JP2005243775A - Substrate processing device and atmosphere substituting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing device which can substitute the inside of a processing chamber by a low oxygen concentration atmosphere in a short time, and an atmosphere substituting method. <P>SOLUTION: Nitrogen gas is supplied to an alignment chamber 131 which performs the alignment of a semiconductor wafer W by a large flow rate or a small flow rate from a blowing-out tube 231. The inside of the alignment chamber 131 can be set in either a strong exhaust state or a weak exhaust state by using the exhaust utility 337 of a factory. When supplying nitrogen gas in the alignment chamber 131 and substituting by the low oxygen concentration atmosphere, if the substrate processing device supplies nitrogen gas per minute from the blowing tube 231 by a large flow rate with 4 times or more and 5 times or less of the internal volume of the alignment chamber 131, and is set in the strong exhaust state, the inside of the alignment chamber 131 can be substituted by the low oxygen concentration atmosphere of 10ppm or less in a short time for about 2 minutes. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention contains a semiconductor substrate, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, a substrate for an optical disk (hereinafter simply referred to as a “substrate”), and a processing chamber in which a predetermined processing is performed by an inert gas. The present invention relates to a substrate processing apparatus and an atmosphere replacement method for replacing with a low oxygen concentration atmosphere.

  In general, the substrate is subjected to a plurality of processes such as cleaning, film formation, resist coating, exposure, development, etching, and heat treatment to produce devices such as semiconductor devices and liquid crystal display devices. Of these various treatments, particularly when performing heat treatment or film formation treatment, treatment in a low oxygen concentration atmosphere is often required to prevent oxidation of the substrate during the treatment. In addition, there is a strong demand to perform the above-described processes on the substrate in an atmosphere in which particles are reduced as much as possible.

  On the other hand, in recent years, there are many system configurations called a multi-chamber system or a cluster tool in which a plurality of processing chambers for individually performing the above-described various processes are arranged around a polygonal transfer chamber containing a transfer robot for transferring a substrate. It is used. Even in such a cluster tool, atmosphere management such as low oxygen concentration and particle free is demanded as a whole system. For this purpose, for example, Patent Document 1 discloses that each chamber is forcibly evacuated by a dry pump and then an inert gas such as nitrogen gas is supplied to replace the atmosphere. It is disclosed that atmosphere management is performed by continuing continuous supply. Further, Patent Document 2 discloses that a pressure difference is provided between the chambers so that the pressure in the chamber that requires the strictest atmosphere management is increased.

JP-A-10-27734 Japanese Patent Laid-Open No. 10-335407

  In the above-described conventional system, the atmosphere is managed by forcibly exhausting the chamber with a vacuum pump. For example, even in the system disclosed in Patent Document 1, each chamber is once evacuated by forcibly evacuating the dry pump when the apparatus is started up.

  However, when the inside of the chamber is once evacuated by a vacuum pump and then filled with an inert gas, it is essential to gently exhaust and supply the inert gas gently to prevent the particles from rising, It took considerable time to replace the atmosphere. It takes a long time to replace the atmosphere, leading to a decrease in throughput. In addition, oilless vacuum pumps used for manufacturing devices such as semiconductor devices are relatively expensive. Furthermore, when the entire cluster tool system is forcibly evacuated by a vacuum pump, not only must each chamber be a pressure-resistant chamber that can withstand the external atmospheric pressure during vacuum, but also a transfer robot, alignment parts, Sensors, cable joints, etc. had to be vacuum-compatible, which caused an increase in cost.

  The present invention has been made in view of the above problems, and an object thereof is to provide a substrate processing apparatus and an atmosphere replacement method capable of replacing a processing chamber with a low oxygen concentration atmosphere in a short time.

  In order to solve the above-mentioned problems, a first aspect of the present invention is a substrate processing apparatus for performing a predetermined process on a substrate in a low oxygen concentration atmosphere. A gas supply means for supplying an inert gas to the processing chamber, a discharge port for discharging the gas from the processing chamber, and a supply flow rate adjustment for adjusting a flow rate of the inert gas supplied from the gas supply means Means for supplying an inert gas into the processing chamber and replacing the atmosphere with a low oxygen concentration atmosphere, the supply flow rate adjusting means is used to supply the gas supply means with a first of 4 V or more and 5 V or less per minute. An inert gas is supplied at a flow rate.

  The substrate processing apparatus according to a second aspect of the present invention is the substrate processing apparatus according to the first aspect of the present invention, further comprising an exhaust flow rate adjusting means for adjusting a flow rate of the gas discharged from the processing chamber, wherein the exhaust port includes the exhaust flow rate. It is connected to an exhaust utility of a factory where the substrate processing apparatus is installed via an adjusting means.

  According to a third aspect of the present invention, in the substrate processing apparatus according to the first or second aspect of the present invention, the supply flow rate is determined after a predetermined time has elapsed from the start of the inert gas supply at the first flow rate. An adjusting means is used to supply the gas supply means with an inert gas at a second flow rate of less than 4 V per minute.

  According to a fourth aspect of the present invention, in the substrate processing apparatus according to any one of the first to third aspects of the present invention, a substrate is conveyed and connected to the conveyance unit to align the substrate. An alignment unit; a heat treatment unit that is connected to the transfer unit and that performs heat treatment of the substrate; and a cooling unit that is connected to the transfer unit and performs a cooling process on the substrate, and the processing chamber includes the alignment unit and / Or provided in the cooling section.

  According to a fifth aspect of the present invention, in the atmosphere replacement method for replacing the atmosphere in the processing chamber of the internal volume V accommodating the substrate with a low oxygen concentration atmosphere, the processing chamber has a first flow rate of 4 V to 5 V per minute. Inert gas is supplied.

  According to a sixth aspect of the present invention, in the atmosphere replacement method according to the fifth aspect of the present invention, exhaust from the processing chamber is performed using an exhaust utility of a factory where the processing chamber is installed.

  The invention according to claim 7 is the atmosphere replacement method according to claim 5 or 6, wherein the processing chamber is provided after a predetermined time has elapsed since the supply of the inert gas at the first flow rate was started. The inert gas is supplied at a second flow rate of less than 4 V per minute.

  Note that in this specification, “processing” includes transporting a substrate in addition to some effect on the substrate such as cooling processing and alignment.

  According to the first aspect of the present invention, when the inert gas is supplied into the processing chamber having the internal volume V and replaced with the low oxygen concentration atmosphere, the inert gas is supplied at a first flow rate of 4 V or more and 5 V or less per minute. Since it is supplied, the processing chamber can be replaced with a low oxygen concentration atmosphere in a short time.

  According to the second aspect of the present invention, since the discharge port is connected to the exhaust utility of the factory where the substrate processing apparatus is installed via the exhaust flow rate adjusting means, a vacuum pump becomes unnecessary, and the components in the processing chamber It is not necessary to make vacuum etc. compatible with vacuum, and cost increase can be suppressed.

  According to the invention of claim 3, the inert gas is supplied to the processing chamber at the second flow rate of less than 4 V / min after a predetermined time has passed since the supply of the inert gas at the first flow rate was started. Since it supplies, the low oxygen concentration atmosphere in a process chamber can be maintained, suppressing the consumption of an inert gas.

