Substrate processing device, substrate processing method, semiconductor device manufacturing method, and program

Abstract

The present invention comprises: a processing chamber that is for processing a plurality of substrates; a plasma generation unit that generates plasma in the processing chamber; and a measurement unit that measures the emission intensity of plasma at two or more locations in a region in which the plurality of substrates are held.

Description

Substrate processing apparatus, substrate processing method, semiconductor device manufacturing method and program

[0001] The present disclosure relates to a substrate processing apparatus, a substrate processing method, a method for manufacturing a semiconductor device, and a program.

[0002] 2. Description of the Related Art Substrate processing apparatuses used in the manufacturing process of semiconductor devices include those configured to process multiple substrates simultaneously while activating a processing gas using plasma (see, for example, Patent Document 1).

[0003] JP 2015-92637 A

[0004] The present disclosure provides a technique for suppressing non-uniformity in processing of multiple substrates.

[0005] According to one aspect of the present disclosure, there is provided a technology comprising: a processing chamber for processing a plurality of substrates; a plasma generation unit for generating plasma within the processing chamber; and a measurement unit for measuring the emission intensity of the plasma at at least two locations in an area where the plurality of substrates are held.

[0006] According to one aspect of the present disclosure, it is possible to prevent non-uniformity in processing of a plurality of substrates.

[0007] 1 is an explanatory diagram showing a schematic configuration example of a substrate processing apparatus according to an embodiment of the present disclosure, showing a processing furnace portion in vertical cross section; FIG. 2 is an explanatory diagram showing a schematic configuration example of a substrate processing apparatus according to an embodiment of the present disclosure, showing the processing furnace portion in cross section along line A-A in FIG. 1; FIG. 3 is an explanatory diagram showing an example of an electrode configuration of a plasma generation portion of a substrate processing apparatus according to an embodiment of the present disclosure; FIG. 4 is an explanatory diagram showing another example of an electrode configuration of a plasma generation portion of a substrate processing apparatus according to an embodiment of the present disclosure; FIG. 5 is an explanatory diagram showing an example of a configuration of a plasma measurement portion of a substrate processing apparatus according to an embodiment of the present disclosure; FIG. 6 is a block diagram showing a schematic configuration example of a controller of a substrate processing apparatus according to an embodiment of the present disclosure; FIG. 7 is a flow diagram showing a procedure of a substrate processing step according to an embodiment of the present disclosure; FIG. 8 is an explanatory diagram (part 1) showing an example of an electrode configuration of a plasma generation portion of a substrate processing apparatus according to another embodiment of the present disclosure, where (a) is a perspective view of the entire electrode and (b) is a cross-sectional view of a main portion; FIG. 9 is an explanatory diagram (part 2) showing an example of an electrode configuration of a plasma generation portion of a substrate processing apparatus according to another embodiment of the present disclosure, where (a) is a perspective view of the entire electrode and (b) is a cross-sectional view of a main portion.

[0008] <One Aspect of the Present Disclosure> One aspect of the present disclosure will be described below with reference to the drawings. Note that all drawings used in the following description are schematic, and the dimensional relationships, ratios, etc. of elements in the drawings do not necessarily match those in reality. Furthermore, the dimensional relationships, ratios, etc. of elements between multiple drawings do not necessarily match.

[0009] (1) Configuration of the Substrate Processing Apparatus A schematic configuration of a substrate processing apparatus according to one aspect of the present disclosure will be described with reference to FIGS. 1 to 3. FIG.

[0010] 1, the substrate processing apparatus according to this embodiment includes a processing furnace 202. The processing furnace 202 is a so-called vertical furnace capable of accommodating substrates in multiple stages in the vertical direction, and includes a heater 207 as a heating device (heating mechanism). The heater 207 is cylindrical and is installed vertically by being supported by a heater base (not shown) as a holding plate.

[0011] (Processing Chamber) A reaction tube 203 is disposed inside the heater 207 concentrically with the heater 207. The reaction tube 203 is made of, for example, quartz (SiO２ The reaction tube 203 is made of a heat-resistant material such as silicon carbide (SiC) or silicon carbide (SiC) and has a cylindrical shape with a closed top and an open bottom. A manifold (inlet flange) 209 is disposed concentrically below the reaction tube 203. The manifold 209 is made of a metal such as stainless steel (SUS) and has a cylindrical shape with open top and bottom ends. The upper end of the manifold 209 engages with the lower end of the reaction tube 203 to support the reaction tube 203. An O-ring 220a is provided as a sealing member between the manifold 209 and the reaction tube 203. The manifold 209 is supported on a heater base, so that the reaction tube 203 is installed vertically. The reaction tube 203 and the manifold 209 mainly constitute a processing vessel (reaction vessel). A processing chamber 201 is formed in the cylindrical hollow portion inside the processing vessel. The processing chamber 201 is enclosed in a reaction tube 203 and is configured to be able to accommodate a plurality of substrates, i.e., wafers 200. Note that the processing vessel is not limited to the above configuration, and there are cases where only the reaction tube 203 is referred to as the processing vessel.

[0012] (Gas Supply Unit) Nozzles 249a and 249b are provided in the processing chamber 201 to penetrate the sidewall of the manifold 209. Gas supply pipes 232a and 232b are connected to the nozzles 249a and 249b, respectively. In this manner, the reaction tube 203 is provided with two nozzles 249a and 249b and two gas supply pipes 232a and 232b, making it possible to supply multiple types of gases into the processing chamber 201. Note that if the manifold 209 is not provided and only the reaction tube 203 is used as a processing vessel, the nozzles 249a and 249b may be provided to penetrate the sidewall of the reaction tube 203.

