JP2011222677A - Substrate processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve quality of treatment and yield by preventing difference of flow rate from increasing between a processing surface and a rim of a substrate and thereby improving uniformity of deposition processing.SOLUTION: A substrate processing apparatus has a substrate holder 18 for holding a substrate 200, a reaction tube 205 which houses the substrate and the substrate holder, gas supply systems 233a, 233b, 240a and 240b which supply processing gas in a direction parallel with the surface to be processed of the substrate, and an exhaust system 231 which exhausts the atmosphere in the reaction tube. The substrate holder has a plurality of columns 113, and a flow straightening member which is placed on the column, is an annular member for mounting the substrate, and has a notch formed in a part thereof. A distance between a circumference of the flow straightening member and an inner wall face of the reaction tube is shorter than a distance between the column and the inner wall face of the reaction tube.

Description

  The present invention relates to a substrate processing apparatus that holds a substrate such as a wafer or a glass substrate by a substrate holder and performs processing such as oxidation processing, diffusion processing, annealing processing, and thin film generation on the substrate.

  As one of the processing steps of a semiconductor device, there is a substrate processing step for performing processing such as oxidation processing, diffusion processing, and thin film generation on a substrate such as a silicon wafer, and there is a substrate processing device as an apparatus for executing the substrate processing step. As one of the substrate processing apparatuses, there is a batch type vertical substrate processing apparatus that includes a vertical processing furnace and processes a predetermined number of substrates at a time.

  In a batch type substrate processing apparatus, a substrate such as a silicon wafer is supported by a substrate holder (boat), the boat is loaded into a processing furnace, and the wafer is processed while being held by the substrate holder in the processing furnace. It is supposed to be done.

  At present, in order to improve the yield, the diameter of the substrate is increasingly increased, and the uniformity of the film thickness is increasingly required as the semiconductor device becomes finer. The uniformity of the film thickness is greatly influenced by the contact state between the processing gas supplied during the substrate processing and the substrate. The uniformity of the processing gas flowing to the substrate surface (substrate processing surface) and the uniformity of the flow velocity are as follows: It greatly affects the uniformity of film thickness.

  As a process gas supply method for improving the uniformity of the film thickness, there is a side flow method.

  10 and 11 show a processing furnace of a conventional substrate processing apparatus adopting a side flow method. In addition, the heater is abbreviate | omitted in FIG. 10, FIG.

  In FIG. 10, reference numeral 61 denotes a furnace port flange. The furnace port flange 61 has an upper flange 62 and a lower flange 63 at the upper and lower ends, respectively, and an inner flange 64 is provided at a required position on the inner surface.

  An outer tube 66 is erected on the upper flange 62, and an inner tube 67 is erected on the inner flange 64, and the furnace port flange 61, the outer tube 66, and the inner tube 67 are concentric.

  A gas supply nozzle 68 is erected along the inner wall surface of the inner tube 67, and an exhaust port 69 extending vertically is provided at a position facing the gas supply nozzle 68. An exhaust pipe 71 is connected to the furnace port flange 61, and the exhaust pipe 71 communicates with a cylindrical space 72 formed between the outer tube 66 and the inner tube 67.

  The opening at the lower end of the furnace port flange 61 is a furnace port part, and the furnace port part is hermetically closed by the seal cap 73, whereby a reaction chamber 74 is defined inside the inner tube 67. The reaction chamber 74 stores a boat 75 erected on the seal cap 73, and the boat 75 is loaded with a predetermined number of substrates (wafers).

  The boat 75 has a plurality of support columns, and a substrate holding groove is engraved in the support column at a predetermined pitch in the vertical direction, and the wafer 76 is inserted into the groove 75 in the vertical direction at a predetermined pitch. It is designed to be held in a horizontal position.

  Gas supply nozzles 68 are provided with gas outlets at a predetermined pitch in the vertical direction, and the processing gas injected from the gas outlets flows horizontally across the boat 75 and enters the space from the exhaust outlet 69. 72 and then exhausted through the exhaust pipe 71.

  The non-uniformity of the film thickness due to the gas flow is caused by the supply amount of the processing gas. The part where the flow rate of the processing gas is large (the gas flow rate is large) is thick and the flow rate of the processing gas is small (the flow rate of the processing gas). The film thickness is small at the site.

  When the above-described conventional side flow process gas flow is analyzed with the volume of the reaction chamber 74 and the exhaust capacity at the outlet of the reaction chamber 74 being constant, the dimension between the peripheral edge of the substrate and the inner wall surface of the inner tube 67 is minimized. Thus, the gap between the outer tube 66 and the inner tube 67 can be maximized, the exhaust conductance when flowing out from the reaction chamber 74 to the space 72 can be increased, and the pressure on the substrate surface can be lowered.

  Further, by reducing the gap between the substrate periphery and the inner wall surface of the inner tube 67, the flow resistance around the substrate periphery increases, and the increase in the flow velocity of the processing gas at the substrate periphery can be suppressed, and it passes over the substrate processing surface. The gas flow rate to be increased can be increased.

  However, there are limits to reducing the gap between the peripheral edge of the substrate and the inner wall surface of the inner tube 67 from the manufacturing accuracy and assembly accuracy of the inner tube 67 and the boat 75.

  Further, as shown in FIG. 11, the boat 75 in the conventional substrate processing apparatus has a plurality of support columns, and a substrate holding groove is engraved at a predetermined pitch in the vertical direction on the support column. By loading the wafer 76, the wafer 76 is held in the boat.

  Therefore, a support post is interposed between the wafer periphery and the inner wall surface of the inner tube 67, and the presence of the support column is a factor that cannot reduce the gap between the substrate periphery and the inner wall surface of the inner tube 67, thereby improving the flow of the processing gas. This hinders the improvement of film formation uniformity.

Japanese Patent Laid-Open No. 2004-6551

  In view of such a situation, the present invention suppresses an increase in the flow rate difference between the substrate processing surface and the peripheral edge of the substrate, improves the uniformity of the film forming process, and improves the processing quality and the yield.

