TWI740133B - Heat treatment apparatus and atmosphere replacement method of heat treatment apparatus - Google Patents

Abstract

The present invention provides a heat treatment device and a method for replacing a gas atmosphere of the heat treatment device. The heat treatment device can completely discharge the reactive gas from a supply pipe for supplying the reactive gas, and fill the supply pipe with an inert gas. Regarding the gas environment substitution method of the heat treatment device of the present invention, the reactive gas pipe 83a is continuously exhausted until the measured value of the supply confirmation pressure gauge 94 becomes below the first pressure, regardless of the full scale of the mass flow controller 95 The size can completely discharge the residual ammonia gas from the reactive gas pipe 83a. In addition, after the ammonia gas is discharged from the reactive gas pipe 83a, the nitrogen gas supply to the reactive gas pipe 83a is continued until the measurement value of the supply confirmation pressure gauge 94 becomes the second pressure higher than the first pressure or more. This is sufficient. Nitrogen gas is supplied and filled into the reactive gas pipe 83a.

Description

Heat treatment device and method for replacing gas environment of heat treatment device

The present invention relates to a heat treatment device that heats a thin-plate-shaped precision electronic substrate such as a semiconductor wafer (hereinafter referred to as "substrate") by irradiating the substrate with light, and a method for replacing the gas atmosphere of the heat treatment device.

In the manufacturing process of semiconductor devices, flash annealing (FLA), which heats semiconductor wafers in a very short time, has attracted attention. Flash lamp annealing is the following heat treatment technology: by using a xenon flash lamp (hereinafter, simply referred to as "flash lamp" means xenon flash lamp) to irradiate the surface of a semiconductor wafer with flash light, and only make the surface of the semiconductor wafer in a very short time ( The temperature rises within a few milliseconds.

The radiation spectrum of the xenon flash lamp ranges from the ultraviolet region to the near-infrared region. Compared with the previous halogen lamps, the wavelength is shorter, which is roughly the same as the basic absorption band of silicon semiconductor wafers. Therefore, when the semiconductor wafer is irradiated with a flash light from the xenon flash lamp, the light transmission is less and the semiconductor wafer can be heated rapidly. In addition, it has also 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 increase the temperature of only the vicinity of the surface of the semiconductor wafer.

This flash lamp annealing is used for processes that require extremely short heating, such as activation of impurities typically implanted into semiconductor wafers. If the flash is irradiated from the flash lamp to the surface of the semiconductor wafer implanted with impurities by the ion implantation method, the surface of the semiconductor wafer can be heated to the activation temperature in a very short time, and the impurities can be kept deep. In the case of diffusion, only impurity activation is performed.

On the other hand, an attempt has been made to perform flash lamp annealing in a reactive gas atmosphere such as ammonia. For example, Patent Document 1 discloses the following: an ammonia gas atmosphere is formed in a chamber containing a semiconductor wafer formed with a high-dielectric constant gate insulating film (high-k film), and the semiconductor wafer is irradiated Flashing and heating are performed, thereby performing post-film heat treatment of the high-dielectric constant gate insulating film. In the device disclosed in Patent Document 1, after the heat treatment of the semiconductor wafer is performed in an ammonia gas atmosphere, the chamber is depressurized to discharge harmful ammonia gas and replace it with a nitrogen gas atmosphere, and then the semiconductor wafer is removed. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2017-045982

[The problem to be solved by the invention]

Of course, the heat treatment device for flash lamp annealing should be maintained regularly or irregularly. During maintenance, the space in the chamber is open to the outside, so harmful reactive gases such as ammonia must be completely discharged from the chamber in advance.

However, there are cases where the pressure loss of the piping is large due to various reasons such as the mass flow controller being installed in the various piping connected to the chamber, or the diameter of the piping is small. In particular, when the pressure loss of the supply piping for supplying reactive gases such as ammonia gas is large, if only the pressure in the chamber is reduced as disclosed in Patent Document 1, even if the ammonia gas in the chamber can be discharged, It is difficult to completely discharge the ammonia gas remaining in the supply pipe.

The present invention was made in view of the above problems, and its object is to provide a heat treatment device and a gas atmosphere replacement for the heat treatment device that can completely discharge the reactive gas from the supply pipe for supplying the reactive gas and fill the supply pipe with an inert gas method. [Technical means to solve the problem]

In order to solve the above-mentioned problems, the invention of claim 1 is a heat treatment device that heats the substrate by irradiating the substrate with light, which is characterized by comprising: a chamber for accommodating the substrate; The substrate is irradiated with light; a first supply pipe that supplies a reactive gas to the chamber; a second supply pipe that supplies an inert gas to the chamber; an exhaust pipe that exhausts the gas environment in the chamber; And a pressure gauge installed in the first supply pipe; and after exhausting the first supply pipe from the exhaust pipe until the measured value of the pressure gauge becomes below the first air pressure, from the second supply pipe to The first supply pipe supplies an inert gas until the measured value of the pressure gauge becomes at least a second gas pressure higher than the first gas pressure.

In addition, the invention of claim 2 is the heat treatment apparatus of the invention of claim 1, characterized in that a mass flow controller is further provided in the first supply pipe.

In addition, the invention of claim 3 is the heat treatment apparatus of the invention of claim 1 or 2, characterized in that the light irradiating section includes a continuous illuminator, and before exhausting from the exhaust pipe, the continuous illuminator Light irradiation heats the gas environment in the chamber.

In addition, the invention of claim 4 is a method for replacing the gas atmosphere of a heat treatment device that heats the substrate by irradiating light on the substrate, and is characterized in that a first supply pipe for supplying reactive gas is connected to a chamber containing the substrate. The second supply pipe for inert gas and the exhaust pipe for exhausting the gas environment in the chamber. A pressure gauge is installed in the first supply pipe, and the method for replacing the gas environment of the heat treatment device includes: an exhaust step, It is performed from the exhaust pipe to exhaust the first supply pipe until the measured value of the pressure gauge becomes below the first air pressure; and the air supply step is performed from the second supply pipe after the exhaust step The inert gas is supplied to the first supply pipe until the measured value of the pressure gauge becomes equal to or higher than the second air pressure higher than the first air pressure.

In addition, the invention of claim 5 is the method for replacing the gas atmosphere of a heat treatment device as the invention of claim 4, which is characterized in that the above-mentioned exhausting step and the above-mentioned gas supplying step are repeatedly performed.

In addition, the invention of claim 6 is the method of replacing the gas environment of the heat treatment device as the invention of claim 4 or 5, and is characterized by further comprising a heating step, which is performed by a continuous illuminator before the exhaust step. Light irradiation heats the gas environment in the chamber. [Effects of Invention]

According to the invention of claim 1 to claim 3, the first supply pipe is exhausted from the exhaust pipe until the measured value of the pressure gauge installed in the first supply pipe becomes equal to or lower than the first air pressure, and then the second supply pipe The first supply pipe supplies inert gas until the measured value of the pressure gauge becomes more than the second pressure higher than the first pressure. Therefore, regardless of the pressure loss of the first supply pipe, the reaction can be completely discharged from the first supply pipe The first supply pipe is filled with an inert gas.