  According to the invention of claim 4, since the processing chamber is provided in the alignment unit and / or the cooling unit, the processing chamber of the alignment unit and / or the cooling unit is replaced with a low oxygen concentration atmosphere in a short time. be able to.

  Further, according to the invention of claim 5, since the inert gas is supplied to the processing chamber having the internal volume V at the first flow rate of 4 V or more and 5 V or less per minute, the processing chamber is reduced in oxygen in a short time. It can be replaced with a concentration atmosphere.

  According to the invention of claim 6, since the exhaust from the processing chamber is performed using the exhaust utility of the factory where the processing chamber is installed, a vacuum pump is unnecessary, and the components in the processing chamber are vacuum-compatible. It is not necessary to do so, and cost increase can be suppressed.

  According to the invention of claim 7, the inert gas is supplied to the processing chamber at a second flow rate of less than 4 V after a predetermined time has elapsed since the supply of the inert gas at the first flow rate was started. Since it supplies, the low oxygen concentration atmosphere in a process chamber can be maintained, suppressing the consumption of an inert gas.

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

<1. Overall configuration of substrate processing apparatus>
FIG. 1 is a plan view showing a substrate processing apparatus 100 according to the present invention, and FIG. 2 is a front view. 1 and FIG. 2 are partially sectional views as appropriate, and details are simplified as appropriate. 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 attached in order 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. On the other hand, the delivery robot 120 that takes in and out the semiconductor wafer W, the alignment unit 130 that positions the unprocessed semiconductor wafer W, the cooling unit (cooler) 140 that cools the processed semiconductor wafer W, the alignment unit 130, and the cooling unit A transfer robot 150 that takes in and out the semiconductor wafer W with respect to 140 and the like, and a heat treatment unit 160 that performs flash heat treatment on the semiconductor wafer W are included.

  In addition, a transfer chamber 170 that houses the transfer robot 150 is provided as a transfer space for the semiconductor wafer W by the transfer robot 150, and the alignment unit 130, the cooling unit 140, and the heat treatment unit 160 are connected to the periphery of the transfer chamber 170. Is 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. . Further, the indexer unit 110 is configured such that the carrier 91 is moved up and down as indicated by an arrow 91U so that an arbitrary semiconductor wafer W can be taken in and out by the delivery robot 120.

  The delivery robot 120 is slidable as indicated by an arrow 120S and is rotatable as indicated by an arrow 120R. With this, the semiconductor wafer W is taken in and out of the two carriers 91. Further, the semiconductor wafer W is delivered to the alignment unit 130 and the cooling 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. In addition, the semiconductor wafer W is transferred between the delivery robot 120 and the alignment unit 130 or the cooling unit 140 by sliding the hand 121 and a semiconductor wafer by a pin (a pin that pushes up the semiconductor wafer W in the alignment unit 130 or the cooling unit 140). This is done by moving W up and down.

  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. Then, the alignment unit 130 rotates the semiconductor wafer W to direct 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 two transfer arms 151a and 151b while moving away from each other by a predetermined pitch by moving up and down a base provided with two link mechanisms.

  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 unit 140, first, the transfer arms 151a and 151b are opposed to the transfer partner. It turns and then moves up and down (or while it is turning) so that 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 part 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”). Since the temperature of the semiconductor wafer W immediately after being processed by the heat processing unit 160 is high, the semiconductor wafer W is placed on the cooling unit 140 and cooled by the transfer robot 150. The semiconductor wafer W cooled by the cooling 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 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 unit 140, respectively, and gate valves are provided between the transfer chamber 170 and the alignment unit 130, the cooling unit 140, and the heat treatment unit 160, respectively. 183, 184, 185 are provided. Then, high-purity nitrogen gas is supplied from the nitrogen gas supply source so that the inside of the alignment unit 130, the cooling unit 140, and the transfer chamber 170 are kept clean, and the excess nitrogen gas is appropriately supplied to the factory exhaust utility. Exhausted. Further, when the semiconductor wafer W is transported, these gate valves are appropriately opened and closed. The atmosphere management of the alignment unit 130 and the like will be further described later.

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

  Further, the substrate processing apparatus 100 is provided with a controller 101 that controls the operation of each part of the entire apparatus. The controller 101 has a configuration similar to that of a general computer, and includes a CPU 102 that performs arithmetic processing, a memory 103 that stores predetermined processing programs and data, a timer 104 that has a time measuring function, and a fixed disk that is not illustrated. And input / output interface. The controller 101 controls the mechanism of each unit such as the alignment unit 130 according to the processing program stored in the memory 103.

<2. Configuration of alignment unit>
3 and 4 are a side sectional view and a perspective view showing a schematic configuration of the alignment unit 130, respectively. The alignment unit 130 is a processing unit that aligns the semiconductor wafer W in a certain direction, and includes an alignment head 132 and a wafer stage 133 inside the alignment chamber 131. The alignment chamber 131 is formed with an opening 136 through which the semiconductor wafer W is delivered from the delivery robot 120 and an opening 137 through which the transfer robot 150 carries out the semiconductor wafer W. The gate valves 181 are formed in the openings 136 and 137, respectively. , 183 are provided. When the gate valves 181 and 183 are closed, the alignment chamber 131 becomes a sealed space.

  The alignment head 132 includes a sensor composed of a pair of light projecting portions and light receiving portions, and detects the notch of the semiconductor wafer W by the sensor (in the case of a semiconductor wafer W of φ300 mm). Note that an orientation flat for alignment is formed on the semiconductor wafer W having a diameter of 200 mm, and the sensor of the alignment head 132 detects the orientation flat.

  Pins 134 are erected on the wafer stage 133. The pins 134 can be moved up and down with respect to the wafer stage 133 by a lifting mechanism (not shown). The pins 134 may be fixed to the wafer stage 133 and the wafer stage 133 itself may be moved up and down. Further, the wafer stage 133 is rotated around the axis along the vertical direction by the motor 135, and the pins 134 are also rotated accordingly.

  Further, the alignment unit 130 is provided with a gas supply mechanism 230 for supplying an inert gas such as nitrogen gas to the alignment chamber 131 and a gas discharge mechanism 330 for discharging gas from the alignment chamber 131. The gas supply mechanism 230 includes two blowing tubes 231, a large flow needle valve 233, a small flow needle valve 232, an air valve 234 and a mass flow meter 235. Two blowing tubes 231 are provided upright through the bottom surface of the alignment chamber 131. The two blowing tubes 231 are erected so that the longitudinal direction thereof is along the vertical direction. The two blow-out tubes 231 are provided at the corner positions of the alignment chamber 131 in plan view. That is, the alignment chamber 131 has a polygonal shape in plan view, and the two blow-out tubes 231 are respectively erected near the corners near both ends of the opening 136. Further, the two blowing tubes 231 are erected so that the upper end of the blowing tube 231 is higher than the semiconductor wafer W held on the wafer stage 133 during alignment. Each of the upper ends of these two blowing tubes 231 becomes a gas discharge port.