  The present invention includes a substrate holder that holds a substrate, a reaction tube that houses the substrate and the substrate holder, a gas supply system that supplies a processing gas in a direction parallel to a surface to be processed of the substrate, and the reaction An exhaust system that exhausts the atmosphere in the tube, and the substrate holder is an annular member that is provided on the column and on which the substrate is placed, and is missing in a part of the ring. And a straightening member formed with a cut portion, wherein a distance between an outer periphery of the straightening member and an inner wall surface of the reaction tube is shorter than a distance between the support column and the inner wall surface of the reaction tube. Is.

  According to the present invention, a substrate holder for holding a substrate, a reaction tube for storing the substrate and the substrate holder, a gas supply system for supplying a processing gas in a direction parallel to the surface to be processed of the substrate, An exhaust system that exhausts the atmosphere in the reaction tube, and the substrate holder is an annular member that is provided on the column and places the substrate, and is a part of the ring. And a distance between the outer periphery of the rectifying member and the inner wall surface of the reaction tube is shorter than the distance between the support column and the inner wall surface of the reaction tube. The conductance between the outer periphery of the rectifying member and the inner wall surface of the reaction tube is reduced, so that more processing gas flows toward the center of the surface to be processed, and the film thickness uniformity is improved. .

It is a schematic perspective view of the substrate processing apparatus which concerns on a present Example. It is a schematic elevation sectional view which shows an example of the processing furnace used for this substrate processing apparatus. It is a schematic plane sectional view of the processing furnace. It is a perspective view of the boat used for a present Example. It is an enlarged view of the support | pillar part of this boat. It is explanatory drawing about the flow of the gas in the conventional boat and the boat of a present Example, (A) is a figure which shows the relationship between the conventional boat, an inner tube, and an outer tube, (B) is a figure of a present Example. The figure which shows the relationship between a boat, an inner tube, and an outer tube, (C) is a graph which shows the distance from the substrate center position in A position, and gas flow velocity distribution. It is explanatory drawing which shows the analysis result of the flow velocity distribution in the board | substrate peripheral part in the conventional boat and the boat which concerns on a present Example, (A1) and (B1) are the conventional boat and the boat of a present Example, respectively. And (A2), (B2) are the flow velocity distributions at the peripheral edge of the substrate in the conventional example and this embodiment, and (A3), (B3) are the conventional boats, respectively. The boat of a present Example is shown, and it has shown that the gas flow rate is a BB arrow direction in a figure. It is explanatory drawing which shows the relationship between the rotation attitude | position of the boat inside an inner tube in this Example, and a gas flow, (A) is a vaporization gas nozzle or a reactive gas nozzle, and a gas exhaust port. FIG. 6B is a diagram showing a case where the cutout portion is located on a straight line that intersects or intersects a straight line that connects the gas and a gas exhaust nozzle, a reactive gas nozzle, and a gas exhaust port. It is a figure which shows the case where it is located on the straight line which connects (C), (C) is a graph which shows the flow-velocity distribution in each state. It is explanatory drawing which shows the other example of a baffle member. It is a schematic explanatory drawing of the conventional process furnace. It is CC arrow line view of FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, an outline of a substrate processing apparatus 1 according to an embodiment of the present invention will be described with reference to FIG.

  A wafer (substrate) (not shown) made of silicon or the like is stored in a cassette 3 serving as a wafer carrier and transported.

  In FIG. 1, reference numeral 4 denotes a housing, and a front maintenance port (not shown) as an opening provided for maintenance can be opened below the front wall 5 of the housing 4. A front maintenance door (not shown) for opening and closing the door is provided. A cassette loading / unloading port (substrate container loading / unloading port) (not shown) is opened on the front maintenance door so as to communicate between the inside and outside of the housing 4, and a cassette stage (substrate housing) is placed inside the housing 4 of the cassette loading / unloading port. 6) is installed. The cassette 3 is loaded onto the cassette stage 6 by an in-process transfer device (not shown) and unloaded from the cassette stage 6.

  On the cassette stage 6, the wafer in the cassette 3 is placed in a vertical posture by the in-process transfer device so that the wafer entrance / exit of the cassette 3 faces upward. The cassette stage 6 can be operated so that the cassette 3 is rotated by 90 ° toward the rear of the housing 4, the wafers in the cassette 3 are in a horizontal posture, and the wafer inlet / outlet of the cassette 3 faces the rear of the housing 4. ing.

  A cassette shelf (substrate container mounting shelf) 7 is installed in a substantially central portion of the casing 4 in the front-rear direction, and the cassette shelf 7 is configured to store a plurality of cassettes 3 in a plurality of rows and a plurality of rows. Has been. The cassette shelf 7 is provided with a transfer shelf 9 in which the cassette 3 is stored, which is a transfer target of a wafer transfer mechanism (substrate transfer mechanism) 8 described later. In addition, a preliminary cassette shelf 11 is provided above the cassette stage 6 so that the cassette 3 is preliminarily stored.

  A cassette transfer device (substrate container transfer device) 12 is installed between the cassette stage 6 and the cassette shelf 7. The cassette transport device 12 includes a cassette elevator (substrate container lifting mechanism) 13 that can be moved up and down while holding the cassette 3, and a cassette transport mechanism (substrate container transport mechanism) 14 as a cassette transport mechanism. By the cooperation of the elevator 13 and the cassette transport mechanism 14, the cassette 3 is transported between the cassette stage 6, the cassette shelf 7, and the spare cassette shelf 11.

  A wafer transfer mechanism 8 is installed behind the cassette shelf 7, and the wafer transfer mechanism 8 is a wafer transfer device (substrate transfer device) 15 capable of rotating or linearly moving a wafer in the horizontal direction, and a wafer. A wafer transfer device elevator (substrate transfer device lifting mechanism) 16 for raising and lowering the transfer device 15 is configured.

  The wafer transfer device 15 has a plurality of tweezers (substrate transfer tools) 17 for attracting and holding wafers, and in cooperation with the wafer transfer device elevator 16, the wafer 18 is loaded (charging) and loaded. It is configured to discharge (discharge). The boat 18 has an annular rectifying member, which will be described later, at a predetermined pitch in the vertical direction, and the wafers are held on the boat 18 in a horizontal posture at a predetermined pitch in the vertical direction by being mounted on the rectifying member. It is like.

  A processing furnace 19 is provided above the rear part of the housing 4. A processing chamber is formed inside the processing furnace 19, the lower end of the processing furnace 19 is a furnace opening, and the furnace opening is opened and closed by a furnace opening shutter (furnace opening / closing mechanism) 21. Yes.

