JP2008028235A - Cooling processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling processing apparatus capable of preventing transfer of a metal contamination substances or particles between substrates. <P>SOLUTION: A first ceramic plate 20, formed of a ceramic having emissivity and thermal conductivity that is larger than that of quartz is formed on a bottom cooling plate 10, having a temperature kept at a predetermined value by the cooling water supplied from a cooling water supply source 15. Support members 50 are erected and provided at three or more portions on the upper surface of the first ceramic plate 20. Push-up pins 31, having received heated a semiconductor wafer W that has moved downward and are embedded in the through holes of the first ceramic plate 20; and thus, the semiconductor wafer W approximates the first ceramic plate 20 in point contact by the support members 50, and are supported and cooled. Since the semiconductor wafer W is supported at point contact by the support members 50, the metal contaminated substance etc. can be prevented from transferring among semiconductor wafers W. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is a semiconductor substrate after heating, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, a substrate for an optical disk, etc. (hereinafter simply referred to as “substrate”), particularly after being heated by flash irradiation from a flash lamp. The present invention relates to a cooling processing apparatus that performs a cooling process on the substrate.

  In recent years, higher integration of semiconductor devices has progressed, and it is desired to reduce the junction depth as the gate length becomes shorter. In order to satisfy the demand for such shallow junctions, only the surface of the semiconductor wafer into which ions are implanted is irradiated for a very short time by irradiating the surface of the semiconductor wafer with a flash using a xenon flash lamp or the like. A technique for raising the temperature to several milliseconds or less has been proposed (for example, Patent Document 1).

  The radiation spectral distribution of a xenon flash lamp ranges from the ultraviolet region to the near infrared region, has a shorter wavelength than the conventional halogen lamp, and almost coincides with the fundamental absorption band of a silicon semiconductor wafer. Therefore, when the semiconductor wafer is irradiated with flash light from the xenon flash lamp, the semiconductor wafer can be rapidly heated with little transmitted light. It has also been found that if the flash irradiation is performed for a very short time of several milliseconds or less, only the vicinity of the surface of the semiconductor wafer can be selectively heated. For this reason, if the temperature is raised for a very short time by a xenon flash lamp, only the ion activation can be performed without diffusing ions deeply.

JP 2004-319754 A

  In the heat treatment apparatus using a xenon flash lamp as disclosed in Patent Document 1, the semiconductor wafer may not be heated up to the target temperature only by flash irradiation for a moment. The semiconductor wafer is preheated to about 600 ° C. For this reason, the semiconductor wafer after the completion of the flash heating is also at a high temperature of about several hundred degrees Celsius, and a cooling step after the flash heating is indispensable for storing in the cassette case for transport.

  A cooling unit incorporated in a heat treatment apparatus using a conventional flash lamp performs a cooling process by directly placing a heated semiconductor wafer on a quartz plate whose back surface is in contact with a metal cooling plate. I was doing. However, in this cooling process, the quartz plate and the back surface of the semiconductor wafer are in surface contact. Therefore, if the back surface of a certain wafer is contaminated with metal components or particles, the contaminated material passes through the quartz plate to the subsequent wafer. There was a risk of being transferred to the back side. That is, there is a problem that metal contamination and particles are transmitted between wafers.

  In the conventional cooling unit, if a heated semiconductor wafer is placed directly on a quartz plate, a gas layer is sandwiched between the quartz plate and the back surface of the wafer, causing a side slip of the semiconductor wafer. A skid prevention pin for preventing this was provided on the quartz plate. However, if the semiconductor wafer placed on the quartz plate slips and collides with the skid prevention pins, the edge of the wafer may be damaged.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a cooling processing apparatus capable of preventing transfer of metal contaminants and particles between substrates.

  In order to solve the above-mentioned problems, a first aspect of the present invention is a cooling processing apparatus for performing a cooling process on a heated substrate, and a bottom cooling plate that is maintained at a predetermined temperature by a cooling mechanism, and placed on the bottom cooling plate The first ceramic plate having a higher emissivity and thermal conductivity than quartz and the upper surface of the first ceramic plate are projected at least at three locations, and the substrate is brought into close contact with the first ceramic plate by point contact. And a supporting member to support.

  According to a second aspect of the present invention, in the cooling processing apparatus according to the first aspect of the present invention, the distance between the top of the support member and the upper surface of the first ceramic plate is 0.2 mm or more and 5 mm or less.

  According to a third aspect of the present invention, in the cooling processing apparatus according to the first or second aspect of the present invention, the planar size of the ceramic plate is equal to or larger than the planar size of the substrate.

  According to a fourth aspect of the present invention, there is provided the cooling processing apparatus according to any one of the first to third aspects, wherein the upper cooling plate is disposed above the bottom cooling plate so as to face the bottom cooling plate. And a second ceramic plate attached to the lower surface of the upper cooling plate and having a higher emissivity and thermal conductivity than quartz.

  According to a fifth aspect of the present invention, there is provided a cooling processing apparatus for performing a cooling process on a heated substrate, an upper cooling plate maintained at a predetermined temperature by a cooling mechanism, and a lower surface of the upper cooling plate, A ceramic plate having a high emissivity and thermal conductivity, at least three push-up pins provided below the ceramic plate and supporting the substrate by point contact from the lower surface, and the at least 3 receiving the heated substrate. And a pin elevating means for raising the push-up pin of the book and holding the substrate at a close position below the ceramic plate.