In particular, according to the invention of claim 3, before exhausting from the exhaust piping, light is irradiated from the continuous illuminator to heat the gas environment in the chamber, so that the thermal motion of the gas molecules in the gas environment can be activated. This shortens the exhaust time required until the measured value of the pressure gauge becomes below the first air pressure.

According to the invention of claim 4 to claim 6, after exhausting the first supply pipe from the exhaust pipe until the measured value of the pressure gauge installed in the first supply pipe becomes below the first air pressure, the second supply pipe The first supply pipe supplies inert gas until the measured value of the pressure gauge becomes more than the second pressure higher than the first pressure. Therefore, regardless of the pressure loss of the first supply pipe, the reaction can be completely discharged from the first supply pipe The first supply pipe is filled with an inert gas.

In particular, according to the invention of technical solution 6, before the exhaust step, light is irradiated from the continuous illuminator to heat the gas environment in the chamber, so the thermal motion of the gas molecules in the gas environment can be activated, thereby shortening the pressure gauge The measured value becomes the exhaust time required until the first air pressure is below.

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

300 mm或

450 mm(本實施形態中為

300 mm)。於搬入至熱處理裝置1前之半導體晶圓W形成有高介電常數膜(high-k膜)作為閘極絕緣膜，藉由利用熱處理裝置1所進行之加熱處理而執行高介電常數膜之成膜後熱處理(PDA：Post Deposition Anneal，沈積後退火)。再者，於圖1及以下各圖中，為容易理解，視需要誇張或簡化地描述各部之尺寸或數量。Fig. 1 is a longitudinal sectional view showing the structure of a heat treatment device 1 of the present invention. The heat treatment device 1 of FIG. 1 is a flash lamp annealing device that heats a semiconductor wafer W of a disc shape as a substrate by flash irradiation. 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). The semiconductor wafer W before being carried into the heat treatment device 1 is formed with a high-k film as a gate insulating film, and the high-k film is formed by the heat treatment performed by the heat treatment device 1 Heat treatment after film formation (PDA: Post Deposition Anneal, post-deposition annealing). Furthermore, in FIG. 1 and the following figures, for easy understanding, the size or quantity of each part is exaggerated or simplified as needed.

The heat treatment apparatus 1 includes a chamber 6 which houses the semiconductor wafer W; a flash heating section 5 which houses a plurality of flash lamps FL; and a halogen heating section 4 which houses a plurality of halogen lamps HL. A flash heating unit 5 is provided on the upper side of the cavity 6, and a halogen heating unit 4 is provided on the lower side. In addition, the heat treatment device 1 is provided inside the chamber 6: a holding portion 7 that holds the semiconductor wafer W in a horizontal posture; and a transfer mechanism 10 that performs the transfer of the semiconductor wafer W between the holding portion 7 and the outside of the device Handover. Furthermore, the heat treatment apparatus 1 includes a control unit 3 that controls each operating mechanism provided in the halogen heating unit 4, the flash heating unit 5, and the chamber 6 to execute the heat treatment of the semiconductor wafer W.

The chamber 6 is configured by mounting a quartz chamber window above and below a cylindrical chamber side 61. The chamber side portion 61 has a substantially cylindrical shape with upper and lower openings, and an upper chamber window 63 is attached to the upper opening to be closed, and a lower chamber window 64 is attached to the lower opening to be closed. The upper chamber window 63 on the top wall constituting the chamber 6 is a disc-shaped member formed of quartz, and functions as a quartz window through which the flash light emitted from the flash heating part 5 penetrates into the chamber 6. In addition, the chamber window 64 at the bottom of the chamber 6 is also a circular plate-shaped member formed of quartz, and functions as a quartz window for transmitting the light from the halogen heating unit 4 into the chamber 6.

In addition, a reflection ring 68 is attached to the upper part of the inner wall surface of the chamber side part 61, and a reflection ring 69 is attached to the lower part. Both the reflection rings 68 and 69 are formed in an annular shape. The reflection ring 68 on the upper side is installed by being embedded from the upper side of the chamber side 61. On the other hand, the reflection ring 69 on the lower side is installed by being inserted from the lower side of the chamber side portion 61 and fixed with a screw (not shown). In other words, the reflection rings 68 and 69 are all detachably attached to the chamber side 61. The space inside 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 and 69 is defined as the heat treatment space 65.

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

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

Furthermore, a through hole 61a is penetrated in the chamber side part 61. As shown in FIG. A radiation thermometer 20 is installed at a portion on the outer wall surface of the chamber side 61 where the through hole 61a is provided. The through hole 61a is a cylindrical hole for guiding the infrared light radiated from the lower surface of the semiconductor wafer W held on the susceptor 74 described below to the radiation thermometer 20. The through hole 61a is provided obliquely with respect to the horizontal direction such that the axis of the penetrating direction intersects the main surface of the semiconductor wafer W held by the susceptor 74. At the end of the through hole 61a facing the heat treatment space 65, a transparent window 21 is installed. The transparent window 21 transmits infrared light in the wavelength range that can be measured by the radiation thermometer 20 and contains a barium fluoride material.

In addition, a gas supply hole 81 _{for supplying processing gas (nitrogen (N 2} ) and/or ammonia (NH ₃ ) in this embodiment) 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 is formed at a position higher than the concave portion 62 and may be provided in the reflection ring 68. The gas supply hole 81 is connected to the gas supply pipe 83 through a buffer space 82 formed in the side wall of the chamber 6 in an annular shape. The gas supply pipe 83 is branched into two. One of the reactive gas pipes (first supply pipe) 83a is connected to the ammonia supply source 91, and the other inert gas pipe (second supply pipe) 83b is connected to the nitrogen supply source 92. The ammonia gas supply source 91 feeds the ammonia gas to the reactive gas pipe 83a under the control of the control unit 3. The nitrogen supply source 92 feeds nitrogen to the inert gas pipe 83b under the control of the control unit 3.

A supply source valve 93, a supply confirmation pressure gauge 94, a mass flow controller 95, and a supply valve 96 are inserted in the middle of the path of the reactive gas pipe 83a. When the supply source valve 93 and the supply valve 96 are opened, the ammonia gas is fed from the ammonia gas supply source 91 to the buffer space 82 through the reactive gas pipe 83 a and the gas supply pipe 83. The supply confirmation pressure gauge 94 determines whether or not the ammonia gas is supplied from the ammonia gas supply source 91 to the reactive gas pipe 83a under a predetermined pressure. The mass flow controller 95 adjusts the flow rate of the ammonia gas flowing through the reactive gas pipe 83a to a predetermined set value.

