TWI671804B - Heat treatment apparatus - Google Patents

Abstract

An object of the present invention is to provide a heat treatment device capable of setting a temperature distribution in a substrate surface to be uniform during light irradiation with a simple configuration.

The means for solving the problem in the present invention is that the substrate support pin 77 is formed of a light absorbing material; the substrate support pin 77 is erected on the upper surface of the quartz holding plate 75 to directly support the semiconductor wafer W; The light absorbing material absorbs the light radiated from the halogen lamp and heats up. When heating by a halogen lamp, the light emitted from the halogen lamp penetrates the holding plate 75 and a part of the light is absorbed by the substrate support pin 77, and the substrate support pin 77 is heated. Thereby, it is possible to suppress a decrease in temperature in the vicinity of the contact portion between the substrate support pin 77 and the semiconductor wafer W, and to make the in-plane temperature distribution of the semiconductor wafer W uniform when heated by a halogen lamp.

Description

   Heat treatment device   

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

In a semiconductor device manufacturing process, impurities are introduced as a step required to form a pn junction in a semiconductor wafer. Nowadays, impurity introduction is generally performed by an ion implantation method and a subsequent annealing method. The ion distribution method is a technique for physically implanting an impurity element by ionizing elements such as boron (B), arsenic (As), and phosphorus (P), and impinging on a semiconductor wafer with a high acceleration voltage. The implanted impurities are activated by annealing. At this time, when the annealing time is about several seconds or more, the value-imparted impurities are deeply diffused by thermal energy, resulting in a deeper junction depth than required, which may prevent the formation of a good device.

Therefore, in recent years, flash lamp annealing (FLA) has attracted attention as an annealing technique for heating semiconductor wafers in a very short time. Flash annealing is a heat treatment technique such as the following: when a xenon flash lamp (hereinafter referred to as a "flash" is referred to as a xenon flash) is used to irradiate the surface of a semiconductor wafer with flash light, thereby only implanting impurities The surface of the semiconductor wafer is heated in a very short time (less than milliseconds).

The xenon flash has a spectral distribution of radiation from the ultraviolet band to the near infrared band. The wavelength is shorter than that of conventional halogen lamps and is approximately the same as the basic absorption band of silicon semiconductor wafers. Therefore, when a semiconductor wafer is irradiated with flash light from a xenon flash lamp, less light is transmitted, and the semiconductor wafer can be rapidly heated. In addition, it has been found that as long as the flash light is irradiated for a very short time of several milliseconds or less, it is possible to selectively heat only the vicinity of the surface of the semiconductor wafer. Therefore, as long as the temperature is raised for a short time by the xenon flash lamp, impurities will not be diffused deeply, and only the activation of the impurities can be performed.

As a heat treatment device using such a xenon flash lamp, a technique is disclosed in Patent Document 1 in which a plurality of bumps (support pins) are formed on the upper surface of a quartz-made support (susceptor), The semiconductor wafer supported by the support pins in point contact is flash-heated. In the device disclosed in Patent Document 1, a halogen lamp is pre-heated by irradiating light from the lower surface of a semiconductor wafer placed on a carrier, and then flash light is irradiated from the flash to the surface of the wafer and flash-heated.

As disclosed in Patent Document 1, when a semiconductor wafer is supported by a plurality of support pins in point contact, heat conduction occurs between the semiconductor wafer and the support pins in the contact portion. When preheating by light irradiation from a halogen lamp, since quartz hardly absorbs light, the semiconductor wafer becomes higher temperature than the carrier of quartz, and heat energy is generated to move from the semiconductor wafer toward the support pin. As a result, the temperature in the vicinity of the portion in contact with the plurality of support pins in the surface of the semiconductor wafer becomes relatively lower than in other regions.

Therefore, in Patent Document 2, a technology has been proposed in which a laser beam emitted from a laser light source is guided to a support pin by a reflecting portion, and a contact between the support pin and a semiconductor wafer that is liable to decrease in temperature is likely to occur. The vicinity of the site is heated auxiliaryly to prevent the relative temperature drop of the site.

[Prior technical literature]

Patent Document 1: Japanese Patent Application Laid-Open No. 2009-164451.

Patent Document 2: Japanese Patent Application Laid-Open No. 2015-18909.

However, in the device disclosed in Patent Document 2, it is necessary to install a plurality of (the same number of support pins) laser light sources in a chamber. From the viewpoint of suppressing the consumption of atmospheric gas, it is required to reduce the capacity in the chamber as much as possible, and it is sometimes difficult to install a large number of laser light sources in the chamber. In addition, it is preferable that the installation of a device that may be a source of pollution is controlled to a minimum in a chamber for accommodating a semiconductor wafer.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a heat treatment device capable of setting a uniform temperature distribution in a substrate surface during light irradiation with a simple structure.

In order to solve the above problems, the first aspect of the invention is a heat treatment device for irradiating a substrate with light to heat the substrate. The heat treatment device is provided with: a chamber for housing the substrate; The chamber supports the substrate via a plurality of support pins standing on the upper surface; and a light irradiating part penetrates the holding plate to irradiate light to the substrate supported by the holding plate; the plurality of support pins are made of light absorbing material The light absorbing material is formed to absorb light emitted from the light irradiating portion.

In addition, a second aspect of the invention is a heat treatment device for irradiating a substrate with light to heat the substrate. The heat treatment device is provided with a chamber for accommodating the substrate and a flat plate-shaped holding plate for quartz placed in the chamber. The substrate is supported by a plurality of support pins standing on the upper surface; and a light irradiating portion penetrates the holding plate to irradiate light to the substrate supported by the holding plate; and the surface of the plurality of support pins is provided with light absorption. A light absorbing film formed of a material, the light absorbing material is used to absorb light radiated from the light irradiating portion.

In addition, a third aspect of the invention is a heat treatment device for irradiating a substrate with light to heat the substrate. The heat treatment device is provided with a chamber for accommodating the substrate, and a flat plate-shaped holding plate for quartz placed in the chamber. The substrate is supported by a plurality of support pins standing on the upper surface; and a light irradiating portion penetrates the holding plate to irradiate light to the substrate supported by the holding plate; and is sandwiched between the plurality of support pins and the holding plate A light absorbing film made of a light absorbing material is incorporated, and the light absorbing material is used to absorb light radiated from the light irradiating portion.

In addition, a fourth aspect of the invention is a heat treatment device for irradiating a substrate with light to heat the substrate. The heat treatment device includes a chamber for receiving the substrate, and a flat plate-shaped holding plate for quartz placed in the chamber. The substrate is supported by a plurality of support pins erected on the upper surface; and the light irradiating portion penetrates the holding plate and irradiates light to the substrate supported by the holding plate; A light absorbing film formed of a light absorbing material is provided in a region where the support pins are opposite to each other, and the light absorbing material is used to absorb light radiated from the light irradiating portion.