  Below the processing furnace 19, a boat elevator (substrate holder lifting mechanism) 22 is provided as a lifting mechanism for moving the boat 18 up and down to the processing furnace 19, and an arm as a connecting tool connected to a lifting platform of the boat elevator 22. A seal cap 24 serving as a lid is horizontally installed on 23, and the seal cap 24 is configured to support the boat 18 vertically and to close the lower end of the processing furnace 19.

  A clean unit 29 composed of a supply fan and a dust-proof filter is provided above the cassette shelf 7 so as to supply clean air, which is a cleaned atmosphere, and distributes clean air inside the housing 4. It is configured like this.

  In addition, a clean unit (not shown) composed of a supply fan and a dustproof filter for supplying clean air to the left end of the housing 4 opposite to the wafer transfer device elevator 16 and the boat elevator 22 side. The clean air blown out from a clean unit (not shown) is circulated through the wafer transfer device 15 and the boat 18 and then sucked into an exhaust device (not shown) and exhausted to the outside of the housing 4. It has become.

  Hereinafter, the operation of the substrate processing apparatus 1 will be described.

  The cassette 3 is loaded from a cassette loading / unloading port (not shown), and is placed on the cassette stage 6 so that the wafer is in a vertical posture and the wafer loading / unloading port of the cassette 3 faces upward. Thereafter, the cassette 3 is placed in a horizontal posture by the cassette stage 6 and the wafer entrance / exit of the cassette 3 faces the rear of the housing 4 so that the cassette 3 is rotated backward 90 ° clockwise. Rotated.

  Next, the cassette 3 is automatically transported and delivered to the designated shelf position of the cassette shelf 7 or the spare cassette shelf 11 by the cassette transport device 12 and temporarily stored. It is conveyed from the preliminary cassette shelf 11 to the transfer shelf 9 by the cassette conveying device 12 or directly to the transfer shelf 9.

  When the cassette 3 is transferred to the transfer shelf 9, the wafer is picked up from the cassette 3 by the tweezer 17 of the wafer transfer device 15 through the wafer loading / unloading port, and the wafer is transported while being placed on the tweezer 17 and sucked. The boat 18 is loaded behind the transfer shelf 9. The wafer transfer device 15 that has delivered the wafer to the boat 18 returns to the cassette 3 and loads the next wafer into the boat 18.

  When a predetermined number of wafers are loaded into the boat 18, the furnace port portion of the processing furnace 19 that has been closed by the furnace port shutter 21 is opened by the furnace port shutter 21. Subsequently, the boat 18 holding the wafer group is lifted by the boat elevator 22 with the seal cap 24 and loaded into the processing chamber of the processing furnace 19. After loading, arbitrary processing is performed on the wafer in the processing furnace 19. After the processing, the wafer and the cassette 3 are discharged to the outside of the housing 4 in the reverse procedure to that described above.

  An example of the processing furnace 19 used in this embodiment will be described with reference to FIGS. 2, 3, and 5.

The processing furnace 19 includes a reaction tube 205 and a furnace port flange 209. The reaction tube 205 includes an inner tube 204 that stores the wafer 200 and an outer tube 203 that stores the inner tube 204. Each of the inner tube 204 and the outer tube 203 is made of a heat-resistant non-metallic material such as quartz (SiO ₂ ) or silicon carbide (SiC), and has a cylindrical shape with its upper end closed and its lower end open. Yes.

  The furnace port flange 209 is made of, for example, a metal material such as SUS, and has a cylindrical shape with an open upper end and a lower end. The inner tube 204 and the outer tube 203 are supported vertically by the furnace port flange 209 from the lower end side. The inner tube 204, the outer tube 203, and the furnace port flange 209 are arranged concentrically with each other. The lower end (furnace port) of the furnace port flange 209 is configured to be hermetically sealed by a seal cap 219 when the boat elevator 22 is raised. A sealing member (not shown) such as an O-ring that hermetically seals the inner tube 204 is provided between the lower end of the furnace port flange 209 and the seal cap 219.

  A processing chamber 201 for processing the wafer 200 is formed inside the inner tube 204. A boat 18 as a substrate holder is inserted into the inner tube 204 (inside the processing chamber 201) from below. The inner diameter of the inner tube 204 and the furnace port flange 209 is configured to be larger than the maximum outer diameter of the boat 18 loaded with the wafers 200.

  The boat 18 is placed on a heat insulating cap 218 that blocks heat conduction. The heat insulating cap 218 is supported from below by the rotating shaft 255. The rotation shaft 255 is provided so as to penetrate the center portion of the seal cap 219 while maintaining airtightness in the inner tube 204. A rotation mechanism 267 that rotates the rotation shaft 255 is provided below the seal cap 219. By rotating the rotating shaft 255 by the rotating mechanism 267, the boat 18 loaded with a plurality of wafers 200 can be rotated while maintaining the airtightness in the inner tube 204.

  On the outer periphery of the reaction tube 205 (outer tube 203), a heater 207 as a heating mechanism is provided concentrically with the reaction tube 205. The heater 207 has a cylindrical shape and is vertically installed by being supported by a heater base (not shown) as a holding plate. A heat insulating material 207 a is provided on the outer peripheral portion and the upper end of the heater 207.

  On the side wall of the inner tube 204, a spare chamber that protrudes radially outside the inner tube 204 (side wall side of the outer tube 203) from the side wall of the inner tube 204 along the direction (vertical direction) in which the wafer 200 is loaded. 201a is provided. No partition wall is provided between the preliminary chamber 201a and the processing chamber 201, and the preliminary chamber 201a and the processing chamber 201 communicate with each other so that gas can flow.

  A vaporized gas nozzle 233a as a first gas nozzle and a reactive gas nozzle 233b as a second gas nozzle are disposed in the preliminary chamber 201a along the circumferential direction of the inner tube 204, respectively. The vaporized gas nozzle 233a and the reactive gas nozzle 233b are each configured in an L shape having a vertical portion and a horizontal portion. The vertical portions of the vaporized gas nozzle 233a and the reactive gas nozzle 233b are respectively arranged (extended) in the preliminary chamber 201a along the direction in which the wafers 200 are stacked. The horizontal portions of the vaporized gas nozzle 233a and the reactive gas nozzle 233b are provided so as to penetrate the side wall of the furnace port flange 209, respectively.