On the other hand, a mass flow controller 97 and a supply valve 98 are inserted in the middle of the path of the inert gas pipe 83b. When the supply valve 98 is opened, nitrogen gas is fed from the nitrogen gas supply source 92 to the buffer space 82 through the inert gas pipe 83 b and the gas supply pipe 83. The mass flow controller 97 adjusts the flow rate of nitrogen gas flowing through the inert gas pipe 83b to a predetermined set value. When the supply valve 93, the supply valve 96, and the supply valve 98 are all opened, the ammonia gas fed from the reactive gas pipe 83a and the nitrogen gas fed from the inert gas pipe 83b are combined in the gas supply pipe 83 to mix the ammonia and nitrogen The gas is fed to the buffer space 82.

In addition, a bypass pipe 84 that communicates and connects the reactive gas pipe 83a and the inert gas pipe 83b is provided. The bypass piping 84 connects the part between the supply source valve 93 of the reactive gas piping 83a and the supply confirmation pressure gauge 94, and connects the part between the nitrogen supply source 92 of the inert gas piping 83b and the mass flow controller 97 connect. A bypass valve 85 is inserted into the bypass pipe 84. When the bypass valve 85 is opened, the reactive gas pipe 83a and the inert gas pipe 83b are in a communicating state.

The processing gas fed from the gas supply pipe 83 and flowing into the buffer space 82 flows to fill the buffer space 82 by spreading in the buffer space 82 whose fluid resistance is smaller than that of the gas supply hole 81. Then, the processing gas filled with the buffer space 82 is fed into the thermal processing space 65 from the gas supply hole 81.

A gas exhaust hole 86 for exhausting the gas in the heat treatment space 65 is formed at the lower part of the inner wall of the chamber 6. The gas exhaust hole 86 is formed at a lower position than the recess 62 and may also be provided in the reflection ring 69. The gas exhaust hole 86 is connected to the gas exhaust pipe 88 through a buffer space 87 formed in the side wall of the chamber 6 in an annular shape. The gas exhaust pipe 88 is connected to the exhaust part 190. In addition, an exhaust valve 89 and a vacuum pressure gauge 191 are inserted in the middle of the path of the gas exhaust pipe 88. When the exhaust valve 89 is opened, the gas in the heat treatment space 65 is exhausted from the gas exhaust hole 86 through the buffer space 87 to the gas exhaust pipe 88. The vacuum pressure gauge 191 directly measures the pressure of the gas exhaust pipe 88. Since the pressure at the part of the gas exhaust pipe 88 where the vacuum pressure gauge 191 is installed is approximately the same as the pressure in the chamber 6, the pressure measured by the vacuum pressure gauge 191 is also the pressure in the chamber 6. Furthermore, the gas supply holes 81 and the gas exhaust holes 86 may be provided in plural along the circumferential direction of the chamber 6, or they may be slit-shaped.

As the exhaust unit 190, a vacuum pump or exhaust equipment of a factory provided with the heat treatment device 1 can be used. When a vacuum pump is used as the exhaust unit 190 to exhaust the gas environment of the heat treatment space 65 as a closed space without any gas supply from the gas supply hole 81, the pressure in the chamber 6 can be reduced to a vacuum gas environment. Moreover, even when a vacuum pump is not used as the exhaust part 190, by exhausting from the gas supply hole 81 instead of supplying gas, the pressure in the chamber 6 can be reduced to a pressure lower than the atmospheric pressure. The pressure in the decompressed chamber 6 is measured with a vacuum pressure gauge 191.

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 base 74. The base ring 71, the connecting portion 72, and the base 74 are all formed of quartz. That is, the entire holding portion 7 is formed of quartz.

The abutment ring 71 is a circular arc-shaped quartz member that is partly missing from the circular ring shape. The missing part is provided to prevent interference between the transfer arm 11 of the transfer mechanism 10 and the abutment ring 71 described below. The abutment ring 71 is supported on the wall surface of the chamber 6 by being placed on the bottom surface of the recess 62 (refer to FIG. 1). On the upper surface of the abutment ring 71, a plurality of connecting portions 72 (four in this embodiment) are erected along the circumferential direction of the ring shape. The connecting portion 72 is also a quartz member, and is fixed to the abutment ring 71 by welding.

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

300 mm之情形時，導環76之內徑為

320 mm。導環76之內周形成為自保持板75朝向上方擴大之傾斜面。導環76由與保持板75相同之石英形成。導環76可焊接於保持板75之上表面，亦可藉由另行加工之銷等而固定於保持板75。或，亦可將保持板75與導環76加工為一體之構件。A guide ring 76 is provided on the peripheral edge of the upper surface of the holding plate 75. The guide ring 76 is a ring-shaped member having an inner diameter larger than the diameter of the semiconductor wafer W. For example, 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 circumference 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 separately processed pin or the like. Or, the holding plate 75 and the guide ring 76 may be processed as an integral member.

300 mm則該圓之直徑為

270 mm～

280 mm(本實施形態中為

270 mm)。各基板支持銷77由石英形成。複數個基板支持銷77可藉由焊接設置於保持板75之上表面，亦可與保持板75加工為一體。The region on the upper surface of the holding plate 75 that is more inside than the guide ring 76 is a planar holding surface 75a 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 every 30° along the circumference of the outer circumference of the holding surface 75a (the inner circumference of the guide ring 76). The diameter of the circle with 12 substrate support pins 77 (the distance between the opposite 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 can be arranged on the upper surface of the holding plate 75 by welding, or can be processed as a whole 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 base 74 are fixed by welding. That is, the base 74 and the abutment ring 71 are fixedly connected by the connecting portion 72. By supporting the abutment ring 71 of the holding part 7 on the wall surface of the chamber 6, the holding part 7 is attached to the chamber 6. In the state where the holding portion 7 is installed in the cavity 6, the holding plate 75 of the base 74 is in a horizontal posture (posture in which the normal line coincides with the vertical direction). That is, the holding surface 75a of the holding plate 75 becomes a horizontal surface.

The semiconductor wafer W carried into the chamber 6 is placed in a horizontal position and held on the susceptor 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 base 74. More strictly speaking, the upper ends of the 12 substrate support pins 77 contact the lower surface of the semiconductor wafer W to support the semiconductor wafer W. Since the height 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) is uniform, the semiconductor wafer W can be supported in a horizontal posture by the 12 substrate support pins 77.

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

In addition, as shown in FIGS. 2 and 3, the holding plate 75 of the base 74 has an opening 78 penetrating vertically and vertically. The opening 78 is provided for the radiation thermometer 20 to receive the radiation light (infrared light) radiated from the lower surface of the semiconductor wafer W. That is, the radiation thermometer 20 receives the light radiated from the lower surface of the semiconductor wafer W through the opening 78 and the transparent window 21 installed in the through hole 61a of the chamber side 61 and measures the temperature of the semiconductor wafer W. Furthermore, the holding plate 75 of the susceptor 74 is provided with four through-holes 79 penetrating through the through-holes 79 for passing through the jacking pins 12 of the transfer mechanism 10 described below, so that the semiconductor wafer W can be transferred.

