TW201941309A - Heat treatment apparatus and heat treatment method - Google Patents

Abstract

When a semiconductor wafer does not exist in a chamber, a halogen lamp is lighted. Light emitted from the halogen lamp successively transmits a lower chamber window and an upper chamber window of a quartz and is received by a spectrophotometer. The spectrophotometer measures spectrum intensity of the transmitted light. A determination unit determines whether or not the lower chamber window and the upper chamber window are contaminated by comparing the measured spectrum intensity of the transmitted light with a reference intensity in a case there is no contamination. Another spectrophotometer monitors time degradation of the halogen lamp.

Description

Heat treatment device and heat treatment method

The present invention relates to a heat treatment apparatus and a heat treatment method for heating a thin plate-shaped precision electronic substrate (hereinafter, simply referred to as a "substrate") by irradiating light to the substrate.

In the process of manufacturing semiconductor devices, flash annealing (FLA) that heats semiconductor wafers in a very short time has attracted much attention. Flash annealing is the use of a hernia flash (hereinafter referred to as "hernia flash" means a hernia flash) to illuminate the front side of a semiconductor wafer, so that only the front side of the semiconductor wafer is heated in a very short time (less than a few milliseconds). Heat treatment technology.

The hernia flash has a spectral distribution from the ultraviolet region to the near-infrared region. The wavelength is shorter than that of the previous halogen lamps, and is generally consistent with the basic absorption band of silicon semiconductor wafers. Therefore, when a semiconductor wafer is irradiated with a flash from a hernia flash, less light is transmitted, and the semiconductor wafer can be rapidly heated. In addition, it has also been found that, if the flash irradiation is performed for a very short time of several milliseconds or less, only the vicinity of the front surface of the semiconductor wafer can be selectively heated.

This flash annealing is applied to processes that require heating in a very short time, such as activation of impurities implanted into a semiconductor wafer. If the front side of the semiconductor wafer with impurities implanted by the ion implantation method is irradiated from the flash lamp, the front side of the semiconductor wafer can be heated to the activation temperature in a very short time, and the impurity can be performed only without deep diffusion Impurities are activated.

In Patent Document 1, a flash lamp annealing device is disclosed. After a semiconductor wafer is preheated by a halogen lamp disposed below the chamber, the front side of the semiconductor wafer is illuminated from the flash lamp disposed above the chamber. flash. In the flash lamp annealing device disclosed in Patent Document 1, a chamber window made of quartz is provided above and below a chamber for accommodating a semiconductor wafer, and flash irradiation is performed from a flash lamp through an upper chamber window, and from a halogen lamp through a lower chamber. The window is illuminated by light.
[Prior technical literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2016-58668

[Problems to be solved by the invention]

In a flash annealing apparatus, a semiconductor wafer as a processing target is often formed with an element pattern and various films are formed. If such a semiconductor wafer is heated in a chamber, a part of the film will be scattered by melting or burning, and the chamber will be polluted. In particular, in the recent manufacturing steps of the most advanced components, the low melting point of the membrane has been developed, and contamination of the chamber during heat treatment has become a significant problem.

If the chamber is contaminated in the flash annealing device, the upper and lower quartz windows will be contaminated, and the transmittance will be reduced. Therefore, the intensity of the light reaching the semiconductor wafer from the flash and the halogen lamp will be reduced. The pollution of the quartz window accumulates with the increase in the number of semiconductor wafers processed. If the pollution of the quartz window progresses to a certain extent, the light intensity will be reduced during the heat treatment, so that the semiconductor wafer cannot reach the target temperature. Become poorly handled. Therefore, when the pollution of the quartz window progresses above a certain level, maintenance is required to clean the quartz window.

In the previous flash annealing device, the pollution status of the quartz window was managed by visually confirming or monitoring the resistance value of the sheet after processing. However, it is necessary to stop the flash annealing device to confirm with the naked eye, so there is a problem that the downtime is increased. In addition, the monitoring of the sheet resistance value confirms the contamination of the quartz window after the fact. Therefore, during the period before the result is judged, a semiconductor wafer which is incompletely processed is generated.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a heat treatment device and a heat treatment method capable of instantly confirming the contamination of a quartz window without stopping the device.
[Technical means to solve the problem]

In order to solve the above-mentioned problem, the invention of claim 1 is a heat treatment device that heats the substrate by irradiating the substrate with light, and is characterized by including a chamber that houses the substrate, and a holding portion that holds the substrate in the chamber. A quartz window provided in the chamber; a light source irradiating light to the substrate held by the holding portion through the quartz window; a light measuring portion that receives the light emitted from the light source and transmitted through the quartz window to measure the light An intensity; and a determination unit that determines whether or not the quartz window is polluted based on the intensity of light received by the light measurement unit when the light source is turned on.

The invention of claim 2 is a heat treatment device according to the invention of claim 1, wherein the light source is turned on when the quartz window is not polluted, and the intensity of light received by the light measuring unit is used as a reference intensity. In addition, the determination unit determines whether or not the quartz window is polluted based on a comparison between the measurement intensity obtained by the light measurement unit and the reference intensity.

In addition, the invention of claim 3 is the heat treatment device according to the invention of claim 1 or 2, characterized in that the quartz window includes: a first quartz window provided on one side of the chamber; and a second quartz window, It is disposed on the other side; the light source includes a flash lamp, which irradiates light to the substrate held by the holding portion via the first quartz window, and a continuous lighting lamp, which is held by the holding portion via the second quartz window pair. The substrate is irradiated with light; and the light measuring unit receives light emitted from the continuous lighting lamp and transmitted through the first quartz window and the second quartz window, and measures the intensity of the light, and the determination unit is based on the continuous lighting lamp point The intensity of the light received by the light measuring unit when lit determines whether the first quartz window and the second quartz window are contaminated.

The invention according to claim 4 is the heat treatment apparatus according to the invention according to claim 3, further comprising a light source monitoring unit that directly receives light emitted from the continuous lighting lamp and measures the intensity of the light.

The invention of claim 5 is the heat treatment device according to the invention of claim 3, wherein the determination unit determines the first quartz window and the first quartz window based on the spectral intensity of the visible light region of the light received by the light measurement unit. 2 Whether the quartz window is polluted.

The invention of claim 6 is the heat treatment device according to the invention of claim 1 or 2, characterized in that the quartz window includes: a first quartz window provided on one side of the chamber; and a second quartz window, It is disposed on the other side; the light source includes a flash lamp, which irradiates light to the substrate held by the holding portion via the first quartz window, and a continuous lighting lamp, which is held by the holding portion via the second quartz window pair. The substrate is irradiated with light; and the light measuring unit receives the light emitted from the flash lamp while passing through the first quartz window and reflected by the substrate while the substrate is held in the holding unit, and measures the intensity of the light, the determining unit The presence or absence of contamination of the first quartz window is determined based on the intensity of light received by the light measuring unit when the flash lamp is lit while the substrate is held in the holding portion.

The invention of claim 7 relates to a heat treatment method for heating a substrate by irradiating the substrate with light. The method is characterized in that it includes an irradiation step for irradiating a light source through a quartz window with a light source through the quartz window. The substrate held by the holding portion in the chamber is irradiated with light; a light intensity measurement step is performed by the light measurement portion to receive the light emitted from the light source and transmitted through the quartz window to measure the intensity of the light; and the determination step is based on the light The intensity of the light measured in the intensity measurement step determines whether or not the quartz window is contaminated.