  A plurality of vaporized gas outlets 248a and reactive gas outlets 248b are provided along the direction (vertical direction) in which the wafers 200 are stacked on the side surfaces of the vaporized gas nozzle 233a and the reactive gas nozzle 233b. Therefore, the vaporized gas outlet 248 a and the reactive gas outlet 248 b are opened at positions projecting radially outward of the inner tube 204 from the side wall of the inner tube 204. The vaporized gas outlet 248a and the reactive gas outlet 248b are provided at an intermediate position (height position) between the upper and lower wafers 200, 200. Further, the opening diameters of the vaporized gas outlet 248a and the reactive gas outlet 248b can be adjusted as appropriate so as to optimize the gas flow distribution and velocity distribution in the inner tube 204. Well, it may be gradually increased from the lower part to the upper part.

  A vaporized gas supply pipe 240a is connected to the horizontal end (upstream side) of the vaporized gas nozzle 233a protruding from the side wall of the furnace port flange 209. Connected to the upstream side of the vaporized gas supply pipe 240a is a vaporizer 260 that vaporizes the liquid raw material to generate vaporized gas as the first raw material gas. The vaporized gas supply pipe 240a is provided with an open / close valve 241a. By opening the opening / closing valve 241a, the vaporized gas generated in the vaporizer 260 is supplied into the inner tube 204 via the vaporized gas nozzle 233a.

  On the upstream side of the vaporizer 260, there are a downstream side of the liquid source supply pipe 240 c that supplies the liquid source into the vaporizer 260 and a downstream side of the carrier gas supply pipe 240 f that supplies the carrier gas into the vaporizer 260. It is connected.

The upstream side of the liquid source supply pipe 240c is connected to a liquid source supply tank 266 that stores a liquid source such as TEMAZr (Tetrakis Ethyl Methyl Amino Zirconium). The upstream side of the liquid source supply pipe 240 c is immersed in the liquid source stored in the liquid source supply tank 266. The liquid source supply pipe 240c is provided with an opening / closing valve 243c, a liquid flow rate controller (LMFC) 242c, and an opening / closing valve 241c in order from the upstream side. Connected to the upper surface of the liquid source supply tank 266 is a downstream side of a pressurized gas supply pipe 240d for supplying an inert gas such as N ₂ gas. The upstream side of the pressurized gas supply pipe 240d is connected to a pressurized gas supply source (not shown) that supplies an inert gas such as He gas as the pressurized gas. An open / close valve 241d is provided in the pressurized gas supply pipe 240d. By opening the opening / closing valve 241d, the pressure feed gas is supplied into the liquid source supply tank 266, and by further opening the opening / closing valve 243c and the opening / closing valve 241c, the liquid source in the liquid source supply tank 266 is pressure fed into the vaporizer 260. (Supplied), and vaporized gas such as TEMAZr gas is generated in the vaporizer 260. Note that the supply flow rate of the liquid material supplied into the vaporizer 260 (that is, the flow rate of the vaporized gas generated in the vaporizer 260 and supplied into the inner tube 204) can be controlled by the liquid flow rate controller 242c. It is configured.

The upstream side of the carrier gas supply pipe 240f is connected to a carrier gas supply source (not shown) that supplies an inert gas (carrier gas) such as N ₂ gas. The carrier gas supply pipe 240f is provided with a flow rate controller (MFC) 242f and an opening / closing valve 241f in order from the upstream. A carrier gas is supplied into the vaporizer 260 by opening the open / close valve 241f and the open / close valve 241a, and a mixed gas of the vaporized gas and the carrier gas generated in the vaporizer 260 passes through the vaporized gas supply pipe 240a and the vaporized gas nozzle 233a. It is comprised so that it may supply in the inner tube 204 via. By supplying the carrier gas into the vaporizer 260, it is possible to promote the discharge of the vaporized gas from the vaporizer 260 and the supply of the vaporized gas into the inner tube 204. The supply flow rate of the carrier gas into the vaporizer 260 (that is, the supply flow rate of the carrier gas into the inner tube 204) is configured to be controllable by the flow rate controller 242f.

  Mainly, vaporized gas supply pipe 240a, vaporizer 260, on-off valve 241a, liquid source supply pipe 240c, on-off valve 243c, liquid flow rate controller 242c, on-off valve 241c, liquid source supply tank 266, pressure gas supply pipe 240d, not shown Vaporized gas supply that supplies vaporized gas into the inner tube 204 via the vaporized gas nozzle 233a by a pressure gas supply source, an open / close valve 241d, a carrier gas supply pipe 240f, a carrier gas supply source (not shown), a flow rate controller 242f, and an open / close valve 241f. A unit (vaporized gas supply system) is configured.

A reaction gas supply pipe 240b is connected to the horizontal end (upstream side) of the reaction gas nozzle 233b protruding from the side wall of the furnace port flange 209. An ozonizer 270 that generates ozone (O ₃ ) gas (oxidant) as a reaction gas is connected to the upstream side of the reaction gas supply pipe 240b. The reaction gas supply pipe 240b is provided with a flow rate controller (MFC) 242b and an opening / closing valve 241b in order from the upstream. The ozonizer 270 is connected to the downstream side of the oxygen gas supply pipe 240e. The upstream side of the oxygen gas supply pipe 240e is connected to an oxygen gas supply source (not shown) that supplies oxygen (O ₂ ) gas. The oxygen gas supply pipe 240e is provided with an opening / closing valve 241e. The oxygen gas is supplied to the ozonizer 270 by opening the opening / closing valve 241e, and the ozone gas generated by the ozonizer 270 by opening the opening / closing valve 241b is supplied into the inner tube 204 through the reaction gas supply pipe 240b. Has been. The supply flow rate of ozone gas into the inner tube 204 is configured to be controllable by the flow rate controller 242b.

  Mainly, a reaction gas supply pipe 240b, an ozonizer 270, a flow rate controller (MFC) 242b, an open / close valve 241b, an oxygen gas supply pipe 240e, an oxygen gas supply source (not shown), and an open / close valve 241e are connected to the inner tube 204 via the reaction gas nozzle 233b. A reaction gas supply unit (reaction gas supply system) for supplying ozone gas is formed.

