JP2010086986A - Wafer processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the issue of control abnormality of a gas flow rate controller caused by abrupt pressure fluctuation, and to improve throughput by cooling a wafer with N2 gas or the like of high flow rate. <P>SOLUTION: The substrate processing apparatus has: a processing chamber 54 for processing a substrate; a preliminary chamber 36 adjacent to the processing chamber, a gas supply line 41 for supplying gas to the preliminary chamber; a pressure reducing valve 79 which is provided to the gas supply line for adjusting a pressure by which gas is allowed to flow into the preliminary chamber based on a set pressure value; a gas flow rate control valve 58 which is provided between the pressure reducing valve at the gas supply line and the preliminary chamber for controlling a flow rate of the gas flowing to the preliminary chamber; and a control part 82 which varies a set pressure of the pressure reducing valve when supplying gas from the gas supply line to the preliminary chamber. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a substrate processing apparatus that forms a thin film on a substrate such as a silicon wafer or a glass substrate, or performs processing such as impurity diffusion, etching, and annealing.

  The process of manufacturing a semiconductor device from a substrate such as a silicon wafer includes substrate processing such as thin film formation, impurity diffusion, etching, annealing treatment, etc. by thermal CVD, and there is a substrate processing apparatus for performing such substrate processing. .

  The substrate processing apparatus includes a processing furnace that heat-processes a substrate, and the processing furnace includes a heater and a processing chamber that is provided in the heater and stores the substrate, and the substrate is heated in the processing chamber. After the processing, the substrate is cooled to a predetermined temperature.

  In substrate processing, a substrate to be processed such as a silicon wafer (hereinafter referred to as a wafer) is loaded into a boat that has been lowered to a retreat position directly below the processing chamber, and is loaded into the processing chamber using a boat lifting mechanism (loading). ). Thereafter, a predetermined film is deposited on the wafer, and after the film formation is completed, the boat is pulled out again to the retracted position (unloading). Thereafter, the wafer is unloaded from the boat using a wafer transfer mechanism.

  The wafer immediately after being pulled out is in a high temperature state, for example, about 300 ° C. due to the thermal influence during the film formation. If the wafer is transported by the wafer transport mechanism in the high temperature state as it is, the wafer transport mechanism is thermally deteriorated due to the heat radiation from the wafer, or the wafer that has been heated and the wafer transport that has been cooled down. There has been a problem that the wafer is damaged due to stress and strain caused by contact of the substrate support of the mechanism.

  In order to prevent thermal deterioration of the wafer transfer mechanism and damage to the wafer, a heat radiation time (delay time) is provided after the wafer is pulled out until the wafer is transferred by the wafer transfer mechanism. By providing a heat dissipation time, the temperature of the wafer can be lowered to a temperature at which heat dissipation from the heated wafer does not cause thermal degradation in the wafer transfer mechanism. After the temperature at which the thermal deterioration of the wafer transfer mechanism hardly occurs, for example, the temperature of the wafer is lowered to 100 ° C. or less, the wafer is transferred from the boat by the wafer transfer mechanism.

  Further, in order to improve the throughput, it is necessary to shorten the heat radiation time. In order to shorten the time, it is a problem how to quickly cool the unloaded wafer. One means for solving this problem is to supply a large amount of cooling gas such as N2 gas to the unloaded wafer.

  However, in order to supply a large amount of cooling gas to the wafer, the primary pressure on the upstream side of the gas must be set high, and the gas flow controller (hereinafter referred to as MFC) is in a state where the primary pressure is high. When the upstream air valve (hereinafter referred to as AV) is opened, the MFC cannot withstand sudden pressure fluctuations and falls into an uncontrolled state for a moment, causing a large amount of overflow gas to flow (see FIG. 6). At this time, depending on the pressure conditions, there is a risk of flowing up to the full scale value of the MFC.

  Such a rapid gas flow vibrates the wafer and generates particles due to rubbing between the wafer and the wafer mounting portion of the boat due to the vibration of the wafer. Further, the wafer mounting position is shifted by moving the wafer on the boat, causing interference with the wafer transfer mechanism during subsequent wafer transfer, or causing unexpected contact of the wafer. There was a risk of hindering transportation.

