WO2009157484A1

WO2009157484A1 - Annealing apparatus

Info

Publication number: WO2009157484A1
Application number: PCT/JP2009/061518
Authority: WO
Inventors: 智博鈴木; 昌剛米田; 繁河西; 和広大矢
Original assignee: 東京エレクトロン株式会社
Priority date: 2008-06-25
Filing date: 2009-06-24
Publication date: 2009-12-30

Abstract

Provided is an annealing apparatus which anneals a subject to be processed. The annealing apparatus is provided with: a processing container wherein the subject to be processed is stored; a supporting means which supports the subject to be processed in the processing chamber; a gas supply means which supplies a processing gas into the processing container; an air-releasing means which releases the atmosphere from the processing container; and a rear-side heating means having a plurality of laser elements which radiate heating light toward the entire rear surface of the subject to be processed.

Description

Annealing equipment

The present invention relates to an annealing apparatus that performs an annealing process on an object to be processed such as a semiconductor wafer, and more particularly to an annealing apparatus that performs an annealing process by irradiating heating light from a laser element or an LED (Light Emitting Diode) element.

Generally, in order to manufacture a semiconductor integrated circuit, various processes such as a film formation process, an oxidation diffusion process, a modification process, an etching process, and an annealing process are repeatedly performed on a semiconductor wafer such as a silicon substrate. Among these processes, in the annealing process for activating impurity atoms doped in the wafer after ion plantation, it is necessary to raise and lower the temperature of the semiconductor wafer at a higher speed in order to minimize impurity diffusion. is there.

In the conventional annealing apparatus, the wafer is heated using a halogen lamp or the like. However, it takes at least about 1 second until the halogen lamp is lit and stabilized as a heat source. Therefore, recently, an annealing process using an LED element that is superior in switching responsiveness and capable of increasing and lowering the temperature faster than a halogen lamp as a heating source has been proposed (Japanese Patent Publication No. 2005-536045). .

In addition, a technique has been proposed in which a laser element is used as another heating source, and the wafer is heated while scanning the surface of the wafer with heating light generated from the laser element (for example, JP-A-2005-244191). .

As described above, when an LED element or a laser element is used as a heating source, there is an advantage that a high-speed heating / cooling operation on the wafer is relatively possible. Further, in the case of the LED element, since the wavelength of the heating light has a certain width, it has an advantage that it can be heated uniformly in the plane without depending on the surface state of the wafer.

However, when an LED element is used, the light emission efficiency is about 10 to 30%, which is considerably lower than the light emission efficiency of the laser element of about 40 to 50%. That is, there is a problem that energy efficiency is lower than in the case of a laser element.

On the other hand, in the case of the laser element, as described above, it is superior in terms of light emission efficiency than the LED element. However, since the heating light is monochromatic light (single wavelength), there is a problem that the temperature distribution is uneven (nonuniform) depending on the structure and surface state of the wafer surface to be heated. For example, when an amorphous part, a metal part, an insulating film part, etc. are mixed on the wafer surface, these have different main light absorption wavelengths depending on the material (the absorptance is different for a specific wavelength). . Accordingly, when these are irradiated with laser light (heating light) that is monochromatic light, a non-uniform temperature distribution is generated on the wafer surface due to the difference between the materials having the absorptance corresponding to the wavelength.

Summary of the Invention

The present invention has been devised to pay attention to the above problems and to effectively solve them. An object of the present invention is to provide an annealing apparatus capable of heating an object to be processed in a short time and with a uniform in-plane temperature and having high energy conversion efficiency and contributing to energy saving. is there.

The present invention provides an annealing apparatus that performs an annealing process on a target object, a processing container in which the target object is accommodated, a support unit that supports the target object in the processing container, Gas supply means for supplying a processing gas to the apparatus, exhaust means for exhausting the atmosphere in the processing container, and back surface side heating means having a plurality of laser elements that irradiate heating light toward the entire back surface of the object to be processed. And an annealing apparatus characterized by comprising:

According to the present invention, by irradiating the object to be processed from the back surface of the object to be processed having a uniform surface state using laser light as heating light, the object to be processed can be obtained in a state where the in-plane temperature is uniform in a short time. Can be heated. In addition, the high energy conversion efficiency by the laser element can contribute to energy saving.

Preferably, the plurality of laser elements are arranged over an area having a size capable of covering at least the entire back surface of the object to be processed.

For example, the laser element is a semiconductor laser element, a solid-state laser element, or a gas laser element.

Also preferably, the heating light emitted from the laser element has a wavelength band that can selectively heat the silicon substrate.

Preferably, either one of the support means and the back surface side heating means is supported rotatably.

Preferably, a surface-side heating unit that is disposed to face the back-side heating unit and irradiates heating light toward the surface of the object to be processed is further provided.

In this case, preferably, the surface side heating means includes a plurality of LED (LightＬＥＤEmitting Diode) elements or SLDs (Super Luminescent Diode) arranged over a region that can cover at least the entire surface of the object to be processed. It has an element.

Thus, when an LED element or an SLD element is used as the surface side heating means, it is possible to irradiate heating light having a wide emission wavelength from the surface side of the object to be processed. Thereby, the said to-be-processed object can be heated in a state with a uniform in-plane temperature for a short time, without depending on the surface state of a to-be-processed object.

Preferably, at least one of the back side heating unit and the front side heating unit is provided with a cooling mechanism for cooling with a refrigerant.

In this case, preferably, the cooling mechanism has a refrigerant passage for flowing the refrigerant, and the refrigerant passage is set so that a cross-sectional area of the flow passage gradually decreases from the refrigerant inlet to the refrigerant outlet. Has been.

As described above, by setting the flow passage area of the refrigerant passage to be gradually reduced from the refrigerant inlet to the refrigerant outlet, the amount of heat per unit length of the refrigerant passage taken by the refrigerant from the object to be cooled can be made constant. As a result, the temperature of the cooling object can be made uniform along the length direction of the refrigerant passage.

In this case, preferably, the width of the refrigerant passage is constant, and the height of the refrigerant passage is determined based on the flow rate of the refrigerant, the specific heat of the refrigerant, the density of the refrigerant, and the distance from the refrigerant inlet. . Furthermore, in this case, preferably, the height f (x) of the refrigerant passage is expressed by the following equation: f (x) =
A ² · (To−T (x)) ² / (Q · cp2 ² · ρ ² · (T ′ (x)) ² )
A: Constant for obtaining heat transfer coefficient Q: Flow rate of refrigerant cp: Specific heat of refrigerant ρ: Density of refrigerant x: Distance from refrigerant inlet T (x): Temperature (function) of refrigerant at distance x
T ′ (x): differentiation of the function T (x) To: given by the target temperature.