[0013] The gas supply pipes 232a and 232b are respectively provided with, in order from the upstream side of the gas flow, mass flow controllers (MFCs) 241a and 241b which are flow rate controllers (flow rate control units) and valves 243a and 243b which are on-off valves. Gas supply pipes 232c and 232d which supply inert gas are connected to the gas supply pipes 232a and 232b downstream of the valves 243a and 243b. The gas supply pipes 232c and 232d are respectively provided with, in order from the upstream side of the gas flow, MFCs 241c and 241d and valves 243c and 243d.

[0014] 2, the nozzle 249a is provided in the space between the inner wall of the reaction tube 203 and the wafers 200, extending from the lower part to the upper part of the inner wall of the reaction tube 203 and rising upward in the loading direction of the wafers 200. That is, the nozzle 249a is provided in a region horizontally surrounding a wafer arrangement region (loading region) on the side of which the wafers 200 are arranged (loaded), and extending along the wafer arrangement region. That is, the nozzle 249a is provided on the side of the edge (periphery) of each wafer 200 loaded into the processing chamber 201, in a direction perpendicular to the surface (flat surface) of the wafer 200.

[0015] Gas supply holes 250a for supplying gas are provided on the side surface of the nozzle 249a. The gas supply holes 250a are open toward the center of the reaction tube 203, making it possible to supply gas toward the wafers 200. A plurality of gas supply holes 250a are provided from the bottom to the top of the reaction tube 203, each having the same opening area, and are also provided at the same opening pitch.

[0016] The nozzle 249b is provided in a buffer chamber 237, which is a gas dispersion space. As shown in FIG. 2, the buffer chamber 237 is provided in a circular space between the inner wall of the reaction tube 203 and the wafers 200 in a plan view, and in a portion extending from the lower part to the upper part of the inner wall of the reaction tube 203 along the stacking direction of the wafers 200. That is, the buffer chamber 237 is formed by a buffer structure 300 in an area horizontally surrounding the wafer arrangement area on the side of the wafer arrangement area and along the wafer arrangement area. Here, the space within the buffer chamber 237, which is partitioned by the buffer structure 300, is referred to as a second buffer chamber. The buffer structure 300 is made of an insulating material such as quartz, and gas supply ports 302, 304, and 306 for supplying gas or activated species (described later) into the process chamber 201 are formed on the arc-shaped wall surface of the buffer structure 300.

[0017] 2, the gas supply ports 302, 304, and 306 are opened toward the center of the reaction tube 203 at opposing wall positions in a plasma generation region 224a between rod-shaped electrodes 269 and 270, a plasma generation region 224b between rod-shaped electrodes 270 and 271, and a region between the rod-shaped electrode 271 and the nozzle 249b, which will be described later, and are capable of supplying gas toward the wafers 200. A plurality of gas supply ports 302, 304, and 306 are provided from the bottom to the top of the reaction tube 203, each having the same opening area and arranged at the same opening pitch.

[0018] The nozzle 249b is provided along the inner wall of the reaction tube 203 from the bottom to the top, rising upward in the stacking direction of the wafers 200. That is, the nozzle 249b is provided inside the buffer structure 300, in an area horizontally surrounding the wafer arrangement area on the side of the wafer arrangement area where the wafers 200 are arranged, so as to extend along the wafer arrangement area. That is, the nozzle 249b is provided on the side of the end of the wafer 200 loaded into the processing chamber 201, in a direction perpendicular to the surface of the wafer 200.

[0019] Gas supply holes 250b for supplying gas are provided on the side surface of the nozzle 249b. The gas supply holes 250b are open toward the wall surface formed radially from the arc-shaped wall surface of the buffer structure 300, making it possible to supply gas toward the wall surface. This allows the reaction gas to be dispersed within the buffer chamber 237 and not directly sprayed onto the rod-shaped electrodes 269-271, thereby suppressing the generation of particles. Similar to the gas supply holes 250a, a plurality of gas supply holes 250b are provided from the bottom to the top of the reaction tube 203.

[0020] A buffer structure 400 having a configuration similar to that of the buffer structure 300 is provided on the inner wall of the reaction tube 203. That is, another portion of the buffer chamber 237 is formed by the buffer structure 400 along the wafer arrangement region in an area horizontally surrounding the wafer arrangement region on the side of the wafer arrangement region. Here, the space within the buffer chamber 237 defined by the buffer structure 400 is referred to as a first buffer chamber. As shown in FIG. 2 , in a plan view, the buffer structure 300 and the buffer structure 400 are arranged symmetrically with respect to a line passing through the centers of the exhaust pipe 231 and the reaction tube 203, sandwiching the exhaust pipe 231 (described later). In addition, in a plan view, the nozzle 249a is provided at positions facing each other on the exhaust pipe 231 with the wafer 200 interposed therebetween. In addition, the nozzle 249b and the nozzle 249c are provided at positions far from the exhaust pipe 231 within the buffer chamber 237 of each of the buffer structures 300 and 400.

[0021] The gas supply pipe 232b branches into two, one of which is connected to the nozzle 249b and the other to the nozzle 249c. The nozzle 249c is provided in the buffer chamber 237 on the buffer structure 400 side, which is a gas dispersion space. In FIG. 1, the buffer structure 400 overlaps with the buffer structure 300 and is therefore not shown.

[0022] Gas supply ports 402, 404, and 406 for supplying gas are formed on the arc-shaped wall surface of the buffer structure 400. As shown in Fig. 2, the gas supply ports 402, 404, and 406 are open toward the center of the reaction tube 203 at opposing wall positions in a plasma generation region 324a between rod-shaped electrodes 369 and 370, a plasma generation region 324b between rod-shaped electrodes 370 and 371, and a region between the rod-shaped electrode 371 and the nozzle 249c, which will be described later, so that gas can be supplied toward the wafers 200. A plurality of gas supply ports 402, 404, and 406 are provided from the bottom to the top of the reaction tube 203, each having the same opening area and arranged at the same opening pitch.