  In order to solve the above problem, there is a conventional method in which two or more gas supply pipes are provided, a flow rate range and a pressure are set for each system, and the systems are sequentially switched. An electromagnetic valve is attached to each of the two or more gas supply pipes and is provided so as to be switchable. Further, since a regulator and an MFC are attached to the gas supply pipe, the gas pressure can be reduced and the flow rate can be controlled.

  For example, when two gas supply pipes are used, the gas is sent to the first gas supply pipe by turning on the first electromagnetic valve while the second electromagnetic valve is turned off. The regulator provided in the first gas supply pipe is depressurized to a pressure somewhat higher than the vacuum, and the cooling gas is supplied to the wafer for a predetermined time by the MFC. Thereafter, the first electromagnetic valve is turned off and the second electromagnetic valve is turned on, whereby the gas is sent to the second gas supply pipe. In the second gas supply pipe, the gas is set to a pressure higher than the atmospheric pressure, and is supplied to the wafer by the MFC.

  In this manner, by performing the two-stage gas supply, the pressure increase rate in the processing chamber can be moderated.

  However, even in the above method, on the second gas supply pipe side, the same conditions as when two or more gas supply pipes are not provided are used, and therefore a sudden pressure fluctuation occurs and an uncontrolled state occurs. In addition, there are problems such as cost due to mounting a plurality of expensive parts and space due to an increase in installation space.

JP 2007-88337 A

  In view of such a situation, the present invention solves the control abnormality of the gas flow rate controller due to a rapid pressure fluctuation, and improves the throughput by cooling the wafer with a large flow rate of cooling gas or the like.

  The present invention provides a processing chamber for processing a substrate, a preliminary chamber adjacent to the processing chamber, a gas supply line for supplying gas to the preliminary chamber, and a gas supply line provided on the basis of a set pressure value. A pressure reducing valve that adjusts the pressure of the gas that flows to the spare chamber, and a gas flow rate adjustment that is provided between the pressure reducing valve and the spare chamber in the gas supply line and adjusts the flow rate of the gas that flows to the spare chamber The present invention relates to a substrate processing apparatus having a valve and a control unit that varies a set pressure of the pressure reducing valve when gas is supplied from the gas supply line to the preliminary chamber.

  According to the present invention, a processing chamber for processing a substrate, a spare chamber adjacent to the processing chamber, a gas supply line for supplying gas to the spare chamber, and a set pressure value provided in the gas supply line A pressure reducing valve that adjusts the pressure of the gas flowing into the spare chamber based on the gas, and a gas that is provided between the pressure reducing valve and the spare chamber in the gas supply line and adjusts the flow rate of the gas flowing into the spare chamber Since it has a flow rate adjustment valve and a control unit that varies the set pressure of the pressure reducing valve when supplying gas from the gas supply line to the preliminary chamber, the wafer is cooled with a large flow rate of cooling gas to improve throughput. In addition, a large flow rate of gas does not flow out due to abnormal control of the gas flow rate controller immediately after the air valve is opened, and it is possible to suppress the generation of particles and problems during transportation. Departure To.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  First, the configuration of a substrate processing apparatus in which the present invention is implemented will be described.

  An example of the substrate processing apparatus described below has a vertical furnace, a processing chamber is formed in the vertical furnace, and the substrate processing apparatus 1 has an airtight preliminary chamber connected to the processing chamber. Is shown. In the substrate processing apparatus 1, the wafer 2 is stored in a hermetically sealed substrate storage container (hereinafter referred to as a pod) 3 for storage and transport.

  1 and 2, reference numeral 4 denotes an airtight housing, and a front maintenance port 6 for maintenance is opened at a lower portion of the front wall 5 of the housing 4, and the front maintenance port 6 includes a front maintenance door 7, 7 is opened and closed.

  A pod transfer stage (substrate storage container delivery base) 8 is provided on the front wall 5 above the front maintenance door 7. The pod transfer stage 8 and the inside of the housing 4 are connected to a pod loading / unloading port (substrate). The pod loading / unloading port 9 is opened and closed by a front shutter (substrate storage container loading / unloading opening / closing mechanism) 11.

  The pod 3 is transferred and transferred to and from the pod transfer stage 8 by an external transfer device (not shown).

  A rotary pod shelf (substrate storage container mounting shelf) 12 is installed at an upper portion of the casing 4 at a substantially central portion in the front-rear direction, and the rotary pod shelf 12 includes a plurality of the pods. 3 is configured to be stored.