  The lower end of the blowing tube 231 is connected to the gas pipe 236 in communication. The base end portion of the gas pipe 236 is connected in communication with a nitrogen gas supply source 237 provided outside the apparatus. The gas pipe 236 is branched in the middle of the path. A large flow needle valve 233 and an air valve 234 are provided in one branch pipe 236a, and a small flow needle valve 232 is provided in the other branch pipe 236b. ing.

  When the air valve 234 is closed, the nitrogen gas supplied from the nitrogen gas supply source 237 does not pass through the branch pipe 236a but passes only through the branch pipe 236b, and the flow rate is regulated by the small flow needle valve 232 2. It flows into the blowing tube 231 of the book and is discharged upward from the upper end portions thereof. On the other hand, when the air valve 234 is opened, the nitrogen gas supplied from the nitrogen gas supply source 237 flows into both the branch pipe 236a and the branch pipe 236b, passes through the blowing tube 231 and is discharged from the upper end portion thereof. . Since the large flow rate needle valve 233 allows a considerably large flow rate compared to the small flow rate needle valve 232, the resistance through which the gas passes through the branch pipe 236a is significantly smaller than the resistance through which the gas passes through the branch pipe 236b. As a result, the flow rate of nitrogen gas passing through the blowing tube 231 is governed by the high flow needle valve 233.

  As described above, in the alignment unit 130 of this embodiment, the flow rate of the nitrogen gas supplied from the blowing tube 231 is adjusted by opening and closing the air valve 234. In the alignment unit 130 of the present embodiment, when the air valve 234 is opened, nitrogen gas is supplied from the two blowing tubes 231 at a large flow rate of 60 L (liters) per minute, and the air valve 234 is closed. When it is, nitrogen gas is supplied at a small flow rate of 15 L (liters) per minute. The flow rate of nitrogen gas supplied from the two blowing tubes 231 is measured by a mass flow meter 235.

  On the other hand, the gas discharge mechanism 330 includes a gas discharge port 331, a large flow needle valve 333, a small flow needle valve 332, an air valve 334, and a mass flow meter 335. A gas discharge port 331 for discharging gas from the alignment chamber 131 is an opening formed on the bottom surface of the alignment chamber 131. The gas discharge port 331 is formed in the vicinity of the opening 137 and is connected in communication with the exhaust pipe 336. The base end portion of the exhaust pipe 336 is connected to an exhaust utility 337 in a factory where the substrate processing apparatus 100 is installed. The exhaust pipe 336 is branched in the middle of the path, and a large flow needle valve 333 and an air valve 334 are provided in one branch pipe 336a, and a small flow needle valve 332 is provided in the other branch pipe 336b. ing.

  When the air valve 334 is closed, the suction force of the factory exhaust utility 337 acts in the alignment chamber 131 only through the branch pipe 336b. The gas exhausted from the alignment chamber 131 does not pass through the branch pipe 336a but only through the branch pipe 336b. The flow rate is regulated by the small flow needle valve 332 and is sucked and discharged to the exhaust utility 337 in the factory. On the other hand, when the air valve 334 is opened, the suction force of the exhaust utility 337 acts in the alignment chamber 131 through both the branch pipes 336a and 336b. The gas exhausted from the alignment chamber 131 passes through both the branch pipe 336a and the branch pipe 336b and is sucked and discharged to the exhaust utility 337. Since the large flow rate needle valve 333 allows a considerably large flow rate compared to the small flow rate needle valve 332, the resistance through which the gas passes through the branch pipe 336a is significantly smaller than the resistance through which the gas passes through the branch pipe 336b. As a result, the flow rate of the gas exhausted from the alignment chamber 131 is controlled by the high flow rate needle valve 333.

  As described above, in the alignment unit 130 of the present embodiment, the gas discharge port 331 and the factory exhaust utility 337 are connected in communication via the flow rate adjusting mechanism that adjusts the flow rate of the gas discharged from the alignment chamber 131. That is, in the alignment unit 130 of the present embodiment, the alignment chamber 131 is exhausted using the factory exhaust utility 337 without using a vacuum pump. When the air valve 334 is opened, a strong exhaust state in which the pressure in the alignment chamber 131 is (−0.5 KPa) to (−0.3 KPa) with respect to the outside (usually a clean room) is realized. When the valve 334 is closed, a weak exhaust state in which the pressure in the alignment chamber 131 is (−0.2 KPa) to (−0.1 KPa) with respect to the outside is realized. That is, opening the air valve 334 results in a strong exhaust state in which a high negative pressure acts in the alignment chamber 131, and closing results in a weak exhaust state in which a lower negative pressure acts. The flow rate of the gas discharged from the alignment chamber 131 to the exhaust utility 337 is measured by the mass flow meter 335.

  With the above configuration, the gate valves 181 and 183 are closed to make the alignment chamber 131 a sealed space, and nitrogen gas is supplied from the two blow-out tubes 231 and gas is exhausted from the gas discharge port 331. The atmosphere in the alignment chamber 131 can be replaced with a clean nitrogen gas atmosphere, that is, a low oxygen concentration atmosphere without particles.

  In addition, two blow-out tubes 231 are erected in the vicinity of the opening 136, and a gas discharge port 331 is formed in the vicinity of the opening 137. That is, since the blow-out tubes 231 and the gas discharge ports 331 are respectively arranged at both ends of the alignment chamber 131, the entire region inside the alignment chamber 131 is horizontally traversed regardless of the magnitude of the nitrogen gas supply flow rate or the strength of exhaust. As described above, nitrogen gas flows from the blowing tube 231 toward the gas outlet 331. Specifically, as shown in FIG. 3, the nitrogen gas blown out from the blow-out tube 231 hits the ceiling of the alignment chamber 131 and the flow is roughly divided into two, one flow flows along the ceiling as it is, The flow flows downward along the side wall and then flows along the bottom surface. Both flows are sucked and exhausted from the gas exhaust port 331 after traversing the entire region inside the alignment chamber 131 along the horizontal direction. For this reason, a nitrogen gas atmosphere is efficiently replaced without generating a gas retention portion over the entire interior of the alignment chamber 131.

  Further, since the upper end of the blowing tube 231 serving as a gas discharge port is configured to be higher than the semiconductor wafer W held on the wafer stage 133 during alignment, nitrogen gas is supplied from the blowing tube 231 at a large flow rate. Even if the gas is ejected, the gas hits the ceiling of the alignment chamber 131 as it is, and the particles staying in the vicinity of the bottom surface are prevented from flying up.

  As described above, the configuration of the alignment unit 130 has been described with a focus on the inert gas supply / discharge mechanism, but the same inert gas supply / discharge mechanism is also provided in the cooling unit 140. That is, the cooling unit 140 is provided with a supply / discharge mechanism similar to the gas supply mechanism 230 and the gas discharge mechanism 330 in addition to the cool plate on which the semiconductor wafer W is placed and cooled. Accordingly, switching between a state in which nitrogen gas is supplied to the chamber of the cooling unit 140 at a large flow rate of 60 L (liter) per minute and a state in which nitrogen gas is supplied at a small flow rate of 25 L (liter) per minute is possible. A strong exhaust state where the pressure in the chamber is (−0.5 KPa) to (−0.3 KPa) and a weak exhaust state where the pressure in the chamber is (−0.2 KPa) to (−0.1 KPa). Can be switched. Thereby, also in the cooling unit 140, the atmosphere in the chamber can be replaced with a clean nitrogen gas atmosphere independently of the alignment unit 130.