FIG. 5 is a top view of the transfer mechanism 10. In addition, 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 a circular arc shape along a substantially circular recess 62. Two jacking 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 the horizontal movement mechanism 13. The horizontal movement mechanism 13 moves the pair of transfer arms 11 to the transfer operation position (the position of the solid line in FIG. 5) for transferring the semiconductor wafer W with respect to the holding portion 7 and the semiconductor wafer held in the holding portion 7 in a plan view. The wafer W is moved horizontally between the overlapping retreat positions (the two-dot chain line position in FIG. 5). The horizontal movement mechanism 13 may be one that rotates each transfer arm 11 by a separate motor, or one that uses a link mechanism and rotates the pair of transfer arms 11 in conjunction with one motor.

In addition, the pair of transfer arms 11 are moved up and down together with the horizontal movement mechanism 13 by the lifting mechanism 14. When the lifting mechanism 14 raises the pair of transfer arms 11 at the transfer operation position, a total of four jacking pins 12 pass through the through holes 79 (refer to FIGS. 2 and 3) provided in the base 74, and the jacking pins 12 The upper end protrudes from the upper surface of the base 74. On the other hand, when the lifting mechanism 14 lowers the pair of transfer arms 11 at the transfer operation position, the jacking pin 12 is pulled out from the through hole 79, and the horizontal movement mechanism 13 opens the pair of transfer arms 11 When moving, each transfer arm 11 moves to the retracted position. The retreat position of the pair of transfer arms 11 is directly above the abutment ring 71 of the holding portion 7. Since the abutment ring 71 is placed on the bottom surface of the recess 62, the retracted position of the transfer arm 11 is inside the recess 62. Furthermore, an exhaust mechanism (not shown) is also installed near the location where the driving part (horizontal movement mechanism 13 and lifting mechanism 14) of the transfer mechanism 10 is installed. The gas environment around the driving part is discharged to the outside of the chamber 6.

Returning to FIG. 1, the flash heating part 5 provided above the chamber 6 is provided with a light source including a plurality of (30 in this embodiment) xenon flash lamps FL on the inside of the housing 51, and covers the top of the light source The reflector 52 is installed in the same manner. In addition, a light radiation window 53 is installed at the bottom of the housing 51 of the flash heating part 5. The lamp radiation window 53 constituting the bottom of the flash heating part 5 is a plate-shaped quartz window formed of quartz. By arranging the flash heating part 5 above the cavity 6, the light radiation window 53 and the upper cavity window 63 are opposed to each other. The flash lamp FL irradiates the heat treatment space 65 with flash from above the chamber 6 through the lamp radiation window 53 and the upper chamber window 63.

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

The xenon flash lamp FL is equipped with: a rod-shaped glass tube (discharge tube), which contains xenon gas inside and is equipped with an anode and a cathode connected to a capacitor at both ends; and a trigger electrode, which is attached to the outer circumference of the glass tube Surface. The xenon gas is an electrical insulator, so even if charge is stored in the capacitor, the electricity will not flow into the glass tube under normal conditions. However, when a high voltage is applied to the trigger electrode to break the insulation, the electricity stored in the capacitor instantly flows into the glass tube, and light is emitted by the excitation of xenon atoms or molecules at this time. This type of xenon flash lamp FL has the following characteristics: because the electrostatic energy stored in the capacitor in advance is converted into an extremely short light pulse of 0.1 millisecond to 100 milliseconds, it can illuminate extremely strongly compared with a light source that continuously illuminates like a halogen lamp HL Light. That is, the flash lamp FL is a pulsed light that emits instantaneously in a very short time of less than 1 second. Furthermore, the light-emitting time of the flash lamp FL can be adjusted according to the coil constant of the lamp power supply for power supply to the flash lamp FL.

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

The halogen heating part 4 provided below the cavity 6 has a plurality of (40 in this embodiment) halogen lamps HL built in the inside of the housing 41. The halogen heating unit 4 is a light irradiation unit that irradiates light from below the chamber 6 to the heat treatment space 65 through the lower chamber window 64 by a plurality of halogen lamps HL, thereby heating 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 arranged in two upper and lower stages. Twenty halogen lamps HL are arranged on the upper section close to the holding portion 7, and 20 halogen lamps HL are arranged on the lower section far from the holding portion 7 on the upper section. Each halogen lamp HL is a rod-shaped lamp with a long cylindrical shape. The upper stage and the lower stage are both 20 halogen lamps HL arranged in such a manner that their length directions are parallel to each other along the main surface of the semiconductor wafer W held by the holding portion 7 (ie, along the horizontal direction). Therefore, the upper section and the lower section are both horizontal planes formed by the arrangement of the halogen lamps HL.

Also, as shown in FIG. 7, both the upper and lower stages are: the arrangement of the halogen lamp HL in the area opposite to the peripheral portion of the semiconductor wafer W held in the holding portion 7 compared to the area opposite to the center portion of the semiconductor wafer W The density is higher. That is, the upper and lower sections are both: the arrangement pitch of the halogen lamps HL at the peripheral part is shorter than that of the central part of the lamp tube arrangement. Therefore, it is possible to irradiate a larger amount of light to the peripheral portion of the semiconductor wafer W that is likely to cause a temperature drop during heating by light irradiation from the halogen heating portion 4.

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

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

In addition, in the housing 41 of the halogen heating part 4, a reflector 43 is also provided under the two-stage halogen lamp HL (FIG. 1). The reflector 43 reflects the light emitted from the plurality of halogen lamps HL to the heat treatment space 65 side.

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 equipped with: a CPU (Central Processing Unit), which is a circuit for performing various arithmetic processing; ROM (Read Only Memory), which is a read-only memory for storing basic programs; RAM (Random Access Memory, random access memory), which is a memory that can be read and written freely for storing various information; and a magnetic disk, which stores control software or data in advance. The processing in the heat treatment device 1 is performed by the CPU of the control unit 3 executing a specific processing program.

In addition to the above structure, in order to prevent excessive temperature rise of the halogen heating part 4, flash heating part 5, and chamber 6 caused by the heat energy generated from the halogen lamp HL and flash lamp FL during the heat treatment of the semiconductor wafer W, the heat treatment device 1 Various cooling structures are also available. For example, a water cooling pipe (not shown) is provided on the wall of the chamber 6. In addition, the halogen heating unit 4 and the flash heating unit 5 are provided with an air cooling structure that forms an airflow inside to discharge heat. In addition, air is also supplied to the gap between the upper chamber window 63 and the light radiation window 53 to cool the flash heating part 5 and the upper chamber window 63.

Next, the processing operation in the heat treatment apparatus 1 will be described. First, the procedure of the heat treatment for the semiconductor wafer W to be processed will be described. Here, the semiconductor wafer W to be processed is a silicon semiconductor substrate in which a high dielectric constant film is formed as a gate insulating film. The high dielectric constant film is deposited on the surface of the semiconductor wafer W by a method such as ALD (Atomic Layer Deposition) or MOCVD (Metal Organic Chemical Vapor Deposition). The heat treatment device 1 irradiates the semiconductor wafer W with a flash in an ammonia gas atmosphere to perform post-film formation heat treatment (PDA), thereby eliminating defects in the high dielectric constant film after film formation. The processing sequence of the heat treatment device 1 described below is performed by the control unit 3 controlling each operation mechanism of the heat treatment device 1.