[0023] The nozzle 249c is provided along the inner wall of the reaction tube 203, rising upward in the direction in which the wafers 200 are stacked. That is, the nozzle 249c is provided inside the buffer structure 400, in a region horizontally surrounding the wafer arrangement region where the wafers 200 are arranged, along the wafer arrangement region. That is, the nozzle 249c is provided on the side of the edge of the wafer 200 loaded into the processing chamber 201, in a direction perpendicular to the surface of the wafer 200. A gas supply hole 250c for supplying gas is provided on the side of the nozzle 249c. The gas supply hole 250c opens toward a wall surface formed radially from the arc-shaped wall surface of the buffer structure 400, enabling gas to be supplied toward the wall surface. This allows the reaction gas to be dispersed within the buffer chamber 237 and not directly sprayed onto the rod-shaped electrodes 369-371, thereby suppressing particle generation. Similar to the gas supply holes 250a, a plurality of gas supply holes 250c are provided from the bottom to the top of the reaction tube 203.

[0024] In this embodiment, gas is delivered via nozzles 249a, 249b, and 249c and two buffer chambers 237 arranged in a vertically elongated space having an annular shape in a plan view defined by the inner wall of the sidewall of the reaction tube 203 and the ends of the plurality of wafers 200 arranged in the reaction tube 203, i.e., a cylindrical space. Then, gas is ejected from gas supply holes 250a, 250b, and 250c and gas supply ports 302, 304, 306, 402, 404, and 406 opened in the nozzles 249a, 249b, and 249c and the two buffer chambers 237, respectively, into the space in the reaction tube 203 where the wafers 200 are placed, near the wafers 200. The main flow of gas in the reaction tube 203 is parallel to the surfaces of the wafers 200, i.e., horizontally. With this configuration, gas can be supplied uniformly to each wafer 200, thereby improving the uniformity of the film thickness formed on each wafer 200. The gas that has flowed over the surface of the wafer 200, i.e., the residual gas after the reaction, flows toward the exhaust port, i.e., the exhaust pipe 231 described below. However, the direction of the flow of this residual gas is appropriately determined depending on the position of the exhaust port, and is not limited to the vertical direction.

[0025] From the gas supply pipe 232a, a raw material containing a predetermined element, for example, a raw material gas containing silicon (Si) as the predetermined element, is supplied into the processing chamber 201 via the MFC 241a, the valve 243a, and the nozzle 249a.

[0026] The raw material gas refers to a raw material in a gaseous state, for example, a gas obtained by vaporizing a raw material that is in a liquid state at room temperature and normal pressure, or a raw material that is in a gaseous state at room temperature and normal pressure, etc. In this specification, the term "raw material" may mean a "liquid raw material that is in a liquid state," a "raw material gas that is in a gaseous state," or both.

[0027] From the gas supply pipe 232b, a reactive gas (reactant) having a different chemical structure from the source material, for example, an oxygen (O)-containing gas, is supplied into the processing chamber 201 via the MFC 241b, the valve 243b, and the nozzles 249b and 249c. The O-containing gas acts as an oxidizing agent (oxidizing gas), i.e., an O source. For example, this gas is plasma-excited using a plasma source described below and supplied as an excited gas.

[0028] Inert gas is supplied from the gas supply pipes 232c and 232d into the processing chamber 201 via MFCs 241c and 241d, valves 243c and 243d, and nozzles 249a, 249b, and 249c, respectively.

[0029] A source gas supply system serving as a first gas supply system is mainly constituted by the gas supply pipe 232a, the MFC 241a, and the valve 243a. A reactive gas supply system (reactant supply system) serving as a second gas supply system is mainly constituted by the gas supply pipe 232b, the MFC 241b, and the valve 243b. An inert gas supply system is mainly constituted by the gas supply pipes 232c and 232d, the MFCs 241c and 241d, and the valves 243c and 243d. The source gas supply system, the reactive gas supply system, and the inert gas supply system are also simply referred to as gas supply systems (gas supply units). Note that in this specification, gases such as source gases and reactive gases used in substrate processing of the wafer 200 may be collectively referred to as process gases, and components such as the source gas supply system and the reactive gas supply system that supply these gases may be collectively referred to as process gas supply systems (process gas supply units).

[0030] (Exhaust Section) The reaction tube 203 is provided with an exhaust pipe 231 that exhausts the atmosphere inside the processing chamber 201. The exhaust pipe 231 is connected to a vacuum pump 246 as a vacuum exhaust device via a pressure sensor 245 as a pressure detector (pressure detection section) that detects the pressure inside the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 as an exhaust valve (pressure adjustment section). The APC valve 244 is configured to evacuate and stop the evacuation of the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating. Furthermore, while the vacuum pump 246 is operating, the APC valve 244 is configured to adjust the pressure inside the processing chamber 201 by adjusting the valve opening based on pressure information detected by the pressure sensor 245. An exhaust system is mainly configured by the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 may be included in the exhaust system. The exhaust pipe 231 is not limited to being provided in the reaction tube 203, but may be provided in the manifold 209 in the same manner as the nozzles 249a and 249b.

[0031] (Substrate Support) As shown in FIG. 1 , the boat 217 serving as a substrate support (substrate support portion) is configured to support multiple wafers 200, e.g., 25 to 200 wafers 200, in a horizontal position, aligned vertically with their centers aligned, in multiple stages, i.e., spaced apart. The boat 217 is made of a heat-resistant material such as quartz or SiC. A heat insulating plate 218 made of a heat-resistant material such as quartz or SiC is supported in multiple stages at the bottom of the boat 217. This configuration makes it difficult for heat from the heater 207 to be transmitted to the seal cap 219. However, this embodiment is not limited to this configuration. For example, instead of providing the heat insulating plate 218 at the bottom of the boat 217, a heat insulating cylinder configured as a cylindrical member made of a heat-resistant material such as quartz or SiC may be provided.