<3. Configuration of transfer chamber>
Next, the configuration of the transfer chamber 170 that houses the transfer robot 150 will be described. 5 and 6 are a side sectional view and a plan view showing a schematic configuration of the transfer chamber 170, respectively. As described above, the transfer robot 150 performs the turning operation around the axis along the vertical direction, and the two transfer arms 151a and 151b are independently moved forward and backward in the horizontal direction. The two transfer arms 151a and 151b can be moved up and down simultaneously. Then, the transfer robot 150 performs the above-described various operations to allow the transfer arms 151a and 151b to access the alignment unit 130, the heat processing unit 160, and the cooling unit 140, thereby delivering the semiconductor wafer W to these processing units. Do.

  In the transfer chamber 170, the semiconductor wafer W is transferred between the opening 171 for receiving the semiconductor wafer W from the alignment unit 130, the opening 172 for passing the semiconductor wafer W to the cooling unit 140, and the heat treatment unit 160. An opening 173 for performing is formed. Gate valves 183, 184 and 185 are provided in the three openings 171, 172 and 173, respectively. By closing the gate valves 183, 184, 185, the inside of the transfer chamber 170 becomes a sealed space.

  The transfer chamber 170 is provided with a gas supply mechanism 270 for supplying an inert gas such as nitrogen gas and a gas discharge mechanism 370 for discharging the internal space gas. The gas supply mechanism 270 includes two blowing tubes 271 and a mass flow controller 272. The two blow-out tubes 271 pass through the bottom surface of the transfer chamber 170 and are erected so that the longitudinal direction thereof is along the vertical direction. The two blow-out tubes 271 are provided at the corner positions of the transfer chamber 170 in plan view. That is, in the plan view, the transfer chamber 170 is polygonal, and the two blow-out tubes 271 are erected near the corners near the openings 171 and 172, respectively. Further, the two blowing tubes 271 are erected so that the upper end of the blowing tube 271 is above the semiconductor wafer W held by the transfer robot 150. Each of the upper ends of these two blowing tubes 271 serves as a gas discharge port.

  The lower end of the blowing tube 271 is connected to the gas pipe 273. The base end portion of the gas pipe 273 is connected in communication with a nitrogen gas supply source 274 provided outside the apparatus. The nitrogen gas supply source 274 may be the same as the nitrogen gas supply source 237 described above. Further, a mass flow controller 272 is interposed in the middle of the path of the gas pipe 273. The mass flow controller 272 has a function of measuring the flow rate of nitrogen gas passing through the gas pipe 273 and adjusting it to a set value. Therefore, in the transfer chamber 170 of the present embodiment, the flow rate of nitrogen gas supplied from the blowing tube 271 is adjusted by the mass flow controller 272. The mass flow controller 272 is supplied with nitrogen gas from the two blow-out tubes 271 at a large flow rate of 80 L (liter) per minute, and at a small flow rate of 30 L (liter) per minute. Switch between different states.

  On the other hand, the gas discharge mechanism 370 includes a gas discharge port 371 and an auto damper 372. The gas discharge port 371 for discharging gas from the transfer chamber 170 is an opening formed on the bottom surface of the transfer chamber 170. The gas exhaust port 371 is formed in the vicinity of the opening 173 and is connected to the exhaust pipe 373. A base end portion of the exhaust pipe 373 is connected to an exhaust utility 337 in a factory where the substrate processing apparatus 100 is installed. An auto damper 372 is interposed in the course of the exhaust pipe 373. The auto damper 372 has a function of adjusting the flow rate of the gas passing through the gas pipe 373.

  As described above, in the transfer chamber 170 of the present embodiment, the gas exhaust port 371 and the factory exhaust utility 337 are connected in communication via the auto damper 372, and the factory exhaust utility 337 is used without using a vacuum pump. The inside of the transfer chamber 170 is exhausted. The auto damper 372 includes a strong exhaust state in which the pressure in the transfer chamber 170 is (−0.5 KPa) to (−0.3 KPa) with respect to the outside, and (−0.2 KPa) to (−0.1 KPa). ) Is switched to the weak exhaust state.

  With such a configuration, the gate valves 183, 184 and 185 are closed to make the inside of the transfer chamber 170 a sealed space, and nitrogen gas is supplied from the two blowing tubes 271 and gas is exhausted from the gas outlet 371. Thus, the atmosphere in the transfer chamber 170 can be replaced with a clean nitrogen gas atmosphere, that is, a low oxygen concentration atmosphere without particles.

  In addition, two blow-out tubes 271 are erected in the vicinity of the openings 171 and 172, and a gas discharge port 371 is formed in the vicinity of the opening 173. That is, since the blow-out tubes 271 and the gas discharge ports 371 are respectively arranged at both ends of the transfer chamber 170, the transfer chamber 170, regardless of the magnitude of the nitrogen gas supply flow rate or the strength of the exhaust, as in the alignment chamber 131 described above. Nitrogen gas flows from the blowing tube 271 toward the gas discharge port 371 so as to cross the entire inner region in the horizontal direction. For this reason, it is efficiently replaced with the nitrogen gas atmosphere without generating a gas retention portion over the entire interior of the transfer chamber 170.

  Furthermore, since the upper end of the blowing tube 271 serving as the gas discharge port is configured to be higher than the semiconductor wafer W held by the transfer robot 150, even if nitrogen gas is blown out from the blowing tube 271 at a large flow rate. The gas hits the ceiling of the transfer chamber 170 as it is, and the particles staying near the bottom are prevented from being rolled up.

  The gas supply mechanism 270 of the transfer chamber 170 may be configured as the gas supply mechanism 230 of the alignment unit 130. Conversely, the gas supply mechanism 230 of the alignment unit 130 may be configured as the gas supply mechanism 270 of the transfer chamber 170. Alternatively, a configuration using a mass flow controller may be used. In addition, the gas discharge mechanism 370 of the transfer chamber 170 may be configured as the gas discharge mechanism 330 of the alignment unit 130, or conversely, the gas discharge mechanism 330 of the alignment unit 130 may be configured as the gas discharge mechanism 370 of the transfer chamber 170. Alternatively, an auto damper may be used.

<4. Configuration of heat treatment unit>
Next, the configuration of the heat treatment unit 160 will be described. 7 and 8 are side sectional views showing the heat treatment unit 160. FIG. In the heat treatment unit 160, flash heating of a substrate such as a semiconductor wafer W is performed.

  The heat treatment unit 160 includes a light transmitting plate 61, a bottom plate 62, and a cylindrical side plate 63 (64), and includes a chamber 65 for accommodating the semiconductor wafer W and performing heat treatment therein. The translucent plate 61 constituting the upper part of the chamber 65 is made of a material having optical transparency such as quartz, for example, and serves as a chamber window that transmits light emitted from the flash lamp 69 and guides it into the chamber 65. It is functioning. Further, on the bottom plate 62 constituting the chamber 65, support pins 70 are provided so as to pass through holding means including a wafer support member 73 and a heating plate 74, which will be described later, and support the semiconductor wafer W from its lower surface. .