  According to a sixth aspect of the present invention, in the cooling processing apparatus according to any one of the first to fifth aspects of the present invention, the temperature of the heated substrate is set to 400 ° C. or higher.

  According to a seventh aspect of the present invention, in the cooling apparatus according to any one of the first to fifth aspects, the heated substrate is a substrate after being heated by flash light irradiation from a flash lamp.

  According to invention of Claim 1, a board | substrate is made to adjoin to a 1st ceramic board at least three places of the upper surface of a 1st ceramic board with a larger emissivity and thermal conductivity than the quartz mounted on the bottom part cooling plate. Since the supporting member that supports by point contact is projected, it is avoided that the substrate to be cooled comes into surface contact with the first ceramic plate, and metal contaminants and particles are prevented from being transferred between the substrates. Can do.

  According to the invention of claim 2, since the distance between the top of the support member and the top surface of the first ceramic plate is 0.2 mm or more and 5 mm or less, the first efficiency is suppressed while suppressing the cooling efficiency of the substrate. Contact between the ceramic plate and the substrate can be reliably prevented.

  According to the invention of claim 3, since the planar size of the ceramic plate is equal to or larger than the planar size of the substrate, the cooling efficiency of the substrate can be further improved.

  According to the invention of claim 4, the cooling efficiency of the substrate is further improved by further including the upper cooling plate and the second ceramic plate having a higher emissivity and thermal conductivity than quartz stuck to the lower surface thereof. Can be made.

  According to the invention of claim 5, the substrate supported by the point contact with the push-up pin is lifted to the ceramic plate having higher emissivity and thermal conductivity than the quartz stuck on the lower surface of the upper cooling plate, and is raised to the close position. Therefore, it is possible to prevent the substrate to be cooled from coming into surface contact with the ceramic plate, and to prevent transfer of metal contaminants and particles between the substrates.

  According to the invention of claim 6, the temperature of the substrate after heating is 400 ° C. or more, and diffusion of metal contaminants into the substrate can be prevented.

  According to the invention of claim 7, the substrate after heating is a substrate after being heated by flash irradiation from a flash lamp, and diffusion of metal contaminants into the substrate can be prevented.

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

  First, a schematic configuration of the entire substrate processing apparatus incorporating the cooling processing apparatus according to the present invention will be described. FIG. 1 is a plan view showing a substrate processing apparatus 100 incorporating a cooling processing unit 140 which is a cooling processing apparatus according to the present invention, and FIG. 2 is a front view thereof. The substrate processing apparatus 100 is an apparatus that performs annealing by irradiating a disk-shaped semiconductor wafer with flash light from a xenon flash lamp. 1 and FIG. 2 are partly cross-sectional views as appropriate, and details are simplified as appropriate. In FIGS. 1 and 2, an XYZ orthogonal coordinate system in which the Z-axis direction is a vertical direction and the XY plane is a horizontal plane is appropriately attached as necessary to clarify the directional relationship.

  As shown in FIGS. 1 and 2, the substrate processing apparatus 100 includes an indexer unit 110 and an indexer unit 110 for loading an unprocessed semiconductor wafer W into the apparatus and unloading the processed semiconductor wafer W outside the apparatus. A delivery robot 120 that takes in and out the semiconductor wafer W, an alignment unit 130 that positions an unprocessed semiconductor wafer W, a cooling processing unit (cooler) 140 that cools the semiconductor wafer W after heating, an alignment unit 130, The apparatus includes a transfer robot 150 that takes in and out the semiconductor wafer W with respect to the cooling processing unit 140 and the like, and a heat treatment unit 160 that performs flash heat treatment on the semiconductor wafer W.

  In addition, a transfer chamber 170 that accommodates the transfer robot 150 is provided as a transfer space of the semiconductor wafer W by the transfer robot 150, and the alignment unit 130, the cooling processing unit 140, and the heating processing unit 160 are connected to the periphery of the transfer chamber 170. Are arranged.

  The indexer unit 110 is a part on which two carriers 91 are transported and placed by an automatic guided vehicle (AGV) or the like, and the semiconductor wafer W is carried into and out of the substrate processing apparatus 100 while being accommodated in the carrier 91. The Further, the indexer unit 110 is configured such that the carrier 91 is moved up and down as indicated by an arrow 91U in FIG. 2 so that an arbitrary semiconductor wafer W can be taken in and out by the delivery robot 120.

  The delivery robot 120 is capable of sliding movement as shown by an arrow 120S, turning operation as shown by an arrow 120R, and slight raising / lowering operation. As a result, the semiconductor wafer W is moved with respect to the two carriers 91. The semiconductor wafer W is transferred to and from the alignment unit 130 and the cooling processing unit 140.

  In addition, the semiconductor wafer W is put in and out of the carrier 91 by the delivery robot 120 by the sliding movement of the hand 121 and the raising and lowering movement of the carrier 91. Further, the delivery of the semiconductor wafer W between the delivery robot 120 and the alignment unit 130 or the cooling processing unit 140 is performed by the sliding movement of the hand 121 and the raising / lowering operation of the delivery robot 120.

  The semiconductor wafer W is delivered from the delivery robot 120 to the alignment unit 130 so that the center of the semiconductor wafer W is located at a predetermined position. The alignment unit 130 rotates the semiconductor wafer W to detect a notch (notch or orientation flat), thereby directing the semiconductor wafer W in an appropriate direction.