The invention of claim 8 is a heat treatment method according to the invention of claim 7, characterized in that when the quartz window is not polluted, the light source is turned on, and the intensity of light received by the light measuring unit is used as a reference intensity, And in the determining step, it is determined whether the quartz window is polluted based on a comparison between the intensity of the light measured in the light intensity measuring step and the reference intensity.

In addition, the invention of claim 9 is the heat treatment method according to the invention of claim 7 or 8, characterized in that the quartz window includes: a first quartz window provided on one side of the chamber; and a second quartz window, It is disposed on the other side; the light source includes a flash lamp, which irradiates light to the substrate held by the holding portion via the first quartz window, and a continuous lighting lamp, which is held by the holding portion via the second quartz window pair. The substrate is irradiated with light; and in the light intensity measurement step, the light measurement unit receives light emitted from the continuous lighting lamp and transmitted through the first quartz window and the second quartz window, and measures the intensity of the light; In the determination step, it is determined whether or not the first quartz window and the second quartz window are contaminated based on the intensity of light measured in the light intensity measurement step.

The invention of claim 10 is a heat treatment method according to the invention of claim 9, further comprising a light source monitoring step. The light source monitoring step directly receives light emitted from the continuous lighting lamp and measures the intensity of the light. .

The invention according to claim 11 is the heat treatment method according to the invention according to claim 9, characterized in that in the determining step, the first quartz window is determined based on a spectral intensity of a visible light region of the light received by the light measuring unit. And whether the second quartz window is polluted.

In addition, the invention of claim 12 is the heat treatment method according to the invention of claim 7 or 8, characterized in that the quartz window includes: a first quartz window provided on one side of the chamber; and a second quartz window, It is disposed on the other side; the light source includes a flash lamp, which irradiates light to the substrate held by the holding portion via the first quartz window, and a continuous lighting lamp, which is held by the holding portion via the second quartz window pair. The substrate is irradiated with light; and in the light intensity measurement step, the light measurement unit receives light emitted from the flash lamp while passing through the first quartz window and reflected by the substrate while the substrate is held in the holding portion, and measures Intensity of the light; in the determination step, it is determined whether the first quartz window is polluted based on the intensity of the light measured in the light intensity measurement step.
[Effect of the invention]

According to the inventions of claims 1 to 6, the presence or absence of pollution of the quartz window is determined based on the intensity of light emitted from the light source and transmitted through the quartz window, so it is not necessary to confirm the pollution of the quartz window with the naked eye, and the quartz window can be confirmed immediately without stopping the device. Pollution.

In particular, the invention according to claim 4 further includes a light source monitoring unit that directly receives light emitted from the continuous lighting lamp and measures the intensity of the light, so that it can monitor the deterioration of the continuous lighting lamp over time.

In particular, according to the invention of claim 5, the presence or absence of contamination of the first quartz window and the second quartz window is determined based on the spectral intensity of the visible light region of the light received by the light measuring unit, so that it is possible to more accurately confirm that the first quartz window and the second quartz window are blocked. Light pollution.

According to the inventions of claims 7 to 12, the presence or absence of pollution of the quartz window is determined based on the intensity of light emitted from the light source and transmitted through the quartz window, so it is not necessary to confirm the pollution of the quartz window with the naked eye, and the quartz window can be confirmed immediately without stopping the device. Pollution.

In particular, according to the invention of claim 10, it further includes a light source monitoring step. The light source monitoring step directly receives light emitted from the continuous lighting lamp and measures the intensity of the light, so that the continuous lighting lamp can be monitored for deterioration over time.

In particular, according to the invention of claim 11, the presence or absence of pollution of the first quartz window and the second quartz window is determined based on the spectral intensity of the visible light region of the light received by the light measurement section, so that it can be more accurately confirmed that the first quartz window and the second quartz window are blocked. Light pollution.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
Fig. 1 is a longitudinal sectional view showing the structure of a heat treatment apparatus 1 according to the present invention. The heat treatment apparatus 1 of FIG. 1 is a flash lamp annealing apparatus that heats the semiconductor wafer W by flash-irradiating the semiconductor wafer W having a circular plate shape as a substrate. The size of the semiconductor wafer W to be processed is not particularly limited, and is, for example, 300 mm or 450 mm (in this embodiment, 300 mm). Moreover, in each of the drawings of FIG. 1 and the subsequent drawings, for ease of understanding, the size or number of each part is exaggerated or simplified as necessary.

The heat treatment apparatus 1 includes a chamber 6 that houses a semiconductor wafer W, a flash heating unit 5 including a plurality of flashes FL, and a halogen heating unit 4 including a plurality of halogen lamps HL. A flash heating section 5 is provided on the upper side of the chamber 6, and a halogen heating section 4 is provided on the lower side. The heat treatment apparatus 1 is provided inside the chamber 6 with a holding section 7 that holds the semiconductor wafer W in a horizontal posture, and a transfer mechanism 10 that transfers the semiconductor wafer W between the holding section 7 and the outside of the apparatus. Further, the heat treatment apparatus 1 includes a control unit 3 that controls the halogen heating unit 4, the flash heating unit 5, and various operating mechanisms provided in the chamber 6 to perform heat treatment of the semiconductor wafer W.

The chamber 6 is formed by attaching a chamber window made of quartz to the cylindrical chamber side portion 61. The chamber side portion 61 has a generally cylindrical shape with an upper and lower opening, and an upper chamber window (first quartz window) 63 is attached to the upper opening and is blocked. A lower chamber window (second quartz window) 64 is attached to the lower opening. And blocked. The chamber window 63 above the top wall constituting the chamber 6 is a disc-shaped member formed of quartz, and functions as a quartz window capable of transmitting the flash emitted from the flash heating section 5 to the chamber 6. The lower chamber window 64 constituting the bottom plate portion of the chamber 6 is also a disc-shaped member formed of quartz, and functions as a quartz window capable of transmitting light from the halogen heating unit 4 to the chamber 6. Hereinafter, when simply referred to as a quartz window, both the upper chamber window 63 and the lower chamber window 64 are included.

A reflection ring 68 is attached to the upper part of the inner wall surface of the chamber side portion 61, and a reflection ring 69 is attached to the lower portion. Both the reflection rings 68 and 69 are formed in a ring shape. The upper reflection ring 68 is fitted by being fitted from the upper side of the chamber side portion 61. On the other hand, the lower reflection ring 69 is fitted by being fitted from the lower side of the chamber side portion 61 and fixed with screws (not shown). That is, each of the reflection rings 68 and 69 is detachably attached to the chamber side portion 61. The inner space of the chamber 6, that is, the space surrounded by the upper chamber window 63, the lower chamber window 64, the chamber side 61, and the reflection rings 68, 69 is defined as the heat treatment space 65.

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

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

Further, a through-hole 61 a is formed in the cavity side portion 61. A radiation thermometer 20 is mounted on a portion of the outer wall surface of the chamber side portion 61 where a through hole 61 a is provided. The through-hole 61 a is a cylindrical hole for guiding infrared light emitted from the lower surface of the semiconductor wafer W held on the wafer holder 74 described below to the radiation thermometer 20. The through-hole 61a is provided obliquely to the horizontal direction so that the axis of the through-direction intersects with the main surface of the semiconductor wafer W held on the wafer holder 74. A transparent window 21 made of a barium fluoride material is attached to an end portion of the through hole 61 a that faces the heat treatment space 65 and transmits infrared light in a wavelength region that can be measured by the radiation thermometer 20.