  Further, an opening 66 for carrying in and out the semiconductor wafer W is formed in the side plate 64 constituting the chamber 65. The opening 66 can be opened and closed by a gate valve 68 that rotates about a shaft 67. The semiconductor wafer W is loaded into the chamber 65 by the transfer robot 150 with the opening 66 being opened. Further, when the semiconductor wafer W is heat-treated in the chamber 65, the opening 66 is closed by the gate valve 68.

  The chamber 65 is provided below the light source 5. The light source 5 includes a plurality of (30 in this embodiment) flash lamps 69 and a reflector 71. The plurality of flash lamps 69 are rod-shaped lamps each having a long cylindrical shape, and are arranged in parallel with each other such that the longitudinal direction thereof is along the horizontal direction. The reflector 71 is disposed above the plurality of flash lamps 69 so as to cover them entirely.

  The xenon flash lamp 69 includes a glass tube in which xenon gas is sealed and an anode and a cathode connected to a capacitor at both ends thereof, and a trigger electrode wound around an external portion of the glass tube. Prepare. Since xenon gas is an electrical insulator, electricity does not flow into the glass tube under normal conditions. However, if the insulation is broken by applying a high voltage to the trigger electrode, the electricity stored in the capacitor instantaneously flows into the glass tube, and the xenon gas is heated by Joule heat at that time, and light is emitted. . In the xenon flash lamp 69, the electrostatic energy stored in advance is converted into an extremely short light pulse of 0.1 millisecond to 10 millisecond. It has the feature that it can. Instead of the xenon flash lamp 69, a flash lamp filled with other rare gas, for example, a krypton flash lamp may be used.

  A light diffusing plate 72 is disposed between the light source 5 and the translucent plate 61. As this light diffusion plate 72, a surface of quartz glass as a light transmitting material subjected to light diffusion processing is used. Instead of using the light diffusing plate 72, the translucent plate 61 may be subjected to surface processing for light diffusion.

  A heating plate 74 and a wafer support member (susceptor) 73 that holds the semiconductor wafer W are provided in the chamber 65. The wafer support member 73 is installed on the upper surface of the heating plate 74. Further, a position shift prevention pin 75 of the semiconductor wafer W is attached to the surface of the wafer support member 73.

  The heating plate 74 is for preheating (assist heating) the semiconductor wafer W. The heating plate 74 is made of aluminum nitride and has a configuration in which a heater and a sensor for controlling the heater are housed. On the other hand, the wafer support member 73 diffuses the heat energy from the heating plate 74 and uniformly preheats the semiconductor wafer W. As a material of the wafer support member 73, high-purity ceramics or quartz is adopted. Note that the wafer support member 73 may be made of aluminum nitride in the same manner as the heating plate 74.

  The wafer support member 73 and the heating plate 74 are configured to move up and down between the loading / unloading position of the semiconductor wafer W shown in FIG. 7 and the heat treatment position of the semiconductor wafer W shown in FIG. .

  That is, the heating plate 74 is connected to the moving plate 42 via the cylindrical body 41. The moving plate 42 can be moved up and down by being guided by a guide member 43 supported by a bottom plate 62 of the chamber 65. A fixed plate 44 is fixed to the lower end portion of the guide member 43, and a motor 40 that rotationally drives a ball screw 45 is disposed at the central portion of the fixed plate 44. The ball screw 45 is screwed with a nut 48 connected to the moving plate 42 via connecting members 46 and 47. Therefore, the wafer support member 73 and the heating plate 74 can be moved up and down between the loading / unloading position of the semiconductor wafer W shown in FIG. 7 and the heat treatment position of the semiconductor wafer W shown in FIG. it can.

  The semiconductor wafer W shown in FIG. 7 is loaded / unloaded by placing the semiconductor wafer W carried in from the opening 66 using the transfer robot 150 on the support pins 70 or on the support pins 70. The wafer support member 73 and the heating plate 74 are lowered so that the semiconductor wafer W can be unloaded from the opening 66. On the other hand, the heat treatment position of the semiconductor wafer W shown in FIG. 8 is a position where the wafer support member 73 and the heating plate 74 are raised above the upper ends of the support pins 70 in order to perform heat treatment on the semiconductor wafer W.

  In a state where the wafer support member 73 and the heating plate 74 that support the semiconductor wafer W are raised to the heat treatment position, the translucent plate 61 is positioned between the semiconductor wafer W held by them and the light source 5. Note that the distance between the wafer support member 73 and the light source 5 at this time can be adjusted to an arbitrary value by controlling the rotation amount of the motor 40.

  Further, between the bottom plate 62 of the chamber 65 and the moving plate 42, a telescopic bellows 77 is disposed so as to surround the cylindrical body 41 and maintain the chamber 65 in an airtight body. When the wafer support member 73 and the heating plate 74 are raised to the heat treatment position, the bellows 77 contracts, and when the wafer support member 73 and the heating plate 74 are lowered to the loading / unloading position, the bellows 77 is expanded and the atmosphere in the chamber 65 is increased. Shut off from outside atmosphere.

  In the side plate 63 opposite to the opening 66 in the chamber 65, an introduction path 78 connected to the on-off valve 80 is formed. The introduction path 78 is for introducing an inert gas such as nitrogen gas into the chamber 65. On the other hand, a discharge passage 79 connected to the on-off valve 81 is formed in the opening 66 in the side plate 64. The discharge path 79 is for discharging the gas in the chamber 65, and is connected to the factory exhaust utility 337 via the on-off valve 81. Therefore, by opening the on-off valve 80 and the on-off valve 81, the inside of the chamber 65 can be made a nitrogen gas atmosphere.

<5. Operation of substrate processing apparatus>
Next, the operation of the substrate processing apparatus 100 according to the present invention 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 describing the wafer flow in the entire substrate processing apparatus 100, the atmosphere management in the apparatus 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 a plurality of semiconductor wafers W 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.

  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 processing unit 160.

  When the transfer robot 150 faces the heat processing unit 160, the lower transfer arm 151b takes out the preceding processed semiconductor wafer W from the heat processing unit 160, and the upper transfer arm 151a heats the unprocessed semiconductor wafer W. It carries in to the part 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.

  Next, the transfer robot 150 turns to face the cooling unit 140, and the lower transfer arm 151 b places the processed semiconductor wafer W in the cooling unit 140. The semiconductor wafer W cooled by the cooling unit 140 is returned to the carrier 91 by the delivery robot 120.

  A heat treatment operation in the heat treatment unit 160 will be briefly described. In the heat processing unit 160, the semiconductor wafer W is moved by the transfer robot 150 through the opening 66 in a state where the wafer support member 73 and the heating plate 74 are arranged at the loading / unloading position of the semiconductor wafer W shown in FIG. It is carried in and placed on the support pin 70. When the loading of the semiconductor wafer W is completed, the opening 66 is closed by the gate valve 68. Thereafter, the wafer support member 73 and the heating plate 74 are raised to the heat treatment position of the semiconductor wafer W shown in FIG. 8 by driving the motor 40, and hold the semiconductor wafer W in a horizontal posture. The opening / closing valve 80 and the opening / closing valve 81 are opened in advance, and the inside of the chamber 65 is in a nitrogen gas atmosphere.