  The transfer robot 150 is turnable as indicated by an arrow 150R about a vertical axis, and has two link mechanisms composed of a plurality of arm segments, and a semiconductor is provided at each end of the two link mechanisms. Transfer arms 151 a and 151 b for holding the wafer W are provided. These transfer arms 151a and 151b are arranged vertically apart from each other by a predetermined pitch, and can be slid linearly in the same horizontal direction independently by a link mechanism. Further, the transfer robot 150 moves up and down the base on which the two link mechanisms are provided, thereby moving the two transfer arms 151a and 151b up and down while being separated by a predetermined pitch.

  When the transfer robot 150 transfers (inserts / removes) the semiconductor wafer W as a transfer partner to the alignment unit 130, the heat processing unit 160, or the cooling process unit 140, first, the transfer arms 151a and 151b are opposed to the transfer partner. And then move up and down (or while turning) and any one of the transfer arms is positioned at a height at which the semiconductor wafer W is delivered to the delivery partner. Then, the transfer arm 151a (151b) is slid linearly in the horizontal direction to deliver the semiconductor wafer W.

  The heat treatment unit 160 is a processing unit that performs heat treatment by irradiating the semiconductor wafer W with flash light from a xenon flash lamp 69 (hereinafter also simply referred to as “flash lamp 69”). In addition to the plurality of xenon flash lamps 69, the heat treatment unit 160 includes a preheating mechanism (assist heating mechanism) that preheats the semiconductor wafer W to a predetermined temperature before flash irradiation. As the preheating mechanism, a heater using a resistance heating element may be used, or a halogen lamp may be adopted.

  Since the temperature of the semiconductor wafer W immediately after being processed in the heat processing unit 160 is high, the semiconductor wafer W is placed on the cooling processing unit 140 and cooled by the transfer robot 150. The configuration of the cooling processing unit 140 will be further described later. The semiconductor wafer W cooled by the cooling processing unit 140 is returned to the carrier 91 by the delivery robot 120 as a processed semiconductor wafer W.

  Further, as described above, in the substrate processing apparatus 100, the periphery of the transfer robot 150 is covered with the transfer chamber 170, and the alignment unit 130, the cooling processing unit 140, and the heat processing unit 160 are connected to the transfer chamber 170. Gate valves 181 and 182 are provided between the delivery robot 120 and the alignment unit 130 and the cooling processing unit 140, respectively. Between the transfer chamber 170 and the alignment unit 130, the cooling processing unit 140 and the heating processing unit 160, respectively. Gate valves 183, 184 and 185 are provided. Then, high-purity nitrogen gas is supplied from a nitrogen gas supply unit (not shown) so that the insides of the alignment unit 130, the cooling processing unit 140, the heat processing unit 160, and the transfer chamber 170 are kept clean. The nitrogen gas is appropriately exhausted from the exhaust pipe. Note that these gate valves are appropriately opened and closed when the semiconductor wafer W is transported.

  In addition, the alignment unit 130 and the cooling processing unit 140 are located at different positions between the delivery robot 120 and the transfer robot 150, and the semiconductor wafer W is temporarily mounted on the alignment unit 130 to position the semiconductor wafer W. In the cooling processing unit 140, the semiconductor wafer W is temporarily placed in order to cool the heated semiconductor wafer W.

  Next, the configuration of the cooling processing unit 140 will be described. FIG. 3 is a diagram showing a main configuration of the cooling processing unit 140. The cooling processing unit 140 of the present embodiment includes a bottom cooling plate 10 and a first ceramic plate 20 placed thereon. In addition, the cooling processing unit 140 includes an elevating mechanism 30 that places the semiconductor wafer W on the first ceramic plate 20 or pushes the semiconductor wafer W away from the first ceramic plate 20 so as to be separated from the first ceramic plate 20. A ceramic plate 90 is provided. Each component shown in FIG. 3 is installed in the chamber of the cooling processing unit 140, and the wafer loading / unloading port of the chamber is opened and closed by the gate valves 182 and 184.

  The bottom cooling plate 10 is a flat plate made of aluminum alloy, and its planar shape is the same as the planar shape of the chamber of the cooling processing unit 140 (see FIG. 1). The bottom cooling plate 10 is formed on the floor portion of the cooling processing unit 140. Inside the bottom cooling plate 10, cooling pipes (not shown) are arranged so as to face almost the entire surface of the plate surface, and cooling water is supplied from the cooling water supply source 15 to the cooling pipe. Is done. The cooling water supplied to the cooling pipe from the cooling water supply source 15 exchanges heat with the bottom cooling plate 10 and then is discharged to a drain outside the figure. By supplying the cooling water from the cooling water supply source 15 to the cooling pipe, the bottom cooling plate 10 is maintained at a predetermined temperature. As the cooling water supply source 15, a utility of a factory where the substrate processing apparatus 100 is installed may be used, or a constant temperature water supply unit may be provided in the substrate processing apparatus 100.