First, the semiconductor wafer W on which the high dielectric constant film is formed is carried into the chamber 6 of the heat treatment apparatus 1. When the semiconductor wafer W is loaded, the gate valve 185 is opened to open the transfer opening 66, and the semiconductor wafer W with the high dielectric constant film formed is transferred into the chamber 6 by the transfer robot outside the device through the transfer opening 66 Within the heat treatment space 65. At this time, the inside and outside of the chamber 6 are at atmospheric pressure, so as the semiconductor wafer W is carried in, the gas environment outside the device is entrained to the heat treatment space 65 in the chamber 6. Therefore, it is also possible to open the supply valve 98 and continuously supply nitrogen from the nitrogen supply source 92 into the chamber 6, thereby causing the nitrogen flow to flow out from the conveying opening 66, thereby influencing the gas environment outside the device into the chamber 6 Inhibition is minimal. Furthermore, it is preferable that when the gate valve 185 is opened, the exhaust valve 89 is closed to stop the exhaust from the chamber 6. As a result, the nitrogen gas supplied into the chamber 6 only flows out from the conveyance opening 66, so the inflow of the external atmosphere can be prevented more effectively.

The semiconductor wafer W carried in by the transport robot enters the position directly above the holding portion 7 and stops. Then, a pair of the transfer arm 11 of the transfer mechanism 10 moves horizontally from the retracted position to the transfer action position and rises, whereby the jacking pin 12 passes through the through hole 79 and protrudes from the upper surface of the holding plate 75 of the base 74 , And receive the semiconductor wafer W. At this time, the jack-up pin 12 rises above the upper end of the board support pin 77.

After the semiconductor wafer W is placed on the jack-up pin 12, the transfer robot withdraws from the heat treatment space 65, and the transfer opening 66 is closed by the gate valve 185. Then, as the pair of transfer arms 11 descend, the semiconductor wafer W is transferred from the transfer mechanism 10 to the base 74 of the holding portion 7 and held from below in a horizontal posture. The semiconductor wafer W is supported by a plurality of substrate support pins 77 erected on the holding plate 75 and held on the base 74. In addition, the semiconductor wafer W is held on the susceptor 74 with the surface on which the high dielectric constant film is formed as the upper surface. A certain interval is formed between the back surface (the main surface on the opposite side to the surface) of the semiconductor wafer W supported by the plurality of substrate supporting pins 77 and the holding surface 75a of the holding plate 75. The pair of transfer arms 11 that have fallen below the base 74 is retracted to the retracted position, that is, inside the recess 62 by the horizontal movement mechanism 13.

The semiconductor wafer W is housed in the chamber 6, and after the transfer opening 66 is closed by the gate valve 185, the pressure in the chamber 6 is reduced to a pressure lower than the atmospheric pressure. Specifically, by closing the conveyance opening 66, the heat treatment space 65 in the chamber 6 becomes a closed space. In this state, the supply valve 96 and the supply valve 98 for supplying air are closed, and the exhaust valve 89 is opened. Thereby, the inside of the chamber 6 is exhausted without gas supply, and the heat treatment space 65 in the chamber 6 is decompressed.

After the pressure in the chamber 6 is reduced to a specific pressure, the exhaust valve 89 is opened, and the supply source valve 93, the supply valve 96, and the supply valve 98 are opened. By opening the supply source valve 93 and the supply valve 96, ammonia gas is fed from the reactive gas pipe 83a. Furthermore, by opening the supply valve 98, nitrogen gas is fed from the inert gas pipe 83b. The fed ammonia gas and nitrogen gas merge in the gas supply pipe 83. Then, the mixed gas of ammonia and nitrogen is supplied to the heat treatment space 65 in the chamber 6. As a result, in the chamber 6, the periphery of the semiconductor wafer W held by the holding portion 7 forms an ammonia gas atmosphere in a reduced pressure state. The concentration of ammonia in the ammonia gas environment (that is, the mixing ratio of ammonia and nitrogen) is not particularly limited, and can be set to an appropriate value, for example, 10 vol.% or less (about 2.5 vol in this embodiment) .%). The concentration of ammonia can be adjusted by using the mass flow controller 95 and the mass flow controller 97 to control the supply flow rates of ammonia and nitrogen, respectively.

Next, the 40 halogen lamps HL of the halogen heating part 4 are lighted together, and the preheating (auxiliary heating) of the semiconductor wafer W 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 base 74 formed of quartz. The semiconductor wafer W is preheated by being irradiated with light from the halogen lamp HL, and the temperature rises. Furthermore, since the transfer arm 11 of the transfer mechanism 10 is retracted to the inside of the recess 62, the heating by the halogen lamp HL is not hindered.

During the preheating using the halogen lamp HL, the temperature of the semiconductor wafer W is measured by the radiation thermometer 20. That is, the radiation thermometer 20 receives the infrared light radiated from the lower surface of the semiconductor wafer W held on the susceptor 74 through the opening 78 through the transparent window 21 to measure the temperature of the wafer during temperature rise. The measured temperature of the semiconductor wafer W is transmitted to the control unit 3. The control unit 3 monitors whether the temperature of the semiconductor wafer W raised by the light from the halogen lamp HL reaches a specific preheating 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 measured value of the radiation thermometer 20 so that the temperature of the semiconductor wafer W becomes the preheating temperature T1. The preheating temperature T1 is 300°C or more and 600°C or less, and is 450°C in this embodiment.

After the temperature of the semiconductor wafer W reaches the preheating temperature T1, the control unit 3 temporarily maintains the semiconductor wafer W at the preheating temperature T1. Specifically, when the temperature of the semiconductor wafer W measured by the radiation thermometer 20 reaches the preheating temperature T1, the control unit 3 adjusts the output of the halogen lamp HL to maintain the temperature of the semiconductor wafer W at approximately the preheating temperature Temperature T1.

By performing such pre-heating using the halogen lamp HL, the entire semiconductor wafer W is uniformly heated to the pre-heating temperature T1. During the pre-heating stage using the halogen lamp HL, the temperature of the peripheral part of the semiconductor wafer W, which is more likely to generate heat to be dissipated, tends to be lower than that of the central part. However, the arrangement density of the halogen lamp HL in the halogen heating part 4 is at the periphery The area facing the substrate W is higher than the area facing the center of the substrate W. Therefore, the amount of light irradiated to the periphery of the semiconductor wafer W that easily generates heat is increased, so that the in-plane temperature distribution of the semiconductor wafer W in the preheating stage can be made uniform.

When the temperature of the semiconductor wafer W reaches the preheating temperature T1 and a specific time has elapsed, the flash lamp FL of the flash heating section 5 flashes the surface of the semiconductor wafer W held on the susceptor 74. At this time, a part of the flash light radiated from the flash lamp FL is directly irradiated into the chamber 6, and the other part is temporarily reflected by the reflector 52 and then irradiated into the chamber 6, so that the semiconductor wafer W is irradiated by these flashes. Flash heating.