  Wafer support member 73 and heating plate 74 are heated to a predetermined temperature in advance by the action of a heater built in heating plate 74. For this reason, in a state where the wafer support member 73 and the heating plate 74 are raised to the heat treatment position of the semiconductor wafer W, the semiconductor wafer W is preheated by coming into contact with the wafer support member 73 in a heated state, and the semiconductor wafer W The temperature gradually increases.

  In this state, the semiconductor wafer W is continuously heated via the wafer support member 73. When the temperature of the semiconductor wafer W rises, the internal temperature of the heating plate 74 is monitored by a temperature sensor inside the heating plate 74 (not shown) so that the surface temperature of the semiconductor wafer W becomes the preheating temperature T1, and reaches the set temperature. Always monitor whether or not

  The preheating temperature T1 is, for example, about 200 ° C. to 600 ° C. Even if the semiconductor wafer W is heated to such a preheating temperature T1, ions implanted into the semiconductor wafer W will not diffuse.

  Eventually, when the surface temperature of the semiconductor wafer W reaches the preheating temperature T1, the flash lamp 69 is turned on to perform flash heating. The lighting time of the flash lamp 69 in this flash heating process is a time of about 0.1 to 10 milliseconds. Thus, in the flash lamp 69, the electrostatic energy stored in advance is converted into such an extremely short light pulse, so that an extremely strong flash light is irradiated.

  By such flash heating, the surface temperature of the semiconductor wafer W instantaneously reaches the temperature T2. This temperature T2 is a temperature necessary for the ion activation treatment of the semiconductor wafer W at about 1000 ° C. to 1100 ° C. When the surface of the semiconductor wafer W is heated to such a processing temperature T2, ions implanted into the semiconductor wafer W are activated.

  At this time, since the surface temperature of the semiconductor wafer W is raised to the processing temperature T2 in an extremely short time of about 0.1 to 10 milliseconds, ion activation in the semiconductor wafer W is completed in a short time. . Therefore, the ions implanted into the semiconductor wafer W do not diffuse, and it is possible to prevent the phenomenon that the profile of the ions implanted into the semiconductor wafer W is lost. Since the time required for ion activation is extremely short compared with the time required for ion diffusion, the ion activation is performed even for a short time in which no diffusion of about 0.1 millisecond to 10 millisecond occurs. Complete.

  Further, before the flash lamp 69 is turned on to heat the semiconductor wafer W, the surface temperature of the semiconductor wafer W is heated to the preheating temperature T1 of about 200 ° C. to 600 ° C. using the heating plate 74. The flash lamp 69 makes it possible to quickly raise the temperature of the semiconductor wafer W to the processing temperature T2 of about 1000 ° C. to 1100 ° C.

  After the flash heating process is completed, the wafer support member 73 and the heating plate 74 are lowered to the loading / unloading position of the semiconductor wafer W shown in FIG. 7 by driving the motor 40 and the opening 66 closed by the gate valve 68. Is released. Then, the semiconductor wafer W placed on the support pins 70 is unloaded by the transfer robot 150. As described above, a series of heat treatment operations is completed.

  Next, atmosphere management in the substrate processing apparatus 100 will be described. Here, the atmosphere management of the alignment unit 130 will be described in particular. FIG. 9 is a flowchart showing the procedure of the initial purge. “Initial purge” is a process of introducing nitrogen gas into a low oxygen concentration atmosphere in a chamber that is in an air atmosphere after the apparatus is started up or after maintenance is completed.

  First, all the gate valves attached to the alignment chamber 131, that is, the gate valves 181 and 183 are closed to make the alignment chamber 131 a sealed space (step S1). In the case of the initial purge, the alignment chamber 131 is still in the atmosphere at this time.

  Next, the controller 101 opens the air valve 234 to supply nitrogen gas from the two blow-out tubes 231 into the alignment chamber 131 at a large flow rate of 60 L per minute, and opens the air valve 334 to open the alignment chamber. A strong exhaust state in which the pressure in 131 is (−0.5 KPa) to (−0.3 KPa) with respect to the outside is set (step S <b> 2). As a result, a nitrogen gas flow from the blowing tube 231 toward the gas discharge port 331 is formed over the entire area in the alignment chamber 131, and the air atmosphere in the alignment chamber 131 is replaced with the nitrogen gas atmosphere.

  Here, the internal volume of the alignment chamber 131 is approximately 12L to 15L. Therefore, nitrogen gas is supplied from the blow-out tube 231 at a flow rate of 4 to 5 times the internal volume of the alignment chamber 131 per minute. When nitrogen gas is supplied at such a large flow rate and a strong exhaust state is set, the atmosphere replacement in the alignment chamber 131 proceeds rapidly.

  In the present embodiment, the atmosphere replacement is performed with the goal that the oxygen concentration in the alignment chamber 131 is 10 ppm or less. According to the experiments by the present inventors, when nitrogen gas is supplied from the blowing tube 231 at a flow rate of 4 to 5 times the internal volume of the alignment chamber 131 per minute and the exhaust valve is in a strong exhaust state, the air valve 234 is used. It was found that the oxygen concentration in the alignment chamber 131 reached 10 ppm or less in about 2 minutes after the air valve 334 was opened. For this reason, the state is continued until 2 minutes elapses after the nitrogen gas large flow rate and the strong exhaust state are set by the timer 104 of the controller 101 (that is, after the air valve 234 and the air valve 334 are opened) (step S3). ).

  Then, when two minutes have elapsed since the start of the large flow rate of nitrogen gas and the strong exhaust state, the process proceeds to step S4, where the controller 101 closes the air valve 234 and enters the alignment chamber 131 from the two blowing tubes 231. Nitrogen gas is supplied at a small flow rate of 15 L in total, and the air valve 334 is closed so that the pressure in the alignment chamber 131 becomes (−0.2 KPa) to (−0.1 KPa) with respect to the outside. State. Once the oxygen concentration in the alignment chamber 131 reaches 10 ppm or less, the low oxygen concentration atmosphere in the alignment chamber 131 is maintained even if the nitrogen gas is at a low flow rate and a weak exhaust state unless the gate valves 181 and 183 are opened. .

  FIG. 10 is a flowchart showing a procedure for purging during conveyance. The “purge during transfer” is a process of maintaining the inside of the chamber in a low oxygen concentration atmosphere when the semiconductor wafer W is transferred while the substrate processing apparatus 100 is in operation.

  As described above, when the gate valves 181 and 183 are closed and the oxygen concentration in the alignment chamber 131 is 10 ppm or less, the air valve 234 and the air valve 334 are closed so that the nitrogen gas has a small flow rate and a weak exhaust state (step S11). . When the semiconductor wafer W is transferred from the indexer unit 110 to the alignment unit 130, first, the gate valve 181 on the indexer unit 110 side is opened (step S12). At substantially the same time, the controller 101 opens the air valve 234 and supplies nitrogen gas from the two blowing tubes 231 into the alignment chamber 131 at a large flow rate of a total of 60 L per minute (step S13). Note that the air valve 334 remains closed and the weak exhaust state is continued. That is, when the gate valve 181 is opened, the nitrogen gas has a large flow rate and a weak exhaust state, and the nitrogen gas supplied at the large flow rate is not only exhausted from the gas exhaust port 331 but also from the opening 136. It will blow out. Thereby, the inflow of air from the indexer unit 110 to the alignment chamber 131 is suppressed to some extent. However, it is impossible to completely prevent the inflow of air from the indexer unit 110 while opening the gate valve 181, and the oxygen concentration in the alignment chamber 131 increases to a maximum of about 7%.