In addition, a fifth aspect of the invention is a heat treatment device for irradiating a substrate with light to heat the substrate. The heat treatment device includes a chamber for receiving the substrate, and a flat plate-shaped holding plate for quartz placed in the chamber. The substrate is supported by a plurality of support pins erected on the upper surface; and the light irradiating portion penetrates the holding plate to irradiate light to the substrate supported by the holding plate; a standing portion of the holding plate is formed of a light absorbing material The light absorbing material is used to absorb the light irradiated from the light irradiating part at the plurality of support pins.

The invention according to the sixth aspect is the heat treatment apparatus according to any one of the first to fifth aspects, wherein the light absorbing material is opaque quartz.

The seventh aspect of the invention is the heat treatment apparatus of the sixth aspect of the invention, wherein the opaque quartz is black synthetic quartz.

The eighth aspect of the invention is the heat treatment apparatus of any one of the first to fifth aspects, wherein the light absorbing material is silicon carbide.

The ninth aspect of the invention is a heat treatment device according to any one of the first to fifth aspects, wherein the shape of the light absorbing material projected onto a horizontal plane is a circle having a diameter of 4 mm or less.

According to the invention of the first aspect, since the plurality of support pins absorb the light from the light irradiating portion and heat up when the light is irradiated by the light irradiating portion, the temperature drop in the vicinity of the contact portion between the support pin and the substrate can be suppressed. The temperature distribution in the substrate surface when the light is irradiated is made uniform with a simple structure.

According to the invention of the second aspect, since the light absorbing film system provided on the surface of the plurality of support pins when heating by the light irradiating section absorbs light from the light irradiating section and heats up, the temperature between the support pin and the substrate can be suppressed. The temperature in the vicinity of the contact portion is reduced, and the temperature distribution in the substrate surface at the time of light irradiation is made uniform with a simple configuration.

According to the invention of the third aspect, the light-absorbing film sandwiched between the plurality of support pins and the holding plate when heating by the light-irradiating section absorbs light from the light-irradiating section and heats up, and generates light from the light-absorbing film. Since heat is transmitted to the support pin, it is possible to suppress a temperature drop in the vicinity of the contact portion between the support pin and the substrate, and to make the temperature distribution in the substrate surface uniform when the light is irradiated with a simple structure.

According to the invention of the fourth aspect, the light absorbing film provided in the area facing the plurality of support pins in the lower surface of the holding plate when heating by the light irradiation section absorbs light from the light irradiation section and heats up, and Since the heat transfer from the light absorption film to the support pin is generated, the temperature drop in the vicinity of the contact portion between the support pin and the substrate can be suppressed, and the temperature distribution in the substrate surface when the light is radiated can be made uniform with a simple structure.

According to the fifth aspect of the invention, since the portion provided with the plurality of support pins in the holding plate while being heated by the light irradiating portion absorbs light from the light irradiating portion and heats up, a transmission from the portion toward the support pin occurs. Because of the heat, the temperature drop in the vicinity of the contact portion between the support pin and the substrate can be suppressed, and the temperature distribution in the substrate surface when the light is radiated can be made uniform with a simple configuration.

According to the invention of the seventh aspect, since the light absorption rate of the black synthetic quartz is high, it is possible to more effectively suppress the temperature drop in the vicinity of the contact portion between the support pin and the substrate.

According to the ninth aspect of the invention, since the shape of the light absorbing material projected to the horizontal plane is a circle with a diameter of 4 mm or less, it is possible to suppress the influence caused by the light-shielding of the light absorbing material and obtain the light absorbing effect.

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‧‧‧ Lifting Pin

13‧‧‧horizontal movement mechanism

14‧‧‧Lifting mechanism

21‧‧‧light absorbing film

22‧‧‧Cylinder

41, 51‧‧‧ frame

43, 52‧‧‧ reflectors

53‧‧‧Flash light emission window

61‧‧‧ side of chamber

62‧‧‧ Recess

63‧‧‧ Upper side chamber window

64‧‧‧ lower side chamber window

65‧‧‧Heat treatment space

66‧‧‧Transport opening

68, 69‧‧‧ reflection ring

71‧‧‧ abutment ring

72‧‧‧ Connection Department

74‧‧‧ Carrier

75‧‧‧ holding plate

75a‧‧‧ holding surface

76‧‧‧Guide ring

77‧‧‧ substrate support pin

78‧‧‧ opening

79‧‧‧through hole

81‧‧‧Gas supply hole

82, 87‧‧‧ buffer space

83‧‧‧Gas supply pipe

84, 89, 192‧‧‧ valves

85‧‧‧Processing gas supply source

86‧‧‧Gas exhaust hole

88、191‧‧‧Gas exhaust pipe

120‧‧‧ radiation thermometer

185‧‧‧Gate valve

190‧‧‧Exhaust

d‧‧‧diameter

FL‧‧‧Flash (Xenon 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.

Fig. 3 is a plan view of the carrier.

Fig. 4 is a sectional view of a carrier.

Fig. 5 is a plan view of a 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 an enlarged view of the vicinity of the substrate support pin of the first embodiment.

FIG. 9 is an enlarged view of the vicinity of a substrate support pin according to the second embodiment.

FIG. 10 is an enlarged view of the vicinity of a substrate support pin according to the third embodiment.

FIG. 11 is an enlarged view of the vicinity of a substrate support pin according to the fourth embodiment.

Fig. 12 is an enlarged view of the vicinity of a substrate support pin according to a fifth embodiment.

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 according to this embodiment is a flash annealing apparatus for irradiating a semiconductor wafer W having a circular plate shape as a substrate with flash light, thereby heating the semiconductor wafer W. Although the size of the semiconductor wafer W to be processed is not particularly limited, it is, for example, ψ 300 mm or ψ 450 mm. In addition, in each of FIG. 1 and the subsequent figures, for ease of understanding, the size and number of each component are exaggerated or briefly described as necessary.

The heat treatment device 1 is provided with a chamber 6 for accommodating a semiconductor wafer W, a flash heating section 5 with a plurality of built-in flashes FL, and a halogen heating section 4 with a plurality of built-in 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 of the chamber 6. In addition, the heat treatment device 1 is provided inside the chamber 6 with a holding portion 7 for holding the semiconductor wafer W in a horizontal posture, and a transfer mechanism 10 for performing the semiconductor wafer W between the holding portion 7 and the outside of the device. Acceptance. The heat treatment apparatus 1 is provided with 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 configured such that a chamber window made of quartz is mounted on the upper and lower sides of the cylindrical chamber side portion 61. The chamber side portion 61 has a substantially cylindrical shape with an upper and lower opening. An upper chamber window 63 is installed in the upper opening and closed, and a lower chamber window 64 is installed in the lower opening. The upper chamber window 63 constituting the ceiling portion of the chamber 6 is a disc-shaped member formed of quartz, and functions as a quartz window that penetrates the flash light emitted from the flash heating unit 5. Into the chamber 6. In addition, the chamber window 64 below the bottom portion of the chamber 6 is also a disc-shaped member formed of quartz, and functions as a quartz window that emits light from the halogen heating unit 4 Penetrates into the cavity 6.