  The first ceramic plate 20 placed on the upper surface of the bottom cooling plate 10 is a disc-like member formed of ceramics having a higher emissivity and thermal conductivity than quartz. The first ceramic plate 20 of the present embodiment is a disc having a diameter of 300 mm formed of sintered SiC. The thickness of the 1st ceramic board 20 is 0.5 mm-5 mm, and is 3 mm in this embodiment. If the thickness of the first ceramic plate 20 is less than 0.5 mm, the workability deteriorates and it becomes difficult to obtain good flatness, and conversely if it exceeds 5 mm, the heat conduction from the semiconductor wafer W to the bottom cooling plate 10. Sexuality decreases. The first ceramic plate 20 is preferably placed on the first ceramic plate 20 by surface contact as much as possible. For this reason, as the flatness of the first ceramic plate 20, the average surface roughness (Ra) is 0.1 mm. The following is desirable. Alternatively, the first ceramic plate 20 may be attached to the upper surface of the bottom cooling plate 10 with an adhesive having good thermal conductivity.

  Support members 50 are projected from a plurality of locations (three locations in the present embodiment) on the upper surface of the first ceramic plate 20. The support member 50 may be formed by embedding the lower part of a ceramic ball having a diameter of several millimeters in the first ceramic plate 20, or the lower part of a ceramic pin having a diameter of 2 mm or less and a height of 5 mm or less. The first ceramic plate 20 may be embedded and formed. Further, the lower part of the ceramic ellipsoid may be embedded in the first ceramic plate 20. As a material of the support member 50, the same material as the first ceramic plate 20, quartz, alumina having excellent workability, or the like can be used.

  The distance between the top of each support member 50 and the upper surface of the first ceramic plate 20 is configured to be not less than 0.2 mm and not more than 5 mm. The semiconductor wafer W also has waviness and warpage of about several tens of μm to several hundreds of μm, and the surface of the first ceramic plate 20 has irregularities in the range where the average surface roughness is 0.1 mm or less as described above. In order to reliably prevent contact between the semiconductor wafer W and the first ceramic plate 20, the distance is preferably set to 0.2 mm or more. Further, as will be described later, in order to obtain good cooling efficiency of the semiconductor wafer W, it is preferable to set the above distance to 5 mm or less.

  When the semiconductor wafer W is supported on the first ceramic plate 20 to be cooled, each support member 50 brings the semiconductor wafer W close to the upper side of the first ceramic plate 20 and supports it by point contact. In order to stably support the semiconductor wafer W, it is necessary to support at least three points. In this embodiment, the upper surface of the first ceramic plate 20 is supported at three locations along the same circumference at every 120 °. The member 50 is protrudingly provided.

  The lifting mechanism 30 includes a plurality of (three in this embodiment) push-up pins 31, a support plate 32, and an actuator 35. The three push-up pins 31 are made of quartz, and are fixedly erected on the support plate 32. The support plate 32 is moved up and down by an actuator 35. Various known actuators such as those using a motor or an air cylinder can be adopted as the actuator 35.

  Further, the bottom cooling plate 10 and the first ceramic plate 20 are provided with through holes having a size enough to allow the push-up pins 31 to be inserted thereinto. Go up and down through the through hole. The through holes are formed alternately with the support members 50 every 120 ° along the same circumference as the three support members 50, for example. When the actuator 35 moves the support plate 32 up and down, the three push-up pins 31 standing on the support plate 32 move up and down all at once.

  The three push-up pins 31 are moved up and down by the actuator 35 between a processing position indicated by a solid line and a delivery position indicated by a two-dot chain line in FIG. As shown in FIG. 3, when the push-up pin 31 is lowered to the processing position, the upper end of the push-up pin 31 is embedded in the through hole of the first ceramic plate 20 or the bottom cooling plate 10. On the other hand, when the push-up pin 31 is raised to the delivery position, the upper end of the push-up pin 31 protrudes from the upper surface of the first ceramic plate 20 and is positioned above the top of the support member 50.

  Further, the cooling processing unit 140 of the present embodiment further includes an upper cooling plate 80 and a second ceramic plate 90 that are disposed above the bottom cooling plate 10 so as to face the bottom cooling plate 10. The upper cooling plate 80 is a flat plate made of aluminum alloy, and is the same member as the bottom cooling plate 10 except that it is formed on the ceiling portion of the cooling processing unit 140. In other words, cooling pipes are arranged around the upper cooling plate 80, and the cooling water is supplied from the cooling water supply source 15 to the cooling pipe, so that the upper cooling plate 80 is maintained at a predetermined temperature. Is done.

  The second ceramic plate 90 is attached to the lower surface of the upper cooling plate 80. The second ceramic plate 90 is the same as the first ceramic plate 20 described above except that the support member 50 and the through hole are not provided. That is, the second ceramic plate 90 is a disk-shaped member made of ceramics (here, sintered SiC) having a larger emissivity and thermal conductivity than quartz, and has a diameter of 300 mm and a thickness of 0.2 mm. 5 mm to 5 mm. The upper cooling plate 80 and the second ceramic plate 90 are arranged so that the distance between the semiconductor wafer W raised to the delivery position described above and the lower surface of the second ceramic plate 90 is at least 10 mm.

  Next, the heat treatment operation of the semiconductor wafer W in the substrate processing apparatus 100 will be described. A semiconductor wafer W to be processed in the substrate processing apparatus 100 is a semiconductor wafer after ion implantation. Here, after briefly explaining the wafer flow in the entire heat treatment apparatus 100, the cooling process of the semiconductor wafer W in the cooling processing unit 140 which is the cooling processing apparatus according to the present invention will be described.