  Next, the delivery robot 120 carries the semiconductor wafer W into the alignment unit 130 and places it on the wafer stage 133 (step S14). Subsequently, after the delivery robot 120 has left the alignment chamber 131, the gate valve 181 on the indexer unit 110 side is closed (step S15). Thereby, the inside of the alignment chamber 131 becomes a sealed space again.

  Then, the supply of nitrogen gas at a high flow rate of 60 L / min is continued, and the controller 101 opens the air valve 334 so that the pressure in the alignment chamber 131 is (−0.5 KPa) to (−0.3 KPa) to the outside. ) (Step S16). Thereby, nitrogen gas is supplied from the blowing tube 231 at a flow rate of 4 to 5 times the internal volume of the alignment chamber 131 per minute, and the gas discharging port is discharged from the blowing tube 231 over the entire area in the alignment chamber 131. A nitrogen gas flow toward 331 is formed, and the oxygen concentration once increased decreases again.

  Even if the oxygen concentration rises to some extent when the gate valve 181 is opened, the inside of the alignment chamber 131 does not completely become an atmospheric atmosphere. Therefore, the inner volume of the alignment chamber 131 is 4 to 5 times per minute from the blowing tube 231. If nitrogen gas is supplied at the following flow rate and a strong exhaust state is set, a low oxygen concentration atmosphere in which the oxygen concentration in the alignment chamber 131 becomes 10 ppm or less in about 1 minute after the air valve 234 and the air valve 334 are opened. Recover. For this reason, the state is continued until 1 minute elapses after the nitrogen gas large flow rate and the strong exhaust state are established by the timer 104 of the controller 101 (that is, after the air valve 334 is opened) (step S17).

  Then, when one minute has passed since the start of the large flow rate of nitrogen gas and the strong exhaust state, the process proceeds to step S18, where the controller 101 closes the air valve 234 and enters the alignment chamber 131 from the two blowing tubes 231. Nitrogen gas is supplied at a small flow rate of 15 L in total, and the air valve 334 is closed to weakly exhaust the pressure in the alignment chamber 131 to (−0.2 KPa) to (−0.1 KPa) with respect to the outside. State. As described above, after the oxygen concentration in the alignment chamber 131 reaches 10 ppm or less, the low oxygen concentration atmosphere in the alignment chamber 131 is maintained even if the nitrogen gas flow rate is low and the exhaust state is weak unless the gate valves 181 and 183 are opened. Is maintained. Such “purge during transfer” is a procedure for transferring the semiconductor wafer W between the indexer unit 110 and the alignment unit 130 or the cooling unit 140, and is a transfer chamber 170 and the alignment unit 130 or cooling unit 140. When the semiconductor wafer W is delivered between the two chambers, both chambers are in a low oxygen concentration atmosphere, so that the wafer is delivered by opening the gate valve with the nitrogen gas at a low flow rate and a weak exhaust state.

  As described above, when nitrogen gas is supplied into the alignment chamber 131 and replaced with a low oxygen concentration atmosphere, the flow rate from the blowing tube 231 is 4 to 5 times the internal volume of the alignment chamber 131 per minute. If nitrogen gas is supplied and a strong exhaust state is set, the alignment chamber 131 can be replaced with a low oxygen concentration atmosphere having an oxygen concentration of 10 ppm or less in a short time of about 2 minutes. Note that the amount of nitrogen gas supplied per minute is 4 to 5 times the internal volume of the alignment chamber 131. If it is less than 4 times, it takes a long time, and if it exceeds 5 times, the supply amount is excessive. This is because the wind pressure in the alignment chamber 131 is increased and a large load is applied to the components.

  Further, since the exhaust utility 337 of the factory is used for exhausting the gas from the alignment chamber 131 without using a vacuum pump, the apparatus configuration can be made inexpensive, and the components in the alignment chamber 131 can be reduced. There is no need for a pressure-resistant structure.

  Then, after the oxygen concentration in the alignment chamber 131 reaches 10 ppm or less, nitrogen gas is supplied from the blowing tube 231 at a small flow rate less than four times the internal volume of the alignment chamber 131 per minute and a weak exhaust state is established. By doing so, consumption of nitrogen gas is suppressed while maintaining a low oxygen concentration atmosphere in the alignment chamber 131.

  Such atmosphere management is performed in the cooling unit 140 in the same manner. That is, when nitrogen gas is supplied into the chamber of the cooling unit 140 and replaced with a low oxygen concentration atmosphere, nitrogen gas is supplied at a large flow rate of 4 to 5 times the chamber volume per minute and strong exhaust is performed. State. By doing so, the inside of the chamber can be replaced with a low oxygen concentration atmosphere having an oxygen concentration of 10 ppm or less in a short time of about 2 minutes after the start of the atmosphere replacement. Then, after the oxygen concentration in the chamber 131 reaches 10 ppm or less, nitrogen gas is supplied at a small flow rate less than 4 times the volume of the chamber per minute and the exhaust gas is in a weakly exhausted state. The consumption of nitrogen gas is suppressed while maintaining an oxygen concentration atmosphere.

  As for the atmosphere management of the transfer chamber 170, the procedure for switching to the nitrogen gas small flow rate and the weak exhaust state after the atmosphere substitution is performed with the nitrogen gas large flow rate and the strong exhaust state and the indoor oxygen concentration becomes 10 ppm or less is the same as above. However, the internal volume of the transfer chamber 170 is relatively large at 165L. On the other hand, when nitrogen gas is supplied at a large flow rate from the blowing tube 271 of the transfer chamber 170, the flow rate is 80 L in total per minute. For this reason, it takes about 20 minutes for the oxygen concentration in the transfer chamber 170 to reach 10 ppm or less after the atmosphere replacement is started. Also in the transfer chamber 170, if nitrogen gas is supplied from the blow-out tube 271 at a flow rate of about 800 L / min and a strong exhaust state is set, the oxygen concentration in the transfer chamber 170 is as low as 10 ppm or less in a short time of about 2 minutes. It can be replaced with an oxygen concentration atmosphere. However, when supplying nitrogen gas at a considerably large flow rate of about 800 L / min, it is necessary to make the gas piping and mass flow meter compatible with it and make the transport robot 150 have a structure capable of withstanding a large wind pressure. There is.

  On the other hand, in the heat treatment unit 160, the supply of nitrogen gas into the chamber 65 at a high flow rate of about 40 L / min and the supply of nitrogen gas at a low flow rate of about 30 L / min are switched. . However, since the gas is supplied according to the heat treatment process in the heat treatment unit 160, the atmosphere management is different from the above.