Preferably, the cooling mechanism is provided with a plurality of heat pipes that promote cooling.

Preferably, a reflection surface is formed on the back surface side heating means.

FIG. 1 is a cross-sectional view showing a schematic configuration of an embodiment of an annealing apparatus according to the present invention. FIG. 2A is a plan view showing the surface (lower surface) of the surface-side heating means. FIG. 2B is an enlarged plan view of a part (one LED module) of the surface (lower surface) of the surface side heating means. FIG. 3 is an enlarged sectional view showing a part A in FIG. 1 which is a part of the surface side heating means. FIG. 4 is a plan view showing the surface (upper surface) of the back surface side heating means. FIG. 5 is an explanatory diagram for explaining a light emission state of the semiconductor laser element. FIG. 6 is a schematic view showing an irradiation state of laser light (heating light) from the laser element. FIG. 7 is an enlarged perspective view showing one refrigerant passage in the upper cooling mechanism of the element mounting head. FIG. 8 is a partial configuration diagram showing a lower part of a processing vessel including a supporting unit according to a modified embodiment of the annealing apparatus of the present invention. FIG. 9 is a schematic diagram for obtaining the temperature change of the refrigerant in a minute section in the length direction of the refrigerant passage. FIG. 10 is a graph showing the height function f (x) of the refrigerant passage. FIG. 11 is a diagram illustrating an example of the height change of the cross-sectional shape of the refrigerant passage. FIG. 12 is a plan view showing an arrangement state of the laser units of the heating means and the semiconductor laser elements. FIG. 13 is a graph showing the distribution of heating light (light output) output from the heating means shown in FIG. FIG. 14 is an enlarged perspective view showing the laser unit. 15A and 15B are graphs showing how the light spots output from the semiconductor laser element spread. FIG. 16 is a plan view showing an example of a modified embodiment of the arrangement state of the laser units of the heating means. FIG. 17 is a graph showing the distribution of heating light (light output) output from the heating means shown in FIG. FIG. 18 is an enlarged perspective view showing an example of a modified embodiment of the laser unit.

Hereinafter, an embodiment of an annealing apparatus according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing a schematic configuration of an embodiment of an annealing apparatus according to the present invention. FIG. 2A is a plan view showing the surface (lower surface) of the surface-side heating means. FIG. 2B is an enlarged plan view of a part of the surface (lower surface) of the surface side heating means. FIG. 3 is an enlarged sectional view showing a part A in FIG. 1 which is a part of the surface side heating means. FIG. 4 is a plan view showing the surface (upper surface) of the back surface side heating means. FIG. 5 is an explanatory diagram for explaining a light emission state of the semiconductor laser element. FIG. 6 is a schematic view showing an irradiation state of laser light (heating light) from the laser element. Here, a semiconductor wafer made of a silicon substrate is used as the object to be processed. An example in which impurities are implanted into the surface and the wafer is annealed will be described.

As shown in FIG. 1, the annealing apparatus 2 of this embodiment has a processing vessel 4 made of aluminum or an aluminum alloy and having a hollow interior. The processing container 4 includes a cylindrical side wall 4A, a ceiling plate 4B joined to the upper end of the side wall 4A, and a bottom plate 4C joined to the bottom of the side wall 4A. On the side wall 4A, a loading / unloading port 6 having a size capable of loading / unloading a semiconductor wafer W as an object to be processed is formed. A gate valve 8 that can be opened and closed is attached to the carry-in / out port 6.

In the processing container 4, support means 10 for supporting the wafer W is provided. The support means 10 has a plurality of, for example, three support pins 12 (only two are shown in FIG. 1) and a lifting arm 14 connected to the lower end of each support pin 12. . Each of the elevating arms 14 can be moved up and down by an actuator (not shown), and can move up and down with the wafer W supported by the upper end portion of the support pins 12.

A gas supply means 16 is formed in a part of the peripheral part of the ceiling plate 4B. The gas supply means 16 includes a gas introduction port 18 formed in the ceiling plate 4B and a gas pipe 20 connected to the gas introduction port 18, and illustrates a necessary processing gas into the processing container 4. It can introduce | transduce, controlling flow volume via the flow controller which is not performed. Here, N ₂ gas or a rare gas such as Ar or He can be used as the processing gas. The ceiling plate 4B is formed with an upper refrigerant passage 19 through which a refrigerant for cooling the ceiling plate 4B flows.

Further, a gas exhaust port 22 is formed in a part of the peripheral portion of the bottom plate 4C. The gas exhaust port 22 is provided with exhaust means 24 for exhausting the atmosphere in the processing container 4. The exhaust means 24 has a gas exhaust pipe 26 connected to the gas exhaust port 22, and a pressure regulating valve 28 and an exhaust pump 30 are sequentially provided in the gas exhaust pipe 26. The bottom plate 4C is formed with a lower refrigerant passage 31 through which a refrigerant for cooling the bottom plate 4C flows.

A large-diameter opening is formed in the center of the ceiling plate 4B, and the surface side heating means 32 is provided in the opening so that the surface (upper surface) of the wafer W can be heated. In addition, a large-diameter opening is also formed in the central portion of the bottom plate 4C, and a back-side heating unit 34, which is a feature of the present invention, is provided in the opening so as to face the front-side heating unit 32. Thus, the back surface (lower surface) of the wafer W can be heated. Here, the surface of the wafer W refers to a surface on which devices and the like are formed by performing various processes such as film formation and etching. On the other hand, the back surface of the wafer W refers to a surface on the side opposite to the wafer surface where no device or the like is formed. Moreover, when the heating amount of the back surface side heating means 34 is sufficiently large, it can be omitted without providing the front surface side heating means 32.

<Description of surface side heating means>
Next, the surface side heating means 32 will be described. The surface side heating means 32 has an element mounting head 36 that is fitted into the opening of the ceiling plate 4B with a slight gap. The element mounting head 36 is made of a material having high thermal conductivity such as aluminum or aluminum alloy. The element mounting head 36 is a portion of a circular ring-shaped mounting flange 36A formed on the upper side of the element mounting head 36, with a thermal insulator 38 made of polyetherimide or the like interposed between the ceiling plate 4B and the ceiling plate 4B. It is supported by the plate 4B.

Further, a sealing material 40 made of an O-ring or the like is interposed on the upper and lower sides of the thermal insulator 38 so that the airtightness of this portion can be maintained. An element mounting recess 42 having a diameter slightly larger than the diameter of the wafer W is formed on the lower surface of the element mounting head 36. A plurality of LED modules 44 are provided in a plane (flat) portion of the element mounting recess 42 over a region that can cover at least the entire surface of the wafer W. In addition, a light transmission plate 45 made of, for example, a quartz plate is attached to the opening portion of the element attachment recess 42.