  The rotary pod shelf 12 includes a support column 13 which is erected vertically and intermittently rotated, and a plurality of shelf boards (substrate storage container mounts) which are radially provided on the support column 13 at upper, middle and lower positions. A plurality of pods 3 are placed on the plurality of shelf boards 14 respectively.

  A pod transfer device (substrate storage container transfer device) 15 is installed between the pod transfer stage 8 and the rotary pod shelf 12. The pod transfer device 15 holds the pod 3 and moves up and down. A pod elevator (substrate storage container lifting mechanism) 16 and a pod transfer mechanism (substrate storage container transfer mechanism) 17 as a transfer mechanism capable of moving back and forth are configured. The pod transfer device 15 includes the pod elevator 16 and a pod. In cooperation with the transport mechanism 17, the pod 3 is transported between the pod transfer stage 8, the rotary pod shelf 12, and a pod opener (substrate storage container lid opening / closing mechanism) 18 described later. Has been.

  An inner casing 19 formed of an airtight casing is provided over the rear end at a lower portion of the casing 4 at a substantially central portion in the front-rear direction. Wafer loading / unloading ports (substrate loading / unloading ports) 22 and 22 for loading / unloading the wafer 2 into / from the inner housing 19 are vertically opened in two steps on the front wall 21 of the inner housing 19. Pod openers 18 and 18 are installed at the wafer loading / unloading ports 22 and 22, respectively.

  The pod opener 18 includes mounting bases 23 and 23 for mounting the pod 3, and cap attaching / detaching mechanisms (lid attaching / detaching mechanisms) 24 and 24 for attaching and detaching caps (lids) of the pod 3. The pod opener 18 is configured to open and close the wafer entrance / exit of the pod 3 by attaching / detaching the cap of the pod 3 placed on the mounting table 23 by the cap attaching / detaching mechanism 24.

  The internal casing 19 constitutes an airtight transfer chamber 25, and a wafer transfer mechanism (substrate transfer mechanism) 26 is installed in the front region of the transfer chamber 25. A wafer transfer device (substrate transfer device) 27 capable of rotating and advancing and retreating the wafer 2 in the horizontal direction, and a wafer transfer device elevator (substrate transfer device lifting mechanism) 28 for raising and lowering the wafer transfer device 27; It consists of

  The wafer transfer mechanism 26 is provided opposite to the wafer loading / unloading port 22, and a tweezer (substrate) of the wafer transfer device 27 is cooperated by the wafer transfer device elevator 28 and the wafer transfer device 27. The holder 2 is configured to load (charge) the wafer 2 with respect to the boat (substrate holder) 31 and discharge (discharge) it. The boat 31 is configured to hold a predetermined number of wafers 2, for example, about 50 to 125 wafers in a horizontal posture in multiple stages.

  A clean unit 33 composed of a supply fan and a dust-proof filter is installed to face the wafer transfer device elevator 28 and supply clean air 32 which is a cleaned atmosphere or inert gas to the transfer chamber 25. Between the clean unit 33 and the wafer transfer device 27, a notch alignment device 34 as a substrate alignment device for aligning the circumferential position of the wafer 2 is installed.

Is the clean air 32 blown from the clean unit 33 circulated through the notch alignment device 34 and the wafer transfer mechanism 26, and then sucked in by a duct (not shown) and exhausted outside the housing 4? Alternatively, it is circulated to the primary side (supply side) that is the suction side of the clean unit 33, and is again blown out to the transfer chamber 25 by the clean unit 33.

  In the rear region of the transfer chamber 25, a pressure-resistant housing 35 having an airtight performance capable of maintaining a pressure lower than atmospheric pressure (hereinafter referred to as negative pressure) is installed. A load lock chamber 36 that is a load lock type spare chamber that has a volume capable of accommodating the boat 31 and that radiates heat of the wafers 2 processed in the processing chamber is formed adjacent to the processing chamber.

  A wafer loading / unloading opening (substrate loading / unloading opening) 38 is formed in the front wall 37 of the pressure-resistant casing 35, and the wafer loading / unloading opening 38 is opened and closed by a gate valve (substrate loading / unloading opening / closing mechanism) 39. It is like. A gas supply pipe 41 for supplying nitrogen gas to the load lock chamber 36 and an exhaust pipe 42 for exhausting the load lock chamber 36 to a negative pressure are respectively provided on a pair of side walls of the pressure-resistant casing 35. It is connected.

