 160 to proceed.

A touch panel that combines the functions of both the display unit 33 and the input unit 34 can be used, and in this embodiment, a liquid crystal touch panel is used that is provided on the outer wall of the heat treatment device 100.

In addition to the above configuration, the heat treatment apparatus 100 is equipped with various cooling structures to prevent excessive temperature rise in the halogen heating unit 4, the flash heating unit 5, and the chamber 6 due to the thermal energy generated by the halogen lamps HL and the flash lamps FL during heat treatment of the semiconductor wafer W.

For example, a water-cooled pipe (not shown) is provided in the wall of the chamber 6. The halogen heating unit 4 and the flash heating unit 5 have an air-cooled structure that creates a gas flow inside to remove heat. Air is also supplied to the gap between the upper chamber window 63 and the lamp light emission window 53 to cool the flash heating unit 5 and the upper chamber window 63.

<Operation of the heat treatment device>
Next, a description will be given of a procedure for processing the semiconductor wafer W in the heat treatment apparatus 100. Fig. 11 is a flow chart showing the procedure for processing the semiconductor wafer W. The procedure for the heat treatment apparatus 100 described below progresses as the control unit 3 controls each operating mechanism of the heat treatment apparatus 100.

First, the air supply valve 84 is opened, and the exhaust valves 89 and 192 are opened to start supplying and exhausting air to and from the chamber 6. When the valve 84 is opened, nitrogen gas is supplied to the heat treatment space 65 from the gas supply hole 81. When the valve 89 is opened, the gas in the chamber 6 is exhausted from the gas exhaust hole 86. This causes the nitrogen gas supplied from the upper part of the heat treatment space 65 in the chamber 6 to flow downward and be exhausted from the lower part of the heat treatment space 65.

In addition, by opening the valve 192, the gas in the chamber 6 is also exhausted from the transport opening 66. Furthermore, the atmosphere around the drive unit of the transfer mechanism 10 is also exhausted by an exhaust mechanism (not shown). During the heat treatment of the semiconductor wafer W in the heat treatment device 100, nitrogen gas is continuously supplied to the heat treatment space 65, and the supply amount is appropriately changed depending on the processing step.

Then, the gate valve 185 is opened to open the transport opening 66, and the semiconductor wafer W to be processed is transported into the heat treatment space 65 in the chamber 6 through the transport opening 66 by a transport robot outside the apparatus (step ST1). At this time, there is a risk that the atmosphere outside the apparatus will be drawn in when the semiconductor wafer W is transported, but since nitrogen gas is continuously supplied to the chamber 6, the nitrogen gas flows out from the transport opening 66, minimizing the drawing in of such external atmosphere.

The semiconductor wafer W carried in by the transport robot advances to a position directly above the holding part 7 and stops there. Then, the pair of transfer arms 11 of the transfer mechanism 10 move horizontally from the retracted position to the transfer operation position and rise, causing the lift pins 12 to pass through the through holes 79 and protrude from the upper surface of the holding plate 75 of the susceptor 74 to receive the semiconductor wafer W. At this time, the lift pins 12 rise above the upper ends of the support pins 77.

After the semiconductor wafer W is placed on the lift pins 12, the transport robot leaves the heat treatment space 65, and the transport opening 66 is closed by the gate valve 185. Then, the pair of transfer arms 11 descend, and the semiconductor wafer W is transferred from the transfer mechanism 10 to the susceptor 74 of the holding unit 7 and held from below in a horizontal position. The semiconductor wafer W is supported by a plurality of support pins 77 erected on the holding plate 75 and held by the susceptor 74. The semiconductor wafer W is also held by the holding unit 7 with the surface to be processed as the upper surface. A predetermined gap is formed between the lower surface (the main surface opposite to the upper surface) of the semiconductor wafer W supported by the plurality of support pins 77 and the holding surface 75a of the holding plate 75. The pair of transfer arms 11 that descend to below the susceptor 74 are retreated to a retreat position, that is, inside the recess 62, by the horizontal movement mechanism 13.

Figure 12 shows the change in temperature of the upper surface of the semiconductor wafer W. After the semiconductor wafer W is loaded into the chamber 6 and held by the susceptor 74, the 40 halogen lamps HL of the halogen heating unit 4 are simultaneously turned on at time t1 to start preheating (assisted heating) (step ST2). The halogen light emitted from the halogen lamps HL passes through the lower chamber window 64 and the susceptor 74, which are made of quartz, and is irradiated onto the lower surface of the semiconductor wafer W. The semiconductor wafer W is preheated by being irradiated with light from the halogen lamps HL, and the temperature rises. Note that the transfer arm 11 of the transfer mechanism 10 is retracted inside the recess 62, so it does not interfere with heating by the halogen lamps HL.