[0032] (Peripheral Devices) A ​​seal cap 219 is provided below the manifold 209 as a furnace port cover that can airtightly close the lower end opening of the manifold 209. The seal cap 219 is configured to abut against the lower end of the manifold 209 from below in the vertical direction. The seal cap 219 is made of a metal such as SUS and is formed in a disk shape. An O-ring 220b is provided on the upper surface of the seal cap 219 as a sealing member that abuts against the lower end of the manifold 209.

[0033] A rotation mechanism 267 for rotating a boat 217 (described later) is installed on the opposite side of the seal cap 219 from the processing chamber 201. A rotation shaft 255 of the rotation mechanism 267 is connected to the boat 217 through the seal cap 219. The rotation mechanism 267 is configured to rotate the wafers 200 by rotating the boat 217. The seal cap 219 is configured to be raised and lowered vertically by a boat elevator 115, which serves as an elevating mechanism installed vertically outside the reaction tube 203. The boat elevator 115 is configured to raise and lower the seal cap 219, thereby enabling the boat 217 to be loaded into and unloaded from the processing chamber 201.

[0034] The boat elevator 115 is configured as a transfer device (transfer mechanism) that transfers the boat 217, i.e., the wafers 200, into and out of the process chamber 201. A shutter 219s is provided below the manifold 209 as a furnace port cover that can airtightly close the lower end opening of the manifold 209 while the seal cap 219 is being lowered by the boat elevator 115. The shutter 219s is made of a metal such as SUS and has a disk shape. An O-ring 220c is provided on the upper surface of the shutter 219s as a sealing member that abuts against the lower end of the manifold 209. The opening and closing operation (lifting and lowering operation, rotating operation, etc.) of the shutter 219s is controlled by a shutter opening and closing mechanism 115s.

[0035] 2, a temperature sensor 263 serving as a temperature detector is installed inside the reaction tube 203. The temperature distribution inside the processing chamber 201 is adjusted to a desired value by adjusting the power supply to the heater 207 based on the temperature information detected by the temperature sensor 263. The temperature sensor 263 is installed along the inner wall of the reaction tube 203, similar to the nozzles 249a and 249b.

[0036] (Plasma Generation Unit) Next, the plasma generation unit will be described with reference to FIGS. 2 to 4. FIG.

[0037] As shown in FIG. 2, a capacitively coupled plasma (CCP) is used to generate plasma inside a buffer chamber 237, which is a vacuum partition made of quartz or the like, when a reactive gas is supplied.

[0038] In the substrate processing apparatus according to this embodiment, three elongated rod-shaped electrodes 269, 270, and 271 made of a conductive material are disposed in the buffer chamber 237 of the buffer structure 300 along the stacking direction of the wafers 200 from the bottom to the top of the reaction tube 203. Each of the rod-shaped electrodes 269, 270, and 271 is disposed parallel to the nozzle 249b. Each of the rod-shaped electrodes 269, 270, and 271 is protected by being covered from top to bottom by an electrode protection tube 275. The electrode protection tube 275 is formed of a quartz tube that protects each of the rod-shaped electrodes 269, 271, and 270. In this embodiment, the three quartz tubes are individually separated. The electrode protection tube may have other shapes, for example, a partition wall shape, to prevent the rod-shaped electrodes 269, 270, and 271 from contacting each other. The rod-shaped electrodes 269 and 270 are arranged so that their tips are located in the upper part of the electrode protection tube 275, and the rod-shaped electrode 271 is arranged so that its tip is located in the lower part of the electrode protection tube 275. The rod-shaped electrodes 269 and 270 have approximately the same length, but the rod-shaped electrode 271 has a different length from the rod-shaped electrodes 269 and 270, more specifically, the length in the direction in which the wafers 200 are stacked is different, and the rod-shaped electrodes 269 and 270 are longer than the rod-shaped electrode 271.

[0039] Of the rod-shaped electrodes 269, 270, and 271, the rod-shaped electrodes 269 and 271 (the rod-shaped electrode 269 as the fourth application electrode and the rod-shaped electrode 271 as the third application electrode) located at both ends are connected to a high-frequency power supply 273 via a matching unit 272, and high-frequency power is applied to them. The rod-shaped electrode 270, which serves as a second reference electrode, is connected to the earth, which is the reference potential, and is grounded to receive the reference potential. As a result, the rod-shaped electrodes connected to the high-frequency power supply 273 and the grounded rod-shaped electrodes are alternately arranged, and the rod-shaped electrode 270 located between the rod-shaped electrodes 269 and 271 connected to the high-frequency power supply 273 is used as a grounded rod-shaped electrode in common with the rod-shaped electrodes 269 and 271. In other words, the rod-shaped electrodes 269 and 271 function as "power supply electrodes" to which high-frequency power is applied, and the rod-shaped electrode 270 functions as a "grounded electrode" that is grounded.

[0040] In other words, the grounded rod-shaped electrode 270 is arranged so as to be sandwiched between rod-shaped electrodes 269 and 271 connected to adjacent high-frequency power supplies 273, and the rod-shaped electrodes 269 and 270, and similarly the rod-shaped electrodes 271 and 270, are configured as pairs to generate plasma. In other words, the grounded rod-shaped electrode 270 is used in common for the rod-shaped electrodes 269 and 271 connected to the two high-frequency power supplies 273 adjacent to the rod-shaped electrode 270. This allows the number of reference electrodes to be reduced. Then, by applying radio-frequency (RF) power from the high-frequency power supply 273 to the rod-shaped electrodes 269 and 271, plasma is generated in a plasma generation region 224a between the rod-shaped electrodes 269 and 270 and a plasma generation region 224b between the rod-shaped electrodes 270 and 271.

[0041] A second plasma electrode unit 277 (see FIG. 3 , the electrode protection tube 275 is omitted) is mainly composed of the rod-shaped electrodes 269, 270, and 271 and the electrode protection tube 275. Although an example in which two rod-shaped electrodes 269 and 271 are used as the application electrodes has been described, the number of application electrodes may be one or three or more.