A gas supply hole 81 is formed in the upper part of the inner wall of the chamber 6 to supply a processing gas to the heat treatment space 65. The gas supply hole 81 is formed on the upper side of the recessed portion 62 and may be provided on the reflection ring 68. The gas supply hole 81 is connected to the gas supply pipe 83 via a buffer space 82 formed inside the side wall of the chamber 6 in a circular shape. The gas supply pipe 83 is connected to a processing gas supply source 85. A valve 84 is inserted in the middle of the path of the gas supply pipe 83. When the valve 84 is opened, the processing gas is transferred from the processing gas supply source 85 to the buffer space 82. The processing gas flowing into the buffer space 82 flows into the buffer space 82 having a fluid resistance smaller than that of the gas supply hole 81 and is supplied from the gas supply hole 81 into the heat treatment space 65. As the processing gas, for example, an inert gas such as nitrogen (N ₂ ), a reactive gas such as hydrogen (H ₂ ), ammonia (NH ₃ ), or a mixed gas obtained by mixing these (in this embodiment, For nitrogen).

On the other hand, a gas exhaust hole 86 is formed in the lower portion of the inner wall of the chamber 6 to exhaust the gas in the heat treatment space 65. The gas exhaust hole 86 is formed at a position lower than the recessed portion 62, and may be provided at the reflection ring 69. The gas exhaust hole 86 is connected to the gas exhaust pipe 88 via a buffer space 87 formed inside the side wall of the chamber 6 in a circular shape. The gas exhaust pipe 88 is connected to the 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 discharged from the gas discharge hole 86 to the gas discharge pipe 88 through the buffer space 87. Further, the gas supply holes 81 and the gas discharge holes 86 may be provided in the circumferential direction of the chamber 6 or may have a slit shape. In addition, the processing gas supply source 85 and the exhaust portion 190 may be a mechanism provided in the heat treatment device 1, or may be auxiliary equipment of a factory in which the heat treatment device 1 is installed.

A gas exhaust pipe 191 is also connected to the front end of the transport opening 66 to exhaust the gas in the heat treatment space 65. The gas exhaust pipe 191 is connected to the exhaust unit 190 via a valve 192. When the valve 192 is opened, the gas in the chamber 6 is discharged through the transfer opening 66.

FIG. 2 is a perspective view showing the overall appearance of the holding portion 7. The holding portion 7 includes a base ring 71, a connecting portion 72, and a pedestal 74. The abutment ring 71, the connection portion 72, and the crystal base 74 are all formed of quartz. That is, the entire holding portion 7 is formed of quartz.

The abutment ring 71 is an arc-shaped quartz member formed by missing a part of the ring shape. This missing portion is provided to prevent interference between the transfer arm 11 and the abutment ring 71 of the transfer mechanism 10 described below. The abutment ring 71 is placed on the bottom surface of the recessed portion 62 and is thereby supported on the wall surface of the cavity 6 (see FIG. 1). On the upper surface of the abutment ring 71, a plurality of connecting portions 72 (four in the present embodiment) are erected along the circumferential direction of the annular shape. The connecting portion 72 is also a quartz member, and is fixed to the abutment ring 71 by welding.

The base 74 is supported by the four connecting portions 72 provided on the abutment ring 71. FIG. 3 is a top view of the crystal base 74. FIG. 4 is a sectional view of the crystal base 74. The wafer holder 74 includes a holding plate 75, a guide ring 76, and a plurality of substrate support pins 77. The holding plate 75 is a substantially circular flat plate-shaped member formed of quartz. The diameter of the holding plate 75 is larger than the diameter of the semiconductor wafer W. That is, the holding plate 75 has a larger planar size than the semiconductor wafer W.

A guide ring 76 is provided on a peripheral edge portion of the upper surface of the holding plate 75. The guide ring 76 is a ring-shaped member having an inner diameter larger than the diameter of the semiconductor wafer W. For example, the diameter of the semiconductor wafer W is In the case of 300 mm, the inner diameter of the guide ring 76 is 320 mm. The inner periphery of the guide ring 76 is formed as an inclined surface that expands upward from the holding plate 75. The guide ring 76 is formed of the same quartz as the holding plate 75. The guide ring 76 may be welded to the upper surface of the holding plate 75, or may be fixed to the holding plate 75 by a pin or the like obtained by a separate processing. Alternatively, the holding plate 75 and the guide ring 76 may be processed as a single member.

A region on the upper surface of the holding plate 75 that is more inward than the guide ring 76 is a planar holding surface 75 a that holds the semiconductor wafer W. A plurality of substrate support pins 77 are erected on the holding surface 75 a of the holding plate 75. In this embodiment, a total of 12 substrate support pins 77 are erected on a circumference that is concentric with the outer circumference (inner circumference of the guide ring 76) along the holding surface 75a. The diameter of the circle provided with the 12 substrate support pins 77 (the distance between the opposing substrate support pins 77) is smaller than the diameter of the semiconductor wafer W. If the diameter of the semiconductor wafer W is 300 mm, the diameter of the circle is 270 mm ～ 280 mm (in this embodiment, 270 mm). Each substrate support pin 77 is formed of quartz. The plurality of substrate support pins 77 may be provided on the upper surface of the holding plate 75 by welding, or may be integrally processed with the holding plate 75.

Returning to FIG. 2, the four connecting portions 72 erected on the abutment ring 71 and the peripheral edge portions of the holding plate 75 of the crystal base 74 are fixed by welding. That is, the base 74 and the abutment ring 71 are fixedly connected by the connecting portion 72. The abutment ring 71 of the holding portion 7 is supported on the wall surface of the chamber 6 so that the holding portion 7 is mounted on the chamber 6. In a state where the holding portion 7 is attached to the chamber 6, the holding plate 75 of the pedestal 74 is in a horizontal posture (a posture in which the normal line matches the vertical direction). That is, the holding surface 75a of the holding plate 75 becomes a horizontal plane.

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

The semiconductor wafer W is supported by a plurality of substrate support pins 77 at a predetermined interval from the holding surface 75 a of the holding plate 75. The thickness of the guide ring 76 is larger than the height of the substrate support pin 77. Therefore, the horizontal positional deviation of the semiconductor wafer W supported by the plurality of substrate support pins 77 is prevented by the guide ring 76.

As shown in FIGS. 2 and 3, the holding plate 75 of the pedestal 74 penetrates up and down to form an opening 78. The opening portion 78 is provided so that the radiation thermometer 20 receives radiation light (infrared light) emitted from the lower surface of the semiconductor wafer W. That is, the radiation thermometer 20 receives light radiated from the lower surface of the semiconductor wafer W through the opening portion 78 and the transparent window 21 mounted in the through hole 61 a of the chamber side portion 61, and measures the temperature of the semiconductor wafer W. Further, four holding holes 79 are formed in the holding plate 75 of the wafer holder 74 so as to pass through the jacking pins 12 of the transfer mechanism 10 described below to pass the semiconductor wafer W therethrough.

FIG. 5 is a plan view of the transfer mechanism 10. FIG. 6 is a side view of the transfer mechanism 10. The transfer mechanism 10 includes two transfer arms 11. The transfer arm 11 is formed in an arc shape along a generally annular concave portion 62. Two lifting pins 12 are erected on each transfer arm 11. The transfer arm 11 and the jacking pin 12 are formed 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 the transfer operation position (the solid line position in FIG. 5) and the retreat position (the two-point chain line position in FIG. 5) with respect to the holding portion 7. The operating position is a position where the semiconductor wafer W is transferred, and the retreat position is a position that does not overlap the semiconductor wafer W held in the holding portion 7 in a plan view. As the horizontal movement mechanism 13, each transfer arm 11 can be rotated by an individual motor, or a pair of transfer arms 11 can be rotated by a motor using a link mechanism.