The temperature of the semiconductor wafer W, which is heated by the light irradiation from the halogen lamps HL, is measured by the lower radiation thermometer 20. That is, the lower radiation thermometer 20 receives infrared light radiated from the underside of the semiconductor wafer W held on the susceptor 74 through the opening 78 through the transparent window 21 and measures the temperature of the underside of the semiconductor wafer W. Temperature measurement by the lower radiation thermometer 20 may be started before preheating by the halogen lamps HL is started.

When using the lower radiation thermometer 20 to measure the temperature of the underside of the semiconductor wafer W in a non-contact manner, it is necessary to set the emissivity of the underside in the lower radiation thermometer 20. If no film is formed on the underside of the semiconductor wafer W, the emissivity of the silicon, which is the wafer base material, can be set in the lower radiation thermometer 20. However, if a film is also formed on the underside of the semiconductor wafer W, the emissivity of the underside will also vary depending on the film.

The temperature of the underside of the semiconductor wafer W measured by the lower radiation thermometer 20 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, which is heated by the light irradiation from the halogen lamp HL, has reached a predetermined preheating temperature T1. That is, the control unit 3 feedback controls the output of the halogen lamp HL so that the temperature of the semiconductor wafer W becomes the preheating temperature T1 based on the measurement value by the lower radiation thermometer 20. In this way, the lower radiation thermometer 20 is also a temperature sensor for controlling the output of the halogen lamp HL in the preheating stage. Note that the lower radiation thermometer 20 measures the temperature of the underside of the semiconductor wafer W, but no temperature difference occurs between the upper and lower surfaces of the semiconductor wafer W during the preheating stage by the halogen lamp HL, and the temperature of the underside measured by the lower radiation thermometer 20 can be considered to be the temperature of the entire semiconductor wafer W. In addition, the preheating temperature T1 is, for example, 200°C or higher and 800°C or lower, and preferably 350°C or higher and 600°C or lower (600°C in this embodiment), so that there is no risk of the impurities added to the semiconductor wafer W diffusing due to heat.

After the temperature of the semiconductor wafer W reaches the preheating temperature T1, the control unit 3 maintains the semiconductor wafer W at the preheating temperature T1 for a while. Specifically, at time t2 when the temperature of the semiconductor wafer W measured by the lower radiation thermometer 20 reaches the preheating temperature T1, the control unit 3 adjusts the output of the halogen lamps HL to maintain the temperature of the semiconductor wafer W at approximately the preheating temperature T1.

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

At time t3, when a predetermined time has elapsed since the temperature of the semiconductor wafer W reached the preheating temperature T1, the flash lamps FL of the flash heating unit 5 irradiate the upper surface of the semiconductor wafer W held on the susceptor 74 with flash light (step ST3). At this time, part of the flash light emitted from the flash lamps FL goes directly into the chamber 6, and the other part goes into the chamber 6 after being reflected by the reflector 52, and the semiconductor wafer W is flash-heated by the irradiation of these flash lights.

Flash heating is performed by irradiating the top surface of the semiconductor wafer W with a flash of light (bright light) from the flash lamps FL, and can raise the temperature of the top surface of the semiconductor wafer W in a short period of time. In other words, the flash of light irradiated from the flash lamps FL is an extremely short and intense flash of light with an irradiation time of about 0.1 milliseconds to 100 milliseconds, in which electrostatic energy previously stored in a capacitor is converted into an extremely short light pulse. Then, the temperature of the top surface of the semiconductor wafer W rises rapidly in an extremely short period of time due to the irradiation of the flash of light from the flash lamps FL.

The temperature of the upper surface of the semiconductor wafer W is monitored by the upper radiation thermometer 25. However, the upper radiation thermometer 25 does not measure the absolute temperature of the upper surface of the semiconductor wafer W, but measures the temperature change of the upper surface. That is, the upper radiation thermometer 25 measures the temperature rise (jump temperature) ΔT of the upper surface of the semiconductor wafer W from the preheating temperature T1 during flash light irradiation. Although the temperature of the lower surface of the semiconductor wafer W is measured by the lower radiation thermometer 20 even during flash light irradiation, when a flash light with an extremely short irradiation time and high intensity is irradiated, only the vicinity of the surface of the semiconductor wafer W is rapidly heated, so that a temperature difference occurs between the upper and lower surfaces of the semiconductor wafer W, and the temperature of the upper surface of the semiconductor wafer W cannot be measured by the lower radiation thermometer 20. Since the light receiving angle of the lower radiation thermometer 20 and the upper radiation thermometer 25 with respect to the semiconductor wafer W is 60° or more and 89° or less, the upper radiation thermometer 25 can accurately measure the temperature rise ΔT of the upper surface of the semiconductor wafer W regardless of the type of film formed on the upper surface of the semiconductor wafer W.