  The upstream side of the vaporized gas vent pipe 240i is connected between the vaporizer 260 and the open / close valve 241a in the vaporized gas supply pipe 240a. The downstream side of the vaporized gas vent pipe 240i is connected to the downstream side of an exhaust pipe 231 described later (between an APC valve 231a and a vacuum pump 231b described later). The vaporized gas vent pipe 240i is provided with an open / close valve 241i. By closing the on-off valve 241a and opening the on-off valve 241i, the supply of the vaporized gas into the inner tube 204 can be stopped while the vaporized gas is continuously generated in the vaporizer 260. ing. Although it takes a predetermined time to stably generate the vaporized gas, the supply / stop of vaporized gas into the inner tube 204 can be switched in a very short time by switching the open / close valve 241a and the open / close valve 241i. It is structured like this.

  Similarly, the upstream side of the reaction gas vent pipe 240j is connected between the ozonizer 270 and the flow rate controller 242b in the reaction gas supply pipe 240b. The downstream side of the reaction gas vent pipe 240j is connected to the downstream side of the exhaust pipe 231 (between the APC valve 231a and the vacuum pump 231b). The reaction gas vent pipe 240j is provided with an open / close valve 241j in order from the upstream. By closing the opening / closing valve 241b and opening the opening / closing valve 241j, it is possible to stop the supply of ozone gas into the inner tube 204 while the generation of ozone gas by the ozonizer 270 is continued. Although it takes a predetermined time to stably generate ozone gas, the supply / stop of ozone gas into the inner tube 204 can be switched in a very short time by the switching operation of the opening / closing valve 241b and the opening / closing valve 241j. It is configured.

The downstream side of the first inert gas supply pipe 240g is connected to the downstream side of the open / close valve 241a in the vaporized gas supply pipe 240a. The first inert gas supply pipe 240g is provided with an inert gas supply source (not shown) for supplying an inert gas such as N ₂ gas, a flow rate controller (MFC) 242g, and an opening / closing valve 241g in order from the upstream side. . Similarly, the downstream side of the second inert gas supply pipe 240h is connected to the downstream side of the on-off valve 241b in the reaction gas supply pipe 240b. The second inert gas supply pipe 240h is provided with an inert gas supply source (not shown) for supplying an inert gas such as N ₂ gas, a flow rate controller (MFC) 242h, and an opening / closing valve 241h in order from the upstream side. .

  The inert gas from the first inert gas supply pipe 240g and the second inert gas supply pipe 240h is configured to function as a carrier gas or as a purge gas.

  For example, by closing the open / close valve 241i and opening the open / close valve 241a and the open / close valve 241g, the gas from the vaporizer 260 (mixed gas of vaporized gas and carrier gas) is not discharged from the first inert gas supply pipe 240g. The inner tube 204 can be supplied while being diluted with an active gas (carrier gas). Similarly, the reaction gas from the ozonizer 270 is diluted with the inert gas (carrier gas) from the second inert gas supply pipe 240h by closing the opening / closing valve 241j and opening the opening / closing valve 241b and the opening / closing valve 241h. The inner tube 204 can be supplied.

  Gas dilution can also be performed in the preliminary chamber 201a. That is, by closing the opening / closing valve 241i and opening the opening / closing valve 241a and the opening / closing valve 241h, the gas from the vaporizer 260 (mixed gas of vaporized gas and carrier gas) is not discharged from the second inert gas supply pipe 240h. It is configured so that it can be supplied into the inner tube 204 while being diluted in the preliminary chamber 201a with the active gas (carrier gas). Similarly, the open / close valve 241j is closed and the open / close valve 241b and the open / close valve 241g are opened, so that ozone gas from the ozonizer 270 is converted into the spare chamber 201a by the inert gas (carrier gas) from the first inert gas supply pipe 240g. It is configured so that it can be supplied into the inner tube 204 while being diluted with the above.

  Further, by closing the opening / closing valve 241a and opening the opening / closing valve 241i, the supply of the vaporized gas into the inner tube 204 is stopped while the generation of the vaporized gas by the vaporizer 260 is continued, and the opening / closing valve 241g and the opening / closing valve 241h. Is configured to supply the inert gas (purge gas) from the first inert gas supply pipe 240g and the second inert gas supply pipe 240h into the inner tube 204. Similarly, by closing the opening / closing valve 241b and opening the opening / closing valve 241j, the supply of ozone gas into the inner tube 204 is stopped while the generation of ozone gas by the ozonizer 270 is continued, and the opening / closing valve 241g and the opening / closing valve 241h are opened. Thus, the inert gas (purge gas) from the first inert gas supply pipe 240g and the second inert gas supply pipe 240h can be supplied into the inner tube 204. In this way, by supplying an inert gas (purge gas) into the inner tube 204, discharge of vaporized gas or ozone gas from the inner tube 204 is promoted.

  A gas exhaust port 204a is formed on the side wall of the inner tube 204 at a position facing the vaporized gas nozzle 233a and the reactive gas nozzle 233b (a position opposite to the vaporized gas nozzle 233a and the reactive gas nozzle 233b by 180 degrees) across the wafer 200.

  The gas exhaust port 204 a according to the present embodiment has a hole shape and is opened at a position (height position) corresponding to each of the plurality of wafers 200. Accordingly, the space 203a formed between the outer tube 203 and the inner tube 204 communicates with the space in the inner tube 204 through the gas exhaust port 204a. The hole diameter of the gas exhaust port 204a can be adjusted as appropriate so as to optimize the flow rate distribution and velocity distribution of the gas in the inner tube 204. For example, the hole diameter may be the same from the lower part to the upper part. It may be gradually increased over time.

  An exhaust pipe 231 is connected to the side wall of the furnace port flange 209. In order from the upstream side, the exhaust pipe 231 includes a pressure sensor 245 as a pressure detector, an APC (Auto Pressure Controller) valve 231a as a pressure regulator, a vacuum pump 231b as a vacuum exhaust device, and harmful components from the exhaust gas. An abatement facility 231c for removal is provided. The inside of the inner tube 204 can be set to a desired pressure by adjusting the opening degree of the opening / closing valve of the APC valve 231a while operating the vacuum pump 231b. The exhaust pipe 231, the pressure sensor 245, the APC valve 231a, the vacuum pump 231b, and the abatement equipment 231c constitute a unit that exhausts the atmosphere in the reaction pipe.