In addition, a reflection ring 68 is attached to the upper part of the inner wall surface of the chamber side portion 61, and a reflection ring 69 is attached to the lower part of the inner wall surface of the chamber side portion 61. 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 from the lower side of the chamber side portion 61 and fixed by bolts (not shown). That is, the reflection rings 68 and 69 are both detachably attached to the chamber side portion 61. The space surrounded by 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.

Reflective rings 68 and 69 are attached to the side portion 61 of the chamber, thereby forming a recessed portion 62 on the inner wall surface of the chamber 6. That is, a recessed 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 recessed portion 62 is formed on the inner wall surface of the chamber 6 in a circular shape along the horizontal direction, and surrounds the holding portion 7 for 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) having excellent strength and heat resistance.

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

In addition, a gas supply hole 81 for supplying a processing gas to the heat treatment space 65 is formed in the upper part of the inner wall of the chamber 6. The gas supply hole 81 may be formed at a position higher than the recessed portion 62 and provided in the reflection ring 68. The gas supply hole 81 is connected to the gas supply pipe 83 via a buffer space 82 formed annularly inside the side wall of the chamber 6. The gas supply pipe 83 is connected to a processing gas supply source 85. A valve 84 is inserted in the middle of the path of the gas supply pipe 83. When the valve 84 is opened, the processing gas is supplied from the processing gas supply source 85 to the buffer space 82. The processing gas system that has flowed into the buffer space 82 flows in a 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, an inert gas such as nitrogen (N ₂ ) or a reactive gas (such as nitrogen in this embodiment) such as hydrogen (H ₂ ) or ammonia (NH ₃ ) can be used.

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 may be formed at a position lower than the recessed portion 62 and provided in the reflection ring 69. The gas exhaust hole 86 is connected to the gas exhaust pipe 88 via a buffer space 87 formed annularly inside the side wall of the chamber 6. 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 system of the heat treatment space 65 is discharged from the gas exhaust hole 86 to the gas exhaust pipe 88 via the buffer space 87. In addition, a plurality of gas supply holes 81 and gas exhaust holes 86 may be provided along the circumferential direction of the chamber 6 and may be slit-shaped holes. In addition, the processing gas supply source 85 and the exhaust portion 190 may be a mechanism provided in the heat treatment apparatus 1, or may be a utility of a factory in which the heat treatment apparatus 1 is installed.

A gas exhaust pipe 191 is also connected to the front end of the conveyance opening 66 to discharge the gas in the heat treatment space 65. 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 through the conveyance opening 66.

FIG. 2 is a perspective view showing the overall appearance of the holding portion 7. The holding portion 7 is configured to include an abutment ring 71, a connection portion 72, and a carrier 74. The abutment ring 71, the connection portion 72, and the carrier 74 are all formed of quartz. That is, the entire holding portion 7 is formed of quartz.

The abutment ring 71 is a circular arc-shaped quartz member with a part of a ring shape. The notch portion is provided to prevent interference between the transfer arm 11 and the abutment ring 71 of the transfer mechanism 10 described later. The abutment ring 71 is placed on the bottom surface of the recessed portion 62 and is supported on the wall surface of the chamber 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 provided standingly along the circumferential direction of the annular shape. The connecting portion 72 is also a member of quartz, and is fixed to the abutment ring 71 by welding.

The carrier 74 is supported by the four connecting portions 72 provided on the abutment ring 71. FIG. 3 is a plan view of the carrier 74. FIG. 4 is a cross-sectional view of the carrier 74. The carrier 74 includes a holding plate 75, a guide ring 76, and a plurality of substrate support pins 77. The holding plate 75 is a substantially circular flat plate member made 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, when the diameter of the semiconductor wafer W is ψ 300 mm, the inner diameter of the guide ring 76 is φ 320 mm. The inner periphery of the guide ring 76 is tapered so as to widen upward from the holding plate 75. The guide ring 76 is formed of quartz similarly to 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 into an integral member.

A region of the upper surface of the holding plate 75 that is further inside than the guide ring 76 is a flat holding surface 75a for holding the semiconductor wafer W. A plurality of substrate support pins 77 are erected on the holding surface 75 a of the holding plate 75. In the present embodiment, a total of 12 substrate support pins 77 are provided on the periphery of the concentric circle with the outer periphery of the holding surface 75a (the inner periphery of the guide ring 76) at intervals of 30 °. The diameter of the circle where the 12 substrate support pins 77 have been arranged (the distance from the opposite substrate support pin 77) is smaller than the diameter of the semiconductor wafer W; if the diameter of the semiconductor wafer W is ψ 300 mm, then The diameter of a circle on which the 12 substrate support pins 77 are arranged is ψ 270 mm to ψ 280 mm (in this embodiment, ψ 280 mm). In the first embodiment, each of the substrate support pins 77 is formed of opaque quartz. Opaque quartz is obtained, for example, because a plurality of fine bubbles are contained in a quartz material. As the opaque quartz, for example, OM-100 manufactured by Shin-Etsu Quartz Products Co., Ltd., OP-3 manufactured by Tosoh Quartz Corporation, and the like can be used.

Returning to FIG. 2, the four connecting portions 72 standing on the abutment ring 71 and the peripheral edge portion of the holding plate 75 of the carrier 74 are fixed by welding. That is, the carrier 74 and the abutment ring 71 are fixedly connected by the connection portion 72. The abutment ring 71 of the holding portion 7 is supported on the wall surface of the chamber 6, and the holding portion 7 is mounted on the chamber 6. In a state where the holding portion 7 is installed in the chamber 6, the holding plate 75 of the carrier 74 is in a horizontal posture (a posture in which the normal line and the vertical direction coincide). That is, the holding surface 75a of the holding plate 75 becomes a horizontal plane. In addition, the shape in which each of the 12 substrate support pins 77 standing on the upper surface of the holding plate 75 is projected to a horizontal plane is a circle having a diameter of 4 mm or less.

The semiconductor wafer W carried into the chamber 6 is placed in a horizontal posture and held on a carrier 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 by the carrier 74. More strictly speaking, the upper end portions of the twelve substrate support pins 77 contact the lower surface of the semiconductor wafer W and support the semiconductor wafer W. Since the height of the twelve substrate support pins 77 (the distance from the upper end of the substrate support pin 77 to the holding surface 75 a of the holding plate 75) is the same, the semiconductor wafer W can be supported by the twelve substrate support pins 77 in a horizontal posture.