In addition, using multiple cameras 142, images of the semiconductor wafer W that may be displaced, such as bouncing off the susceptor 74, after being irradiated with the flash light are captured (step ST4). Preferably, the images of the semiconductor wafer W are captured continuously using cameras 142 capable of high-speed shuttering. The image data obtained by the imaging of the cameras 142 is input to the calculation unit 143.

The control unit 3 also calculates the maximum temperature reached by the upper surface of the semiconductor wafer W during flash light irradiation. The temperature of the lower surface of the semiconductor wafer W is continuously measured by the lower radiation thermometer 20 at least from time t2 when the semiconductor wafer W reaches a constant temperature during preheating to time t3 when the flash light is irradiated. At the preheating stage before flash light irradiation, no temperature difference occurs between the upper and lower surfaces of the semiconductor wafer W, and the temperature of the lower surface of the semiconductor wafer W measured by the lower radiation thermometer 20 before flash light irradiation is also the temperature of the upper surface. The control unit 3 calculates the maximum temperature reached by the upper surface by adding the temperature rise ΔT of the upper surface of the semiconductor wafer W during flash light irradiation measured by the upper radiation thermometer 25 to the temperature of the lower surface of the semiconductor wafer W measured by the lower radiation thermometer 20 between time t2 and time t3 immediately before the flash light is irradiated. The control unit 3 may display the calculated maximum temperature reached by the upper surface 33. The maximum temperature T2 is expected to be, for example, 800°C or higher and 11100°C or lower, and preferably 1000°C or higher and 1100°C or lower (1000°C in this embodiment).

By adding the temperature rise ΔT of the upper surface of the semiconductor wafer W measured by the upper radiation thermometer 25 to the temperature of the lower surface of the semiconductor wafer W (= the temperature of the upper surface) accurately measured by the lower radiation thermometer 20, the maximum temperature T2 reached by the upper surface of the semiconductor wafer W during irradiation with flash light can be accurately calculated.

After the flash light irradiation is completed, the halogen lamp HL is turned off at time t4 after a predetermined time has elapsed. As a result, the temperature of the semiconductor wafer W is rapidly lowered from the preheating temperature T1. The temperature of the semiconductor wafer W during the temperature drop is measured by the lower radiation thermometer 20, and the measurement result is transmitted to the control unit 3. The control unit 3 monitors whether the temperature of the semiconductor wafer W has dropped to a predetermined temperature based on the measurement result of the lower radiation thermometer 20. Then, after the temperature of the semiconductor wafer W has dropped to a predetermined temperature or lower, the pair of transfer arms 11 of the transfer mechanism 10 again move horizontally from the retreat position to the transfer operation position and rise, so that the lift pins 12 protrude from the upper surface of the susceptor 74 and receive the semiconductor wafer W after heat treatment from the susceptor 74. Next, the transfer opening 66 closed by the gate valve 185 is opened, and the semiconductor wafer W placed on the lift pins 12 is transferred from the chamber 6 by a transfer robot outside the apparatus, completing the heat treatment of the semiconductor wafer W (step ST5).

<Classification of measurement frequency distribution>
In the following, an operation of calculating a measured frequency distribution, which is a frequency distribution of the semiconductor wafer W, based on the image data obtained in step ST4 in Fig. 11 and further classifying the measured frequency distribution will be described. Note that this operation is performed by the calculation unit 143 and the classification unit 144.

Figure 13 is a diagram showing an example of the displacement of the semiconductor wafer W after being irradiated with flash light, obtained by analyzing image data captured by the camera 142 in the calculation unit 143. In Figure 13, the vertical axis indicates height (vertical displacement), and the horizontal axis indicates time. Note that the scales on the vertical and horizontal axes do not correspond to specific numerical values, but are merely conceptual values shown for convenience. Also, although Figure 13 shows the vertical displacement of the semiconductor wafer W, the direction of the displacement of the semiconductor wafer W obtained by analyzing the image data is not limited to the vertical direction.

Figure 13 shows three graphs (A, B, and C, in ascending order of voltage value) corresponding to the application of three patterns of voltage values to the flash lamp FL. In Figure 13, pattern A is shown by a solid line, pattern B by a dotted line, and pattern C by a thick line.