Further, as described above, after the oxygen concentration in the chamber of each part reaches 10 ppm or less, the nitrogen gas has a small flow rate and a weak exhaust state, and the nitrogen gas supply amount to each chamber is 15 L / min. The cooling unit 140 is 25 L / min, the transfer chamber 170 is 30 L / min, and the heat treatment unit 160 is 30 L / min. When the nitrogen gas supply amount to the respective chambers is adjusted in this way and a weak exhaust state using the factory exhaust utility 337 is performed during steady processing including transfer to the semiconductor wafer W, all chambers are external. On the other hand, a slight negative pressure up to (−0.15 KPa) is obtained, and there is no possibility that gases such as NH ₃ and N ₂ O leak to the outside.

  Furthermore, if the nitrogen gas supply amount to the chambers of each part is adjusted as described above and a weak exhaust state using the factory exhaust utility 337 is used, the differential pressure between the chambers of each part should be sufficiently reduced to 0.1 KPa or less. Even if the gate valve between the chambers is opened as it is without adjusting the pressure with a special pressure adjusting mechanism, it is possible to prevent particles from rising due to gas movement due to the differential pressure.

<6. Modification>
While the embodiments of the present invention have been described above, the present invention is not limited to the above examples. For example, in each of the above embodiments, the light source 5 is provided with 30 flash lamps 69, but the present invention is not limited to this, and the number of flash lamps 69 may be arbitrary.

  Further, the technique according to the present invention can be applied to a heat treatment apparatus that includes another type of lamp (for example, a halogen lamp) instead of the flash lamp 69 in the light source 5 and heats the semiconductor wafer W by light irradiation from the lamp. Can be applied. Furthermore, the technique according to the present invention can be applied to other single wafer heat treatment apparatuses such as a CVD apparatus.

  Moreover, in the said embodiment, although the two carriers 91 are mounted in the board | substrate accommodating part 110, only one carrier 91 may be mounted and three or more may be sufficient. Further, although the delivery robot 120 moves between the two carriers 91, two delivery robots 120 may be provided.

  In the above embodiment, both the alignment unit 130 and the cooling unit 140 supply nitrogen gas at a large flow rate of 4 to 5 times the chamber internal volume per minute and are in a strong exhaust state. Alternatively, the air supply / exhaust may be performed.

  In the above embodiment, the semiconductor wafer is irradiated with light to perform the ion activation process. However, the substrate to be processed by the substrate processing apparatus according to the present invention is not limited to the semiconductor wafer. Absent. For example, the glass substrate on which various silicon films such as a silicon nitride film and a polycrystalline silicon film are formed may be processed by the substrate processing apparatus according to the present invention. As an example, an amorphous silicon film made amorphous by ion implantation of silicon into a polycrystalline silicon film formed on a glass substrate by a CVD method is formed, and a silicon oxide film serving as an antireflection film is further formed thereon. Form. In this state, the entire surface of the amorphous silicon film can be irradiated with the substrate processing apparatus according to the present invention to form a polycrystalline silicon film in which the amorphous silicon film is polycrystallized.

  Further, a substrate according to the present invention is formed on a TFT substrate having a structure in which a base silicon oxide film and a polysilicon film obtained by crystallizing amorphous silicon are formed on a glass substrate, and the polysilicon film is doped with impurities such as phosphorus and boron. It is also possible to activate the impurities implanted in the doping process by irradiating light with a processing apparatus.

It is a top view which shows the substrate processing apparatus concerning this invention. It is a front view which shows the substrate processing apparatus concerning this invention. It is a sectional side view which shows schematic structure of the alignment part of the substrate processing apparatus of FIG. It is a perspective view which shows schematic structure of the alignment part of the substrate processing apparatus of FIG. It is a sectional side view which shows schematic structure of the conveyance chamber of the substrate processing apparatus of FIG. It is a top view which shows schematic structure of the conveyance chamber of the substrate processing apparatus of FIG. It is a sectional side view which shows the heat processing part of the substrate processing apparatus of FIG. It is a sectional side view which shows the heat processing part of the substrate processing apparatus of FIG. It is a flowchart which shows the procedure of an initial purge. It is a flowchart which shows the procedure of the purge during conveyance.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 Light source 65 Chamber 69 Flash lamp 100 Substrate processing apparatus 110 Indexer part 130 Alignment part 131 Alignment chamber 140 Cooling part 150 Transfer robot 160 Heat processing part 170 Transfer chamber 181,182,183,184,185 Gate valve 230,270 Gas supply mechanism 231,271 Blowing tube 232,332 Small flow rate needle valve 233,333 Large flow rate needle valve 234,334 Air valve 235,335 Mass flow meter 272 Mass flow controller 330,370 Gas exhaust mechanism 331,371 Gas exhaust port 372 Auto damper 337 Exhaust utility W Semiconductor wafer

Claims (7)

A substrate processing apparatus for performing predetermined processing on a substrate in a low oxygen concentration atmosphere,
A processing chamber having an internal volume V for accommodating the substrate and performing the predetermined processing;
Gas supply means for supplying an inert gas to the processing chamber;
An outlet for discharging gas from the processing chamber;
Supply flow rate adjusting means for adjusting the flow rate of the inert gas supplied from the gas supply means;
With
When supplying an inert gas into the processing chamber and replacing it with a low oxygen concentration atmosphere, the supply flow rate adjusting means supplies the gas supply means with an inert gas at a first flow rate of 4 V to 5 V per minute. A substrate processing apparatus. The substrate processing apparatus according to claim 1,
An exhaust flow rate adjusting means for adjusting the flow rate of the gas discharged from the processing chamber;
The substrate processing apparatus, wherein the discharge port is connected to an exhaust utility of a factory where the substrate processing apparatus is installed via the exhaust flow rate adjusting means. In the substrate processing apparatus of Claim 1 or Claim 2,
After a predetermined time has elapsed since the start of the inert gas supply at the first flow rate, the supply flow rate adjusting means causes the gas supply means to supply an inert gas at a second flow rate of less than 4 V per minute. A substrate processing apparatus. In the substrate processing apparatus in any one of Claims 1-3,
A transport unit for transporting the substrate;
An alignment unit connected to the transport unit and performing alignment of the substrate;
A heat treatment unit connected to the transfer unit and performing a heat treatment of the substrate;
A cooling unit connected to the transfer unit and performing a cooling process on the substrate;
Have
The substrate processing apparatus, wherein the processing chamber is provided in the alignment unit and / or the cooling unit. An atmosphere replacement method for replacing an atmosphere in a processing chamber having an internal volume V for accommodating a substrate with a low oxygen concentration atmosphere,
An atmosphere replacement method, wherein an inert gas is supplied to the processing chamber at a first flow rate of 4 V to 5 V per minute. In the atmosphere substitution method according to claim 5,
An atmosphere replacement method, wherein exhaust from the processing chamber is performed using an exhaust utility of a factory where the processing chamber is installed. In the atmosphere substitution method according to claim 5 or 6,
Atmosphere replacement, wherein an inert gas is supplied to the processing chamber at a second flow rate of less than 4 V per minute after a predetermined time has passed since the supply of the inert gas at the first flow rate was started. Method.

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