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 guide ring 76 prevents positional displacement of the semiconductor wafer W supported by the plurality of substrate support pins 77 in the horizontal direction.

In addition, as shown in FIGS. 2 and 3, the holding plate 75 of the carrier 74 is formed with an opening portion 78 penetrating vertically. The opening 78 is provided so that the radiation thermometer 120 (refer to FIG. 1) receives radiation (infrared rays) emitted from the lower surface of the semiconductor wafer W held by the carrier 74. That is, the radiation thermometer 120 receives light radiated from the lower surface of the semiconductor wafer W held by the carrier 74 through the opening 78, and measures the temperature of the semiconductor wafer W by a detector provided separately. . In addition, four through holes 79 are penetrated in the holding plate 75 of the carrier 74, and the four through holes 79 are used for penetrating the lift pins 12 of the transfer mechanism 10 to be described later to perform semiconductor wafers. Acceptance of W.

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 is provided with two transfer arms 11. The transfer arm 11 is formed in a circular arc shape along a substantially annular recess 62. Two lifting pins 12 are erected on each transfer arm 11. Each transfer arm 11 can be rotated by a horizontal moving mechanism 13. The horizontal movement mechanism 13 moves a 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). This transfer operation position is used for The retreat position is a position where the semiconductor wafer W is transferred to the holding portion 7, and the retreat position is a position that does not overlap with the semiconductor wafer W held by the holding portion 7 in a plan view. The horizontal movement mechanism 13 may be a mechanism in which each transfer arm 11 is individually rotated by an individual motor, or a pair of transfer arms 11 may be rotated in conjunction by a motor using a link mechanism Institution.

In addition, the pair of transfer arms 11 is moved up and down together with the horizontal movement mechanism 13 by the raising and lowering mechanism 14. When the lifting mechanism 14 raises the pair of transfer arms 11 at the transfer operation position, a total of 4 lifting pins 12 pass through the through-hole 79 (see FIGS. 2 and 3) penetrating the carrier 74, and the lifting pins 12 The upper end is projected from the upper surface of the carrier 74. On the other hand, the lifting mechanism 14 lowers the pair of transfer arms 11 at the transfer operation position, and removes the lifting pin 12 from the through hole 79. When the horizontal movement mechanism 13 moves to open the pair of transfer arms 11 At this time, each transfer arm 11 moves to the retreat position. The retreat position of the pair of transfer arms 11 is 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 becomes the inside of the recessed portion 62. In addition, an exhaust mechanism (not shown) is provided in the vicinity of the portion where the drive unit (horizontal movement mechanism 13 and lifting mechanism 14) is provided in the transfer mechanism 10, and the drive unit 10 and the periphery of the drive unit The atmosphere is exhausted to the outside of the chamber 6.

Returning to FIG. 1, the flash heating section 5 provided above the chamber 6 is configured to include a light source on the inside of the frame 51 and is composed of a plurality of (30 in this embodiment) xenon flash FL And a reflector 52 is provided so as to cover the light source. A flash light emission window 53 is attached to the bottom of the frame 51 of the flash heating unit 5. The flash light emission window 53 constituting the bottom plate portion of the flash heating portion 5 is a plate-shaped quartz window formed of quartz. The flash heating section 5 is provided above the chamber 6, whereby the flash light emission window 53 is opposed to the upper chamber window 63. The flash FL irradiates the heat treatment space 65 with flash light through the flash light emission window 53 and the upper chamber window 63 from above the chamber 6.

The plurality of flashes FL are rod lights each having an elongated cylindrical shape, and the major surfaces of the semiconductor wafers W held by the holding portion 7 in the length direction of each of them are parallel to each other (that is, along the horizontal direction). The arrangement is planar. Therefore, the plane formed by the arrangement of the flashes FL is also a horizontal plane.

The xenon flash FL is provided with a rod-shaped glass tube (discharge tube) inside which is sealed with xenon gas, and both ends are provided with an anode and a cathode connected to a capacitor; and a trigger electrode is attached to the glass tube. On the outer peripheral surface. Since the xenon gas is an electrical insulator, even if electric charges are accumulated in the capacitor, electric energy does not flow in the glass tube in a normal state. However, in the case where a high voltage is applied to the trigger electrode to break the insulation, the electric energy stored in the capacitor is instantaneously circulated in the glass tube, and light is emitted by the excitation of xenon atoms or molecules at that time. In this kind of xenon flash FL, the electric energy stored in the capacitor is converted into extremely short light pulses of 0.1 milliseconds to 100 milliseconds, so it has a higher energy efficiency than a continuous light source such as a halogen lamp HL. Features of extremely strong light. That is, the flash FL is a pulse light emitting lamp that emits light instantaneously within a very short time of less than one second. In addition, the lighting time of the flash FL can be adjusted by a 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 entire plurality of flashes FL. The basic function of the reflector 52 is to reflect the flash light 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 surface (the surface facing the side of the flash FL) is subjected to a roughening process by a blast process.

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 unit 4 is a light irradiation unit that irradiates light to the heat treatment space 65 from below the chamber 6 through the lower chamber window 64 by a plurality of halogen lamps HL and heats the semiconductor wafer W.

FIG. 7 is a plan view showing the arrangement of a plurality of halogen lamps HL. The 40 halogen lamps HL are divided into two sections. Twenty halogen lamps HL are disposed near the upper section of the holding section 7, and 20 halogen lamps HL are disposed farther from the lower section than the upper section. Each halogen lamp HL is a rod-shaped lamp having an elongated cylindrical shape. The 20 halogen lamps HL in the upper stage and the lower stage are arranged so that their lengthwise directions are parallel to each other along the main surfaces of the semiconductor wafers W (that is, along the horizontal direction) held by the holding portion 7. Therefore, the planes formed by the arrangement of the upper and lower halogen lamps HL are all horizontal planes.

In addition, as shown in FIG. 7, the arrangement density of the halogen lamps HL in the regions facing the peripheral portion in the upper and lower segments is higher than the center of the semiconductor wafer W held by the holding portion 7 in the upper and lower segments. The arrangement density of the halogen lamps HL in the region facing the other parts is also high. That is, the arrangement of the lamps in the upper and lower stages is that the arrangement pitch of the halogen lamps HL in the peripheral portion is shorter than the arrangement pitch of the halogen lamps HL in the center portion. Therefore, it is possible to irradiate the peripheral portion of the semiconductor wafer W, which is liable to cause a temperature drop when heating is performed by irradiation with light from the halogen heating portion 4, with a large amount of light.

Moreover, the lamp group which consists of the halogen lamp HL of an upper stage, and the lamp group which consists of the halogen lamp HL of a lower stage are arrange | positioned so that it may cross | intersect in a grid | lattice. That is, a total of 40 halogen lamps HL are arranged so that the longitudinal directions of the 20 halogen lamps HL arranged in the upper stage and the longitudinal directions of the 20 halogen lamps HL arranged in the lower stage are orthogonal to each other.