As shown in FIG. 2A, here, the LED modules 44 are formed in, for example, a regular hexagonal shape with one side of about 25 mm, and are arranged close to each other or closely arranged so that adjacent sides are substantially in contact with each other. For example, when the diameter of the wafer W is 300 mm, about 80 LED modules 44 are provided. FIG. 2B shows an enlarged plan view of one LED module. As shown in FIGS. 2B and 3, each LED module 44 is configured by arranging a large number of LED elements 46 vertically and horizontally on the surface thereof. In this case, the size of each LED element 46 is about 0.5 mm × 0.5 mm, and about 1000 to 2000 LED elements 46 are mounted on one LED module 44. The LED elements 46 are grouped into a plurality of groups within one LED module 44, and the LED elements 46 in the same group are connected in series.

And as shown in FIG.1 and FIG.3, the upper side cooling mechanism 48 is provided above the LED module 44. FIG. The upper cooling mechanism 48 has a refrigerant passage 50 having a rectangular cross section provided in the element mounting head 36. A refrigerant inlet pipe 50A is connected to the refrigerant inlet 51 at one end of the refrigerant passage 50, and a refrigerant discharge pipe 50B is connected to the refrigerant outlet 53 at the other end. Thereby, the LED module 44 can be cooled by flowing the refrigerant through the refrigerant passage 50 and taking away the heat generated from the LED module 44. Fluorinert, Galden (trade name) or the like can be used as the refrigerant. Here, the coolant passage 50 is formed so as to be folded back in a meandering manner over substantially the entire surface of the element mounting head 36 so as to efficiently remove heat from the upper surface side of the LED module 44 and cool it. It has become.

As shown in FIGS. 1 and 3, heat pipes 52 each having a U-shape extending in the vertical direction are embedded in both side wall portions of each refrigerant passage 50. Thereby, the LED module 44 can be cooled more efficiently.

Furthermore, a power supply control box 54 is provided above the ceiling plate 4B, and a control board 56 corresponding to each LED module 44 is provided there. A power supply line 58 extends from the control board 56 to each LED module 44 so that power can be supplied to each LED module 44.

<Description of backside heating means>
Next, the back surface side heating means 34 will be described. A thick light transmission plate 62 made of, for example, a transparent quartz glass plate is airtightly attached to the opening of the bottom plate 4C by a fixture 66 through a seal member 64 such as an O-ring. The back surface side heating means 34 has a plurality of laser modules 60 arranged below the light transmission plate 62. Specifically, a laser mounting casing 61 is attached so as to cover the lower part of the light transmission plate 62 provided in the opening of the bottom plate 4C, and a plurality of laser modules 60 are attached and fixed to the laser mounting casing 61. Has been.

As shown in FIG. 4, the laser modules 60 are distributed substantially evenly over the entire area of a size that can cover at least the entire back surface of the wafer W. In this case, the size of one laser module 60 is set to a size of, for example, about 50 mm × 60 mm × 25 mm, which is considerably larger than the LED module 44, and the output of one laser module 60 is also large. Unlike the LED module 44, it is not necessary to provide it as closely packed.

Therefore, when the diameter of the wafer W is 300 mm, about 50 to 100 laser modules 60 are provided. Each laser module 60 has one laser element 68 and a cooling unit 70 as a cooling mechanism. Therefore, the laser element 68 is arranged over a region that can cover the entire back surface of the wafer W. As shown in FIG. 5, the laser element 68 includes a light emitting layer 72 sandwiched between two electrodes, and an irradiation area of laser light emitted from the light emitting layer 72, that is, the heating light L1. 74 is an ellipse having a major axis in a direction perpendicular to the extending direction of the light emitting layer 72.

In this case, the spreading angle of the heating light L1 in the major axis direction is about 30 to 50 degrees, and the spreading angle in the minor axis direction is 10 degrees or less. Therefore, in order to realize in-plane uniform heating on the back surface of the wafer W, the major axis direction of the elliptical irradiation area 74 is set to be the radial direction of the wafer W as shown in FIG. It is preferable to do. The emission wavelength of the laser element 68 is a specific wavelength in the range of ultraviolet light to near-infrared light, for example, in the range of 360 to 1000 nm, particularly in the range of 800 to 970 nm, which has a high absorption rate for the wafer W of the silicon substrate. It is preferable to use a specific wavelength (monochromatic light). Specifically, as the laser element 68, for example, a semiconductor laser element using GaAs can be used. Here, the arrangement of the laser modules 60 shown in FIG. 4 is merely an example, and the present invention is not limited to this.

Referring back to FIG. 1, a power supply line 76 is connected to each laser element 68 of the laser module 60 so that power is supplied. The cooling units 70 of the laser module 60 are connected in series with each other through a refrigerant passage 78. A cooling medium introduction pipe 80 is connected to the cooling section 70 on the most upstream side, and a cooling medium discharge pipe 82 is connected to the cooling section 70 on the most downstream side. Can be cooled. As this refrigerant, water, Fluorinert or Galden (trade name) can be used.

Further, a reflection surface 84 that has been subjected to a surface treatment or the like is formed on the inner side surface of the laser mounting casing 61. Thereby, the heating light reflected by the back surface side of the wafer W can be reflected upward again. Here, the laser module 60 in which the laser element 68 and the cooling unit 70 are integrated is described as an example, but a structure in which both are separated and provided separately may be employed.

The overall operation control of the annealing apparatus 2 formed as described above, for example, various controls such as process temperature, process pressure, gas flow rate, on / off of the front side heating means 32 and the back side heating means 34 are performed by, for example, a computer. This is performed by the control unit 86. A computer-readable program necessary for this control is normally stored in the storage medium 88. As the storage medium 88, for example, a flexible disk, a CD (Compact Disc), a CD-ROM, a hard disk, a flash memory, a DVD, or the like is used.

Next, an annealing process performed using the annealing apparatus 2 configured as described above will be described. First, a semiconductor wafer W made of, for example, a silicon substrate is previously brought into a reduced-pressure atmosphere through a gate valve 8 opened from a load-lock chamber, a transfer chamber, or the like (not shown) that has been previously in a reduced-pressure atmosphere by a transfer mechanism (not shown). Is carried into the processing container 4.