The flash heating is performed by flash irradiation from the flash lamp FL, so the surface temperature of the semiconductor wafer W can be increased in a short time. That is, the flash light irradiated from the flash lamp FL is an extremely short and strong flash after the electrostatic energy previously stored in the capacitor is converted into an extremely short light pulse, and the irradiation time is about 0.1 millisecond to 100 milliseconds. Moreover, by irradiating the flash from the flash lamp FL to the surface of the semiconductor wafer W on which the high dielectric constant film is formed, the surface of the semiconductor wafer W including the high dielectric constant film is instantly heated to the processing temperature T2, thereby performing the film formation After heat treatment. The processing temperature T2, which is the highest temperature (peak temperature) that the surface of the semiconductor wafer W reaches by flash irradiation, is 600° C. or more and 1200° C. or less, and is 1000° C. in this embodiment.

When the surface of the semiconductor wafer W is heated to the processing temperature T2 in an ammonia gas atmosphere and the post-film formation heat treatment is performed, the nitridation of the high dielectric constant film is promoted, and the point defects in the high dielectric constant film, etc. The defect disappeared. Furthermore, since the irradiation time from the flash lamp FL is a short time of 0.1 millisecond or more and 100 milliseconds or less, the time required for the surface temperature of the semiconductor wafer W to rise from the preheating temperature T1 to the processing temperature T2 is also less than 1 second It's a very short time. The surface temperature of the semiconductor wafer W immediately after the flash irradiation drops from the processing temperature T2.

After the flash heating process is completed, the supply valve 96 and the supply valve 98 are closed, and the pressure in the chamber 6 is reduced again. Thereby, harmful ammonia gas can be discharged from the heat treatment space 65 in the chamber 6. Then, the exhaust valve 89 is closed and the supply valve 98 is opened, and nitrogen is supplied into the chamber 6 from the nitrogen supply source 92 to return it to normal pressure (atmospheric pressure). Thereby, the inside of the chamber 6 is replaced with a nitrogen gas atmosphere. In addition, the halogen lamp HL is also turned off, whereby the semiconductor wafer W is also cooled from the preheating temperature T1. The temperature of the semiconductor wafer W during cooling is measured by the radiation thermometer 20, and the measurement result is transmitted to the control unit 3. The control unit 3 monitors whether the temperature of the semiconductor wafer W is lowered to a specific temperature based on the measurement result. Then, after the temperature of the semiconductor wafer W drops below a certain level, one of the transfer arms 11 of the transfer mechanism 10 moves horizontally from the retreat position to the transfer operation position and rises, whereby the jacking pin 12 is lifted from the base 74 The upper surface protrudes so as to receive the heat-treated semiconductor wafer W from the base 74. Then, the transfer opening 66 closed by the gate valve 185 is opened, the semiconductor wafer W placed on the jacking pin 12 is removed by the transfer robot outside the device, and the heating process of the semiconductor wafer W in the heat treatment device 1 is completed .

In addition, the above-mentioned heat treatment device 1 should be maintained regularly or irregularly. The case where maintenance is performed irregularly is a case where some failure occurs in the heat treatment device 1. When performing maintenance of the heat treatment device 1, the inside of the chamber 6 is opened and various pipes are removed. Therefore, it is necessary to completely discharge the harmful ammonia gas from the heat treatment space 65 in the chamber 6 and the entire heat treatment device 1 containing various pipes before maintenance.

However, there are cases in which if only the exhaust valve 89 is opened to exhaust the gas environment in the chamber 6, it is difficult to completely exhaust the ammonia gas remaining in the reactive gas pipe 83a. The ease of discharging the ammonia gas from the reactive gas pipe 83a largely depends on the mass flow controller 95. In the reactive gas piping 83a, mass flow controllers 95 of various full scale sizes are provided according to the purpose of the manufacturing process. For example, when it is necessary to use a larger ammonia gas supply flow, a mass flow controller 95 with a larger full scale size (for example, 100 liters/min) is installed in the reactive gas pipe 83a. On the other hand, when high-precision ammonia gas supply flow control is required, a mass flow controller 95 with a small full scale size (for example, 20 liters/minute) is installed in the reactive gas pipe 83a.

The pressure loss of the smaller full-scale mass flow controller 95 is greater than that of the larger full-scale mass flow controller 95. Therefore, when the reactive gas piping 83a is provided with a smaller full-scale mass flow controller 95, it is difficult to exhaust from the reactive gas piping 83a, and it is difficult to discharge the ammonia gas remaining in the pipe. Therefore, in this embodiment, the ammonia gas is completely discharged from the reactive gas pipe 83a regardless of the full scale size of the mass flow controller 95 as follows. Furthermore, there is no need to open the chamber 6 in the middle of the above-mentioned semiconductor wafer W process, so even if only a small amount of ammonia gas remains in the reactive gas piping 83a when exhausting from the chamber 6 is performed, it will not be a problem .

FIG. 8 is a flowchart showing the sequence of the method of replacing the gas atmosphere of the heat treatment device 1. First, the halogen lamp HL is turned on in a state where there is no semiconductor wafer W in the chamber 6 before maintenance (step S1). By the light from the halogen lamp HL, the gas environment in the chamber 6 is heated to increase the temperature, and the thermal motion of the gas molecules in the gas environment is activated. The heating temperature of the gas environment in step S1 is not particularly limited. For example, by light irradiation from the halogen lamp HL for about 30 minutes, the gas environment in the chamber 6 is heated to about 300°C.

After the gas environment in the chamber 6 is heated, exhaust of the reactive gas pipe 83a is performed (step S2). When performing the exhaust of step S2, the supply source valve 93, the bypass valve 85, and the supply valve 98 are closed, and the supply valve 96 and the exhaust valve 89 are opened. Thereby, from the gas exhaust pipe 88, the chamber 6 and the reactive gas pipe 83a including the mass flow controller 95 (to be precise, the position on the downstream side of the supply source valve 93) is exhausted. The pressure in the gas pipe 83a is reduced. However, as described above, when the full scale size of the mass flow controller 95 installed in the reactive gas piping 83a is small, it is difficult to exhaust from the reactive gas piping 83a, and ammonia gas tends to remain.

Therefore, in this embodiment, exhaust is continued until the measured value of the supply confirmation pressure gauge 94 becomes equal to or lower than the preset first pressure (step S3). Specifically, for example, the supply confirmation pressure gauge 94 is set in advance at atmospheric pressure -90 kPa as the first pressure, and when the measured value becomes equal to or lower than the first pressure, the supply confirmation pressure gauge 94 is caused to transmit an abnormal signal.