The halogen lamp HL is a filament-type light source, and the filament-type light source heats up the filament and emits light by energizing the filament arranged inside the glass tube. A gas in which a halogen element (iodine, bromine) is trace-introduced into an inert gas such as nitrogen or argon is enclosed in the glass tube. By introducing a halogen element, it is possible to suppress the breakage of the filament and set the temperature of the filament to a high temperature. Therefore, the halogen lamp HL has the following characteristics: It has a longer life than ordinary incandescent lamps and can continuously irradiate strong light. 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, and by arranging the halogen lamp HL in a horizontal direction, it has excellent radiation efficiency for the semiconductor wafer W above.

A reflector 43 is also provided on the lower side of the two-stage halogen lamp HL in the housing 41 of the halogen heating unit 4 (FIG. 1). The reflector 43 reflects the light emitted from the plurality of halogen lamps HL to the heat treatment space 65.

The control unit 3 controls the above-mentioned various operating mechanisms provided in the heat treatment apparatus 1. The configuration of the hardware as 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; central processing unit) belonging to a circuit that performs various arithmetic processing; a ROM (Read Only Memory) that belongs to a read-only memory, Basic memory programs; RAM (Random Access Memory), which is a readable and writable memory, that stores various information; magnetic disks, and software and data for memory control. The CPU of the control unit 3 executes processing in the heat treatment apparatus 1 by executing a predetermined processing program.

In addition to the above-mentioned structure, the heat treatment device 1 also has various cooling structures to prevent the heat generated from the halogen lamp HL and the flasher FL during the heat treatment of the semiconductor wafer W from causing the halogen heating section 4 and the flash heating section 5 And the temperature of the chamber 6 rises 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 have an air-cooled structure in which a gas flow is formed inside and heat is exhausted. In addition, air is also supplied to the gap between the upper chamber window 63 and the flash light emission window 53 to cool the flash heating section 5 and the upper chamber window 63.

Next, a processing procedure of the semiconductor wafer W in the heat treatment apparatus 1 will be described. Here, the semiconductor wafer W to be processed is a semiconductor substrate to which impurities (ions) have been added by an ion implantation method. The activation of the impurities is performed by irradiating a heat treatment (annealing) with the flash light for the heat treatment device 1. The processing sequence of the heat treatment apparatus 1 described below is performed by the control unit 3 controlling various operating mechanisms of the heat treatment apparatus 1.

First, the gate valve 185 is opened and the transfer opening 66 is opened, and a semiconductor robot W is transferred into the heat treatment space 65 in the chamber 6 through the transfer opening 66 by a transfer robot outside the apparatus. The semiconductor wafer W carried in by the transfer robot is moved in and out and stopped at a position directly above the holding portion 7. Next, the pair of transfer arms 11 of the transfer mechanism 10 are horizontally moved from the retracted position and raised to the transfer operation position, whereby the lift pin 12 is protruded from the upper surface of the holding plate 75 of the carrier 74 through the through hole 79 and Take the semiconductor wafer W. At this time, the lift pin 12 is raised above the upper end of the substrate support pin 77.

After the semiconductor wafer W is placed on the lift 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. Next, the pair of transfer arms 11 is lowered, whereby the semiconductor wafer W is awarded from the transfer mechanism 10 to the carrier 74 of the holding portion 7 and is held in a horizontal posture from below. The semiconductor wafer W is supported by a plurality of substrate support pins 77 standing on a holding plate 75 and held by a carrier 74. In addition, the semiconductor wafer W is held on the holding portion 7 as a top surface on which a pattern has been formed and an impurity has been implanted. A predetermined interval is formed between the back surface (the main surface on the opposite side of the 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 that has been lowered to the lower side of the carrier 74 is retreated to the retreat position by the horizontal moving mechanism 13, that is, retreat to the inside of the recess 62.

In addition, after the conveyance opening 66 is closed by the gate valve 185 and the heat treatment space 65 is made a closed space, the atmosphere in the chamber 6 is adjusted. Specifically, the valve 84 is opened, and the processing gas is supplied from the gas supply hole 81 to the heat treatment space 65. In this embodiment, a nitrogen gas is supplied as a processing gas to the heat treatment space 65 in the chamber 6. Further, the valve 89 is opened, and the gas in the chamber 6 is exhausted from the gas exhaust hole 86. Thereby, the processing gas system supplied from the upper part of the heat treatment space 65 in the chamber 6 flows downward and is exhausted from the lower part of the heat treatment space 65, and the heat treatment space 65 is replaced with a nitrogen atmosphere. In addition, by opening the gate 192, the gas in the chamber 6 is also exhausted from the conveyance opening 66. In addition, the atmosphere around the drive section of the transfer mechanism 10 is also exhausted by an exhaust mechanism (not shown).

After the interior of the chamber 6 is replaced with a nitrogen atmosphere and the semiconductor wafer W is held by the carrier 74 of the holding portion 7 from below in a horizontal posture, the 40 halogen lamps HL of the halogen heating portion 4 light up together and start pre-heating (assisted heating). ). The halogen light emitted from the halogen lamp HL penetrates the lower chamber window 64 and the carrier 74 formed of quartz and irradiates the back surface of the semiconductor wafer W. When the light from the halogen lamp HL is irradiated, the semiconductor wafer W is preheated and the temperature rises. In addition, since the transfer arm 11 of the transfer mechanism 10 is retracted to the inside of the recessed portion 62, it does not become an obstacle when the halogen lamp HL is heated.

When the halogen lamp HL is pre-heated, the temperature of the semiconductor wafer W is measured by the radiation thermometer 120. That is, the radiation thermometer 120 receives infrared light emitted from the back surface of the semiconductor wafer W held by the carrier 74 through the opening 78 and measures the temperature of the wafer while the temperature is increasing. The measured temperature of the semiconductor wafer W is transmitted to the control unit 3. The control unit 3 monitors whether or not the temperature of the semiconductor wafer W heated by the irradiation of light from the halogen lamp HL has reached a predetermined pre-heating temperature T1, and controls the output of the halogen lamp HL. That is, the control unit 3 feedback-controls the output of the halogen lamp HL based on the measurement value of the radiation thermometer 120 so that the temperature of the semiconductor wafer W becomes the pre-heating temperature T1. The preheating temperature T1 is controlled to about 200 ° C to 800 ° C, and preferably controlled to about 350 ° C to 600 ° C (in this embodiment, 600 ° C).

After 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 120 reaches the pre-heating temperature T1, the control unit 3 adjusts the output of the halogen lamp HL and maintains the temperature of the semiconductor wafer W approximately to the pre-heating. Temperature T1.