On the surface of the wafer W, amorphous silicon, a metal, an oxide film, or the like as described above is formed, and a surface state in which various fine regions having different absorptances with respect to the wavelength of the heating light are formed. ing. The loaded wafer W is transferred onto the support pins 12 provided on the lift arm 14 by driving the lift arm 14 up and down. Thereafter, the transfer mechanism is retracted, the gate valve 8 is closed, and the inside of the processing container 4 is sealed.

Next, a processing gas, for example, N ₂ gas or Ar gas, is flowed from the gas pipe 20 of the gas supply means 16 while the flow rate is controlled, and the inside of the processing container 4 is maintained at a predetermined pressure. At the same time, the front side heating means 32 provided on the ceiling plate 4B and the back side heating means 34 provided on the bottom plate 4C are both turned on, and the LED element 46 and the back side heating means of the front side heating means 32 are turned on. Both of the 34 laser elements 68 are turned on and irradiated with heating light. Thereby, the wafer W is heated from both the upper and lower surfaces and annealed. In this case, the process pressure is, for example, about 100 to 10000 Pa, the process temperature (wafer temperature) is, for example, about 800 to 1100 ° C., and the lighting times of the LED element 46 and the laser element 68 are about 1 to 10 seconds, respectively.

Since the surface (upper surface) of the wafer W is heated by the heating light having a certain emission width emitted from each LED element 46, the surface side of the wafer W is not dependent on the surface state of the wafer W. Can be heated to a state in which the in-plane temperature is substantially uniform.

Further, monochromatic heating light is radiated from the laser elements 68 to the back surface (lower surface) of the wafer W. With this radiated light, as shown in FIG. 6, an elliptical irradiation area 74 is formed on the back surface of the wafer W in a state of being distributed substantially evenly over the entire back surface of the wafer. In this case, as described above, the heating light L1 (see FIG. 5) emitted from the laser element 68 is monochromatic light, but the back surface of the wafer W is in a uniform state with silicon or silicon oxide. The wavelength of L1 is set to a wavelength having a high absorption rate for silicon or silicon oxide, for example, a specific wavelength in the range of 360 to 1000 nm, more preferably a specific wavelength in the range of 800 to 970 nm. Therefore, the back surface side of the wafer can be heated to a state in which the in-plane temperature is substantially uniform. That is, the wafer W can be heated evenly and quickly in a short time with a high uniformity of in-plane temperature from the front side and the back side.

Further, the laser element 68 (light conversion efficiency: 40 to 50%) used for the back surface side heating means 34 is more than the LED element 46 (light conversion efficiency: 10 to 30%) used for the surface side heating means 32. High energy conversion efficiency. Therefore, it can be said that it can contribute to energy saving as compared with the case where the LED element is used as the back surface side heating means.

Furthermore, since the front surface side heating means 32 and the back surface side heating means 34 are heated from the front and back (upper and lower) surfaces of the wafer W, there is almost no deviation in temperature distribution in the thickness direction of the wafer W. As a result, it is possible to prevent the wafer W from warping due to the temperature difference between the front and back surfaces of the wafer W.

Further, the element mounting head 36 is heated by a large amount of heat generated in the surface side heating means 32, but this is caused by flowing a refrigerant through the refrigerant passage 50 of the upper cooling mechanism 48 provided in the element mounting head 36. It can be cooled efficiently. Further, in this case, since the heat pipe 52 is provided along the height direction of the refrigerant passage 50 as shown in FIGS. 1 and 3, the heat conversion efficiency in this portion is increased, and the element mounting head is correspondingly increased. The cooling efficiency of 36 can be further increased. For example, when copper is used as the material of the element mounting head 36, the thermal conductivity is 300 to 350 W / m · deg, whereas by providing the heat pipe 52, the thermal conductivity is 400 to 600 W / m · deg. deg can be improved.

Similarly, a large amount of heat is generated also in the back surface side heating means 34, and the laser element 68 becomes hot, but by flowing a coolant through the cooling unit 70 as a cooling mechanism provided in each laser module 60, The heat is removed, and each laser element 68 can be efficiently cooled.

Here, both the front surface side heating means 32 and the back surface side heating means 34 are provided. However, as described above, the front surface side heating means 32 may not be provided, and only the back surface side heating means 34 may be provided. Good. In this case, the rate of temperature rise is slightly lower than when both the heating means 32 and 34 are provided, but in this case as well, the entire wafer W is rapidly heated in a state where the in-plane temperature is highly uniform. can do.

As described above, in the annealing apparatus that performs the annealing process on the object to be processed, for example, the semiconductor wafer W, the back surface side heating unit 34 having the plurality of laser elements 68 is provided, and the laser light is used as the heating light L1 to obtain the surface state. By irradiating the object to be processed from the back surface of the object to be processed, the object to be processed can be heated in a state where the in-plane temperature is uniform in a short time. In addition, the high energy conversion efficiency by the laser element can contribute to energy saving.

<Modification of backside heating means>
In the description of the back surface side heating means, each laser module 60 has one laser element. However, here, a plurality of laser elements 68, more specifically, three laser elements are grouped into lasers. The laser module 160 is unitized by being mounted on the module 160, and a plurality of the laser modules 160 are installed in combination in a planar manner. As shown in FIG. 14, the laser module 160 has a housing 194 formed in a regular polygon, that is, a regular hexagonal cylinder, and the three laser elements are disposed in the housing 194. 68 are installed so as to be parallel to each other, and laser light can be output as heating light from the upper end surface side of the housing 194.

In the case shown in FIG. 12, a total of 37 regular hexagonal laser modules 160 are arranged densely in a substantially concentric manner so that the sides are adjacent to each other. Therefore, 111 laser elements 68 are provided. FIG. 12 also shows an elliptical irradiation area 74 formed by laser light, which is heating light output from each laser element 68.

Here, as shown in FIG. 14, the three laser elements 68 are mounted in parallel so that their length directions are orthogonal to a line segment connecting a pair of opposing angles. The three laser elements 68 are electrically connected in series with each other internally, and two power supply lines 76 extend from the laser module 160 to supply power.

In addition, a cooling unit 70 is integrally provided in the laser module 160 in order to cool the heat generated from the laser element 68, and the cooling unit 70 has flexibility for circulating a refrigerant. A refrigerant inflow pipe 202 and a refrigerant outflow pipe 204 are provided (see FIG. 14). The refrigerant inflow pipe 202 and the refrigerant outflow pipe 204 are connected in series between the adjacent laser modules 160 so that the refrigerant flows in series across the cooling units 70 of all the laser modules 160. Yes.

A refrigerant introduction pipe 80 is connected to the cooling unit 70 on the most upstream side, and a refrigerant discharge pipe 82 is connected to the cooling unit 70 on the most downstream side (see FIG. 1), and the refrigerant flows therethrough. As a result, the laser module 160 is cooled. As this refrigerant, water, Fluorinert or Galden (trade name) can be used.