[0042] Additionally, within the buffer chamber 237 of the buffer structure 400, three elongated rod-shaped electrodes 369, 370, and 371 made of a conductor are disposed from the bottom to the top of the reaction tube 203 along the stacking direction of the wafers 200. Each of the rod-shaped electrodes 369, 370, and 371 is disposed parallel to the nozzle 249c. Each of the rod-shaped electrodes 369, 370, and 371 is protected by being covered from top to bottom by an electrode protection tube 375. The electrode protection tube 375 is formed of a quartz tube that protects each of the rod-shaped electrodes 369, 371, and 370. In this embodiment, the three quartz tubes are individually separated. The electrode protection tube may have other shapes, for example, a partition wall shape, to prevent the rod-shaped electrodes 369, 370, and 371 from contacting each other. The rod-shaped electrodes 369 , 370 , and 371 are arranged so that their tips are located above the electrode protection tube 375 .

[0043] The rod-shaped electrodes 369, 370, and 371 have approximately the same length, and also have approximately the same length as the rod-shaped electrodes 269 and 270. The rod-shaped electrodes 369, 370, and 371 have a different length from the rod-shaped electrode 271, more specifically, a different length in the stacking direction of the wafer 200. The rod-shaped electrodes 369, 370, and 371 are longer than the rod-shaped electrode 271.

[0044] Of the rod-shaped electrodes 369, 370, and 371, the rod-shaped electrodes 369 and 371 (the rod-shaped electrode 369 as the first application electrode and the rod-shaped electrode 371 as the second application electrode) located at both ends are connected to a high-frequency power supply 373 via a matching unit 372, and high-frequency power is applied to them. The rod-shaped electrode 370, which serves as a first reference electrode, is connected to earth, which is the reference potential, and is grounded to receive the reference potential. As a result, the rod-shaped electrodes connected to the high-frequency power supply 373 and the grounded rod-shaped electrodes are alternately arranged, and the rod-shaped electrode 370 located between the rod-shaped electrodes 369 and 371 connected to the high-frequency power supply 373 is used as a grounded rod-shaped electrode in common with the rod-shaped electrodes 369 and 371. In other words, the rod-shaped electrodes 369 and 371 function as "power supply electrodes" to which high-frequency power is applied, and the rod-shaped electrode 370 functions as a grounded "ground electrode."

[0045] In other words, the grounded rod-shaped electrode 370 is arranged so as to be sandwiched between rod-shaped electrodes 369 and 371 connected to adjacent high-frequency power supplies 373, and the rod-shaped electrodes 369 and 370, and similarly the rod-shaped electrodes 371 and 370, are configured as pairs to generate plasma. In other words, the grounded rod-shaped electrode 370 is used in common for the rod-shaped electrodes 369 and 371 connected to the two high-frequency power supplies 373 adjacent to the rod-shaped electrode 370. This allows the number of reference electrodes to be reduced. Then, by applying high-frequency power from the high-frequency power supply 373 to the rod-shaped electrodes 369 and 371, plasma is generated in a plasma generation region 324a between the rod-shaped electrodes 369 and 370 and a plasma generation region 324b between the rod-shaped electrodes 370 and 371.

[0046] A first plasma electrode unit 377 (see FIG. 3; the electrode protection tube 375 is omitted) is mainly composed of the rod-shaped electrodes 369, 370, and 371 and the electrode protection tube 375. Although an example in which two rod-shaped electrodes 369 and 371 are used as the application electrodes has been described, the number of application electrodes may be one or three or more.

[0047] The first plasma electrode unit 377 and the second plasma electrode unit 277 as described above constitute a plasma generation unit as a plasma source. The matching boxes 272, 372 and the high-frequency power supplies 273, 373 may also be included in the plasma generation unit. As will be described later, the plasma generation unit functions as a plasma excitation unit (activation mechanism) that excites (activates) the gas into a plasma state. In other words, plasma is generated in the processing chamber 201 by this plasma generation unit.

[0048] The substrate processing apparatus according to this embodiment is provided with two buffer structures (buffer structures 300, 400) each equipped with a plasma generation unit, and each buffer structure 300, 400 is equipped with a high-frequency power supply 273, 373 and a matching unit 272, 372. Each high-frequency power supply 273, 373 is connected to a controller 121, enabling plasma control for each buffer chamber 237 of the buffer structures 300, 400. In other words, the controller 121 independently controls each high-frequency power supply 273, 373, thereby enabling individual adjustment of the high-frequency power supplied to each plasma generation unit equipped in the buffer structures 300, 400.

[0049] In the substrate processing apparatus according to this embodiment, the lengths of the rod-shaped electrodes 269, 270, 369, 370, and 371 in the reaction tube 203 are set to be approximately equal, with the length of the rod-shaped electrode 271 being shorter than these. That is, at least two or more power supply electrodes are provided in the plasma generation unit, and the lengths of at least two of the power supply electrodes are different. Therefore, by utilizing the difference in the lengths of the power supply electrodes in the plasma generation units of the buffer structures 300 and 400 and the individual adjustment of the high-frequency power supplied to each plasma generation unit, it is possible to individually adjust the density of the plasma generated in the reaction tube 203 in the upper and lower parts of the reaction tube 203.

[0050] In the above-described configuration example, the rod-shaped electrodes 369, 370, and 371 of the first plasma electrode unit 377 and the rod-shaped electrodes 269 and 270 of the second plasma electrode unit 277 are approximately the same length, but this is not necessarily limited to this. For example, as shown in FIG. 4 , the rod-shaped electrode 371 may be a rod-shaped electrode 371-1, which is shorter than the rod-shaped electrodes 369, 370, 269, and 270 and longer than the rod-shaped electrode 271. The first plasma electrode unit in this configuration example is designated by the reference numeral 377-1. In this way, even with a configuration in which the length of the rod-shaped electrode 371-1 is set, the plasma distribution in the vertical direction of the processing chamber 201 can be adjusted.