On the other hand, FIG. 14 is a diagram showing an example of the frequency distribution (measured frequency distribution) of the semiconductor wafer W after being irradiated with flash light, which is obtained by performing a fast Fourier transform in the calculation unit 143 on the displacement and acceleration of the semiconductor wafer W, the example of which is shown in FIG. 13. In FIG. 14, the vertical axis indicates the amplitude, and the horizontal axis indicates the frequency. Note that the scales on the vertical and horizontal axes do not correspond to specific numerical values, but are merely conceptual values shown for convenience.

When the flash light is irradiated, the temperature of the upper surface of the semiconductor wafer W momentarily becomes high (for example, 1000°C or higher), while the temperature of the lower surface of the semiconductor wafer W does not rise significantly from the preheating temperature. Therefore, a large temperature difference occurs between the upper and lower surfaces of the semiconductor wafer W. Then, a sudden thermal expansion occurs only on the upper surface of the semiconductor wafer W, so that the semiconductor wafer W warps so that its upper surface becomes convex. In the next moment, heat is transferred from the upper surface to the lower surface of the semiconductor wafer W, and the semiconductor wafer W warps so that its lower surface becomes convex due to the reaction of the above-mentioned warping. Thereafter, the semiconductor wafer W vibrates by repeating the warping action so that its upper and lower surfaces alternately become convex. The mode of the vibration is considered to depend on the conditions when the flash light is irradiated (for example, output energy or pulse width, etc.) or the temperature distribution of the semiconductor wafer W before the flash light is irradiated. In addition, when the semiconductor wafer W bounces off the susceptor 74, the above-mentioned vibration continues even while the semiconductor wafer W is separated from the susceptor 74.

Figure 14 shows three graphs (A, B, and C, in ascending order of voltage value) that indicate the above vibrations when three patterns of voltage value are applied to the flash lamp FL. In Figure 14, pattern A is shown by a solid line, pattern B by a dotted line, and pattern C by a thick line.

For the measured frequency distribution shown in FIG. 14, the classification unit 144 calculates the similarity using the first frequency distribution and the second frequency distribution. The similarity between the distributions is calculated using, for example, Euclidean distance. Then, the measured frequency is classified as belonging to the same group as the frequency distribution with the higher similarity between the first frequency distribution and the second frequency distribution.

Here, the first frequency distribution and the second frequency distribution are each stored in advance in the storage unit 145. The first frequency distribution is the frequency distribution of a semiconductor wafer W that has cracks after being irradiated with flash light. For example, the first frequency distribution may be a collection of multiple frequency distribution patterns of a semiconductor wafer W that has cracks after being irradiated with flash light, or may be the average value of the collection of such frequency distribution patterns. On the other hand, the second frequency distribution is the frequency distribution of a semiconductor wafer W that has no cracks after being irradiated with flash light. For example, the second frequency distribution may be a collection of multiple frequency distribution patterns of a semiconductor wafer W that has no cracks after being irradiated with flash light, or may be the average value of the collection of such frequency distribution patterns.

Classifying the measured frequency distribution as belonging to the same group as the first frequency distribution means that the measured frequency distribution is classified as a frequency distribution that is likely to produce the same result as the first frequency distribution (i.e., cracks occurring after the flash light is applied).

Similarly, classification of the measured frequency distribution as belonging to the same group as the second frequency distribution means that the measured frequency distribution is classified as a frequency distribution that is likely to produce the same result as the second frequency distribution (i.e., no cracks occurring after the flash light is applied).

The first frequency distribution and the second frequency distribution are each generated by associating data on the actual frequency distribution of the semiconductor wafer W after the flash light is irradiated with data on whether or not cracks have actually occurred in the semiconductor wafer W, and sequentially storing the data in the memory unit 145. When storing the first frequency distribution and the second frequency distribution, the setting conditions such as the output energy or pulse width of the flash lamp FL can be changed in various ways.

Here, the classification by the classification unit 144 may be performed using a trained model that has been created in advance by machine learning. In this case, the first frequency distribution and the second frequency distribution are first associated with the presence or absence of cracks in the semiconductor wafer W in the corresponding frequency distributions to generate training data. Then, the training data is used to generate a trained model by performing training using, for example, a neural network.

<Adjusting the measurement frequency distribution>
Furthermore, the control unit 3 can adjust the vibrations occurring in the semiconductor wafer W so that the measured frequency distribution approaches the second frequency distribution. Specifically, the vibrations occurring in the semiconductor wafer W can be adjusted by adjusting the frequency components that have a large contribution to the amplitude.

To identify the frequency components that contribute greatly to the amplitude, the control unit 3 first varies the output energy of the flash lamp FL, one of the set conditions, and examines the correlation between the amplitude and the output energy of each frequency component in the measured frequency distribution at that time. Then, it calculates the correlation coefficient for each frequency component.