  In the substrate processing apparatus 100, first, a plurality of semiconductor wafers W after ion implantation are placed on the indexer unit 110 in a state where they are accommodated in the carrier 91. Then, the delivery robot 120 takes out the semiconductor wafers W one by one from the carrier 91 and places them on the alignment unit 130. In the alignment unit 130, the semiconductor wafer W is positioned by rotating the semiconductor wafer W around the vertical axis around the center portion and detecting optically a notch or the like.

  The semiconductor wafer W positioned by the alignment unit 130 is taken out into the transfer chamber 170 by the transfer arm 151 a on the upper side of the transfer robot 150, and turns so that the transfer robot 150 faces the heat treatment unit 160. When the transfer robot 150 faces the heat treatment unit 160, the lower transfer arm 151b takes out the preceding heat-treated semiconductor wafer W from the heat treatment unit 160, and the upper transfer arm 151a heats the unprocessed semiconductor wafer W. It is carried into the processing unit 160. At this time, the transfer robot 150 slides the transfer arms 151 a and 151 b perpendicular to the longitudinal direction of the flash lamp 69.

  In the heat treatment unit 160, first, preheating is performed for about 60 seconds, and the temperature of the semiconductor wafer W rises to a preset preheating temperature. The preheating temperature is about 200 ° C. to 600 ° C., preferably about 350 ° C. to 550 ° C., in which impurities added to the semiconductor wafer W are not likely to diffuse due to heat. After a preheating time of about 60 seconds has elapsed, flash heating is performed by irradiating flash light from the flash lamp 69 toward the semiconductor wafer W. Since the flash heating is performed by flash irradiation from the flash lamp 69, the surface temperature of the semiconductor wafer W can be increased in a short time.

  That is, the light emitted from the flash lamp 69 is a very short and strong flash with an irradiation time of about 0.1 milliseconds to 10 milliseconds, in which electrostatic energy stored in advance is converted into an extremely short light pulse. . The surface temperature of the semiconductor wafer W flash-heated by flash irradiation from the flash lamp 69 instantaneously rises to a processing temperature of about 1000 ° C. to 1100 ° C., and the impurities added to the semiconductor wafer W are activated. After that, the surface temperature drops rapidly. Thus, since the surface temperature of the semiconductor wafer W can be raised and lowered in a very short time, the impurity can be activated while suppressing diffusion of the impurity added to the semiconductor wafer W due to heat. Since the time required for activation of the added impurity is extremely short compared to the time required for thermal diffusion, activation is possible even for a short time when no diffusion of about 0.1 millisecond to 10 millisecond occurs. Is completed. After the flash heating is completed and after waiting for about 10 seconds, the heated semiconductor wafer W is unloaded by the transfer arm 151b of the transfer robot 150.

  Next, the transfer robot 150 turns to face the cooling processing unit 140, and the lower transfer arm 151 b carries the heated semiconductor wafer W into the cooling processing unit 140. The semiconductor wafer W after being heated by flash light irradiation from the flash lamp 69 is not sufficiently lowered in the standby time of about 10 seconds, and the temperature of the semiconductor wafer W when it is carried into the cooling processing unit 140 is still 400 ° C. It is the above high temperature. The transfer arm 151 b that holds the heated semiconductor wafer W enters the cooling processing unit 140 and is positioned above the bottom cooling plate 10. Then, the three push-up pins 31 are raised to the delivery position (the two-dot chain line position in FIG. 3) by driving the actuator 35 and receive the semiconductor wafer W from the transfer robot 150. Subsequently, after the transfer robot 150 retracts the transfer arm 151b from the cooling processing unit 140, the three push-up pins 31 are lowered to the processing position (solid line position in FIG. 3) by the actuator 35, so that three supports are provided. The semiconductor wafer W is brought close to the upper side of the first ceramic plate 20 by the member 50 and supported by point contact. When the distance between the top of the support member 50 and the upper surface of the first ceramic plate 20 is 0.2 mm, the push-up pin 31 is lowered as low as possible to prevent the semiconductor wafer W from slipping. It is preferable to make it.

The bottom cooling plate 10 is maintained at a predetermined temperature by supplying the cooling water from the cooling water supply source 15, and the heat of the heated semiconductor wafer W is applied to the bottom cooling plate 10 via the first ceramic plate 20. By being transmitted, the cooling process proceeds. Here, the semiconductor wafer W supported by the support member 50 and the first ceramic plate 20 are arranged in close proximity to each other. As described above, the radiant heat flow q ₁₂ between the objects facing each other (more precisely, the net radiant heat flow from the object 1 to the object 2) is expressed by the following equation 1 (here, the semiconductor wafer W). ) is given by the difference between the radiant heat flow Q ₂₁ directed from the object 2 (radiant heat flow Q ₁₂ and the object 2 toward the first ceramic plate 20) to the object 1 from.

The radiant heat flows Q ₁₂ and Q ₂₁ are as follows, assuming that the areas of the objects 1 and 2 are A ₁ and A ₂ , the form factors are F ₁₂ and F ₂₁ , and the radiant heat flows per unit area are E ₁ and E ₂ , respectively. Are expressed by the following formulas 2 and 3. If the semiconductor wafer W to be processed is 300 mm in diameter, the semiconductor wafer W and the first ceramic plate 20 are the same in area and shape, the areas A ₁ and A ₂ are equal, and the form factor Both F ₁₂ and F ₂₁ are equal.