  A processing furnace 43 is provided above the load lock chamber 36. The furnace port at the lower end of the processing furnace 43 is configured to be opened and closed by a furnace port gate valve (furnace port opening / closing mechanism) 44. A furnace port gate valve cover 45 that houses the furnace port gate valve 44 when the furnace port portion is opened is attached to the upper end portion of the front wall 37.

  In the load lock chamber 36, a boat elevator (substrate holder lifting mechanism) 46 for raising and lowering the boat 31 is installed. The boat elevator 46 has an arm 47 extending in the horizontal direction, and a seal cap 48 as a lid is provided horizontally on the arm 47, and the seal cap 48 supports the boat 31 vertically. The furnace port portion can be closed.

  Next, the operation of the substrate processing apparatus in which the present invention is implemented will be described.

  When the pod 3 is supplied to the pod transfer stage 8, the pod loading / unloading port 9 is opened by the front shutter 11, and the pod 3 on the pod transfer stage 8 is moved to the housing by the pod transfer device 15. The pod is loaded into the body 4 from the pod loading / unloading port 9.

  The loaded pod 3 is transported and placed by the pod transport device 15 to the designated shelf plate 14 of the rotary pod shelf 12 and temporarily stored. It is transported to the pod opener 18 and transferred to the mounting table 23, or directly transferred to the pod opener 18 and transferred to the mounting table 23. At this time, the wafer loading / unloading port 22 is closed by the cap attaching / detaching mechanism 24, and clean air 32 is circulated and filled in the transfer chamber 25. For example, when the transfer chamber 25 is filled with nitrogen gas as clean air 32, the oxygen concentration is set to 20 ppm or less, much lower than the oxygen concentration inside the housing 4 (atmosphere). Yes.

  The side surface end of the opening of the pod 3 placed on the mounting table 23 is pressed against the opening edge of the wafer loading / unloading port 22, and the cap of the pod 3 is removed by the cap attaching / detaching mechanism 24. The doorway is opened.

  Further, the gate loading / unloading opening 38 of the pressure-resistant casing 35 in which the load lock chamber 36 is in an atmospheric pressure state is opened by the gate valve 39.

  When the pod 3 is opened by the pod opener 18 and the wafer loading / unloading opening 38 is opened, the wafer 2 is picked up from the pod 3 by the tweezer 29 through the wafer loading / unloading port and After the alignment, the wafer is carried into the load lock chamber 36 through the wafer carry-in / out opening 38. In the load lock chamber 36, the boat 31 is previously lowered (unloaded) by the boat elevator 46 and is in a standby state, and the wafer 2 is loaded into the boat 31 by the wafer transfer device 27.

  The wafer transfer device 27 having loaded the wafer 2 on the boat 31 returns to the pod 3 and loads the next wafer 2 on the boat 31.

  During the operation in which the wafer 2 of the upper or lower pod opener 18 is loaded by the wafer transfer mechanism 26, the other (lower or upper) pod opener 18 has another pod from the rotary pod shelf 12. 3 is transported by the pod transport device 15, and the opening operation of the pod 3 by the pod opener 18 is simultaneously performed.

  When a predetermined number of wafers 2 are loaded into the boat 31, the wafer loading / unloading opening 38 is closed by the gate valve 39, and the load lock chamber 36 is evacuated from the exhaust pipe 42. Depressurized.

  When the load lock chamber 36 is decompressed to the same pressure as the processing chamber of the processing furnace 43, the furnace port portion is opened by the furnace port gate valve 44, and the furnace port gate valve 44 is opened to the furnace port gate valve cover 45. It is stored in. The boat 31 is lifted by the boat elevator 46 and loaded (loaded) into the processing chamber. When the boat 31 is inserted, the furnace port portion is hermetically closed by the seal cap 48.

  After loading, the processing furnace 43 performs a required process on the wafer 2 as will be described later.

  After the processing, the wafer 2 and the pod 3 are discharged to the outside of the housing 4 by the reverse procedure described above except for the alignment process of the wafer 2 by the notch alignment device 34.

  Next, the processing furnace 43 and the substrate processing will be described with reference to FIG. In the following, a low pressure CVD processing furnace will be described as an example of the processing furnace.