Figure 15 is a diagram showing an example of the correlation between output energy and amplitude for a certain frequency component. In Figure 15, the vertical axis represents amplitude, and the horizontal axis represents output energy.

As shown in Fig. 15, when the output energy changes in the order of _E1 , _E2 , and _E3 , and the amplitude of the frequency component changes in the order of _A1 , _A2 , and _A3 , the slope of the approximation line for these plots corresponds to the correlation coefficient. Note that the approximation line is not limited to a straight line, and may be a curved line.

Then, the control unit 3 calculates the correlation coefficient for each frequency component under other setting conditions (for example, setting conditions in which the pulse width of the flash light is different) in the same manner as described above.

Next, the control unit 3 multiplies the correlation coefficients of the corresponding frequency components between the multiple setting conditions to obtain a feature amount, and identifies the frequency components that contribute greatly to the amplitude. Specifically, by utilizing the fact that the correlation coefficient of a frequency component with low correlation approaches 0, the control unit 3 identifies the frequency components (and their multiples) that correspond to the feature amount close to 1 after multiplication of the correlation coefficients as frequency components that contribute greatly to the amplitude.

Next, specific means for adjusting the frequency components will be described. FIG. 16 is a cross-sectional view showing an example of the configuration of the holding unit 7a equipped with multiple damper mechanisms 280. Note that there may be only one damper mechanism 280.

As shown in the example in FIG. 16, in the holding portion 7a, a plurality of damper mechanisms 280 are arranged on the underside of the holding plate 75, and further, the connecting portion 72 is arranged on the underside of the damper mechanisms 280. In other words, the damper mechanisms 280 are arranged between the holding plate 75 and the connecting portion 72.

Here, the damper mechanism 280 adjusts the vibrations generated in the semiconductor wafer W, and includes an elastic spring 280a and a variable damper 280b that suppresses the expansion and contraction displacement of the spring 280a.

The control unit 3 can indirectly control the vibrations occurring in the holding plate 75 and further in the semiconductor wafer W supported on the holding plate 75 via the support pins 77 by adjusting the control amount of the variable damper 280b (the control amount may be different between the multiple damper mechanisms 280). Thus, the control unit 3 can adjust the measured frequency distribution to approach the second frequency distribution.

The relationship between the control amount of the variable damper 280b and the amount of change of any frequency component is measured in advance by experiments or the like for each set condition (output energy, pulse width, etc.), and a correspondence table that associates and stores them is stored in the storage unit 145. The control unit 3 determines the control amount of the variable damper 280b, taking into account the positive and negative correlation coefficients of the corresponding frequency components.

Figure 17 is a cross-sectional view showing an example of the configuration of the holding unit 7b having multiple damper mechanisms 281. Note that there may be only one damper mechanism 281.

As shown in the example in FIG. 17, in the susceptor 74b of the holding unit 7b, multiple damper mechanisms 281 are arranged on the upper surface of the holding plate 75, and further, the semiconductor wafer W is arranged on the upper end of the damper mechanisms 281. In other words, the damper mechanisms 281 are arranged between the holding plate 75 and the semiconductor wafer W, and support the semiconductor wafer W instead of the support pins.

The damper mechanism 281 adjusts vibrations generated in the semiconductor wafer W, and like the damper mechanism 280, includes an elastic spring and a variable damper that suppresses the expansion and contraction displacement of the spring. The damper mechanism 281 may be provided so as to penetrate the holding plate 75. The damper mechanism 281 may also be provided together with the damper mechanism 280 in FIG. 16.

The control unit 3 can directly control the vibrations occurring in the semiconductor wafer W supported by the damper mechanism 281 by adjusting the control amount of the variable damper in the damper mechanism 281 (the control amount may be different between the multiple damper mechanisms 281). Thus, the control unit 3 can adjust the measurement frequency distribution to approach the second frequency distribution.

The relationship between the control amount of the variable damper in the damper mechanism 281 and the amount of change in any frequency component is assumed to have been measured in advance by experiments or the like for each set condition (output energy, pulse width, etc.), and a correspondence table correlating and storing them is stored in the memory unit 145. The control unit 3 determines the control amount of the variable damper in the damper mechanism 281, taking into consideration the positive and negative correlation coefficients of the corresponding frequency components.

Figure 18 is a cross-sectional view showing an example of the configuration of a holding unit 7c having multiple ultrasonic transducers 282. Note that there may be only one ultrasonic transducer 282.

As shown in the example in FIG. 18, in the holding unit 7c, multiple ultrasonic transducers 282 are arranged in the chamber 6. Each ultrasonic transducer 282 is arranged in a direction that generates ultrasonic waves toward the upper surface of the semiconductor wafer W supported by the support pins 77. Each ultrasonic transducer 282 adjusts the vibrations generated in the semiconductor wafer W by ultrasonic waves.