However, as described above, the preheating of the halogen lamp HL is performed in a state where the semiconductor wafer W is supported by the 12 substrate support pins 77. As in the past, in the case where the substrate support pin 77 is formed of quartz, the substrate support pin 77 hardly absorbs the light radiated from the halogen lamp HL but allows the light to pass through. Therefore, during pre-heating, the semiconductor wafer W absorbs light from the halogen lamp HL and heats up. On the other hand, the carrier 74 including the substrate support pin 77 is less likely to heat up and relatively becomes larger than the semiconductor wafer. W is also cold. Therefore, heat conduction occurs from the semiconductor wafer W to the substrate support pins 77 that are in direct contact, and the wafer temperature near the contact portion of the twelve substrate support pins 77 becomes relatively lower than other regions. As a result, the in-plane temperature distribution of the semiconductor wafer W tends to become uneven.

Therefore, in the first embodiment, twelve substrate support pins 77 standing on the upper surface of the holding plate 75 are formed of opaque quartz. Opaque quartz is a light absorbing material that absorbs light emitted from the halogen lamp HL and heats up. That is, in the first embodiment, the twelve substrate support pins 77 are formed of a light absorbing material for absorbing light emitted from the halogen lamp HL and heating up.

FIG. 8 is an enlarged view of the vicinity of the substrate support pin 77 of the first embodiment. The light emitted from the halogen lamp HL is irradiated to the lower surface of the holding plate 75. Since the holding plate 75 is usually formed of transparent quartz, the light emitted from the halogen lamp HL is transmitted. The light that has passed through the holding plate 75 is irradiated onto the back surface of the semiconductor wafer W. In addition, a part of the light that has penetrated the holding plate 75 is also irradiated to the substrate support pin 77. Since the substrate support pin 77 is formed of opaque quartz, the substrate support pin 77 absorbs light that has passed through the holding plate 75 and heats up. Therefore, the relative temperature decrease in the vicinity of the contact portion of the semiconductor wafer W with the substrate support pin 77 is suppressed, and as a result, the temperature difference between the vicinity of the contact portion and the peripheral region can be suppressed to a minimum, and The in-plane temperature distribution of the semiconductor wafer W during the pre-heating is made uniform.

The shape of the substrate support pin 77 projected to the horizontal plane is a circle, and the diameter d of the circle is 4 mm or less. When the diameter d of the circle of the substrate support pin 77 projected to the horizontal plane is larger than 4 mm, the light shielding effect becomes larger than the light absorption effect of the substrate support pin 77, and it becomes a semiconductor wafer through the substrate support pin 77. A shadow is formed on the back surface of W, and thus the temperature drop in the vicinity of the contact portion of the semiconductor wafer W with the substrate support pin 77 becomes large. Therefore, the diameter d of the circle projecting the substrate support pin 77 to the horizontal plane is limited to 4 mm or less.

When the temperature of the semiconductor wafer W reaches the pre-heating temperature T1 and a predetermined time has elapsed, the flash FL of the flash heating unit 5 irradiates the surface of the semiconductor wafer W with flash light. At this time, a part of the flash light emitted from the flash FL is directly directed into the chamber 6, and the other part is reflected by the reflector 52 and directed into the chamber 6, and the flash heating of the semiconductor wafer W is performed by irradiation of these flash light. .

Since the flash heating is performed by irradiation with flash light (flash) from the flash FL, the surface temperature of the semiconductor wafer W can be raised in a short time. That is, the flash light radiated from the flash FL is an extremely short and strong flash in which the electric energy stored in the capacitor has been converted into an extremely short light pulse wave and the irradiation time is about 0.1 milliseconds to 100 milliseconds. Next, the surface temperature of the semiconductor wafer W heated by the flash light by the flash light from the flash FL is instantaneously raised to a processing temperature T2 of 1000 ° C. or higher, and after the impurities implanted into the semiconductor wafer W are activated, The surface temperature drops rapidly. As described above, in the heat treatment apparatus 1, since the surface temperature of the semiconductor wafer W can be raised and lowered in a very short time, the impurities implanted into the semiconductor wafer W can be suppressed from being diffused due to thermal energy, and the impurities can be activated. In addition, compared with the time required for thermal diffusion of impurities, since the time required for activation of impurities is extremely short, the activation is completed even in a short time of about 0.1 milliseconds to 100 milliseconds which does not cause diffusion.

In this embodiment, since the twelve substrate support pins 77 are formed of opaque quartz that absorbs light emitted from the halogen lamp HL and heats up, the vicinity of the contact portion between the substrate support pins 77 and the semiconductor wafer W is suppressed. The temperature is reduced, and the in-plane temperature distribution of the semiconductor wafer W in the pre-heating stage is made uniform. As a result, the in-plane temperature distribution on the surface of the semiconductor wafer W when the flash light is radiated can also be made uniform.

After the flash heat treatment is completed and a predetermined time has elapsed, the halogen lamp HL is turned off. Thereby, the semiconductor wafer W is rapidly cooled from the preheating temperature T1. The temperature of the semiconductor wafer W being cooled is measured by the radiation thermometer 120, and the measurement result is transmitted to the control unit 3. The control unit 3 monitors whether or not the temperature of the semiconductor wafer W has dropped to a predetermined temperature based on a measurement result of the radiation thermometer 120. Next, after the temperature of the semiconductor wafer W is lowered below a predetermined value, the pair of transfer arms 11 of the transfer mechanism 10 are moved horizontally from the retreated position and raised to the transfer operation position again, whereby the lift pins 12 are removed from the carrier. The upper surface of 74 protrudes and receives the heat-treated semiconductor wafer W from the carrier 74. Next, the conveyance opening 66 closed by the gate valve 185 is opened, and the semiconductor wafer W placed on the lift pin 12 is carried out by a conveyance robot outside the apparatus, and the heat treatment of the semiconductor wafer W in the thermal processing apparatus 1 is completed.

In the first embodiment, the twelve substrate support pins 77 standing on the upper surface of the holding plate 75 are formed of a light absorbing material for absorbing light emitted from the halogen lamp HL and heating it. Thereby, when preheating by the halogen lamp HL, the 12 substrate support pins 77 absorb light from the halogen lamp HL and heat up, so that it is possible to suppress the vicinity of the contact portion between the substrate support pin 77 and the semiconductor wafer W. The temperature of the semiconductor wafer W is reduced, and the in-plane temperature distribution of the semiconductor wafer W during pre-heating can be made uniform. As a result, the in-plane temperature distribution on the surface of the semiconductor wafer W during flash heating can be made uniform.

In addition, in the first embodiment, the in-plane temperature distribution of the semiconductor wafer W is made uniform only by forming the twelve substrate support pins 77 with a light absorbing material. That is, no special mechanism or design change is required for heating the contact portion between the substrate support pin 77 and the semiconductor wafer W, and the in-plane temperature of the semiconductor wafer W when light is irradiated with a simple structure The distribution is set to be uniform.