  An outer tube (hereinafter referred to as an outer tube) 49 is made of, for example, quartz (SiO2), and has a cylindrical shape with an upper end closed and an opening at the lower end. An inner tube (hereinafter referred to as an inner tube) 51 has a cylindrical shape having openings at both ends of an upper end and a lower end, and is disposed concentrically in the outer tube 49. A cylindrical space 52 is formed between the outer tube 49 and the inner tube 51, and the gas rising from the upper opening of the inner tube 51 descends the cylindrical space 52 and is exhausted from the exhaust pipe 53. It is like. The outer tube 49 and the inner tube 51 constitute a reaction tube, and a processing chamber 54 is defined inside the reaction tube.

  A manifold 55 made of, for example, stainless steel is engaged with lower ends of the outer tube 49 and the inner tube 51, and the outer tube 49 and the inner tube 51 are held by the manifold 55. The manifold 55 is fixed to the heater base 56 by required holding means. An annular flange is provided at each of the lower end portion of the outer tube 49 and the upper end opening end portion of the manifold 55, and a seal member such as an O-ring is provided between the flanges so that the space between the two is airtight. It is sealed.

  The lower end opening of the manifold 55 constitutes a furnace opening, and the seal cap 48 made of, for example, stainless steel is opened and closed so as to be hermetically sealed through a seal member such as an O-ring. A gas supply pipe 57 for supplying a processing gas is provided in the seal cap 48 so as to penetrate therethrough. The gas supply pipe 57 is connected to a gas flow rate adjusting valve (hereinafter referred to as a mass flow controller (MFC)) 58, and the MFC 58 is connected to a gas flow rate control unit 61, and the flow rate of the gas to be supplied is predetermined. The amount can be controlled.

  Reference numeral 62 in the figure denotes a main control unit composed of sub-control units such as a temperature control unit 63, the gas flow rate control unit 61, a pressure control unit 64, and a drive control unit 65, and controls the entire substrate processing apparatus. ing.

  At the upper part of the manifold 55, there is a pressure regulator (for example, APC (Automatic Exhaust Pressure Control System), N2 ballast controller) connected to the exhaust pipe 53 toward the downstream side of the exhaust pipe 53. 66) and an exhaust device (hereinafter referred to as a vacuum pump) 67 are connected, and the gas flowing through the cylindrical space 52 between the outer tube 49 and the inner tube 51 is discharged, and the outer The pressure in the tube 49 is controlled by the APC 66 and detected by a pressure detecting means (hereinafter referred to as a pressure sensor) 68 so as to make a reduced pressure atmosphere of a predetermined pressure, and the pressure control unit 64 controls the pressure.

  The seal cap 48 is provided with a rotating means 69, and a boat mounting table 72 is connected via a rotating shaft 71 of the rotating means 69, and the boat 31 is mounted on the boat mounting table 72. It is like. The rotating means 69 rotates the boat 31 and the wafer 2 held on the boat 31 via the boat mounting table 72. The seal cap 48 is connected to the boat elevator 46 through the arm 47.

  The rotating means 69 and the boat elevator 46 are controlled by the drive control unit 65 so as to be driven at a predetermined speed.

  On the outer periphery of the outer tube 49, heating means (hereinafter referred to as a heater 73) is disposed concentrically with the outer tube 49. The heater 73 detects the temperature by temperature detection means (hereinafter referred to as a thermocouple 74) so that the temperature in the outer tube 49 is set to a predetermined processing temperature, and is controlled by the temperature control unit 63.

  An example of the low pressure CVD processing method using the processing furnace 43 will be described. First, the boat elevator 46 is moved down to the load lock chamber 36 by the boat elevator 46. A predetermined number of wafers 2 are loaded into the boat 31 by the wafer transfer device 27. Next, the temperature in the outer tube 49 is set to a predetermined processing temperature while being heated by the heater 73.

  The outer tube 49 is filled with an inert gas in advance by the MFC 58, the boat 31 is lifted by the boat elevator 46 and charged into the processing chamber 54, and the temperature of the processing chamber 54 is set to a predetermined level. Maintain at processing temperature. After the processing chamber 54 is evacuated to a predetermined vacuum state, the boat 31 and the wafer 2 held on the boat 31 are rotated by the rotating means 69. At the same time, a processing gas is supplied from the gas supply pipe 57. The supplied gas rises in the inner tube 51 and is evenly supplied to the wafer 2.