In addition, the pair of transfer arms 11 are moved up and down together with the horizontal moving mechanism 13 by the lifting mechanism 14. When the lifting mechanism 14 raises the pair of transfer arms 11 at the transfer operation position, a total of four jacking pins 12 pass through the through holes 79 (see FIGS. 2 and 3) provided in the crystal base 74 to jack up the pins 12. The upper end protrudes from the upper surface of the crystal base 74. On the other hand, the lifting mechanism 14 lowers the pair of transfer arms 11 at the transfer operation position, and pulls out the jacking pin 12 from the through hole 79. If the horizontal movement mechanism 13 causes the pair of transfer arms 11 to be opened, When the mode is moved, each transfer arm 11 moves to the retreat position. The retreat position of the pair of transfer arms 11 is located directly above the abutment ring 71 of the holding portion 7. Since the abutment ring 71 is placed on the bottom surface of the recessed portion 62, the retreat position of the transfer arm 11 is located inside the recessed portion 62. Furthermore, an exhaust mechanism (not shown) is also provided near the portion where the drive unit (horizontal movement mechanism 13 and lifting mechanism 14) of the transfer mechanism 10 is provided, and is configured to surround the drive unit of the transfer mechanism 10. The ambient gas is discharged to the outside of the chamber 6.

Returning to FIG. 1, the flash heating portion 5 provided above the chamber 6 is located inside the housing 51 and includes a light source including a plurality of (in this embodiment, 30) hernia flashes FL, and covers the light The reflector 52 is provided above the light source. A light emitting window 53 is attached to the bottom of the casing 51 of the flash heating unit 5. The light emission window 53 constituting the bottom plate portion of the flash heating portion 5 is a plate-shaped quartz window formed of quartz. By providing the flash heating portion 5 above the chamber 6, the light emission window 53 faces the upper chamber window 63. The flash FL irradiates the semiconductor wafer W held by the holding portion 7 with a flash from above the chamber 6 through a light emission window 53 and an upper chamber window 63.

Each of the plurality of flashes FL is a rod-shaped lamp having a long cylindrical shape, and is flat in such a manner that the major surfaces of the semiconductor wafers W held in the holding portion 7 (that is, in the horizontal direction) are parallel to each other along their respective length directions.状 Arranged. Therefore, the plane formed by the arrangement of the flashes FL is also a horizontal plane. The area for arranging the plurality of flashes FL is larger than the planar size of the semiconductor wafer W.

The hernia flash FL includes a cylindrical glass tube (discharge tube) with a hernia sealed inside, and an anode and a cathode connected to a capacitor are disposed at both ends; and a trigger electrode attached to the outer periphery of the glass tube Surface. Hernias are electrical insulators, so no electrical current will flow through the glass tube under normal conditions, even if a charge is stored in the capacitor. However, when a high voltage is applied to the trigger electrode and the insulation is destroyed, the electricity stored in the capacitor will flow into the glass tube instantly, and the light will be emitted by the excitation of hernia atoms or molecules. In this type of hernia flash FL, the electrostatic energy stored in the capacitor in advance is converted into extremely short light pulses of 0.1 milliseconds to 100 milliseconds. Therefore, compared with a continuously illuminated light source such as a halogen lamp HL, it can illuminate extremely strong light Characteristics. In other words, the flash FL is a pulse light emitting lamp that emits light instantaneously within a very short time of less than 1 second. In addition, the lighting time of the flash FL can be adjusted by the coil constant of a lamp power supply for supplying power to the flash FL.

The reflector 52 is provided above the plurality of flashes FL so as to cover the entirety of the plurality of flashes FL. The basic function of the reflector 52 is to reflect the flashes emitted from the plurality of flashes FL to the side of the heat treatment space 65. The reflector 52 is formed of an aluminum alloy plate, and the front surface (the side facing the flash FL) is roughened by sandblasting.

A plurality of (in this embodiment, 40) halogen lamps HL are built in the halogen heating section 4 provided below the chamber 6 inside the housing 41. The halogen heating portion 4 heats the semiconductor wafer W held by the semiconductor wafer W held by the holding portion 7 by light irradiation of a plurality of halogen lamps HL from below the chamber 6 through the lower chamber window 64.

FIG. 7 is a plan view showing the arrangement of a plurality of halogen lamps HL. The 40 halogen lamps HL are arranged in two sections. Twenty halogen lamps HL are arranged in the upper section closer to the holding section 7, and 20 halogen lamps HL are also arranged in the lower section closer to the holding section 7 in the lower section. Each halogen lamp HL is a rod-shaped lamp having a long cylindrical shape. In the upper stage and the lower stage, the 20 halogen lamps HL are arranged in such a manner that their lengthwise directions are parallel to each other along the main surface of the semiconductor wafer W held in the holding portion 7 (that is, in the horizontal direction). Accordingly, in the upper and lower stages, the planes formed by the arrangement of the halogen lamps HL are horizontal planes.

As shown in FIG. 7, the arrangement density of the halogen lamp HL in the upper and lower sections is higher than that in the area facing the central portion of the semiconductor wafer W held in the holding portion 7 and the area facing the peripheral portion. . In other words, the arrangement pitch of the halogen lamp HL in the peripheral portion is shorter than that in the central portion of the lamp arrangement. Therefore, it is possible to irradiate a larger amount of light to the peripheral portion of the semiconductor wafer W, which is liable to drop in temperature when heated by light irradiation from the halogen heating portion 4.

In addition, a lamp group composed of the upper-stage halogen lamp HL and a lamp group composed of the lower-stage halogen lamp HL are arranged in a grid-like arrangement. That is, a total of 40 halogen lamps HL are arranged such that the length direction of the 20 halogen lamps HL arranged in the upper stage and the length direction of the 20 halogen lamps HL arranged in the lower stage are orthogonal to each other.

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

In the case 41 of the halogen heating unit 4, a reflector 43 is also provided below the two-stage halogen lamp HL (FIG. 1). The reflector 43 reflects light emitted from the plurality of halogen lamps HL toward the side of the heat treatment space 65.

Returning to FIG. 1, a spectrophotometer 91 is provided between the flash heating section 5 and the chamber window 63 on the upper side of the chamber 6. The spectrophotometer 91 is a device for measuring the intensity of each wavelength of the spectrum of the received light. The spectrophotometer 91 can measure the intensity (spectral intensity) of each wavelength in at least the visible light region (wavelength range of about 380 nm to about 810 nm). The spectrophotometer 91 measures the spectral intensity of light transmitted from the heat treatment space 65 in the chamber 6 through the upper chamber window 63.

On the other hand, a spectrophotometer 92 is provided near the halogen heating section 4. The spectrophotometer 92 is the same as the spectrophotometer 91 described above, and can measure the spectral intensity in at least the visible light region. The spectrophotometer 92 directly receives light emitted from the halogen lamp HL of the halogen heating section 4 and measures the spectral intensity of the light.