The ultrasonic transducer 282 is a device that converts high-frequency power into ultrasonic vibrations, and may be either an electrostrictive type or a magnetostrictive type. Note that, although the ultrasonic transducer 282 is disposed above the semiconductor wafer W and spaced apart from the semiconductor wafer W in FIG. 18, the position of the ultrasonic transducer 282 is not limited to this case. The ultrasonic transducer 282 may be provided together with at least one of the damper mechanism 280 in FIG. 16 and the damper mechanism 281 in FIG. 17.

The control unit 3 can directly control the vibrations generated in the semiconductor wafer W by adjusting the frequency or amplitude of the ultrasonic vibrations generated by the ultrasonic transducer 282 (the frequency or amplitude may be different between the multiple ultrasonic transducers 282). Thus, the control unit 3 can adjust the measurement frequency distribution to approach the second frequency distribution.

The relationship between the frequency and amplitude of the ultrasonic vibration generated by the ultrasonic transducer 282 and the amount of change in any frequency component is assumed to have been measured in advance by experiments or the like for each set condition (output energy, pulse width, etc.), and a correspondence table correlating and storing these is stored in the memory unit 145. The control unit 3 determines the frequency or amplitude of the ultrasonic vibration generated by the ultrasonic transducer 282, taking into consideration the positive and negative correlation coefficients of the corresponding frequency components.

<Effects of the above-described embodiment>
Next, examples of effects obtained by the above-described embodiment will be described. Note that in the following description, the effects will be described based on the specific configurations exemplified in the above-described embodiment, but the effects may be replaced with other specific configurations exemplified in the present specification as long as the same effects are obtained.

According to the embodiment described above, the heat treatment apparatus includes a holding unit, a flash lamp FL, at least one detection unit, a calculation unit 143, a memory unit 145, and a classification unit 144. Here, the holding unit corresponds to, for example, any one of the holding units 7, 7a, 7b, or 7c (hereinafter, for convenience, any one of these may be described in correspondence). The detection unit corresponds to, for example, the camera 142. The holding unit 7 holds a substrate (semiconductor wafer W). The flash lamp FL heats the semiconductor wafer W by irradiating it with a flash light. The camera 142 detects the displacement of the semiconductor wafer W after the flash light is irradiated. The calculation unit 143 calculates a measurement frequency distribution, which is a frequency distribution of the semiconductor wafer W, based on the detected displacement of the semiconductor wafer W. The memory unit 145 prestores a first frequency distribution, which is a frequency distribution of a semiconductor wafer W that has cracks after being irradiated with a flash light, and a second frequency distribution, which is a frequency distribution of a semiconductor wafer W that has no cracks after being irradiated with a flash light. The classification unit 144 classifies the measured frequency distribution based on the similarity between the measured frequency distribution and the first frequency distribution, and the similarity between the measured frequency distribution and the second frequency distribution.

With this configuration, the frequency distribution of the semiconductor wafer W irradiated with the flash light can be measured and the frequency distribution can be classified into cases where the semiconductor wafer W is likely to crack due to the flash light and cases where the semiconductor wafer W is unlikely to crack. For example, by adjusting the setting conditions such as the output energy or pulse width of the flash light to achieve a frequency distribution classified into cases where the semiconductor wafer W is unlikely to crack, it is possible to prevent the semiconductor wafer W from cracking due to irradiation with the flash light.

The same effect can be achieved even if other configurations, examples of which are shown in this specification, are added to the above configuration, i.e., other configurations in this specification that are not mentioned as the above configuration are added.

According to the embodiment described above, the holding unit 7a, the holding unit 7b, or the holding unit 7c includes at least one vibration adjustment unit for adjusting the vibration generated in the semiconductor wafer W. Here, the vibration adjustment unit corresponds to, for example, any one of the damper mechanism 280, the damper mechanism 281, or the ultrasonic vibrator 282. The heat treatment device includes a control unit 3 that controls the vibration adjustment unit so that the measurement frequency distribution approaches the second frequency distribution. According to this configuration, the measurement frequency distribution can be brought closer to the second frequency distribution by adjusting the vibration generated in the semiconductor wafer W under the control of the control unit 3. Therefore, it is possible to suppress the occurrence of cracks in the semiconductor wafer W irradiated with the flash light.

Furthermore, according to the embodiment described above, the vibration adjustment unit is a damper mechanism 281 that contacts the underside of the semiconductor wafer W and supports the semiconductor wafer W. With this configuration, the control unit 3 can directly control the vibrations generated in the semiconductor wafer W supported by the damper mechanism 281 by adjusting the control amount of the variable damper in the damper mechanism 281.