  The space 203a communicates with the space in the inner tube 204 through the gas exhaust port 204a. For this reason, by supplying gas into the inner tube 204 via the vaporized gas nozzle 233a or the reactive gas nozzle 233b, the exhaust unit evacuates the space 203a sandwiched between the outer tube 203 and the inner tube 204, thereby causing vaporized gas injection. A horizontal gas flow 100 from the outlet 248a and the reactive gas outlet 248b to the gas exhaust port 204a is generated in the inner tube 204.

  The controller 280 as a control unit includes a heater 207, an APC valve 231a, a vacuum pump 231b, a rotation mechanism 267, a boat elevator 22, open / close valves 241a, 241b, 241c, 243c, 241d, 241e, 241f, 241g, 241h, 241i, 241j. Are connected to a liquid flow rate controller 242c, flow rate controllers 242b, 242f, 242g, 242h, and the like. The controller 280 adjusts the temperature of the heater 207, opens and closes the APC valve 231a and adjusts the pressure, starts and stops the vacuum pump 231b, adjusts the rotation speed of the rotating mechanism 267, moves up and down the boat elevator 22, and opens and closes the valves 241a and 241b. Controls such as opening / closing operations of 241c, 243c, 241d, 241e, 241f, 241g, 241h, 241i, 241j, flow rate adjustment of the liquid flow rate controller 242c, and flow rate controllers 242b, 242f, 242g, 242h are performed.

  Hereinafter, the substrate processing will be described.

First, the open / close valve 241 d is opened to supply the pressure gas into the liquid source supply tank 266. Then, the open / close valves 243c and 241c are opened, and TEMAZr as a liquid material is pumped (supplied) from the liquid material supply tank 266 into the vaporizer 260, and the TEMAZr gas (vaporized) is vaporized in the vaporizer 260. Gas). Further, the open / close valve 241 f is opened to supply N ₂ gas (carrier gas) into the vaporizer 260. Until the TEMAZr gas is stably generated, the open / close valve 241a is closed, the open / close valve 241i is opened, and the mixed gas of the TEMAZr gas and the N ₂ gas is discharged from the vaporized gas vent pipe 240i.

When the TEMAZr gas is stably generated, the on-off valve 241i is closed, the on-off valve 241a is opened, and the mixed gas of TEMAZr gas and N ₂ gas is fed into the inner tube 204 through the vaporized gas nozzle 233a. Supply. At this time, the open / close valve 241g is opened, and the mixed gas from the vaporizer 260 is supplied into the inner tube 204 while being diluted with an inert gas such as N ₂ gas (carrier gas) from the first inert gas supply pipe 240g. To do. At this time, the flow rate of TEMAZr gas, for example 0.35 g / min, the flow rate of N ₂ gas from the carrier gas supply pipe 240f example and 1 slm, the flow rate of N ₂ gas from the first inert gas supply pipe 240g e.g. 8 slm.

  The mixed gas supplied into the inner tube 204 from the vaporized gas nozzle 233a becomes a horizontal gas flow 100 from the vaporized gas outlet 248a to the gas exhaust port 204a as shown in FIG. 3, and is exhausted from the exhaust pipe 231. . At that time, the TEMAZr gas is supplied to the surface of each of the stacked wafers 200, and the gas molecules of the TEMAZr gas are adsorbed on each wafer 200.

After continuing for a predetermined time (for example, 120 seconds), the on-off valve 241a is closed, the on-off valve 241i is opened, and the supply of the TEMAZr gas into the inner tube 204 is stopped while the generation of the TEMAZr gas is continued. Note that the open / close valve 241f is kept open, and the supply of N ₂ gas into the vaporizer 260 is continued.

Subsequently, the opening / closing valve 241 g and the opening / closing valve 241 h are opened, and N ₂ gas (purge gas) is supplied into the inner tube 204. At this time, the flow rate of N ₂ gas from the first inert gas supply pipe 240g example a 5 slm, and the flow rate of N ₂ gas from the second inert gas supply pipe 240h example 4 slm. As a result, discharge of the TEMAZr gas from the inner tube 204 is promoted. When the atmosphere in the inner tube 204 is replaced with N ₂ gas after a predetermined time (for example, 20 seconds), the on-off valve 241g and the on-off valve 241h are closed to stop the supply of N ₂ gas into the inner tube 204. Further, the inside of the inner tube 204 is exhausted for a predetermined time (for example, 20 seconds).

  Subsequently, the open / close valve 241e is opened to supply oxygen gas to the ozonizer 270 to generate ozone gas (oxidant) as a reaction gas. Until the ozone gas is stably generated, the open / close valve 241b is closed, the open / close valve 241j is opened, and the ozone gas is discharged from the reaction gas vent pipe 240j.

When the ozone gas is stably generated, the open / close valve 241j is closed, the open / close valve 241b is opened, and the ozone gas is supplied into the inner tube 204 through the reaction gas nozzle 233b. At this time, the open / close valve 241g is opened, and ozone gas from the reaction gas nozzle 233b is supplied into the inner tube 204 while being diluted in the preliminary chamber 201a with N ₂ gas (carrier gas) from the first inert gas supply pipe 240g. . At this time, the flow rate of ozone gas is, for example, 6 slm, and the flow rate of N ₂ gas from the first inert gas supply pipe 240g is, for example, 2 slm.

The ozone gas supplied from the reaction gas nozzle 233b into the inner tube 204 becomes a horizontal gas flow 100 from the reaction gas outlet 248b to the gas exhaust port 204a as shown in FIG. 3, and is exhausted from the exhaust pipe 231. At that time, ozone gas is supplied to the surface of each laminated wafer 200, and the gas molecules of the TEMAZr gas adsorbed on the wafer 200 and the ozone gas chemically react with each other, so that one atomic layer to several atomic layers are formed on the wafer 200. Thus, a high dielectric constant film (ZrO ₂ film) is produced.

  When the supply of the reaction gas is continued for a predetermined time, the opening / closing valve 241b is closed, the opening / closing valve 241j is opened, and the supply of the reaction gas into the inner tube 204 is stopped while the generation of ozone gas is continued.