The control unit 3 controls the above-mentioned various operating mechanisms provided in the heat treatment apparatus 1. The hardware configuration of the control unit 3 is the same as that of a general computer. That is, the control unit 3 is provided with a CPU (Central Processing Unit) which is a circuit for performing various arithmetic processing and a ROM (Read Only Memory) which is a read-only memory for storing a basic program ; RAM (Random Access Memory), which is a free read-write memory that stores various information; and magnetic disks, which are software or data for memory control. The CPU in the control unit 3 executes a specific processing program, and the processing in the heat treatment device 1 is performed. The control unit 3 is provided with a determination unit 31 (FIG. 8). The determination unit 31 is a function processing unit that is realized by the CPU of the control unit 3 executing a specific processing program. The processing content of the determination unit 31 will be described later.

In addition to the above configuration, the heat treatment device 1 also has various cooling structures to prevent the thermal energy generated from the halogen lamp HL and the flash lamp FL during the heat treatment of the semiconductor wafer W from causing the halogen heating section 4, the flash heating section 5, and the chamber 6 to The temperature has risen excessively. For example, a water cooling pipe (not shown) is provided on the wall of the chamber 6. In addition, the halogen heating section 4 and the flash heating section 5 are formed in an air-cooled structure that generates airflow inside and exhausts heat. In addition, air is also supplied between the upper chamber window 63 and the light emission window 53 to cool the flash heating section 5 and the upper chamber window 63.

Next, a processing operation in the heat treatment apparatus 1 will be described. First, a typical heat treatment step performed on the semiconductor wafer W to be processed will be described. Here, the semiconductor wafer W to be processed is a semiconductor substrate to which impurities (ions) are added by an ion implantation method. The activation of the impurities is performed by a flash irradiation heat treatment (annealing) performed by the heat treatment device 1. The processing steps of the semiconductor wafer W described below are performed by the control unit 3 controlling each operation mechanism of the heat treatment apparatus 1.

First, the valve 84 for supplying air is opened, and the valves 89 and 192 for exhausting are opened to start supplying and exhausting air into the chamber 6. After the valve 84 is opened, nitrogen is supplied from the gas supply hole 81 to the heat treatment space 65. When the valve 89 is opened, the gas in the chamber 6 is discharged from the gas discharge hole 86. Thereby, the nitrogen gas supplied from the upper part of the heat treatment space 65 in the chamber 6 flows downward, and is discharged from the lower part of the heat treatment space 65.

Furthermore, by opening the valve 192, the gas in the chamber 6 is also discharged from the transfer opening 66. Furthermore, with an exhaust mechanism (not shown), ambient gas around the drive section of the transfer mechanism 10 is also exhausted. When the semiconductor wafer W is subjected to heat treatment in the heat treatment apparatus 1, nitrogen gas is continuously supplied to the heat treatment space 65, and the supply amount thereof is appropriately changed according to the processing steps.

Then, the gate valve 185 is opened to open the transfer opening 66, and a semiconductor robot W as a processing target is transferred into the heat treatment space 65 in the chamber 6 by the transfer robot outside the apparatus through the transfer opening 66. At this time, there is a concern that the ambient gas may be drawn into the outside of the device as the semiconductor wafer W is carried in. However, since nitrogen is continuously supplied in the chamber 6, the nitrogen may flow out from the conveyance opening 66, so that such an external air can be taken out. The involvement of ambient gas is controlled to a minimum.

The semiconductor wafer W carried in by the transfer robot enters and exits to a position directly above the holding portion 7 and stops there. Then, one of the transfer mechanism 10 pair of the transfer arm 11 moves horizontally from the retreat position to the transfer operation position and rises, whereby the jacking pin 12 protrudes from the upper surface of the holding plate 75 of the crystal base 74 through the through hole 79 and receives it Semiconductor wafer W. At this time, the jacking pin 12 rises higher than the upper end of the substrate support pin 77.

After the semiconductor wafer W is placed on the jack pin 12, the transfer robot is withdrawn from the heat treatment space 65, and the transfer opening 66 is closed by the gate valve 185. Then, the pair of transfer arms 11 is lowered, whereby the semiconductor wafer W is transferred from the transfer mechanism 10 to the wafer holder 74 of the holding portion 7 and is held from below in a horizontal posture. The semiconductor wafer W is supported by a plurality of substrate support pins 77 erected on the holding plate 75 and held on the wafer holder 74. In addition, the semiconductor wafer W is held on the holding portion 7 with a front surface on which a pattern is formed and impurities are implanted. A specific gap is formed between the back surface (the main surface opposite to the front surface) of the semiconductor wafer W supported by the plurality of substrate support pins 77 and the holding surface 75 a of the holding plate 75. One of the pair of transfer arms 11 lowered to the bottom of the pedestal 74 is retracted by the horizontal moving mechanism 13 to the retracted position, that is, the inside of the recess 62.

After the semiconductor wafer W is held in a horizontal posture from below by the crystal holder 74 of the holding section 7 formed of quartz, the 40 halogen lamps HL of the halogen heating section 4 are turned on together, and pre-heating (assisted heating) is started. The halogen light emitted from the halogen lamp HL is irradiated to the lower surface of the semiconductor wafer W through the lower chamber window 64 and the crystal base 74 formed of quartz. When the light from the halogen lamp HL is irradiated, the semiconductor wafer W is preheated, and the temperature rises. Furthermore, since the transfer arm 11 of the transfer mechanism 10 has been retracted to the inside of the recessed portion 62, it does not prevent the halogen lamp HL from heating.

When preheating by the halogen lamp HL, the temperature of the semiconductor wafer W is measured by the radiation thermometer 20. That is, the infrared light radiated from the lower surface of the semiconductor wafer W held by the pedestal 74 through the opening 78 passes through the transparent window 21 and is received by the radiation thermometer 20 to measure the temperature of the wafer during the temperature increase. The measured temperature of the semiconductor wafer W is transmitted to the control section 3. The control unit 3 controls the output of the halogen lamp HL while monitoring whether or not the temperature of the semiconductor wafer W heated by the light from the halogen lamp HL reaches a specific pre-heating temperature T1. That is, the control unit 3 feedback-controls the output of the halogen lamp HL based on the measurement value measured by the radiation thermometer 20 so that the temperature of the semiconductor wafer W becomes the pre-heating temperature T1. The pre-heating temperature T1 is about 200 ° C. to 800 ° C., preferably about 350 ° C. to 600 ° C. (in this embodiment, 600 ° C.), without the possibility that impurities added to the semiconductor wafer W diffuse through heat.

When the temperature of the semiconductor wafer W reaches the pre-heating temperature T1, the control unit 3 temporarily maintains the semiconductor wafer W to the pre-heating temperature T1. Specifically, at a time point when the temperature of the semiconductor wafer W measured by the radiation thermometer 20 reaches the preheating temperature T1, the control unit 3 adjusts the output of the halogen lamp HL to maintain the temperature of the semiconductor wafer W approximately as the preheating. Temperature T1.

At a point in time after the temperature of the semiconductor wafer W reaches the pre-heating temperature T1 and a specific time has passed, the flash FL of the flash heating section 5 flash-irradiates the front surface of the semiconductor wafer W held on the wafer holder 74. At this time, a part of the flash light emitted from the flash FL is directly directed into the chamber 6, and the other parts are first reflected by the reflector 52, and then directed into the chamber 6, and the semiconductor wafer W is irradiated by the flashes. Flash heating.