<Second Embodiment>

Next, a second embodiment of the present invention will be described. The overall configuration of the heat treatment apparatus 1 according to the second embodiment is substantially the same as that of the first embodiment. The processing sequence of the semiconductor wafer W in the heat treatment apparatus 1 of the second embodiment is also the same as that of the first embodiment. A point of difference between the second embodiment and the first embodiment is a form in which a light absorbing material is provided.

FIG. 9 is an enlarged view of the vicinity of the substrate support pin 77 according to the second embodiment. In the second embodiment, a light absorbing film 21 made of a light absorbing material is provided on the surface of twelve substrate support pins 77 standing on the upper surface of the holding plate 75. The light absorbing material is used to absorb light from a halogen lamp. HL light. In the second embodiment, the substrate support pin 77 is formed of quartz. A light absorbing film 21 made of a light absorbing material is formed on the surface of the quartz substrate supporting pin 77.

In the second embodiment, silicon nitride (SiC) is used as the light absorbing material. The light-absorbing film 21 is formed by coating silicon nitride on the surface of the substrate support pin 77 of quartz by a method such as sputtering, vapor deposition, and coating. The shape in which the light absorbing film 21 is projected to a horizontal plane is a circle having a diameter of 4 mm or less.

In the second embodiment, when preheating by the halogen lamp HL, the light absorbing film 21 provided on the surface of the 12 substrate support pins 77 absorbs light from the halogen lamp HL and heats up, so that the substrate support can be suppressed. The temperature in the vicinity of the contact portion between the pin 77 and the semiconductor wafer W (strictly, the vicinity of the contact portion between the light absorbing film 21 and the semiconductor wafer W) is reduced, and the semiconductor wafer W at the time of preheating can be reduced. The in-plane temperature distribution is set to be uniform. As a result, as in the first embodiment, the in-plane temperature distribution on the surface of the semiconductor wafer W during flash heating can be made uniform.

In addition, in the second embodiment, the in-plane temperature distribution of the semiconductor wafer W is made uniform only by providing the light absorption film 21 on the surface of the twelve substrate support pins 77. That is, no special mechanism or design change is required for heating the contact portion between the substrate support pin 77 and the semiconductor wafer W, and the in-plane temperature of the semiconductor wafer W when light is irradiated with a simple structure The distribution is set to be uniform.

<Third Embodiment>

Next, a third embodiment of the present invention will be described. The overall configuration of the heat treatment apparatus 1 according to the third embodiment is substantially the same as that of the first embodiment. The processing sequence of the semiconductor wafer W in the heat treatment apparatus 1 of the third embodiment is also the same as that of the first embodiment. A point of difference between the third embodiment and the first embodiment is a form in which a light absorbing material is provided.

FIG. 10 is an enlarged view of the vicinity of the substrate support pin 77 according to the third embodiment. In the third embodiment, a light absorbing film 21 made of a light absorbing material is provided between the 12 substrate supporting pins 77 and the holding plate 75. The light absorbing material is used to absorb the light emitted from the halogen lamp HL. Light. In the third embodiment, the body of twelve substrate support pins 77 standing on the upper surface of the holding plate 75 is also formed of quartz. In addition, as in the second embodiment, silicon nitride was used as the light absorbing material.

In the third embodiment, silicon nitride is formed on the upper surface of the holding plate 75 on the upper surface of the holding plate 75 by sputtering, evaporation, coating, or the like to form silicon nitride and form a light absorbing film 21. . Next, a substrate support pin 77 is erected on the light absorption film 21 to sandwich the light absorption film 21 between the substrate support pin 77 and the holding plate 75. The film thickness of the light absorption film 21 is 0.1 mm to 0.5 mm. The shape of the light absorbing film 21 projected to the horizontal plane is a circle having a diameter of 4 mm or less (that is, the diameter of the light absorbing film 21 having a circular plate shape is 4 mm or less).

In the third embodiment, during the preheating by the halogen lamp HL, the light absorbing film 21 sandwiched between the twelve substrate support pins 77 and the holding plate 75 absorbs light from the halogen lamp HL and heats up. Since the substrate support pin 77 is also heated by transferring thermal energy from the heated light absorbing film 21 to the substrate support pin 77, it is possible to suppress a decrease in temperature in the vicinity of the contact portion between the substrate support pin 77 and the semiconductor wafer W, and The in-plane temperature distribution of the semiconductor wafer W during pre-heating can be made uniform. As a result, as in the first embodiment, the in-plane temperature distribution on the surface of the semiconductor wafer W during flash heating can be made uniform.

In addition, in the third embodiment, the in-plane temperature distribution of the semiconductor wafer W is made uniform only by providing the light absorption film 21 between the twelve substrate support pins 77 and the holding plate 75. That is, no special mechanism or design change is required for heating the contact portion between the substrate support pin 77 and the semiconductor wafer W, and the in-plane temperature of the semiconductor wafer W when light is irradiated with a simple structure The distribution is set to be uniform.

<Fourth Embodiment>

Next, a fourth embodiment of the present invention will be described. The overall configuration of the heat treatment apparatus 1 according to the fourth embodiment is substantially the same as that of the first embodiment. The processing sequence of the semiconductor wafer W in the heat treatment apparatus 1 of the fourth embodiment is also the same as that of the first embodiment. The difference between the fourth embodiment and the first embodiment is a form in which a light absorbing material is provided.

FIG. 11 is an enlarged view of the vicinity of the substrate support pin 77 according to the fourth embodiment. In the fourth embodiment, a light absorbing film 21 made of a light absorbing material is provided in a region of the lower surface of the holding plate 75 opposite to the 12 substrate supporting pins 77, and the light absorbing material is used for absorbing Light from a halogen lamp HL. In the fourth embodiment, the body of twelve substrate support pins 77 standing on the upper surface of the holding plate 75 is also formed of quartz. In addition, as in the second embodiment, silicon nitride was used as the light absorbing material.

In the fourth embodiment, silicon nitride is applied to a region of the lower surface of the holding plate 75 opposed to the twelve substrate support pins 77 standing on the upper surface by means of sputtering, vapor deposition, coating, and the like. Formed a light absorbing film 21. The film thickness of the light absorption film 21 is 0.1 mm to 0.5 mm. The shape of the light absorbing film 21 projected to the horizontal plane is a circle having a diameter of 4 mm or less (that is, the diameter of the light absorbing film 21 having a circular plate shape is 4 mm or less).

In the fourth embodiment, when preheating by the halogen lamp HL, the light absorbing film 21 provided on the lower surface of the holding plate 75 in a region facing the 12 substrate supporting pins 77 absorbs the light from the halogen lamp HL The light is heating up. Since the heat is transmitted from the heated light absorbing film 21 to the holding plate 75 and the substrate support pin 77 upward, and the substrate support pin 77 body also heats up, the vicinity of the contact portion between the substrate support pin 77 and the semiconductor wafer W can be suppressed. The intermediate temperature is reduced, and the in-plane temperature distribution of the semiconductor wafer W during pre-heating can be made uniform. As a result, as in the first embodiment, the in-plane temperature distribution on the surface of the semiconductor wafer W during flash heating can be made uniform.