Therefore, the radiant heat flow rate q ₁₂ between the semiconductor wafer W and the first ceramic plate 20 that are in close proximity to each other can be expressed as the following Expression 4.

The above form factor is determined only by the geometric relationship between the semiconductor wafer W and the first ceramic plate 20, and does not depend on the temperature. Then, the following relationship is established between the form factor F ₁₂ and the form factor F ₂₁ .

  That is, there is compatibility in the form factor between the semiconductor wafer W and the first ceramic plate 20. Equation 6 is derived from the relationship of Equation 5 and Equation 4.

On the other hand, assuming that the black body radiant heat flow rate at temperature T (K) is Lb (T) and the emissivities of the surfaces of the objects 1 and 2 are ε1 and ε2, the radiant heat flow rates E ₁ and E ₂ are It is expressed as Equation 8.

  The following Equation 9 is derived from Equations 7, 8, and 6.

In Equation 9, A ₁ and ε 1 are the area and emissivity of the semiconductor wafer W and are constants depending on the semiconductor wafer W, respectively. T ₁ is the temperature of the semiconductor wafer W supported by the support member 50 and depends on the heat treatment conditions in the heat treatment unit 160, that is, depends on the process conditions and can be changed at the stage of the cooling treatment. is not. Therefore, in order to increase the net radiant heat flow rate q ₁₂ from the semiconductor wafer W to the first ceramic plate 20 to improve the cooling rate, the shape factor F ₁₂ is increased and the first ceramic plate 20 the temperature T ₂ may be lower.

In general, the form factor is 1 or less, and its value is determined only by the geometric relationship between the two surfaces. As in the present embodiment, when the first ceramic plate 20 of the semiconductor wafer W and the disc of the disc is parallel to opposite each other, form factor F _12, the surface distance L between both discs is a value defined by the radius R ₂ of the radius R ₁ and a first ceramic plate 20 of the semiconductor wafer W, is given by the following equation 10.

As described above, the diameter of the first ceramic plate 20 is 300 mm. Further, there are two types of semiconductor wafers W to be processed by the substrate processing apparatus 100: φ200 mm or φ300 mm. In any case, the planar size of the first ceramic plate 20 is equal to or larger than the planar size of the semiconductor wafer W. When processing a semiconductor wafer W having a diameter of 300 mm, R ₁ = R ₂ = 150 mm, and when processing a semiconductor wafer W having a diameter of 200 mm, R ₁ = 100 mm and R ₂ = 150 mm. FIG. 4 shows the relationship between the form factor F ₁₂ derived from Equation 10 and the inter-plane distance L under these two types of conditions. In the drawing, the shape factor F ₁₂ of the semiconductor wafer W having a diameter of 300 mm is indicated by a solid line, and the semiconductor wafer W having a diameter of 200 mm is indicated by a one-dot chain line.

As is apparent from FIG. 4, when the semiconductor wafer W having a diameter of 300 mm is processed, the form factor F ₁₂ decreases linearly as the inter-surface distance L increases. That is, as the distance between the semiconductor wafer W and the first ceramic plate 20 increases, the cooling efficiency of the semiconductor wafer W decreases linearly. If the inter-surface distance L between the semiconductor wafer W and the first ceramic plate 20 (equal to the distance between the top of the support member 50 and the upper surface of the first ceramic plate 20) is 5 mm or less, the form factor F As a result, about 0.97 or more can be secured as ₁₂ , and good cooling efficiency of the semiconductor wafer W can be obtained. On the other hand, small influence of interplanar distances L when processing a semiconductor wafer W of .phi.200 mm, view factor interplanar distance L is 0.97 or more up to about 20mm between the semiconductor wafer W and the first ceramic plate 20 F ₁₂ Can be obtained.

  Further, the amount of heat J absorbed from the surface of the first ceramic plate 20 is given by the following equation (11).

That is, the greater the emissivity ε2 of the first ceramic plate 20 and the lower the temperature T ₂ , the greater the amount of heat J absorbed by the first ceramic plate 20. For this reason, as the material of the first ceramic plate 20, ceramics having a higher emissivity than quartz is used. The temperature T ₂ of the first ceramic plate 20 is a temperature defined by the bottom cooling plate 10 and is a value depending on the cooling water supply source 15. However, the cooling efficiency improves as the temperature T ₂ decreases. It is clear from Equation 9 and Equation 11.

  In the cooling processing unit 140 of this embodiment, an upper cooling plate 80 and a second ceramic plate 90 are also provided above the semiconductor wafer W. That is, the semiconductor wafer W is cooled so as to be sandwiched between the first ceramic plate 20 and the second ceramic plate 90. For this reason, the cooling efficiency of the semiconductor wafer W in the cooling processing unit 140 can be further improved. However, in this embodiment, since the distance between the second ceramic plate 90 and the semiconductor wafer W is larger than the distance between the first ceramic plate 20 and the semiconductor wafer W, the contribution to the cooling efficiency is first. The ceramic plate 20 is larger.