Here, as described above with reference to FIG. 12, the regular hexagonal laser module 160 is concentrically arranged in a region having a size that can cover the entire back surface of the semiconductor wafer W. Each laser module 160 is individually detachable from the laser mounting casing 61 so as to be detachable, and the mounting angle can be adjusted individually.

In this case, the spreading angle of the heating light L1 in the minor axis direction is ± 10 degrees or less as shown in FIG. 15A, and the spreading angle in the major axis direction is about ± 15 to ± 25 degrees as shown in FIG. 15B. It is. Therefore, here, in order to uniformly heat the back surface of the wafer W in the plane, the major axis direction of the elliptical irradiation area 74 is set so as to be as close as possible to the circumferential direction of the wafer W as shown in FIG. Yes.

Specifically, as described above, the laser modules 160 are concentrically arranged here, and are concentrically divided into four zones here. The innermost zone is composed of one laser module 160 located in the center, the outer middle zone is composed of six laser modules 160, and the outer inner zone is 12 outside. The outermost outermost zone is composed of 18 laser modules 160.

Each laser module 160 is detachable so that the mounting angle (rotational position) can be adjusted, and the major axis of the elliptical irradiation area 74 formed by the mounted laser element 68 is as much as possible. The mounting angle (rotation position) is adjusted and mounted so as to align along the circumferential direction of the wafer W. In this case, since the housing 194 of the laser module 160 is a regular hexagon, the mounting angle can be adjusted in units of 60 degrees.

Therefore, the laser module 160 in each of the four zones has to be attached so that the major axis direction of the irradiation area 74 does not completely coincide with the circumferential direction of the wafer W. Alternatively, the position of the laser module 160 is adjusted by rotating the mounting angle of the laser module 160 by 60 degrees, for example, so that the angle formed by the circumferential direction (tangential direction) of the wafer W and the major axis direction is as small as possible. Install. For the laser module 160 in the innermost peripheral zone, the mounting angle is not limited due to its characteristics, and the spread of the irradiation area with respect to the outer inner / inner peripheral zone is the same regardless of the direction.

FIG. 13 shows the relationship between the radial direction of the wafer W having a diameter of 300 mm, the light output from each zone, and the total light output of each zone. In the graph of FIG. 13, the curve A1 indicates the light output from the innermost zone, the curve A2 indicates the light output from the middle inner zone, the curve A3 indicates the light output from the outer inner zone, and the curve A4 indicates the light output from the outermost peripheral zone, and the curve A0 indicates the total light output obtained by adding the curves A1 to A4.

As is clear from this graph, the light output for each zone is shown with a steep peak, the directivity of the heating light for each zone is high, and the spreading of the heating light to the adjacent zones is very large. It is running low. Therefore, as shown by the curve A0, the total light output is substantially constant light output from the center of the semiconductor wafer over the entire radial region, and the in-plane of the irradiation amount of the heating light is obtained. It can be seen that the uniformity can be set high.

Here, the emission wavelength of the laser element 68 is a specific wavelength in the range of ultraviolet light to near infrared light, for example, in the range of 360 to 1000 nm, in particular, 800 to 970 nm, which has a high absorption rate on the wafer W of the silicon substrate. It is preferable to use a specific wavelength (monochromatic light) within the range. As the laser element 68, for example, a semiconductor laser element using GaAs can be used. Here, the arrangement of the laser modules 160 shown in FIG. 12 is merely an example, and the present invention is not limited to this.

Moreover, in the laser module 160 equipped with the three laser elements 68, the power is controlled individually for each of the four zones, and the major axis direction of the elliptical irradiation area 74 with high directivity is in the circumferential direction of the wafer W. Therefore, the spread of the irradiation area 74 in the radial direction of the wafer W becomes very small, and the temperature controllability is improved for each zone as shown in FIG. 13. As a result, as shown in FIG. As the total light output shown by the curve A0, the irradiation amount from the center to the peripheral part of the wafer W can be made relatively uniform, so that the in-plane temperature uniformity of the wafer W can be improved.

Further, as described above, since the irradiation is performed so that the major axis direction of the elliptical irradiation area 74 is along the circumferential direction of the wafer W, light leakage to the outside of the wafer W is reduced, and the light energy is reduced accordingly. It can be used efficiently.

In addition, when the temperature distribution in the wafer surface changes due to long-term use or the like, or when the temperature distribution is finely adjusted to perform different heat treatment, the laser module 160 corresponding to the corresponding part is attached to the laser mounting casing. The distribution of the irradiation amount of the heating light L1 can be adjusted to be optimum by individually extracting from 61 and rotating the mounting angle by, for example, 60 degrees to change the mounting angle.

<Modified Embodiment of Laser Module Arrangement>
Next, a modified embodiment of the arrangement state of the laser modules of the back surface side heating means will be described. In the embodiment described above, as shown in FIG. 12, each laser module 160 is mounted such that irradiation is performed so that the major axis direction of the elliptical irradiation area 74 is as close to the circumferential direction of the wafer W as possible. Although the angle is adjusted, the present invention is not limited to this, and the irradiation area 74 may be arranged so that irradiation is performed such that the major axis direction of the irradiation area 74 is along the radial direction of the wafer.

16 is a plan view showing an example of a modified embodiment of the arrangement state of the laser modules of the back surface side back surface heating means, and FIG. 17 shows the distribution of the heating light (light output) output from the back surface side heating means shown in FIG. It is a graph to show. As described above, here, the mounting angle is such that the major axis of the elliptical irradiation area 74 formed by the laser element 68 of each laser module 160 of the back surface side heating means 34 is aligned along the radial direction of the wafer W as much as possible. (Rotation position) is adjusted. Also in this case, the laser modules 160 in each of the four zones include a part of the laser modules 160 that must be mounted so that the major axis direction of the irradiation area 74 does not completely coincide with the radial direction of the wafer W. Occurs in

The distribution of the light output from each zone of the heating / reverse heating means 34 at this time is shown in FIG. 17, where the curve B1 indicates the light output from the innermost zone and the curve B2 from the middle inner zone. The light output is shown, the curve B3 shows the light output from the outer and inner peripheral zone, the curve B4 shows the light output from the outermost peripheral zone, and the curve B0 shows the total light output including the curves B1 to B4. .

As is clear from this graph, the light output is expressed in a state where the peak is gentle for each zone as compared with the case shown in FIG. There is considerable spread of heating light. Therefore, as shown by the curve B0, the total light output is gradually decreased as the central portion of the semiconductor wafer is considerably large and goes in the radial direction. Accordingly, in this case, the in-plane uniformity of the irradiation amount of the heating light is deteriorated as compared with the case described with reference to FIGS. It can be seen that the sex can be increased to some extent.