[0051] That is, if the lengths of the power supply electrodes in the plurality of plasma generating units are different, it is possible to adjust the plasma distribution in the vertical direction of the processing chamber 201. Therefore, the electrode configuration in the plasma generating unit may be a configuration other than that shown in Fig. 3 or 4 as long as it is possible to adjust the plasma distribution.

[0052] (Plasma Measuring Unit) The substrate processing apparatus according to this embodiment includes a plasma measuring unit 500 as a measuring unit for measuring the emission intensity of plasma in the reaction tube 203. The plasma measuring unit 500 will be described below with reference to FIG.

[0053] The plasma measurement unit 500 is primarily composed of an optical emission spectrometer (hereinafter simply referred to as "OES"). The OES 500 is configured to perform various measurements, including measurement of the emission intensity of the plasma, by, for example, performing spectral analysis of light emitted by the plasma. The OES 500 is connected to the controller 121 and is capable of notifying the controller 121 of the results of various measurements.

[0054] To perform such measurements, OES 500 includes a main body 501 having a detection unit 501a and a prism head 502 having a reflector 502a near its tip, which are connected by an optical fiber cable 503. Reflector 502a reflects the light emitted by the plasma and changes the optical axis direction of the plasma light. With this configuration, the light emitted by the plasma is detected by detection unit 501a via prism head 502 having reflector 502a and optical fiber cable 503.

[0055] In such an OES 500, at least the prism head 502 is arranged so as to be located inside the reaction tube 203. More specifically, the prism head 502 is arranged so as to be located inside a protection tube 505 provided inside the reaction tube 203.

[0056] The protective tube 505 penetrates the seal cap 219 and is provided so as to rise upward in the reaction tube 203 along the loading direction of the wafers 200. The protective tube 505 is made of a light-transmitting material such as quartz and has a tubular shape with an open lower end and a sealed upper end. This isolates the space inside the protective tube 505 from the space inside the reaction tube 203.

[0057] By arranging the prism head 502 inside the protective tube 505 extending vertically inside the reaction tube 203, the reflecting portion 502a of the prism head 502 reflects light from the lower vertical side inside the reaction tube 203 in a horizontal direction (i.e., a direction parallel to the surface (flat surface) of each wafer 200 loaded into the processing chamber 201).

[0058] The prism head 502 is disposed in the protective tube 505 so as to be movable at least along the tube axis direction (for example, the vertical direction when the reaction tube 203 extends in the vertical direction) within the protective tube 505. The movement of the prism head 502 is performed, for example, by using an elevating mechanism (not shown). However, this is not necessarily limited to this, and the prism head 502 may be movable by other methods (for example, manually). Furthermore, it is preferable that the prism head 502 is movable not only along the tube axis direction of the protective tube 505 but also in a rotational direction around the tube axis.

[0059] In this way, if the prism head 502 can move in the tube axial direction within the protective tube 505, the prism head 502 can move to multiple locations in the vertical direction within the protective tube 505, and measure the plasma emission intensity at each location. The multiple locations to which the prism head 502 moves are areas where multiple wafers 200 are held by the boat 217. In other words, by moving the prism head 502 within the protective tube 505, the OES 500 equipped with the prism head 502 can measure the plasma emission intensity at at least two locations in the area where multiple wafers 200 are held. Furthermore, if the prism head 502 can also move in the rotational direction, it becomes possible to position the prism head 502 so that the reflecting portion 502a of the prism head 502 faces the area where the wafers 200 are held.

[0060] (Control Device) Next, the control device will be described with reference to Fig. 6. As shown in Fig. 6, the controller 121, which is a control unit (control device), is configured as a computer including a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O port 121d. The RAM 121b, the storage device 121c, and the I / O port 121d are configured to be able to exchange data with the CPU 121a via an internal bus 121e. An input / output device 122, which is configured as, for example, a touch panel, is connected to the controller 121.

[0061] The storage device 121c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), etc. Control programs for controlling the operation of the substrate processing apparatus, process recipes describing procedures and conditions for film formation processes (described later), etc., are readably stored in the storage device 121c. The process recipes are combinations of procedures for various processes (film formation processes) (described later) that are executed by the controller 121 to obtain predetermined results, and function as programs. Hereinafter, process recipes, control programs, etc. are collectively referred to simply as programs. Furthermore, process recipes are also simply referred to as recipes. In this specification, the term "program" may refer to a recipe alone, a control program alone, or both. The RAM 121b is configured as a memory area (work area) in which programs, data, etc. read by the CPU 121a are temporarily stored.

[0062] The I / O port 121d is connected to the above-mentioned MFCs 241a to 241d, valves 243a to 243d, pressure sensor 245, APC valve 244, vacuum pump 246, heater 207, temperature sensor 263, matching box 272, high-frequency power supply 273, impedance measuring instrument 274, rotation mechanism 267, boat elevator 115, shutter opening / closing mechanism 115s, etc.

[0063] The CPU 121a is configured to read and execute a control program from the storage device 121c, and also to read a recipe from the storage device 121c in response to input of an operation command from the input / output device 122. The CPU 121a is configured to control the rotation mechanism 267, the flow rate adjustment of various gases by the MFCs 241a to 241d, the opening and closing of the valves 243a to 243d, the adjustment of the high frequency power source 273 based on impedance monitoring by the impedance measuring device 274, the opening and closing of the APC valve 244 and the pressure adjustment by the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment of the heater 207 based on the temperature sensor 263, the forward / reverse rotation of the boat 217 by the rotation mechanism 267, the adjustment of the rotation angle and rotation speed, the lifting and lowering of the boat 217 by the boat elevator 115, and the like, in accordance with the contents of the read recipe.