  In the outer tube 49 during the low pressure CVD process, the process gas is exhausted through the exhaust pipe 53, the pressure is controlled by the APC 66 so as to be in a predetermined vacuum state, and the low pressure CVD process is performed for a predetermined time.

  In this way, when the low pressure CVD process is completed, the inside of the outer tube 49 is replaced with an inert gas, the pressure is set to normal pressure, and then the boat 31 is lowered by the boat elevator 46. The processed wafer 2 is taken out from the processing chamber 54 to the load lock chamber 36. The processed wafer 2 on the boat 31 taken out from the processing chamber 54 is cooled to a required temperature in the load lock chamber 36.

  The processed wafer 2 is discharged by the wafer transfer device 27 and the unprocessed wafer 2 is loaded into the boat 31. Again, as described above, the boat 31 is raised into the processing chamber 54, and a low pressure CVD process is performed.

  Note that, up to one example, the processing conditions to be processed in the processing furnace 43 of the present embodiment are as follows: in the formation of a nitride film, the wafer temperature is 750 ° C., the gas species supply amount is DCS (dichlorosilane), 0.5 SLM, NH3 (ammonia), 1.0 SLM, treatment pressure is 20 Pa.

  Next, the cooling device for the wafer 2 in the present invention will be described with reference to FIG. In FIG. 4, the inner tube 51, the boat elevator 46 and the like are not shown. In FIG. 4, the same components as those shown in FIGS. 1 to 3 are denoted by the same reference numerals, and the description thereof is omitted.

  The pressure-resistant casing 35 is provided with a gas supply nozzle 75 extending in the vertical direction along one wall surface, and the gas supply nozzle 75 has a length equivalent to the height of the load lock chamber 36 and is spaced at a required interval. A gas ejection hole (not shown) is formed. A gas supply system 76 is connected to the gas supply nozzle 75 through the gas supply pipe 41.

  The gas supply system 76 includes an F (filter) 77, the MFC (gas flow rate adjusting valve) 58, AV 78, the pressure sensor 68, a regulator (pressure reducing valve) 79, a gas supply source 81, and a sequencer (control unit) 82. The gas supply source 81 supplies a clean inert gas such as nitrogen gas.

  The gas supply pipe 41 is provided with the regulator 79, the AV 78, the MFC 58, and the F 77 from the upstream side, and the pressure sensor 68 is connected between the regulator 79 and the AV 78. The sequencer 82 is connected to the regulator 79, the AV 78, and the MFC 58.

  A gas exhaust nozzle 83 is provided in the pressure-resistant housing 35 at a position facing the gas supply nozzle 75, the gas exhaust nozzle 83 is connected to the exhaust pipe 42, and the exhaust pipe 42 is an exhaust gas (not shown). It is connected to an exhaust means having a pump or the like. The gas exhaust nozzle 83 is provided with suction holes (not shown) at required intervals.

  The gas flow rate control by the MFC 58, the opening and closing of the AV 78, and the pressure setting by the regulator 79 are performed by the sequencer 82 which is a control unit of the gas supply system 76, and the sequencer 82 is preset with a pressure corresponding to each gas flow rate range. Set it.

  An example of the gas flow rate and the set pressure is shown in FIG.

  The sequencer 82 gradually increases the pressure in accordance with a preset set value based on the open signal of the AV 78, and increases the gas flow rate in conjunction with the increase in pressure.

  In addition, a gas flow parallel to the load lock chamber 36 is formed by exhausting from the gas exhaust nozzle 83 while the inert gas is being supplied from the gas supply nozzle 75.

  Hereinafter, the cooling action of the wafer 2 will be described.

  While the wafer 2 is being processed in the processing chamber 54, the load lock chamber 36 is replaced with nitrogen gas including a decompression step, and the moisture (oxygen) concentration in the load lock chamber 36 is reduced. .

  When the processing of the wafer 2 is finished, the boat 31 is unloaded from the processing chamber 54 to the load lock chamber 36. At the stage where the boat 31 is completely unloaded into the load lock chamber 36, the AV 78 provided on the upstream side of the MFC 58 is opened.

  Thereafter, based on the open signal of the AV 78, the set gas flow rate controlled by the MFC 58 is gradually increased from 0 SLM to a predetermined gas flow rate, and the set pressure of the regulator 79 is gradually increased from 0 MPa to a predetermined pressure. Raise up to.