When the measured value of the supply confirmation pressure gauge 94 becomes below the first pressure and the supply confirmation pressure gauge 94 sends an abnormal signal, the process proceeds to step S4, the exhaust is stopped, and the nitrogen supply to the reactive gas pipe 83a is performed. At this time, the supply source valve 93, the supply valve 96, and the supply valve 98 are closed, and the bypass valve 85 is opened. Thereby, the nitrogen supplied from the nitrogen supply source 92 passes through the bypass pipe 84 and is then filled into the reactive gas pipe 83a (to be precise, the portion between the supply source valve 93 and the supply valve 96) including the mass flow controller 95. Furthermore, while the reactive gas pipe 83a is being supplied with nitrogen, the exhaust valve 89 is also continuously opened, and the pressure in the chamber 6 is reduced.

In this embodiment, the supply of nitrogen to the reactive gas pipe 83a is continued until the measurement value of the supply confirmation pressure gauge 94 becomes equal to or higher than the second pressure set in advance (step S5). The second pressure is higher than the first pressure. Specifically, for example, 170 kPa is set as the second pressure in the supply confirmation pressure gauge 94 in advance, and when the measured value becomes equal to or higher than the second pressure, the supply confirmation pressure gauge 94 is caused to transmit a normal signal.

When the measured value of the supply confirmation pressure gauge 94 becomes equal to or higher than the second pressure and the supply confirmation pressure gauge 94 sends a normal signal, the process proceeds to step S6, and the control unit 3 determines whether to repeat the above-mentioned exhaust gas and nitrogen supply for a set number of times. For the control unit 3, the set number of repetitions is set in advance using GUI (Graphical User Interface), for example. When the exhaust and nitrogen supply are not repeated the set number of times, step S2 to step S5 are repeated again. For example, when the set number of repetitions is set to "10", the above exhaust and nitrogen supply are repeated 10 times.

In the present embodiment, the exhaust of the reactive gas pipe 83a is continued until the measured value of the supply confirmation pressure gauge 94 becomes equal to or lower than the first pressure. When the full scale size of the mass flow controller 95 is small, it may be difficult to exhaust from the reactive gas piping 83a, but by continuing to exhaust the reactive gas piping 83a until it is supplied to the confirmation pressure gauge Until the measured value of 94 becomes below the first pressure, regardless of the full scale size of the mass flow controller 95, the reactive gas piping 83a can be decompressed to below the first pressure and the residual ammonia gas can be completely removed from the reactive gas piping 83a.地出。 Ground discharge.

Furthermore, after the ammonia gas is discharged from the reactive gas pipe 83a, the supply of nitrogen gas to the reactive gas pipe 83a is continued until the measured value of the supply confirmation pressure gauge 94 becomes the second pressure or more. When the full scale size of the mass flow controller 95 is small, it is difficult to supply gas to the reactive gas piping 83a, but by continuing to supply nitrogen to the reactive gas piping 83a until the supply confirmation pressure gauge 94 Until the measured value becomes the second pressure or higher, regardless of the full scale size of the mass flow controller 95, it is possible to sufficiently supply and fill the reactive gas pipe 83a with nitrogen gas.

In this way, by supplying nitrogen gas after the exhaust gas described above, the ammonia gas can be completely discharged from the reactive gas pipe 83a for supplying ammonia gas, and the reactive gas pipe 83a can be filled with nitrogen gas. As a result, even if the inside of the chamber 6 is opened during maintenance, there is no possibility of leakage of ammonia gas remaining in the reactive gas pipe 83a in a small amount. In addition, by repeating such exhaust from the reactive gas piping 83a and nitrogen supply to the reactive gas piping 83a multiple times, it is possible to more reliably discharge the ammonia gas from the reactive gas piping 83a and to the reactive gas piping Nitrogen is filled in 83a.

The supply confirmation pressure gauge 94 used to determine whether the exhaust gas is stopped and the supply of nitrogen gas is stopped is originally an element for determining whether the ammonia gas is supplied from the ammonia gas supply source 91 at a reasonable pressure. That is, as in the present embodiment, it is possible to completely discharge ammonia gas from the reactive gas pipe 83a and to fill the reactive gas pipe 83a with nitrogen gas without requiring a new special mechanism. Moreover, it is only necessary to stop the exhaust after the supply confirmation pressure gauge 94 sends an abnormal signal, and stop the nitrogen supply after the supply confirmation pressure gauge 94 sends a normal signal, so the control of the supply and exhaustion is easier.

In addition, in this embodiment, light is irradiated from the halogen lamp HL to heat the gas environment in the chamber 6 before exhausting. Thereby, the thermal motion of the gas molecules in the gas environment in the chamber 6 is activated, and the gas molecules are quickly exhausted in the subsequent exhausting step. As a result, it is possible to shorten the exhaust time required until the measured value of the supply confirmation pressure gauge 94 becomes equal to or lower than the first pressure.

The embodiments of the present invention have been described above, but the present invention can be modified in various ways other than the above without departing from the gist of the present invention. For example, in the above step S3, the evacuation is continued until the measurement value of the supply confirmation pressure gauge 94 becomes below the preset first pressure. In addition to this, the evacuation can also be continued until the measurement value of the vacuum pressure gauge 191 Until it becomes a specific value (for example, 0.1 kPa) or less. However, when the full scale size of the mass flow controller 95 is small and it is difficult to exhaust from the reactive gas piping 83a, in most cases, the measured value of the pressure gauge 94 in the supply confirmation becomes the preset first pressure At the following point in time, the measured value of the vacuum pressure gauge 191 has become below the specified value.

In addition, in the above embodiment, the ammonia gas is supplied from the reactive gas pipe 83a, but it is not limited to this. Oxygen (O ₂ ), hydrogen (H ₂ ), and chlorine (Cl _{2) may be supplied from the reactive gas pipe 83a.} ), hydrogen chloride (HCl), ozone (O ₃ ), nitric oxide (NO), nitrous oxide (N ₂ O), nitrogen dioxide (NO ₂ ), nitrogen trifluoride (NF ₃ ), etc. as reactivity gas. In addition, the gas supplied from the inert gas pipe 83b is not limited to nitrogen, and argon (Ar), helium (He), etc. may be supplied as the inert gas from the inert gas pipe 83b. Even when these various gases are used, by applying the technology of the present invention, the reactive gas can be completely discharged from the reactive gas piping 83a and the reactive gas piping 83a can be filled with an inert gas.

In addition, the technology of the present invention is not limited to the case where the full scale size of the mass flow controller 95 is small, and can be preferably applied to the case where the reactive gas piping 83a has a small pipe diameter and large pressure loss, for example.

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

In addition, in the above embodiment, the halogen lamp HL of the filament method is used as a continuous illuminator that emits light continuously for 1 second or longer to preheat the semiconductor wafer W, but it is not limited to this, and a discharge arc lamp may also be used ( For example, a xenon arc lamp) replaces the halogen lamp HL as a continuous lighting lamp for preheating. In this case, the gas environment in the chamber 6 is heated by the light from the arc lamp before exhausting.

In addition, depending on the heat treatment device 1, the substrate to be processed 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 solar cells. In addition, in the heat treatment device 1, activation of implanted impurities, bonding of metal and silicon, or crystallization of polysilicon can also be performed.