[0064] The controller 121 can be configured by installing the above-mentioned program stored in an external storage device 123 (for example, a magnetic disk such as a hard disk, an optical disk such as a CD, a magneto-optical disk such as an MO, or a semiconductor memory such as a USB memory) into a computer. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these will be collectively referred to as recording media. When the term recording media is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both. Note that the program may be provided to the computer using a communication means such as the Internet or a dedicated line, without using the external storage device 123.

[0065] (2) Substrate Processing Step Next, an example of a process for forming a film on a substrate as one step in the manufacturing process of a semiconductor device using the substrate processing apparatus configured as described above will be described with reference to Fig. 7. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by a controller 121.

[0066] 7 may be expressed as follows for convenience: Similar notations will be used in the following descriptions of modified examples and other embodiments.

[0067] (raw material gas → reactive gas) × n

[0068] In this specification, the term "wafer" may mean "the wafer itself" or "a laminate of a wafer and a predetermined layer, film, etc. formed on its surface." In this specification, the term "surface of a wafer" may mean "the surface of the wafer itself" or "the surface of a predetermined layer, etc. formed on the wafer." In this specification, the phrase "forming a predetermined layer on a wafer" may mean "forming a predetermined layer directly on the surface of the wafer itself" or "forming a predetermined layer on a layer, etc. formed on the wafer."

[0069] Furthermore, in this specification, the term "substrate" is synonymous with the term "wafer."

[0070] (Loading step: S1) When a plurality of wafers 200 are loaded into the boat 217 (wafer charge), the shutter 219s is moved by the shutter opening / closing mechanism 115s to open the lower end opening of the manifold 209 (shutter open). Thereafter, as shown in FIG. 1 , the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115 and loaded into the processing chamber 201 (boat load). In this state, the seal cap 219 seals the lower end of the manifold 209 via the O-ring 220b.

[0071] (Pressure and temperature adjustment step: S2) The inside of the processing chamber 201, i.e., the space in which the wafer 200 is present, is evacuated (reduced pressure exhausted) by the vacuum pump 246 so that the desired pressure (vacuum level) is reached. At this time, the pressure inside the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on this measured pressure information. The vacuum pump 246 is kept in a constantly operating state at least until the film formation step described below is completed.

[0072] The wafers 200 in the processing chamber 201 are heated by the heater 207 to a desired temperature. At this time, the power supply to the heater 207 is feedback-controlled based on temperature information detected by the temperature sensor 263 so that a desired temperature distribution is achieved in the processing chamber 201. Heating of the processing chamber 201 by the heater 207 continues at least until the film formation step, which will be described later, is completed.

[0073] Next, the rotation mechanism 267 starts to rotate the boat 217 and the wafers 200. The rotation mechanism 267 continues to rotate the boat 217 and the wafers 200 at least until the film forming step, which will be described later, is completed.

[0074] (Film Forming Steps: S3, S4, S5, S6) Thereafter, the film forming steps are performed by sequentially executing steps S3, S4, S5, and S6.

[0075] (Source gas supply steps: S3, S4) In step S3, a source gas is supplied to the wafers 200 in the processing chamber 201. The valve 243a is opened to allow the source gas to flow into the gas supply pipe 232a. The flow rate of the source gas is adjusted by the MFC 241a, and the source gas is supplied from the gas supply hole 250a into the processing chamber 201 via the nozzle 249a and is exhausted from the exhaust pipe 231. At this time, the source gas is supplied to the wafers 200. At the same time, the valve 243c is opened to allow an inert gas to flow into the gas supply pipe 232c. The flow rate of the inert gas is adjusted by the MFC 241c, and the inert gas is supplied into the processing chamber 201 together with the source gas and is exhausted from the exhaust pipe 231.

[0076] In addition, in order to prevent the source gas from entering the nozzle 249b, the valve 243d is opened to allow an inert gas to flow into the gas supply pipe 232d. The inert gas is supplied into the processing chamber 201 via the gas supply pipe 232d and the nozzle 249b, and is exhausted from the exhaust pipe 231.

[0077] Examples of the processing conditions in this step include: processing temperature: room temperature (25° C.) to 550° C., preferably 400 to 500° C. processing pressure: 1 to 4000 Pa, preferably 100 to 1000 Pa raw material gas supply flow rate: 0.1 to 3 slm raw material gas supply time: 1 to 100 seconds, preferably 1 to 50 seconds inert gas supply flow rate (per gas supply pipe): 0 to 10 slm

[0078] In this specification, when a numerical range such as "25 to 550°C" is expressed, it means that the lower limit and the upper limit are included in the range. Therefore, for example, "25 to 550°C" means "25°C or higher and 550°C or lower." The same applies to other numerical ranges. In this specification, the processing temperature means the temperature of the wafer 200 or the temperature inside the processing chamber 201, and the processing pressure means the pressure inside the processing chamber 201. A gas supply flow rate of 0 slm means that the gas is not supplied. These also apply to the following explanations.

[0079] By supplying the source gas to the wafer 200 under the above conditions, a first layer is formed on the wafer 200 (on the surface of the base film). For example, when a silicon (Si)-containing gas, which will be described later, is used as the source gas, a Si-containing layer is formed as the first layer.

[0080] After the first layer is formed, the valve 243a is closed to stop the supply of the source gas into the processing chamber 201. At this time, the APC valve 244 is left open, and the processing chamber 201 is evacuated by the vacuum pump 246 to remove the source gas, reaction by-products, and the like remaining in the processing chamber 201, either unreacted or having contributed to the formation of the Si-containing layer, from the processing chamber 201 (S4). Furthermore, the valves 243c and 243d are left open, and an inert gas is supplied into the processing chamber 201. The inert gas acts as a purge gas.