  The cooling gas whose pressure and flow rate are controlled is ejected from the gas supply nozzle 75 and is exhausted from the gas exhaust nozzle 83 across the boat 31 and the wafer 2.

  As described above, the MFC 58, the AV 78, and the regulator 79 are automatically controlled, and the change in the gas flow rate and the gas pressure are linked to prevent a sudden change in the flow rate or pressure. Further, since the control abnormality of the MFC 58 immediately after the AV 78 is opened can be suppressed by preventing a sudden change, the MFC 58 causes a control abnormality when a large flow rate of cooling gas is supplied. The flow of gas does not flow out to generate particles or damage the wafer 2 due to vibration.

  Therefore, a controllable large flow rate of cooling gas can be sprayed onto the wafer 2, and by spraying a large flow rate of cooling gas onto the wafer 2, the wafer 2 is rapidly cooled, and the temperature drop rate is greatly increased. .

  The gas flow rate detected by the flow sensor attached to the MFC 58 is fed back to finely adjust the gas flow rate of the MFC 58, and the detection result of the pressure sensor 68 is fed back to finely adjust the control pressure of the regulator 79. By doing so, it becomes possible to control while measuring the actual flow rate and the actual pressure, so that more precise control is possible.

  In addition, it is not a control method in which the pressure is set stepwise for each flow rate described above, but it goes without saying that the relationship between the flow rate and the pressure is expressed by an equation, and more precise control is possible by performing continuous control. .

  In the present invention, the MFC 58, the AV 78, and the regulator 79 are controlled by the sequencer 82. However, the MFC 58, the AV 78, and the regulator 79 are controlled by the sub-control that constitutes the main controller 62 described above. You may go in the department.

(Appendix)
The present invention includes the following embodiments.

  (Supplementary Note 1) A processing chamber for processing a substrate, a spare chamber adjacent to the processing chamber, a gas supply line for supplying gas to the spare chamber, and a gas supply line provided on the basis of a set pressure value A pressure reducing valve that adjusts the pressure of the gas that flows to the spare chamber, and a gas flow rate adjustment that is provided between the pressure reducing valve and the spare chamber in the gas supply line and adjusts the flow rate of the gas that flows to the spare chamber A substrate processing apparatus comprising: a valve; and a control unit configured to vary a set pressure of the pressure reducing valve when gas is supplied from the gas supply line to the preliminary chamber.

  (Appendix 2) The gas flow rate adjustment valve is set to adjust the flow rate of the gas flowing into the preliminary chamber based on a set flow rate, and the control unit is configured to set the preset pressure and the preset flow rate. The substrate processing apparatus according to appendix 1, wherein the pressure reducing valve and the gas flow rate adjusting valve are controlled based on the correlation of

  (Supplementary Note 3) After processing the substrate in the processing chamber, and after carrying the substrate from the processing chamber to the spare chamber, supplying gas from the gas supply line having a pressure reducing valve and a gas flow rate adjusting valve to the spare chamber, And a step of varying a set pressure of the pressure reducing valve.

1 is a schematic side sectional view of a substrate processing apparatus according to an embodiment of the present invention. It is an AA arrow line view of FIG. The cross-sectional schematic which shows an example of the processing furnace in the substrate processing apparatus of this invention. It is the schematic of the substrate processing apparatus which shows embodiment of this invention. It is explanatory drawing which shows the relationship between the gas flow rate and gas setting pressure of this invention. It is a graph which shows the flow volume characteristic of the conventional MFC.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate processing apparatus 2 Wafer 3 Pod 12 Rotating pod shelf 18 Pod opener 26 Wafer transfer mechanism 27 Wafer transfer apparatus 31 Boat 35 Pressure-resistant housing 36 Load lock chamber 43 Processing furnace 54 Processing chamber 58 MFC
75 Gas supply nozzle 76 Gas supply system 78 AV
79 Regulator 81 Gas supply source 82 Sequencer 83 Gas exhaust nozzle

Claims (1)

  A processing chamber for processing the substrate; a spare chamber adjacent to the processing chamber; a gas supply line for supplying gas to the spare chamber; and the gas supply line. A pressure reducing valve that adjusts the pressure of the gas to flow; a gas flow rate adjusting valve that is provided between the pressure reducing valve and the spare chamber in the gas supply line; A substrate processing apparatus, comprising: a control unit configured to vary a set pressure of the pressure reducing valve when gas is supplied from the gas supply line to the preliminary chamber.

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