Subsequently, the opening / closing valve 241 g and the opening / closing valve 241 h are opened, and N ₂ gas (purge gas) is supplied into the inner tube 204. At this time, the flow rate of N ₂ gas from the first inert gas supply pipe 240g and the second inert gas supply pipe 240h is set to 4 slm, for example. Thereby, discharge | emission of the ozone gas and the reaction product from the inner tube 204 is promoted. When the atmosphere in the inner tube 204 is replaced with N ₂ gas after a predetermined time (for example, 10 seconds) has elapsed, the opening / closing valve 241g and the opening / closing valve 241h are closed to stop the supply of N ₂ gas into the inner tube 204. Further, the inner tube 204 is evacuated for a predetermined time (for example, 15 seconds).

Thereafter, the vaporized gas supply process to the purge process are set as one cycle, and this cycle is repeated a predetermined number of times, whereby the TEMAZr gas and the ozone gas are alternately supplied into the inner tube 204 without being mixed with each other, and a desired thickness is formed on the wafer 200. A high dielectric constant film (ZrO ₂ film) is formed.

  Next, the boat 18 used in the present embodiment will be described with reference to FIGS.

  In the boat 18, a pair of end plates 111 and 112, and a plurality of (for example, four) columns 113 are vertically provided between the pair of end plates 111 and 112 in a bilaterally symmetrical manner with respect to the center of the boat 18. It is installed vertically between the plates 111 and 112.

  Of the symmetry, one of the support pillars 113a and 113a is provided with a rectifying member 114a, which is a semi-annular plate, extending horizontally over the support pillars 113a and 113a and concentrically with the center of the boat 18, and further rectifying. A predetermined number of members 114a are provided at a predetermined pitch in the vertical direction. The number of rectifying members 114a is at least as many as the number of wafers that can be processed at one time.

  Similarly, the rectifying member 114b, which is a semi-annular plate member, is provided horizontally on the supporting columns 113b and 113b on the other side of the supporting columns 113b and 113b. The rectifying members 114a and 114b Are in the same plane. The rectifying member 114a and the rectifying member 114b form the same circular ring, and the formed circular ring is cut out at two locations, and the two cut-out portions 115 are located on the same diameter.

  Further, the outer diameter of the ring formed by the rectifying member 114 a and the rectifying member 114 b is larger than the outer diameter of the wafer 200, and the inner diameter of the annular ring is smaller than the inner diameter of the wafer 200. Further, the width of the notch 115 is larger than the width of the tweezers 17.

  The wafer 200 is placed on the rectifying members 114a and 114b. Accordingly, the outer peripheral edges of the rectifying members 114a and 114b protrude from the peripheral edge of the wafer 200 (see FIG. 5).

  Further, the mounting of the columns 113a and 113b, the rectifying member 114a, and the rectifying member 114b is considered so that the maximum outer diameter of the boat 18 is the periphery of the rectifying member 114a and the rectifying member 114b. For example, as shown in FIG. 5, notches 116 for inserting the rectifying member 114a and the rectifying member 114b are inserted into the support columns 113a and 113b, and the relief portions of the support columns 113a and 113b (in FIG. 5) are inserted into the rectifying member 114a and the rectifying member 114b. , The hatch portion of the support 113 may be formed, and the maximum outer diameter of the rectifying member 114 may be the maximum outer diameter of the boat 18. In FIG. 5, the outer edge of the support 113 and the outer edge of the rectifying member 114 are the same. However, the outer edge of the rectifying member 114 protrudes more closely to the inner wall surface of the inner tube 204 than the outer edge of the support 113. May be.

  Note that the end plates 111 and 112, the support column 113, and the rectifying member 114 are made of a heat-resistant non-metallic material such as quartz or silicon carbide.

  The transfer of the wafer 200 to the boat 18 by the wafer transfer device 15 is performed with the wafer 200 placed and held on the tweezer 17 with the vertical position of the wafer 200 between the upper and lower rectifying members 114 and from the notch 115. The wafer 200 is caused to enter the boat 18 in the horizontal direction, the tweezer 17 is further lowered, and the wafer 200 is placed on the rectifying member 114. Thereafter, the tweezer 17 is moved backward. By repeating such a series of operations, a predetermined number of wafers 200 are transferred to the boat 18.

  Further, the positional relationship between the boat 18 and the inner tube 204 is to reduce the conductance of the periphery of the wafer 200, that is, the periphery of the boat 18, that is, to increase the flow resistance in the periphery of the boat 18 as much as possible. The gap between the inner tube 204 and the inner tube 204 is set to a minimum value g obtained in consideration of manufacturing errors, assembly errors, and the like. In this case, as shown in FIG. 5, the maximum outer diameter of the boat is equal to the maximum outer diameter of the rectifying member 114.

  Next, in FIG. 6, the analysis result of the gas flow of the conventional boat and the boat according to the present embodiment will be described.

  6A shows the relationship between the conventional boat and the inner tube 204 and the outer tube 203, and FIG. 6B shows the relationship between the boat of this embodiment and the inner tube 204 and the outer tube 203. Yes. FIG. 6C shows the distance from the center position of the substrate at position A and the gas flow rate.

  As shown in FIG. 6C, the gas flow velocity at the peripheral edge of the substrate is significantly reduced and the flow velocity at the central portion of the substrate is increased as compared with the conventional case. That is, it can be seen that the flow velocity difference is greatly improved between the central portion and the peripheral portion of the substrate.

  FIG. 7 shows the analysis result of the flow velocity distribution at the peripheral edge of the substrate in the conventional boat 75 and the boat 18 according to this embodiment.

  7A1 and FIG. 7B1 show the relationship between the conventional boat 75 and the boat 18 of this embodiment, the inner tube 204, and the outer tube 203, respectively, and FIG. 7A2 and FIG. FIG. 7 (A3) and FIG. 7 (B3) show the conventional boat 75 and the boat 18 of this embodiment, respectively, and the gas flow velocity is shown in FIG. It shows that it is the middle BB arrow direction.