The flash heating is performed by flash light irradiation from the flash FL, so the front surface temperature of the semiconductor wafer W can be raised in a short time. That is, the flash light irradiated from the flash FL is a strong flash that is converted from electrostatic energy stored in a capacitor in advance into an extremely short light pulse and the irradiation time is extremely short to about 0.1 milliseconds to 100 milliseconds. In addition, the front temperature of the semiconductor wafer W heated by the flash is instantaneously increased to a processing temperature T2 of 1000 ° C. or higher by the flash irradiation from the flash FL. After the impurities injected into the semiconductor wafer W are activated, the front temperature drops rapidly. In this way, in the heat treatment apparatus 1, the front surface temperature of the semiconductor wafer W can be raised and lowered in a very short time, so that the impurities injected into the semiconductor wafer W can be suppressed from being diffused by heat and the impurities can be activated. Furthermore, the time required for the activation of impurities is extremely short compared to the time required for thermal diffusion, so activation can be completed within a short time of about 0.1 milliseconds to 100 milliseconds before diffusion has occurred.

After the flash heating process is completed and a specific time has elapsed, the halogen lamp HL is turned off. Thereby, the semiconductor wafer W is rapidly cooled from the pre-heating temperature T1. The temperature of the semiconductor wafer W during the temperature reduction is measured by the radiation thermometer 20, and the measurement result is transmitted to the control unit 3. The control unit 3 monitors whether the temperature of the semiconductor wafer W has dropped to a specific temperature based on the measurement result of the radiation thermometer 20. Then, after the temperature of the semiconductor wafer W is lowered below a certain temperature, one of the transfer arms 10 moves the transfer arm 11 horizontally from the retreat position to the transfer operation position and rises, thereby jacking the pin 12 from the wafer holder 74. The upper surface protrudes, and the heat-treated semiconductor wafer W is received from the wafer base 74. Then, the transfer opening 66 closed by the gate valve 185 is opened, and the semiconductor wafer W placed on the jack pin 12 is removed by a transfer robot outside the device, and the semiconductor wafer W in the heat treatment apparatus 1 is heated up to this point. Processing is complete.

In the heat treatment apparatus 1, various types of films are often formed on the semiconductor wafer W to be processed. If the semiconductor wafer W formed with the film is pre-heated and flash-heated in the chamber 6, a part of the film will be scattered in the heat treatment space 65 by melting or burning, and will be attached to the upper chamber window 63 and the lower side Chamber window 64. As such, the upper chamber window 63 and the lower chamber window 64 are contaminated. If the upper chamber window 63 is contaminated, the transmittance of the upper chamber window 63 decreases, and the intensity of the flash light radiated from the flash FL to the semiconductor wafer W decreases. When the lower chamber window 64 is contaminated, the transmittance of the lower chamber window 64 decreases, and the intensity of light radiated from the halogen lamp HL to the semiconductor wafer W decreases.

Therefore, in this embodiment, the contamination status of the upper chamber window 63 and the lower chamber window 64 is confirmed as follows. The timing of the contamination confirmation described below is appropriately set, for example, it can be performed during the idle time of the processing of the semiconductor wafer W, it can also be performed during the idle time of different batch processes, or it can be performed periodically once a day.

Fig. 8 is a diagram schematically showing the pollution confirmation of the quartz window in the first embodiment. First, when the semiconductor wafer W does not exist in the chamber 6, the halogen lamp HL is turned on at a predetermined lamp power. The light emitted from the halogen lamp HL is sequentially transmitted through the quartz lower chamber window 64 and the upper chamber window 63 to the upper side of the chamber 6. Then, a part of the light transmitted through the upper chamber window 63 is received by the spectrophotometer 91 to measure the spectral intensity of the light. The spectral intensity of the transmitted light measured by the spectrophotometer 91 is transmitted to the control section 3.

When the lower chamber window 64 and the upper chamber window 63 are not polluted, the halogen lamp HL lights up and the spectral intensity of the light received by the spectrophotometer 91 is stored in advance as a reference intensity in the memory section of the control section 3 (for example, magnetic dish). Such a measurement of the reference strength is preferably performed immediately after the lower chamber window 64 and the upper chamber window 63 are cleaned, for example, during maintenance of the heat treatment apparatus 1. After cleaning the lower chamber window 64 and the upper chamber window 63 to remove the pollution, the halogen lamp HL immediately lights up, and the light emitted from the halogen lamp HL and transmitted through the lower chamber window 64 and the upper chamber window 63 is spectrophotometric. The meter 91 receives and measures the spectral intensity of the light. Then, the obtained spectral intensity is stored as a reference intensity in the memory section of the control section 3.

The determination unit 31 of the control unit 3 determines whether the lower chamber window 64 and the upper chamber window 63 are contaminated by comparing the spectral intensity of the transmitted light measured with the spectrophotometer 91 with the reference intensity. FIG. 9 is a diagram showing an example of the spectral intensity of transmitted light measured by the spectrophotometer 91. In FIG. 9, those indicated by dashed lines are used as reference intensities, and those indicated by single-dot chain lines are used as the spectral intensity of the transmitted light measured by the spectrophotometer 91 when the pollution is confirmed. If the lower chamber window 64 and the upper chamber window 63 are contaminated, the transmittance of the lower chamber window 64 and the upper chamber window 63 decreases. Therefore, the spectral intensity of the transmitted light measured by the spectrophotometer 91 is It is lower than the reference intensity according to the degree of pollution.

The determination unit 31 determines, for example, that the lower chamber window 64 and / or the ratio of the average value of the measured spectral intensity in the visible light region to the average value of the reference intensity in the visible light region is below a specific threshold. The upper chamber window 63 is contaminated. When it is determined by the determination unit 31 that the lower chamber window 64 and / or the upper chamber window 63 are contaminated, for example, a message indicating that maintenance is required is sent to a display unit such as a touch panel of the control unit 3. When such a message is transmitted, it is preferable to quickly perform maintenance of the heat treatment device 1 and clean the lower chamber window 64 and the upper chamber window 63.

On the other hand, when the ratio of the average value of the measured spectral intensity in the visible light region to the average value of the reference intensity in the visible light region is larger than a specific threshold, the determination unit 31 determines that the lower chamber window 64 and The upper chamber window 63 is not contaminated (more strictly, it is determined that it is not contaminated to the extent that it hinders processing). When it is determined by the determination unit 31 that the lower chamber window 64 and the upper chamber window 63 are not contaminated, the semiconductor wafer W continues to be processed normally.

In the first embodiment, for example, during the idle time of the semiconductor wafer W, the halogen lamp HL is turned on, and the lower chamber window 64 and the upper chamber window are determined based on the intensity of the transmitted light received by the spectrophotometer 91. 63 Whether there is pollution. Therefore, the contamination of the lower chamber window 64 and the upper chamber window 63 can be confirmed immediately without stopping the heat treatment apparatus 1.

In addition, the above technology is based on the premise that the reference intensity is always fixed when the quartz window is not contaminated, but actually the reference intensity itself changes due to the deterioration of the halogen lamp HL over time. That is, due to the deterioration of the halogen lamp HL with time, the intensity of the emitted light will decrease, and as a result, the intensity of the transmitted light received by the spectrophotometer 91 will also decrease. If so, there is a possibility that although the quartz window is not contaminated, the determination unit 31 incorrectly determines that it is contaminated.