1‧‧‧Heat treatment device 3‧‧‧Control Department 4‧‧‧Halogen heating part 5‧‧‧Flash heating section 6‧‧‧Chamber 7‧‧‧Retention Department 10‧‧‧Transfer agency 11‧‧‧Transfer arm 12‧‧‧Ejector pin 13‧‧‧Horizontal movement mechanism 14‧‧‧Lifting mechanism 20‧‧‧Radiation Thermometer 21‧‧‧Transparent window 41‧‧‧Shell 43‧‧‧Reflector 51‧‧‧Shell 52‧‧‧Reflector 53‧‧‧Light radiation window 61‧‧‧The side of the chamber 61a‧‧‧Through hole 62‧‧‧Concave 63‧‧‧Upper chamber window 64‧‧‧Lower chamber window 65‧‧‧Heat treatment space 66‧‧‧Transport opening 68‧‧‧Reflective ring 69‧‧‧Reflective ring 71‧‧‧Abutment Ring 72‧‧‧Connecting part 74‧‧‧Pedestal 75‧‧‧Holding plate 75a‧‧‧Keep the surface 76‧‧‧Guide Ring 77‧‧‧Substrate support pin 78‧‧‧Opening 79‧‧‧Through hole 81‧‧‧Gas supply hole 82‧‧‧Buffer space 83‧‧‧Gas supply pipe 83a‧‧‧Reactive gas piping 83b‧‧‧Inert gas piping 84‧‧‧Bypass piping 85‧‧‧Bypass valve 86‧‧‧Gas vent 87‧‧‧Buffer space 88‧‧‧Gas exhaust pipe 89‧‧‧Exhaust valve 91‧‧‧Ammonia supply source 92‧‧‧Nitrogen supply source 93‧‧‧Supply source valve 94‧‧‧Supply confirmation pressure gauge 95‧‧‧Mass Flow Controller 96‧‧‧Supply valve 97‧‧‧Mass Flow Controller 98‧‧‧Supply valve 185‧‧‧Gate valve 190‧‧‧Exhaust 191‧‧‧Vacuum Pressure Gauge FL‧‧‧Flash HL‧‧‧Halogen lamp S1‧‧‧Step S2‧‧‧Step S3‧‧‧Step S4‧‧‧Step S5‧‧‧Step S6‧‧‧Step W‧‧‧Semiconductor Wafer

Fig. 1 is a longitudinal sectional view showing the structure of the heat treatment device 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 base. Figure 4 is a cross-sectional view of the base. Figure 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 flowchart showing the sequence of the gas environment replacement method of the heat treatment device.

1‧‧‧Heat treatment device

3‧‧‧Control Department

4‧‧‧Halogen heating part

5‧‧‧Flash heating section

6‧‧‧Chamber

7‧‧‧Retention Department

10‧‧‧Transfer agency

20‧‧‧Radiation Thermometer

21‧‧‧Transparent window

41‧‧‧Shell

43‧‧‧Reflector

51‧‧‧Shell

52‧‧‧Reflector

53‧‧‧Light radiation window

61‧‧‧The side of the chamber

61a‧‧‧Through hole

62‧‧‧Concave

63‧‧‧Upper chamber window

64‧‧‧Lower chamber window

65‧‧‧Heat treatment space

66‧‧‧Transport opening

68‧‧‧Reflective ring

69‧‧‧Reflective ring

74‧‧‧Pedestal

81‧‧‧Gas supply hole

82‧‧‧Buffer space

83‧‧‧Gas supply pipe

83a‧‧‧Reactive gas piping

83b‧‧‧Inert gas piping

84‧‧‧Bypass piping

85‧‧‧Bypass valve

86‧‧‧Gas vent

87‧‧‧Buffer space

88‧‧‧Gas exhaust pipe

89‧‧‧Exhaust valve

91‧‧‧Ammonia supply source

92‧‧‧Nitrogen supply source

93‧‧‧Supply source valve

94‧‧‧Supply confirmation pressure gauge

95‧‧‧Mass Flow Controller

96‧‧‧Supply valve

97‧‧‧Mass Flow Controller

98‧‧‧Supply valve

185‧‧‧Gate valve

190‧‧‧Exhaust

191‧‧‧Vacuum Pressure Gauge

FL‧‧‧Flash

HL‧‧‧Halogen lamp

W‧‧‧Semiconductor Wafer

Claims (5)

A heat treatment device is characterized in that it heats the substrate by irradiating the substrate with light, and is provided with: a chamber for accommodating the substrate; a light irradiation section for irradiating the substrate accommodated in the chamber with light; 1 supply pipe, which supplies reactive gas to the chamber; the second supply pipe, which supplies inert gas to the chamber; exhaust pipe, which exhausts the gas environment in the chamber; pressure gauge, which is installed in The first supply piping; a mass flow controller installed in the first supply piping; a gate valve installed in the first supply piping; and a bypass piping that connects the first supply piping and the second supply piping; and In the first supply pipe, the gate valve, the pressure gauge, and the mass flow controller are sequentially installed from the upstream side; the bypass pipe is connected between the gate valve and the pressure gauge of the first supply pipe; The exhaust pipe exhausts the first supply pipe until the measured value of the pressure gauge becomes below the first air pressure, and then supplies the inert gas from the second supply pipe through the bypass pipe to the first supply pipe until the pressure is reached. The measured value of the meter becomes more than the second atmospheric pressure higher than the above-mentioned first atmospheric pressure. The heat treatment device of claim 1, wherein the light irradiating part includes a continuous illuminating lamp, Before exhausting from the exhaust pipe, light is irradiated from the continuous illuminator to heat the gas environment in the chamber. A method for replacing a gas atmosphere of a heat treatment device, which is characterized in that it is a method for replacing a gas environment of a heat treatment device that heats the substrate by irradiating light on the substrate, and a first chamber for accommodating the substrate is connected with a reactive gas supply. The supply piping, the second supply piping for supplying inert gas, and the exhaust piping for exhausting the gas environment in the chamber, the first supply piping and the second supply piping are connected by bypass piping, and are connected to the first The supply piping is provided with a gate valve, a pressure gauge and a mass flow controller in order from the upstream side, and the bypass piping is connected between the gate valve and the pressure gauge of the first supply piping; the gas atmosphere substitution method of the heat treatment device It includes: an exhaust step, which is performed from the exhaust pipe to exhaust the first supply pipe until the measured value of the pressure gauge becomes below the first air pressure; and an air supply step, which is after the exhaust step, The inert gas is supplied to the first supply pipe from the second supply pipe through the bypass pipe until the measured value of the pressure gauge becomes equal to or higher than the second air pressure higher than the first air pressure. For example, the gas environment substitution method of the heat treatment device of claim 3, which repeats the above-mentioned exhausting step and the above-mentioned gas supplying step. Such as the gas environment substitution method of the heat treatment device of claim 3 or 4, which is further equipped with heating Step, the heating step is before the exhaust step, light irradiation is performed from the continuous illuminator to heat the gas environment in the chamber.

Images