  When the semiconductor wafer W is cooled to about 50 ° C. or less as described above, the three push-up pins 31 rise to the delivery position, and the cooled semiconductor wafer W supported by the support member 50 is removed. Receive it and push it up. Then, the delivery robot 120 advances the hand 121 below the semiconductor wafer W supported by the push-up pins 31, and then the three push-up pins 31 are lowered to the processing position, whereby the semiconductor wafer W is delivered to the hand 121. . Thereafter, the delivery robot 120 moves the hand 121 out of the cooling processing unit 140, thereby unloading the semiconductor wafer W. A series of flash heating processes are completed when the delivery robot 120 returns the semiconductor wafer W carried out of the cooling processing unit 140 to the carrier 91.

  In this way, the semiconductor wafer W to be cooled by the cooling processing unit 140 is not placed on the first ceramic plate 20 by surface contact but is supported by the support member 50 by point contact. Therefore, even if the back surface of a certain semiconductor wafer W is contaminated with metal components or particles, the contaminant is prevented from being transferred to the back surface of the subsequent semiconductor wafer W through the first ceramic plate 20. Can do.

  In addition, when the push-up pin 31 that has received the semiconductor wafer W is lowered to the processing position, the semiconductor wafer W is supported by point contact by the three support members 50, so that the semiconductor wafer W slides sideways. Will no longer occur. For this reason, it is not necessary to provide a skid prevention pin on the first ceramic plate 20, and there is no possibility that the skid semiconductor wafer W collides with the skid prevention pin and breaks the edge portion.

  In addition, since the semiconductor wafer W is cooled on the metal bottom cooling plate 10 via the first ceramic plate 20, there is no possibility that the heated semiconductor wafer W directly contacts the metal plate. When a semiconductor wafer W having a high temperature of 400 ° C. or higher is in direct contact with a metal plate like the semiconductor wafer W after flash heating, the metal component may be diffused into the silicon wafer. By doing so, such metal contamination can be surely prevented.

  By the way, when the semiconductor wafer W is brought close to the first ceramic plate 20 and cooled as in the present embodiment, it is compared with the conventional cooling in which the semiconductor wafer W is directly placed on the quartz plate in surface contact. Cooling efficiency must be reduced. For this reason, in this embodiment, the 1st ceramics board 20 is formed with the ceramic whose emissivity and thermal conductivity are larger than quartz. If the emissivity and thermal conductivity of the first ceramic plate 20 are larger than that of the quartz plate, a cooling efficiency greater than that of the quartz plate can be obtained. As a result, the semiconductor wafer W is separated from the first ceramic plate 20 and cooled. Therefore, it is possible to minimize the decrease in cooling efficiency. That is, the technical significance of supporting the semiconductor wafer W to be cooled by point contact with the support member 50 while bringing the semiconductor wafer W close to the first ceramic plate 20 is that the semiconductor wafer W is suppressed while minimizing the decrease in cooling efficiency. This is to prevent the transfer of metal contaminants and particles between them.

  In particular, as in the present embodiment, the inter-surface distance between the semiconductor wafer W and the first ceramic plate 20 is 5 mm or less, and the planar size of the first ceramic plate 20 is equal to or larger than the planar size of the semiconductor wafer W. By doing so, the flow rate of radiant heat from the semiconductor wafer W toward the first ceramic plate 20 is increased, and better cooling efficiency can be obtained.

While the embodiments of the present invention have been described above, the present invention can be modified in various ways other than those described above without departing from the spirit of the present invention. For example, in the above embodiment, although the size of the first ceramic plate 20 had a diameter of 300 mm, from the viewpoint of further increasing the form factor F _12, it is preferable that as large as possible a planar size of the first ceramic plate 20 . However, the upper limit of the planar size of the first ceramic plate 20 is restricted by the size of the cooling processing unit 140.

  The material of the first ceramic plate 20 and the second ceramic plate 90 is not limited to sintered SiC, but ceramics having a higher emissivity and thermal conductivity than quartz, such as black AlN, or a SiC film on the surface. Or graphite with a PBN film formed thereon. Furthermore, it is also possible to employ silicon (Si) instead of sintered SiC. In this case, a silicon semiconductor wafer can be used as it is. The first ceramic plate 20 and the second ceramic plate 90 may be different ceramic materials.

  In addition, the number of protrusions of the support member 50 is not limited to three, and the number of the push-up pins 31 is not limited to three. However, in order to stably support the semiconductor wafer W, it is necessary to provide at least three support members 50, and in order to stably push up, at least three push-up pins 31 are required.

  In the above embodiment, the upper cooling structure constituted by the upper cooling plate 80 and the second ceramic plate 90 is provided in addition to the lower cooling structure constituted by the bottom cooling plate 10 and the first ceramic plate 20. The upper cooling structure is not necessarily an essential element, and even if only the lower cooling structure is used, transfer of metal contaminants and particles between the semiconductor wafers W can be prevented. However, it is possible to obtain better cooling efficiency of the semiconductor wafer W by providing the upper cooling structure constituted by the upper cooling plate 80 and the second ceramic plate 90.

  In contrast, only the upper cooling structure composed of the upper cooling plate 80 and the second ceramic plate 90 may be provided. FIG. 5 is a diagram showing a main configuration of a cooling processing unit provided with only the upper cooling structure. In the figure, the same reference numerals as those in FIG. In the cooling processing unit shown in FIG. 5, the upper cooling plate 80 and the second ceramic plate 90 are provided on the unit ceiling without providing the bottom cooling plate 10 and the first ceramic plate 20. The material and shape of the second ceramic plate 90 are the same as in the above embodiment.