Therefore, in the first embodiment, the spectrophotometer 92 directly receives the light emitted from the halogen lamp HL, measures the spectral intensity of the light, and monitors the deterioration of the halogen lamp HL over time. In FIG. 9, a solid line indicates the spectral intensity of the direct light from the halogen lamp HL measured by the spectrophotometer 92. The light received by the spectrophotometer 92 is not light transmitted through a quartz window, but is light directly radiated from the halogen lamp HL. Therefore, the intensity of the light measured by the spectrophotometer 92 is completely unaffected by the pollution of the quartz window. The reference intensity is then calibrated based on the intensity measured by the spectrophotometer 92. Specifically, for example, when the reference intensity is obtained and compared, when the intensity of the halogen light measured by the spectrophotometer 92 is reduced by 20%, the correction is performed so that the reference intensity is also reduced by 20%. Thereby, it becomes a reference intensity reflecting the aging deterioration of the halogen lamp HL, and the influence of the aging deterioration can be excluded, and contamination of the lower chamber window 64 and the upper chamber window 63 can be accurately confirmed.

<Second Embodiment>
Next, a second embodiment of the present invention will be described. The structure of the heat treatment apparatus 1 of the second embodiment is completely the same as that of the first embodiment. The processing steps of the semiconductor wafer W in the heat treatment apparatus 1 of the second embodiment are also substantially the same as those of the first embodiment. The second embodiment differs from the first embodiment in a method for confirming the contamination of a quartz window.

Fig. 10 is a diagram schematically showing the contamination confirmation of the quartz window in the second embodiment. In the second embodiment, the contamination of the quartz window is performed while the semiconductor wafer W in the chamber 6 is held by the holding portion 7. As the semiconductor wafer W to be used at this time, a wafer (for example, a bare wafer) in which a patterned surface or a film-formed front surface has a substantially mirror surface is preferred. In a state where the semiconductor wafer W is held in the holding portion 7 in the chamber 6, the flash FL emits light. The light emitted from the flash FL passes through the upper chamber window 63 of the quartz, and then is reflected by the front surface of the semiconductor wafer W, passes through the upper chamber window 63 again, and is emitted to the upper side of the chamber 6. Then, a part of the light transmitted through the upper chamber window 63 is received by the spectrophotometer 91 to measure the spectral intensity of the light. The spectral intensity of the transmitted light measured by the spectrophotometer 91 is transmitted to the control section 3. Thereafter, as in the first embodiment, the determination unit 31 of the control unit 3 determines whether or not the upper chamber window 63 is contaminated by comparing the spectral intensity of the transmitted light measured with the spectrophotometer 91 with the reference intensity.

In the first embodiment, contamination of both the lower chamber window 64 and the upper chamber window 63 was confirmed. In contrast, in the second embodiment, only the contamination of the upper chamber window 63 was confirmed. In the heat treatment apparatus 1, for the following reasons, it is more technically significant to confirm the presence or absence of pollution of the upper chamber window 63 than the lower chamber window 64. When the lower chamber window 64 is contaminated, the transmittance of the lower chamber window 64 decreases, and the intensity of light radiated from the halogen lamp HL to the semiconductor wafer W decreases. However, when the semiconductor wafer W is preheated by the halogen lamp HL, as described above, 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. Therefore, even if the lower chamber window 64 is contaminated somewhat, the output of the halogen lamp HL is increased by the control unit 3, and the semiconductor wafer W can be heated to a specific pre-heating temperature T1. On the other hand, it is difficult to feedback-control the irradiation of the flash FL with a very short light-emission time. Therefore, if the upper chamber window 63 is contaminated, the illumination of the front side of the semiconductor wafer W and the temperature reached on the front side during flash irradiation will be The larger impact is even directly related to the difference in component performance. Therefore, the technical significance of confirming the presence or absence of pollution in the upper chamber window 63 is greater.

In the second embodiment, the spectrophotometer 91 receives light transmitted through only the upper chamber window 63 and measures its intensity. That is, the spectral intensity of the transmitted light measured by the spectrophotometer 91 is completely unaffected by the contamination of the lower chamber window 64. Therefore, in the second embodiment, it is possible to accurately confirm the contamination of the upper chamber window 63 separately from the lower chamber window 64.

＜ Modifications ＞
As mentioned above, although embodiment of this invention was described, this invention can be changed variously in addition to the said content in the range which does not deviate from the meaning. For example, in the above embodiment, the spectral intensity of light is measured by the spectrophotometers 91 and 92, but it is not limited to this, and only the intensity of light may be measured. Of course, the spectroscopic distribution of the flash emitted from the flash FL is strong in the visible light region. If the presence or absence of pollution of the quartz window is determined based on the spectral intensity in the visible light region as in the above embodiment, the pollution that would hinder the flash can be confirmed more accurately.

Moreover, in the first embodiment, the comparison between the reference intensity and the measured spectral intensity is performed based on the average value of the spectral intensity, but it is not limited to this. For example, the peak value or the integrated value of the spectral intensity may be used for comparison. Comparison of the reference intensity with the measured spectral intensity.

In the first embodiment, the spectrophotometer 92 that directly receives light emitted from the halogen lamp HL is not an essential element. As long as at least a spectrophotometer 91 for measuring the spectral intensity of transmitted light is provided, contamination of the quartz window can be confirmed. Of course, the spectrophotometer 92 provided to monitor the deterioration of the halogen lamp HL can more accurately confirm the pollution of the quartz window.

In the second embodiment, a dedicated light source for measurement may be provided on the upper side of the holding portion 7 in the chamber 6 instead of the flash FL. In a state where the semiconductor wafer W in the chamber 6 is held by the holding portion 7, the light source for measurement is turned on, and the spectrophotometer 91 receives light transmitted through the upper chamber window 63. In this way, as in the second embodiment, the spectrophotometer 91 receives light transmitted through only the upper chamber window 63 and measures its intensity, so that it can be separated from the lower chamber window 64 to accurately confirm the upper chamber window 63 Pollution.

When the determination unit 31 determines that at least the upper chamber window 63 is contaminated, the intensity of the flash light radiated from the flash FL can also be increased. Specifically, the voltage stored in the capacitor that supplies power to the flash FL is increased by the control of the control unit 3. More preferably, a table related to the ratio of the measured spectral intensity to the reference intensity and the voltage stored in the capacitor is stored in the memory section of the control unit 3, and the voltage stored in the capacitor is set based on the related table. If this is the case, even if the transmittance of the upper chamber window 63 decreases due to contamination, the intensity of the flash light is increased and this decline is offset. Therefore, the illuminance of the flash light shining on the front side of the semiconductor wafer W can be maintained constant .

In the above-mentioned embodiment, the flash heating unit 5 includes 30 flashes FL, but the number of flashes FL may not be limited to this. In addition, the flash FL is not limited to a hernia flash, but may also be a gas flash. The number of halogen lamps HL included in the halogen heating unit 4 is not limited to 40, and may be any number.

In the above embodiment, the filament-type halogen lamp HL is used as a continuous lighting lamp that continuously emits light for more than one second to pre-heat the semiconductor wafer W. However, it is not limited to this, and a discharge-type arc may also be used. A lamp (for example, a hernia arc lamp) is pre-heated instead of the halogen lamp HL as a continuous lighting lamp. In this case, the arc lamp is turned on to determine whether or not the quartz window is polluted.

The substrate to be processed by the heat treatment device 1 is not limited to a semiconductor wafer, and may be a glass substrate for a flat panel display such as a liquid crystal display device or a substrate for a solar cell. In addition, the heat treatment performed by the heat treatment device 1 can also be applied to heat treatment of a high dielectric constant gate insulating film (High-k film), joining of metal to silicon, or crystallization of polycrystalline silicon.