The mounting angles of the respective laser modules 160 in FIGS. 12 and 16 show the extreme cases, and are merely examples, and it is needless to say that the mounting angles are not limited to these mounting angles. .

<Modified Embodiment of Laser Module>
Next, a modified embodiment of the laser module 160 will be described. In the laser module 160 shown in FIG. 14, the three laser elements 68 mounted on the laser module 160 are arranged in parallel so that their length directions are perpendicular to a line segment connecting a pair of opposing angles. However, the present invention is not limited to this, and the length direction of the three laser elements 68 may be orthogonal to the line segments orthogonal to the pair of opposing sides.

FIG. 18 is an enlarged perspective view showing an example of a modified embodiment of such a laser module. As shown in FIG. 18, here, the three laser elements 68 mounted on the laser module 160 are mounted so that their length directions are orthogonal to the line segments orthogonal to the pair of opposing sides. Yes. The laser modules 160 formed in this way may be arranged in a state as shown in FIG.

Furthermore, the laser module 160 as shown in FIG. 14 and the laser module 160 as shown in FIG. 18 may be mixed and provided in combination. For example, in FIG. 12, the laser module 160 shown in FIG. 14 is applied to all the inner and inner peripheral zones, and the major axis direction of the irradiation area 74 in the outer and outer peripheral zones is the peripheral direction of the wafer W. The laser modules 160 shown in FIG. 18 may be applied to portions that are greatly different. According to this, since the amount of the heating light spreading in the radial direction of the wafer W can be further reduced, the light energy can be used more efficiently correspondingly.

In each of the above embodiments, the case where the number of laser elements 68 mounted on one laser module 160 is three has been described as an example, but it is needless to say that the number is not limited thereto. Here, the shape of the laser module 160 is a regular hexagon, but is not limited to this, and may be a regular polygon such as a regular triangle, a regular pentagon, or a regular octagon.

<Modification of heat pipe>
In the above embodiment, the heat pipe 52 provided in the element mounting head 36 is provided so as to be completely embedded outside the refrigerant passage 50 as shown in FIG. 3, but is not limited thereto. For example, you may comprise as shown in FIG. FIG. 7 is an enlarged perspective view showing one refrigerant passage in the upper cooling mechanism of the element mounting head.

In this case, the upper end portion of the heat pipe 52 formed in a U-shape is exposed in the upper portion of the refrigerant passage 50. A plurality (many) of such heat pipes 52 are arranged at substantially equal pitches along the flow direction of the refrigerant passage 50. According to this aspect, since the upper end portion of the heat pipe 52 is in direct contact with the refrigerant, the heat exchange rate for cooling can be further improved, and the cooling efficiency can be increased accordingly.

<Modified Embodiment>
Next, a modified embodiment of the annealing apparatus according to the present invention will be described. In the previous embodiment, since the position of the irradiation area 74 irradiated on the back surface of the semiconductor wafer W is fixed, it can be said that a slight temperature distribution may occur in the in-plane direction of the wafer W. Therefore, in this modified embodiment, the irradiation area 74 can be relatively scanned (moved), and the uniformity of the wafer temperature in the in-plane direction is further improved. FIG. 8 is a partial configuration diagram showing a lower part of a processing vessel including a supporting unit in a modified embodiment of such an annealing apparatus. In FIG. 8, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

In order to relatively scan (move) the irradiation area 74, here, the support means 10 that supports the semiconductor wafer W is attached to the rotation mechanism 89 and is rotated. In other words, here, the support means 10 that supports the wafer W is configured integrally with the rotating levitating body 90 that forms part of the rotating mechanism 89. The base end portion of each lifting arm 14 of the support means 10 is attached and fixed to a ring-shaped member 92. On the other hand, a plurality of strip-shaped support pillars 93 extending in the vertical direction are arranged at an equal pitch along the circumferential direction of the virtual cylinder, and their upper ends are connected to a cylindrical floating upper ferromagnetic body 94. A ring-shaped member 92 is further connected to the floating upper ferromagnetic body 94.

Also, the lower end side of each support column 93 is connected to a circular ring-shaped floating upper lower ferromagnetic body 96. The circular ring-shaped floating lower ferromagnetic member 96 extends in a flange shape in the horizontal direction. With such a configuration, as will be described later, the rotary levitator 90 can be moved up and down while being lifted, whereby the support pins 12 that support the wafer W can be raised and lowered.

The bottom plate 4C of the lower portion of the processing container 4 has a double cylindrical body in which a space that can accommodate the rotary levitating body 90 and can move the rotary levitating body 90 up and down by a predetermined stroke amount is formed. The floating housing 98 of the structure is connected. The lower region of the floating housing portion 98 is a horizontal housing portion 100 that accommodates the floating upper lower ferromagnetic member 96 and is large enough to move the floating upper lower ferromagnetic member 96 up and down by a predetermined stroke amount. .

A plurality of levitation electromagnet assemblies 102 are arranged at a predetermined pitch along the circumferential direction on the upper surface side of the upper partition wall 100A that partitions the horizontal housing portion 100. A ferromagnetic body 104 is attached to the lower surface side of the upper partition wall 100A. In addition, the vertical position sensor 106 is disposed on the inner surface side (upper surface side) of the lower partition wall 100B that partitions the horizontal housing portion 100 so that the floating lower ferromagnetic member 96 is sandwiched between the lower ferromagnetic member 104 and the ferromagnetic member 104. Is attached.

Thus, the support means 10 is set to an arbitrary height by adjusting the electromagnetic force of the levitation electromagnet assembly 102 while detecting the height position of the levitation lower lower ferromagnetic body 96 by the vertical position sensor 106. Can be done. In this case, a plurality of vertical position sensors 106 are provided along the circumferential direction to prevent tilting of the rotating levitated body 90.

Here, rotation control is performed with the position where, for example, 2 mm has been raised from the state in which the rotating levitated body 90 is in contact with the bottom plate side as a fixed position. A position that is raised by 10 mm, for example, from this fixed position is a transfer position at which the wafer W is transferred.

Also, a plurality of rotating electromagnet assemblies 108 are arranged at a predetermined pitch along the circumferential direction on the outer side of the outer peripheral wall 98A of the levitation accommodating portion 98. A ferromagnetic body 110 is attached to the inner side of the outer peripheral wall 98A. In addition, a horizontal position sensor 112 is attached to the outer peripheral side of the inner peripheral wall 98B of the levitation accommodating portion 98 so as to sandwich the floating upper ferromagnetic material 94 with the ferromagnetic material 110. As a result, while the horizontal position sensor 112 detects the horizontal position of the floating upper ferromagnetic body 94, a rotating magnetic field is applied to the rotating electromagnet assembly 108, thereby rotating the rotating levitating body 90 in a fixed position. Can be done.