In addition, in the fourth embodiment, the in-plane temperature distribution of the semiconductor wafer W is made uniform only by providing the light absorbing film 21 on the lower surface of the holding plate 75. That is, no special mechanism or design change is required for heating the contact portion between the substrate support pin 77 and the semiconductor wafer W, and the in-plane temperature of the semiconductor wafer W when light is irradiated with a simple structure The distribution is set to be uniform.

<Fifth Embodiment>

Next, a fifth embodiment of the present invention will be described. The overall configuration of the heat treatment apparatus 1 according to the fifth embodiment is substantially the same as that of the first embodiment. The processing sequence of the semiconductor wafer W in the heat treatment apparatus 1 of the fifth embodiment is also the same as that of the first embodiment. A point of difference between the fifth embodiment and the first embodiment is a form in which a light absorbing material is provided.

FIG. 12 is an enlarged view of the vicinity of the substrate support pin 77 according to the fifth embodiment. In the fifth embodiment, a portion of the holding plate 75 in which twelve substrate support pins 77 are standing is formed of a light absorbing material, and this light absorbing material is used to absorb light emitted from the halogen lamp HL. In the fifth embodiment, the body of twelve substrate support pins 77 standing on the upper surface of the holding plate 75 is also formed of quartz. In addition, as in the first embodiment, opaque quartz was used as the light absorbing material.

In the fifth embodiment, a hole is formed in the holding plate 75 where 12 substrate support pins 77 should be erected up and down, and a cylindrical portion 22 of opaque quartz is buried in the hole by welding or the like. Next, a substrate support pin 77 is erected on the cylindrical portion 22. The height of the cylindrical portion 22 of the opaque quartz is the same as the thickness of the holding plate 75. The shape of the cylindrical portion 22 of the opaque quartz projected on the horizontal plane is a circle with a diameter of 4 mm or less (that is, the diameter of the cylindrical portion 22 is 4 mm or less).

In the fifth embodiment, when preheating by the halogen lamp HL, the cylindrical portion 22 of opaque quartz provided below the 12 substrate support pins 77 absorbs light from the halogen lamp HL and heats up. Since the thermal energy is transmitted from the heated cylindrical portion 22 to the substrate support pin 77 and the substrate support pin 77 body is also heated, the temperature drop in the vicinity of the contact portion between the substrate support pin 77 and the semiconductor wafer W can be suppressed, and the temperature can be reduced. The in-plane temperature distribution of the semiconductor wafer W during pre-heating was made uniform. As a result, as in the first embodiment, the in-plane temperature distribution on the surface of the semiconductor wafer W during flash heating can be made uniform.

In addition, in the fifth embodiment, the in-plane temperature distribution of the semiconductor wafer W is made uniform only by forming a part of the holding plate 75 with a light absorbing material. That is, no special mechanism or design change is required for heating the contact portion between the substrate support pin 77 and the semiconductor wafer W, and the in-plane temperature of the semiconductor wafer W when light is irradiated with a simple structure The distribution is set to be uniform.

<Modifications>

Although the embodiments of the present invention have been described above, the present invention can be variously modified in addition to the above embodiments as long as it does not depart from the spirit of the present invention. For example, silicon nitride can be used as the light absorbing material in the first and fifth embodiments, and opaque quartz can also be used as the light absorbing material in the second to fourth embodiments. In addition, in each embodiment, opaque quartz used as a light absorbing material may be black synthetic quartz. Since black synthetic quartz has higher light absorption than white opaque quartz, it can absorb the light from the halogen lamp HL and heat up to a higher temperature, and can more effectively suppress the substrate support pin 77 and the semiconductor wafer W. The temperature in the vicinity of the contact portion decreases.

In addition, two or more light absorbing materials provided with the first to fifth embodiments may be appropriately combined. For example, the first embodiment and the third embodiment may be combined, and the light absorbing film 21 may be sandwiched between a substrate support pin 77 and a holding plate 75 provided between opaque quartz. Alternatively, the substrate support pins 77 of opaque quartz may be provided on the upper side of the cylindrical portion 22 of the opaque quartz by combining the first embodiment and the fifth embodiment.

Alternatively, the surface of the quartz substrate support pin 77 may be made opaque by a roughening process such as sandblasting. In this way, as in the case where the substrate support pin 77 is formed of opaque quartz, the surface of the substrate support pin 77 absorbs light from the halogen lamp HL and heats up, so that the contact between the substrate support pin 77 and the semiconductor wafer W can be suppressed. The temperature in the vicinity of the site decreases.

In the above-mentioned embodiment, although the flash heating unit 5 is provided with 30 flashes FL, it is not limited to this, and the number of the flashes FL may be any number. In addition, the flash FL is not limited to a xenon flash, and may be a krypton flash. The number of halogen lamps HL included in the halogen heating unit 4 is not limited to 40, and may be any number.

The substrate to be processed by the heat treatment device of the present invention is not limited to a semiconductor wafer, and may be a glass substrate used for a flat-panel display such as a liquid crystal display device or a substrate for a solar cell. In addition, the technology of the present invention can also be applied to the joining of metal and silicon, or it can also be applied to the crystallization of polycrystalline silicon.

In addition, the heat treatment technology of the present invention is not limited to a flash lamp annealing device, and can also be applied to heat sources other than a flash lamp using a blade-type lamp annealing device using a halogen lamp or a CVD (chemical vapor phase deposition) device. Device. In particular, the present invention can also be suitably applied to a backside anneal device. The backside anneal device is a semiconductor wafer provided with a halogen lamp under the chamber and supported by a plurality of substrate support pins on a quartz carrier. The back surface is irradiated with light and heat-treated.

Claims (4)

A heat treatment device is configured to irradiate a substrate with light to heat the substrate. The heat treatment device is provided with: a chamber for receiving the substrate; and a flat plate-shaped holding plate of quartz, which is erected on the upper surface in the chamber. A plurality of support pins supporting the substrate; and a light irradiating portion that penetrates the holding plate to irradiate light to the substrate supported by the holding plate; and is provided on a surface of the plurality of support pins fixedly provided on the holding plate A light absorbing film formed of a light absorbing material, the light absorbing material is used to absorb light irradiated from the light irradiating portion; the shape of the light absorbing material projected to a horizontal plane is a circle with a diameter of 4 mm or less. The heat treatment apparatus according to claim 1, wherein the light absorbing material is opaque quartz. The heat treatment apparatus according to claim 2, wherein the opaque quartz is black synthetic quartz. The heat treatment apparatus according to claim 1, wherein the light absorbing material is silicon carbide.