In addition, according to the embodiment described above, the holding unit 7a includes support pins 77 that contact the underside of the semiconductor wafer W and support the semiconductor wafer W, and a holding plate 75 on whose upper surface the support pins 77 are disposed. The vibration adjustment unit is a damper mechanism 280 that contacts the underside of the holding plate 75 and supports the holding plate 75. With this configuration, the control unit 3 adjusts the control amount of the variable damper 280b in the damper mechanism 280, thereby indirectly controlling vibrations occurring in the holding plate 75 and further in the semiconductor wafer W supported by the holding plate 75 via the support pins 77.

Furthermore, according to the embodiment described above, the vibration adjustment unit is an ultrasonic transducer 282 that generates ultrasonic waves toward the semiconductor wafer W. With this configuration, the control unit 3 can directly control the vibration generated in the semiconductor wafer W by adjusting the frequency or amplitude of the ultrasonic vibration generated from the ultrasonic transducer 282.

Furthermore, according to the embodiment described above, the classification unit 144 performs machine learning using the first frequency distribution and the second frequency distribution as teacher data, and classifies the measured frequency distribution using a trained model obtained by machine learning. With such a configuration, the accuracy of classification can be improved by classifying the measured frequency distribution using a trained model obtained by machine learning.

According to the embodiment described above, in the heat treatment method, the semiconductor wafer W is held. Then, the semiconductor wafer W is heated by irradiating it with a flash light. Then, the displacement of the semiconductor wafer W after the flash light is irradiated is detected. Then, based on the detected displacement of the semiconductor wafer W, a measured frequency distribution, which is the frequency distribution of the semiconductor wafer W, is calculated. Then, the frequency distribution of the semiconductor wafer W that has cracks after being irradiated with the flash light is set as a first frequency distribution, and the frequency distribution of the semiconductor wafer W that has not cracked after being irradiated with the flash light is set as a second frequency distribution, and the measured frequency distribution is classified based on the similarity between the measured frequency distribution and the first frequency distribution and the similarity between the measured frequency distribution and the second frequency distribution.

With this configuration, the frequency distribution of the semiconductor wafer W irradiated with the flash light can be measured and the frequency distribution can be classified into cases where the semiconductor wafer W is likely to crack due to the flash light and cases where the semiconductor wafer W is unlikely to crack. For example, by adjusting the setting conditions such as the output energy or pulse width of the flash light to achieve a frequency distribution classified into cases where the semiconductor wafer W is unlikely to crack, it is possible to prevent the semiconductor wafer W from cracking due to irradiation with the flash light.

However, unless there are special restrictions, the order in which each process is performed can be changed.

Furthermore, the same effect can be achieved even if other configurations, examples of which are shown in this specification, are appropriately added to the above configuration, i.e., other configurations in this specification that were not mentioned as the above configuration are appropriately added.

<Modifications of the above-described embodiments>
The semiconductor wafer W to be processed by the heat treatment apparatus 100 may be a semiconductor wafer W in which a high dielectric constant film is formed as a gate insulating film on the upper surface of a silicon oxide film, or a semiconductor wafer W in which a metal gate is further formed on the upper surface of the high dielectric constant film. Here, for example, titanium nitride (TiN), titanium aluminum (TiAl), or tungsten (W) can be used as the material of the metal gate. The semiconductor wafer W to be processed may be a wafer in which a metal film is formed and a silicide or germanide is formed by a flash heat treatment using the metal film. Furthermore, the semiconductor wafer W to be processed may be a wafer in which an implanted impurity is activated by a flash heat treatment.

In the embodiment described above, the semiconductor wafer W is imaged by the camera 142, but an optical sensor or the like may also be used as a device for measuring the position of the semiconductor wafer W.

In the embodiments described above, the material, composition, dimensions, shape, relative positional relationship, and implementation conditions of each component may be described, but these are merely examples in all respects and are not limited to those described in this specification.

Thus, numerous variations and equivalents not shown are contemplated within the scope of the technology disclosed in this specification. For example, this includes modifying, adding, or omitting at least one component.

In addition, in the embodiments described above, when a material name is mentioned without being specifically specified, it is assumed that the material in question contains other additives, such as alloys, unless a contradiction arises.

Furthermore, each component in the embodiments described above is a conceptual unit, and the scope of the technology disclosed in this specification includes cases where one component is made up of multiple structures, where one component corresponds to a part of a structure, and even where multiple components are provided in one structure.