1‧‧‧ heat treatment equipment

3‧‧‧Control Department

4‧‧‧ Halogen heating section

5‧‧‧Flash heating section

6‧‧‧ chamber

7‧‧‧ holding department

10‧‧‧ Transfer Agency

11‧‧‧ transfer arm

12‧‧‧ jacking pin

13‧‧‧horizontal movement mechanism

14‧‧‧Lifting mechanism

20‧‧‧ radiation thermometer

21‧‧‧Transparent window

31‧‧‧Judgment Division

41‧‧‧shell

43‧‧‧ reflector

51‧‧‧shell

52‧‧‧ reflector

53‧‧‧light emission window

61‧‧‧ side of chamber

61a‧‧‧through hole

62‧‧‧ Recess

63‧‧‧ Upper side chamber window

64‧‧‧ lower side chamber window

65‧‧‧Heat treatment space

66‧‧‧Transport opening

68‧‧‧Reflective ring

69‧‧‧Reflective ring

71‧‧‧ abutment ring

72‧‧‧ Connection Department

74‧‧‧ crystal seat

75‧‧‧ holding plate

75a‧‧‧ holding surface

76‧‧‧Guide ring

77‧‧‧ substrate support pin

78‧‧‧ opening

79‧‧‧through hole

81‧‧‧Gas supply hole

82‧‧‧ buffer space

83‧‧‧Gas supply pipe

84‧‧‧ Valve

85‧‧‧Processing gas supply source

86‧‧‧Gas exhaust hole

87‧‧‧ buffer space

88‧‧‧Gas exhaust pipe

89‧‧‧ Valve

91‧‧‧ Spectrophotometer

92‧‧‧ Spectrophotometer

185‧‧‧Gate valve

190‧‧‧Exhaust

191‧‧‧Gas exhaust pipe

192‧‧‧ Valve

FL‧‧‧Flash

HL‧‧‧halogen lamp

W‧‧‧Semiconductor wafer

Fig. 1 is a longitudinal sectional view showing the structure of a heat treatment apparatus of the present invention.

FIG. 2 is a perspective view showing the overall appearance of the holding portion.

Figure 3 is a top view of the crystal base.

Figure 4 is a sectional view of the crystal base.

FIG. 5 is a top view of the transfer mechanism.

Figure 6 is a side view of the transfer mechanism.

Fig. 7 is a plan view showing the arrangement of a plurality of halogen lamps.

Fig. 8 is a diagram schematically showing the pollution confirmation of the quartz window in the first embodiment.

FIG. 9 is a diagram showing an example of the spectral intensity of transmitted light measured by a spectrophotometer.

Fig. 10 is a diagram schematically showing the contamination confirmation of the quartz window in the second embodiment.

Claims (12)

A heat treatment device characterized in that the substrate is heated by irradiating the substrate with light and includes: Chamber, which contains a substrate; A holding portion that holds the substrate in the cavity; A quartz window, which is disposed in the cavity; A light source, which irradiates light to the substrate held by the holding portion through the quartz window; A light measuring unit that receives light emitted from the light source and transmitted through the quartz window, and measures the intensity of the light; and The determining unit determines whether or not the quartz window is polluted based on the intensity of light received by the light measuring unit when the light source is turned on. The heat treatment apparatus of claim 1, wherein When the quartz window is not polluted, the light source is turned on, and the intensity of light received by the light measurement unit is used as a reference intensity, and The determination unit determines whether or not the quartz window is contaminated based on a comparison between the measured intensity obtained by the light measurement unit and the reference intensity. If the heat treatment device of claim 1 or 2, wherein The quartz window includes: a first quartz window provided on one side of the cavity; and a second quartz window provided on the other side; The light source includes a flash lamp that irradiates light to the substrate held by the holding portion via the first quartz window; and a continuous lighting lamp that irradiates light to the substrate held by the holding portion via the second quartz window; and The light measuring unit receives light emitted from the continuous lighting lamp and transmitted through the first quartz window and the second quartz window, and measures the intensity of the light. The determination unit determines whether or not the first quartz window and the second quartz window are contaminated based on the intensity of light received by the light measurement unit when the continuous lighting lamp is turned on. The heat treatment device according to claim 3, further comprising a light source monitoring unit, The light source monitoring unit directly receives light emitted from the continuous lighting lamp, and measures the intensity of the light. The heat treatment device of claim 3, wherein The determination unit determines whether or not the first quartz window and the second quartz window are contaminated based on a spectral intensity of a visible light region of the light received by the light measurement unit. If the heat treatment device of claim 1 or 2, wherein The quartz window includes: a first quartz window provided on one side of the cavity; and a second quartz window provided on the other side; The light source includes a flash lamp that irradiates light to the substrate held by the holding portion via the first quartz window; and a continuous lighting lamp that irradiates light to the substrate held by the holding portion via the second quartz window; and The light measuring unit receives light emitted from the flash lamp while passing through the first quartz window and reflected by the substrate while the substrate is held in the holding unit, and measures the intensity of the light. The determining unit determines whether or not the first quartz window is contaminated based on the intensity of light received by the light measuring unit when the flash is turned on while the substrate is held in the holding unit. A heat treatment method, characterized in that the substrate is heated by irradiating the substrate with light, and comprises: An irradiating step of irradiating light from a light source to a substrate held in a holding portion in a chamber provided with a quartz window through the quartz window; A light intensity measurement step in which light emitted from the light source and transmitted through the quartz window is received by a light measurement unit, and the intensity of the light is measured; and The determination step is to determine whether or not the quartz window is polluted based on the intensity of light measured in the light intensity measurement step. The heat treatment method of claim 7, wherein When the quartz window is not polluted, the light source is turned on, and the intensity of light received by the light measurement unit is used as a reference intensity, and In the determination step, it is determined whether the quartz window is polluted based on a comparison between the intensity of the light measured in the light intensity measurement step and the reference intensity. The heat treatment method of claim 7 or 8, wherein The quartz window includes: a first quartz window provided on one side of the cavity; and a second quartz window provided on the other side; The light source includes a flash lamp that irradiates light to the substrate held by the holding portion via the first quartz window; and a continuous lighting lamp that irradiates light to the substrate held by the holding portion via the second quartz window; and In the light intensity measurement step, the light measurement unit receives light emitted from the continuous lighting lamp and transmitted through the first quartz window and the second quartz window, and measures the intensity of the light; In the determination step, it is determined whether or not the first quartz window and the second quartz window are contaminated based on the intensity of light measured in the light intensity measurement step. The heat treatment method according to claim 9, further comprising a light source monitoring step, The light source monitoring step is to directly receive light emitted from the continuous lighting lamp and measure the intensity of the light. The heat treatment method of claim 9, wherein In the determining step, it is determined whether or not the first quartz window and the second quartz window are contaminated based on a spectral intensity of a visible light region of the light received by the light measuring unit. The heat treatment method of claim 7 or 8, wherein The quartz window includes: a first quartz window provided on one side of the cavity; and a second quartz window provided on the other side; The light source includes a flash lamp that irradiates light to the substrate held by the holding portion via the first quartz window; and a continuous lighting lamp that irradiates light to the substrate held by the holding portion via the second quartz window; and In the light intensity measurement step, the light measurement unit receives light emitted from the flash lamp while passing through the first quartz window and reflected by the substrate while the substrate is held in the holding portion, and measures the intensity of the light; In the determination step, it is determined whether or not the first quartz window is polluted based on the intensity of light measured in the light intensity measurement step.