  In the cooling processing unit of FIG. 5, the three push-up pins 31 that have received the heated semiconductor wafer W at the delivery position (the two-dot chain line position in FIG. 5) are further raised by driving the actuator 35, and the semiconductor wafer W is raised to the proximity position (solid line position in FIG. 5). The distance between the upper surface of the semiconductor wafer W and the lower surface of the second ceramic plate 90 at this close position is not less than 0.2 mm and not more than 5 mm. That is, it is about the same as the distance between the semiconductor wafer W and the first ceramic plate 20 in the above embodiment. Therefore, as shown in FIG. 5, the cooling process through the second ceramic plate 90 is performed with the same cooling efficiency as the semiconductor wafer W is cooled through the first ceramic plate 20 in the above embodiment. It can be carried out. In the cooling processing unit of FIG. 5, since the semiconductor wafer W to be cooled and the second ceramic plate 90 are completely non-contact, the transfer of metal contaminants and particles between the semiconductor wafers W and the semiconductor wafer W are performed. Of course, no side slip occurs.

  Further, in the cooling processing unit 140 of FIG. 3, the push-up pins 31 that have received the heated semiconductor wafer W at the delivery position as shown in FIG. 5 are further raised so that the semiconductor wafer W comes close to the second ceramic plate 90. Anyway.

  Further, the number of flash lamps 69 in the heat treatment unit 160 may be arbitrary. The flash lamp 69 is not limited to a xenon flash lamp, and may be a krypton flash lamp.

  Further, the heat treatment unit 160 is not limited to a unit that heats the semiconductor wafer W by flash light irradiation from the flash lamp 69, and may be of another heating method. However, when the semiconductor wafer W after heating is a high-temperature unit such as flash heating, when the metal contaminants are transferred by the subsequent cooling processing unit 140, the silicon wafer is relatively not transferred to the silicon wafer. Since the metal diffuses easily and has a serious influence, the technical significance of preventing the transfer of contaminants as in the present invention is great.

  In the above embodiment, two carriers 91 are placed on the indexer unit 110, but only one carrier 91 may be placed, or three or more carriers 91 may be placed. Further, although the delivery robot 120 moves between the two carriers 91, two delivery robots 120 may be provided.

  Also, the upper transfer arm 151a of the transfer robot 150 is designed as a dedicated arm for holding the unprocessed semiconductor wafer W, and the lower transfer arm 151b is designed as a dedicated arm for holding the processed semiconductor wafer W. Thus, the transport robot 150 can be reduced in size and transport reliability can be improved.

  The substrate to be processed by the cooling processing apparatus according to the present invention is not limited to a semiconductor wafer, and may be a liquid crystal glass substrate.

It is a top view of the whole substrate processing apparatus incorporating the cooling processing apparatus which concerns on this invention. It is a front view of the substrate processing apparatus of FIG. It is a figure which shows the principal part structure of a cooling processing unit. It is a figure which shows the correlation of a form factor and the distance between surfaces. It is a figure which shows the other example of a cooling processing unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Bottom part cooling plate 15 Cooling water supply source 20 1st ceramic plate 30 Elevating mechanism 31 Push-up pin 35 Actuator 50 Support member 69 Flash lamp 80 Upper cooling plate 90 2nd ceramic plate 100 Substrate processing apparatus 130 Alignment unit 140 Cooling processing unit 150 Conveyance Robot 160 Heat treatment unit W Semiconductor wafer

Claims (7)

A cooling processing apparatus that performs a cooling process on a heated substrate,
A bottom cooling plate maintained at a predetermined temperature by a cooling mechanism;
A first ceramic plate placed on the bottom cooling plate and having a greater emissivity and thermal conductivity than quartz;
A support member that protrudes from at least three locations on the upper surface of the first ceramic plate and supports the substrate in a point contact with the substrate close to the first ceramic plate;
A cooling processing apparatus comprising: The cooling processing apparatus according to claim 1,
The distance between the top part of the said supporting member and the upper surface of a said 1st ceramic board is 0.2 mm or more and 5 mm or less, The cooling processing apparatus characterized by the above-mentioned. In the cooling processing apparatus according to claim 1 or 2,
The cooling processing apparatus according to claim 1, wherein a planar size of the ceramic plate is equal to or larger than a planar size of the substrate. In the cooling processing apparatus in any one of Claims 1-3,
An upper cooling plate disposed above the bottom cooling plate and facing the bottom cooling plate;
A second ceramic plate affixed to the lower surface of the upper cooling plate and having a larger emissivity and thermal conductivity than quartz;
The cooling processing apparatus further comprising: A cooling apparatus that performs a cooling process on a heated substrate,
An upper cooling plate maintained at a predetermined temperature by a cooling mechanism;
A ceramic plate that is affixed to the lower surface of the upper cooling plate and has a higher emissivity and thermal conductivity than quartz,
At least three push-up pins provided below the ceramic plate and supporting the substrate by point contact from the bottom surface;
A pin elevating means for raising the at least three push-up pins that have received the heated substrate and holding the substrate in a close position below the ceramic plate;
A cooling processing apparatus comprising: In the cooling processing apparatus in any one of Claims 1-5,
The substrate is heated at a temperature of 400 ° C. or higher. In the cooling processing apparatus in any one of Claims 1-5,
The substrate after heating is a substrate after being heated by flash light irradiation from a flash lamp.

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