In addition, each of the components described in the above embodiments is considered to be software or firmware, and also corresponding hardware. When considered as software or firmware, each component is referred to as, for example, a "module." When considered as hardware, each component is referred to as, for example, a "processing circuit" or a "unit." In both of these concepts, each component is referred to as, for example, a "part."

3 Control unit 4 Halogen heating unit 5 Flash heating unit 6 Chamber 7, 7a, 7b, 7c Holding unit 10 Transfer mechanism 11 Transfer arm 12 Lift pin 13 Horizontal movement mechanism 14 Lifting mechanism 20 Lower radiation thermometer 21, 26, 26a Transparent window 22, 27 Temperature measurement unit 24, 29 Infrared sensor 25 Upper radiation thermometer 33 Display unit 34 Input unit 41, 51 Housing 43, 52 Reflector 53 Lamp light emission window 61 Chamber side 61a, 61b, 61c, 79 Through hole 62 Recess 63 Upper chamber window 64 Lower chamber window 65 Heat treatment space 66 Transport opening 68, 69 Reflecting ring 71 Base ring 72 Connection unit 74, 74b Susceptor 75 Holding plate 75a Holding surface 76 Guide ring 77 Support pin 78 Opening 81 Gas supply hole 82, 87 Buffer space 83 Gas supply pipe 84, 89, 192 Valve 85 Processing gas supply source 86 Gas exhaust hole 88, 191 Gas exhaust pipe 100 Heat treatment apparatus 101 Indexer section 110 Load port 120 Delivery robot 121 Hand 130, 140 Cooling section 131 First cool chamber 141 Second cool chamber 142 Camera 143 Calculation section 144 Classification section 145 Memory section 150 Transport robot 151a, 151b Transport hand 160 Heat treatment section 170 Transport chamber 181, 182, 183, 184, 185 Gate valve 190 Exhaust section 230 Alignment section 231 Alignment chamber 280, 281 Damper mechanism 280a Spring 280b Variable damper 282 Ultrasonic transducer

Claims (7)

A holder for holding the substrate;
a flash lamp for heating the substrate by irradiating the substrate with a flash light;
at least one detector for detecting a displacement of the substrate after the flash light is irradiated;
a calculation unit for calculating a measured frequency distribution, which is a frequency distribution of the substrate, based on the detected displacement of the substrate;
a storage unit for storing in advance a first frequency distribution, which is the frequency distribution of the substrate on which a crack occurs after the flash light is irradiated, and a second frequency distribution, which is the frequency distribution of the substrate on which a crack does not occur after the flash light is irradiated;
a classification unit for classifying the measured frequency distribution based on a similarity between the measured frequency distribution and the first frequency distribution and a similarity between the measured frequency distribution and the second frequency distribution.
Heat treatment equipment. The heat treatment device according to claim 1,
the holding unit includes at least one vibration adjusting unit for adjusting vibrations generated in the substrate,
A control unit that controls the vibration adjustment unit so that the measured frequency distribution approaches the second frequency distribution.
Heat treatment equipment. The heat treatment device according to claim 2,
The vibration adjustment unit is a damper mechanism that contacts a lower surface of the substrate and supports the substrate.
Heat treatment equipment. The heat treatment device according to claim 2 or 3,
The holding portion is
a support pin that contacts a lower surface of the substrate and supports the substrate;
a holding plate on an upper surface of which the support pin is disposed,
The vibration adjustment unit is a damper mechanism that contacts a lower surface of the holding plate and supports the holding plate.
Heat treatment equipment. A heat treatment apparatus according to any one of claims 2 to 4,
The vibration adjustment unit is an ultrasonic transducer that generates ultrasonic waves toward the substrate.
Heat treatment equipment. A heat treatment apparatus according to any one of claims 1 to 5,
the classification unit performs machine learning using the first frequency distribution and the second frequency distribution as teacher data, and classifies the measured frequency distribution using a trained model obtained by the machine learning.
Heat treatment equipment. holding a substrate;
heating the substrate by applying a flash of light;
detecting a displacement of the substrate after the flash of light is applied;
calculating a measured frequency distribution, which is a frequency distribution of the substrate, based on the detected displacement of the substrate;
a step of classifying the measured frequency distribution based on a similarity between the measured frequency distribution and the first frequency distribution and a similarity between the measured frequency distribution and the second frequency distribution, the frequency distribution of the substrate on which a crack has occurred after the flash light has been irradiated being a first frequency distribution and the frequency distribution of the substrate on which a crack has not occurred after the flash light has been irradiated being a second frequency distribution, and the similarity between the measured frequency distribution and the first frequency distribution and the similarity between the measured frequency distribution and the second frequency distribution.
Heat treatment method.

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