As described above, since the wafer W can be rotated while being supported on the rotating levitated body 90, an elliptical irradiation area 74 irradiated on the back surface of the wafer W as shown in FIG. The wafer W can be relatively rotated in the circumferential direction of the wafer W. Thereby, the uniformity of the in-plane temperature of the wafer W can be further improved.

Further, by rotating the wafer W in this way, it is possible to cancel the nonuniformity of the thermal condition in the circumferential direction of the inner wall surface of the processing container 4. From this point, the uniformity of the in-plane temperature of the wafer W can be further improved. The configuration of the rotation mechanism 89 is merely an example, and is not limited to this. For example, a rotation mechanism disclosed in Japanese Patent Laid-Open No. 2002-280318 may be used. Furthermore, the semiconductor wafer W side is rotated here, but instead, the back surface side heating means 34 side may be rotated.

<Modification of cooling mechanism>
In the above-described upper cooling mechanism 48, heat is taken from the upper surface side of the LED module 44 by flowing the refrigerant through the refrigerant passage 50, thereby cooling it. The flow passage cross-sectional area of the refrigerant passage 50 having a rectangular cross section is set to be constant along the flow direction of the refrigerant passage 50. For this reason, in the part close to the refrigerant inlet, the refrigerant sufficiently takes heat from the LED module 44 side, which is the object to be cooled, and cooling is performed efficiently. However, as the refrigerant flows down to the downstream side, the temperature of the refrigerant It is conceivable that the cooling efficiency gradually decreases as the temperature rises.

That is, the cooling efficiency changes along the flow direction of the refrigerant passage 50. For this reason, there is a concern that the temperature distribution becomes uneven depending on the arrangement position of the LED modules 44 that are the objects to be cooled, and the temperature becomes non-uniform. That is, the LED modules 44 arranged on the upstream side of the refrigerant passage 50 are efficiently cooled, whereas the LED modules 44 arranged on the downstream side are not efficiently cooled, and the LED modules 44 are not efficiently cooled. There is a concern that the temperature distribution will be uneven.

Therefore, in this modification of the cooling mechanism, in order to remove the fear, the cross-sectional area of the flow path is set so as to gradually decrease from the refrigerant inlet 51 to the refrigerant outlet 53 of the refrigerant passage 50. Thereby, the cooling efficiency is made constant along the flow direction of the refrigerant passage 50, the temperature of the entire cooling object is kept constant, and the temperature non-uniformity does not occur.

Here, the principle for making the temperature of the cooling object constant by making the cooling efficiency constant along the flow direction of the refrigerant passage 50 will be described. FIG. 9 is a schematic diagram for obtaining the temperature change of the refrigerant in a minute section in the length direction of the refrigerant passage. Here, in order to facilitate understanding of the present invention, the simulation was performed with the width of the refrigerant passage being constant (unit length = 1 m) and the height of the refrigerant passage being expressed as a function of “f (x)”. In FIG. 9, the horizontal axis “x” indicates the distance from the refrigerant inlet 51 to the refrigerant outlet 53, and the vertical axis “y” indicates the height “f (x)” of the refrigerant passage 50.

It is assumed that the refrigerant is flowing from the refrigerant inlet 51 toward the refrigerant outlet 53 at a flow rate “Q”. And the temperature of the refrigerant | coolant in the position of distance "x" is represented as "T (x)." Here, if the condition that the temperature of the bottom surface of the refrigerant passage 50 along the x-axis is constant at To is satisfied, the temperature of the object to be cooled can be maintained constant along the flow direction of the refrigerant passage 50.

First, the heat transfer coefficient h of the refrigerant is expressed as the following Expression 1.
h = 0.664 (ρ ^1/2 ) (μ ^−1/6 ) (cp ^1/3 ) (k ^2/3 ) (L ^−1/2 ) (u ^1/2 ) (1)
Here, each symbol is as follows.
ρ: Density of refrigerant (kg / m ³ )
μ: Viscosity of refrigerant (kg / m · sec)
cp: Specific heat of refrigerant (J / kg · K)
k: Refrigerant thermal conductivity (W / m · K)
L: Cooling part length (m)
u: Refrigerant speed (m / sec)
If it is considered that there is not much temperature change, it can be set as a constant A except for the speed of the refrigerant, and can be regarded as a function only of the speed of the refrigerant. That is, the constant A is defined as follows.
0.664 (ρ ^1/2 ) (μ ^−1/6 ) (cp ^1/3 ) (k ^2/3 ) (L ^−1/2 )
= A (constant)

In FIG. 9, when the amount of heat flowing into the refrigerant when the refrigerant advances by Δx is “W”, the following equation 2 is obtained.
W = {T (x + Δx) −T (x)} · cp · ρ · Δx · f (x)
= A · Δx · (To−T (x)) · Δt√u (x) (2)
cp: Specific heat of refrigerant ρ: Refrigerant density u (x): Refrigerant flow velocity at position x Δt: Time required for refrigerant to advance by Δx A: Constant for obtaining heat transfer coefficient where Δt / Δx = Summarizing the above equations as 1 / u (x), u (x) = Q / f (x), the following equation 3 is obtained.
cp · ρ · (T (x + Δx) −T (x)) / Δx = A · (To−T (x)) / √ (Q · f (x)) (3)
If the above formula 3 is arranged, the following formula 4 is obtained.
f (x) = A ² · (To−T (x)) ² / (Q · cp ² · ρ ² · (T ′ (x)) ² ) (4)
Note that “T ′ (x) = (T (x + Δx) −T (x)) / Δx”.

Thus, the height function f (x) of the refrigerant passage 50 depends on the temperature change T (x) of the refrigerant. In other words, if the temperature change is determined, the height of the refrigerant passage 50 is naturally determined.