  7 (A1) and 7 (B1), g in the drawings is the minimum distance between the maximum outer diameter of the boat and the inner wall surface of the inner tube 204. Conventionally, the inner wall surface of the support column 113 and the inner tube 204 And the minimum distance g appears between the straightening member 114 and the inner wall surface of the inner tube 204 in this embodiment.

  As shown in FIG. 7A2, in the prior art, the maximum flow velocity at the periphery of the substrate appears at the periphery of the substrate, and the range where the flow velocity is fast reaches the center of the substrate. Further, the smallest range of the flow velocity appears on the surface inside the substrate. On the other hand, as shown in FIG. 7 (B2), in this embodiment, the maximum flow velocity appears at the periphery of the rectifying member 114, and the flow velocity decreases at the portion reaching the substrate periphery. Furthermore, the smallest range of the flow velocity appears above the gap between the substrates, and no decrease in the flow velocity is observed on the substrate surface (substrate processing surface). Therefore, in this embodiment, the non-uniformity of the flow velocity distribution at the peripheral edge of the substrate is improved.

  FIG. 8 shows the result of analysis of the rotation posture of the boat 18 of this embodiment inside the inner tube 204 and the gas flow in this embodiment.

  FIG. 8A shows a case where the notch 115 is located on a straight line orthogonal to or intersecting with a straight line connecting the vaporized gas nozzle 233a or the reactive gas nozzle 233b and the gas exhaust port 204a. Yes, the flow velocity distribution at this time is represented by a curve in FIG. FIG. 8B shows the case where the notch 115 is located on a straight line connecting the vaporized gas nozzle 233a or the reaction gas nozzle 233b and the gas exhaust port 204a, that is, the notch 115 is the vaporized gas nozzle 233a or the reaction gas nozzle. 233b and / or the gas exhaust port 204a, the flow velocity distribution at this time is represented by a curve b in FIG.

  As can be seen from comparison between the a curve and the b curve, when the notch 115 coincides with the vaporized gas nozzle 233a or the reactive gas nozzle 233b and / or the gas exhaust port 204a, the flow velocity at the peripheral edge of the substrate decreases. The flow velocity inside the substrate surface is increasing. That is, when the notched portion 115 matches the vaporized gas nozzle 233a or the reactive gas nozzle 233b and / or the gas exhaust port 204a, the conductance between the periphery of the rectifying member 114 and the inner wall surface of the inner tube 204 becomes small, and the gas It can be seen that the flowability of is improved.

  Thus, the rotation position of the boat 18 in which the notch 115 coincides with the vaporized gas nozzle 233a or the reaction gas nozzle 233b and / or the gas exhaust port 204a is detected, and a predetermined position around the rotation position or the rotation position is detected. By temporarily increasing the supply amount of the processing gas in the rotation range, it becomes possible to more effectively supply the processing gas to the processing surface of the wafer. Therefore, the uniformity of the film thickness within the wafer surface can be improved.

  FIG. 9 shows an example of another rectifying member 114. In the rectifying member 114, one cutout portion 115 is formed at a portion where the tweezer 17 enters. In addition, two escape portions 117 are formed in a portion of the rectifying member 114 facing the notch 115. The escape portion 117 is provided so that the rectifying member 114 and the tweezer 17 do not interfere when the wafer is placed on the rectifying member 114 by the tweezer 17. Accordingly, the cutout portion 115 may have a shape such that at least one tweezer 17 is provided on the entry side and the tweezer 17 does not interfere with other portions.

  In the above embodiment, the wafer is placed directly on the rectifying member 114. However, a pin is projected from the support 113 toward the center of the boat, and the substrate is placed on the pin. Also good.

  According to the present invention, by providing the rectifying member 114, the velocity distribution of the gas flow velocity on the substrate surface is improved, and the uniformity of the film thickness is improved. Furthermore, by forming the notch 115 in the rectifying member 114, a space corresponding to two pitches (two substrate loading pitches) can be used when the substrate is transferred, so that one pitch interval can be narrowed, and the same processing space can be used. The number of processed sheets can be increased, and productivity can be improved.

(Appendix)
The present invention includes the following embodiments.

  (Appendix 1) A substrate holder for holding a substrate, a processing chamber for storing the substrate and the substrate holder, and a desired process in a direction parallel to the surface to be processed of the substrate stored in the substrate processing chamber Gas supply means for supplying a gas; rectifying means for flowing the processing gas in a horizontal direction with respect to the processing surface of the substrate; and exhaust means for flowing the processing gas in a horizontal direction with respect to the processing surface of the substrate; And a rectifying member that is held in the processing chamber in a circumferential shape from the center of the substrate, in a rectifying unit that circulates a larger amount of the processing gas toward the center of the substrate. And a rectifying plate held by the substrate holder, and the outer periphery of the rectifying member is equal to or larger than the outer periphery of the substrate holder.

  (Additional remark 2) The substrate processing apparatus of additional remark 1 which has two or more support | pillars used for the said substrate holder, and has a structure connected with the said rectification | straightening member and at least 1 or more said support | pillars in a horizontal direction.

  (Additional remark 3) The said baffle plate is a substrate processing apparatus of additional remark 1 with which one part is missing in the circumferential direction of the said board | substrate.

  (Additional remark 4) The said baffle plate is a substrate processing apparatus of additional remark 1 arrange | positioned between the said board | substrate between the said board | substrates in the circumferential direction of the said board | substrate.

DESCRIPTION OF SYMBOLS 1 Substrate processing apparatus 15 Wafer transfer apparatus 17 Tweezer 18 Boat 19 Processing furnace 100 Gas flow 113 Support | pillar 114 Rectification member 115 Notch part 117 Escape part 200 Wafer 203 Outer tube 203a Space 204 Inner tube 204a Gas exhaust port 205 Reaction tube 233a Vaporization Gas nozzle 233b Reaction gas nozzle

Claims (1)

  A substrate holder for holding a substrate, a reaction tube for storing the substrate and the substrate holder, a gas supply system for supplying a processing gas in a direction parallel to a surface to be processed of the substrate, and an atmosphere in the reaction tube An exhaust system for exhausting, and the substrate holder is a ring-shaped member on which the substrate is placed, and a notch is formed in a part of the ring. A substrate processing apparatus, wherein a distance between an outer periphery of the rectifying member and an inner wall surface of the reaction tube is shorter than a distance between the support column and the inner wall surface of the reaction tube.

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