Here, using a specific numerical example, when substituting into Equation 4 above, Equation 5 is obtained. Specific numerical examples are as follows.
Refrigerant flow rate Q: 2 liter / min (= 2 × 10 ⁻³ / 60 m ³ / sec)
Target temperature To: 100 ° C
Refrigerant passage width: 10mm
Length of refrigerant passage: 5m
Medium inlet temperature: -50 ° C, medium outlet temperature: -40 ° C
(Assuming that the temperature change changes linearly, “T (x) = 2 · x−50”)
Specific heat of refrigerant cp: 1000 J / kg · K
Refrigerant density ρ: 1800 kg / m ³
Constant A: 230
Here, in consideration of the unit and the width of the refrigerant passage, the refrigerant flow rate Q is converted to a unit [m ³ / sec], and in the above-described simulation, the width of the refrigerant passage is set to a unit length of 1 m (= 1000 mm). Since it is set, f (x) is multiplied by 1/100 to convert this into the width of the refrigerant passage of 10 mm.
f (x) = 230 ² · [100− (2 · x−50)] ² / [(2 × 10 ⁻³ / 60) × 1000 ² × 1800 ² × 2 ² × 100] (5)
Here, the above equation 5 is represented in a graph as shown in FIG. That is, at the refrigerant inlet 51 of the refrigerant passage 50, the height of the refrigerant passage 50 is set to about 27.6 mm, and the height of the refrigerant passage 50 is sequentially reduced according to the distance from the refrigerant inlet 51 to reduce the flow passage cross-sectional area. Then, the refrigerant outlet 53 corresponds to an aspect in which the height of the refrigerant passage 50 is set to about 24 mm.

FIG. 11 shows an example of the change in the height of the cross-sectional shape of the refrigerant passage 50 corresponding to this aspect. In this case, the height of the refrigerant passage 50 is gradually decreased toward the downstream side. In this case, of course, the flow rate of the refrigerant gradually increases as it goes downstream.

In this manner, by setting the height of the refrigerant passage 50 to gradually decrease toward the downstream side (when the width of the refrigerant passage 50 is constant), the temperature of the lower surface of the refrigerant passage 50 is set to 100 ° C. (= To ) Can be kept constant.

In the above specific example, the case where the width of the refrigerant passage 50 is made constant has been described. However, when the height of the refrigerant passage 50 is made constant, the width of the refrigerant passage 50 is gradually reduced to gradually increase the cross-sectional area of the flow path. Can be narrowed. Of course, the above numerical examples are merely examples, and the present invention is not limited thereto.

Thus, by setting the flow passage area of the refrigerant passage 50 to be gradually reduced from the refrigerant inlet 51 toward the refrigerant outlet 53, the unit of the refrigerant passage 50 taken by the refrigerant from the object to be cooled, for example, the LED module 44. The amount of heat per length can be made constant. As a result, the temperature of the cooling target can be made uniform along the length direction of the refrigerant passage 50.

Although the semiconductor laser using GaAs has been described as an example of the laser element 68, the present invention is not limited to this, and other solid-state laser elements such as a YAG laser element and a garnet laser element can of course be used. . Furthermore, a gas laser element can also be used. Although the case where the LED element 46 is used as the surface side heating unit 32 has been described as an example here, the present invention is not limited to this, and an SLD (Super Luminescent Diode) element can also be used.

In addition, here, a semiconductor wafer is described as an example of the object to be processed, but this semiconductor wafer includes a silicon substrate and a compound semiconductor substrate such as GaAs, SiC, and GaN. Furthermore, the present invention is not limited to these substrates, and the present invention can also be applied to glass substrates, ceramic substrates, and the like used in liquid crystal display devices.

Claims

In an annealing apparatus that performs an annealing process on a workpiece,
A processing container in which the object to be processed is accommodated;
A support means for supporting the object to be processed in the processing container;
Gas supply means for supplying a processing gas into the processing container;
Exhaust means for exhausting the atmosphere in the processing vessel;
Back surface side heating means having a plurality of laser elements that irradiate heating light toward the entire back surface of the object to be processed;
An annealing apparatus comprising:
2. The annealing apparatus according to claim 1, wherein the plurality of laser elements are arranged over a region having a size capable of covering at least the entire back surface of the object to be processed.
The annealing apparatus according to claim 1, wherein the laser element includes a semiconductor laser element, a solid-state laser element, or a gas laser element.
The annealing apparatus according to any one of claims 1 to 3, wherein the heating light emitted from the laser element has a wavelength band capable of selectively heating the silicon substrate.
5. The annealing apparatus according to claim 1, wherein any one of the support unit and the back surface side heating unit is rotatably supported. 6.
6. The apparatus according to claim 1, further comprising a surface-side heating unit that is disposed to face the back-side heating unit and irradiates heating light toward the surface of the object to be processed. The annealing apparatus as described.
The surface-side heating means has a plurality of LED (Light Emitting Diode) elements or SLD (Super Luminescent Diode) elements arranged over a region that can cover at least the entire surface of the object to be processed. An annealing apparatus according to claim 6.
The annealing apparatus according to claim 6 or 7, wherein at least one of the back surface side heating means and the front surface side heating means is provided with a cooling mechanism for cooling with a refrigerant.
The cooling mechanism has a refrigerant passage for flowing the refrigerant,
The annealing apparatus according to claim 8, wherein the refrigerant passage is set such that a cross-sectional area of the flow path gradually decreases from a refrigerant inlet toward a refrigerant outlet.
The width of the refrigerant passage is constant, and the height of the refrigerant passage is determined based on the flow rate of the refrigerant, the specific heat of the refrigerant, the density of the refrigerant, and the distance from the refrigerant inlet. Item 10. An annealing apparatus according to Item 9.
The height f (x) of the refrigerant passage is given by the following formula f (x) =
A 2 · (To−T (x)) 2 / (Q · cp2 2 · ρ 2 · (T ′ (x)) 2 )
A: Constant for obtaining heat transfer coefficient Q: Flow rate of refrigerant cp: Specific heat of refrigerant ρ: Density of refrigerant x: Distance from refrigerant inlet T (x): Temperature (function) of refrigerant at distance x
The annealing apparatus according to claim 10, wherein T ′ (x): differentiation of the function T (x) is given at a target temperature.
The annealing apparatus according to any one of claims 8 to 11, wherein the cooling mechanism includes a plurality of heat pipes that promote cooling.
The annealing apparatus according to any one of claims 1 to 12, wherein a reflective surface is formed on the back surface side heating means.
The heating light output from each laser element has an elliptical irradiation area,
2. The annealing apparatus according to claim 1, wherein each of the laser elements is arranged such that a major axis direction of the elliptical irradiation area is along a circumferential direction of the object to be processed.
The annealing apparatus according to claim 14, wherein the plurality of laser elements are grouped into a plurality of zones concentrically and are controllable for each group.
The annealing apparatus according to claim 14 or 15, wherein a plurality of the laser elements are collectively mounted on a plurality of laser modules and unitized.
The annealing apparatus according to claim 16, wherein the laser module is formed in a regular polygon shape.
The annealing apparatus according to claim 16 or 17, wherein the laser module is detachably attached so that position adjustment is possible.