[0081] As the source gas, for example, a gas containing Si and a halogen, i.e., a halosilane gas, can be used. Halogen includes chlorine (Cl), fluorine (F), bromine (Br), iodine (I), etc. As the halosilane gas, for example, a chlorosilane gas containing Si and Cl can be used. More specifically, as the silane source gas, for example, monochlorosilane (SiH ３ Cl) gas, trichlorosilane (SiHCl ３ ) gas, tetrachlorosilane (SiCl ４ ) gas, hexachlorodisilane (Si ２ Cl ６ ) gas, octachlorotrisilane (Si ３ Cl ８ As the silane source gas, chlorosilane gas such as tetrafluorosilane (SiF ４ ) gas, tetrabromosilane (SiBr ４ ) gas, tetraiodosilane (SiI ４ That is, various halosilane gases such as chlorosilane gases, fluorosilane gases, bromosilane gases, and iodosilane gases can be used as the silane source gas.

[0082] The inert gas may be, for example, nitrogen (N ２ In addition, rare gases such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, and xenon (Xe) gas can be used. As the inert gas, one or more of these can be used. This also applies to each step described later.

[0083] (Reaction Gas Supply Steps: S5, S6) After the source gas supply step is completed, plasma-excited reaction gas is supplied to the wafers 200 in the processing chamber 201 (S5).

[0084] In this step, the valves 243b to 243d are controlled to open and close in the same manner as the valves 243a, 243c, and 243d in step S3. The flow rate of the reactive gas is adjusted by the MFC 241b, and the reactive gas is supplied into the buffer chamber 237 via the nozzles 249b and 249c. At this time, the high-frequency power supply 273 supplies (applies) high-frequency power to the rod-shaped electrodes 269, 270, and 271. In addition, the high-frequency power supply 373 supplies (applies) high-frequency power to the rod-shaped electrodes 369, 370, and 371. The reactive gas supplied into each buffer chamber 237 is excited into a plasma state inside the processing chamber 201, supplied to the wafers 200 as activated species, and exhausted from the exhaust pipe 231.

[0085] Examples of processing conditions in this step include: processing temperature: room temperature (25°) to 550°C, preferably 400 to 500°C; processing pressure: 10 to 300 Pa; reactive gas supply flow rate: 0.1 to 10 slm; reactive gas supply time: 10 to 100 seconds, preferably 1 to 50 seconds; inert gas supply flow rate (per gas supply pipe): 0 to 10 slm; RF power: 50 to 1000 W; RF frequency: 13.56 MHz or 27 MHz.

[0086] By exciting the reactive gas into a plasma state and supplying it to the wafer 200 under the above-described conditions, a modification process is performed on the first layer formed on the surface of the wafer 200 by the action of ions generated in the plasma and electrically neutral active species, and the first layer is modified into a second layer.

[0087] When an oxidizing gas (oxidizer) such as an oxygen (O)-containing gas is used as the reactive gas, the O-containing gas is excited into a plasma state to generate O-containing active species, which are then supplied to the wafer 200. In this case, the action of the O-containing active species causes an oxidation treatment as a modification treatment to the first layer formed on the surface of the wafer 200. In this case, if the first layer is, for example, a Si-containing layer, the Si-containing layer as the first layer is modified into a silicon oxide layer (SiO layer) as the second layer.

[0088] Furthermore, when a nitriding gas (nitriding agent) such as a nitrogen (N) and hydrogen (H)-containing gas is used as the reactive gas, the N- and H-containing gas is excited into a plasma state to generate N- and H-containing active species, which are then supplied to the wafer 200. In this case, the N- and H-containing active species act to perform a nitriding process as a modification process on the first layer formed on the surface of the wafer 200. In this case, when the first layer is, for example, a Si-containing layer, the Si-containing layer as the first layer is modified into a silicon nitride layer (SiN layer) as the second layer.

[0089] After the first layer is modified into the second layer, the valve 243b is closed to stop the supply of the reactive gas. The supply of high-frequency power to the rod-shaped electrodes 269, 271, 369, and 371 is also stopped. Then, the reactive gas and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201 using the same processing procedures and conditions as in step S4 (S6). Note that step S6 may be omitted and may be simply a reactive gas supply step.

[0090] As described above, for example, an O-containing gas or an N- and H-containing gas can be used as the reactive gas. For example, the O-containing gas can be oxygen (O ２ ) gas, nitrous oxide (N ２ O) gas, nitric oxide (NO) gas, nitrogen dioxide (NO ２ ) gas, ozone (O ３ ) gas, hydrogen peroxide (H ２ O ２ ) gas, water vapor (H ２ O), ammonium hydroxide (NH ４ (OH) gas, carbon monoxide (CO) gas, carbon dioxide (CO ２ As the N and H-containing gas, ammonia (NH ３ ) gas, diazene (N ２ H ２ ) gas, hydrazine (N ２ H ４ ) gas, N ３ H ８ As the reactive gas, one or more of these gases can be used.

[0091] As the inert gas, for example, the various inert gases exemplified in step S4 can be used.

[0092] (Performed a Predetermined Number of Times: S7) The above-described steps S3, S4, S5, and S6 are performed asynchronously, i.e., non-synchronized, in this order, constituting one cycle. By performing this cycle a predetermined number of times (n times, where n is an integer greater than or equal to 1), i.e., one or more times, a film of a predetermined composition and a predetermined thickness can be formed on the wafer 200. It is preferable to repeat the above-described cycle multiple times. That is, it is preferable to set the thickness of the second layer formed per cycle to be smaller than the desired thickness, and to repeat the above-described cycle multiple times until the thickness of the film formed by stacking the second layers reaches the desired thickness. Note that, when a Si-containing layer, for example, is formed as the first layer, and a SiO layer, for example, is formed as the second layer, a silicon oxide film (SiO film) is formed as the film. Furthermore, when a Si-containing layer, for example, is formed as the first layer, and a SiN layer, for example, is formed as the second layer, a silicon nitride film (SiN film) is formed as the film.

[0093] (Atmospheric pressure restoration step: S8) When the above-described film formation process is completed, an inert gas is supplied into the processing chamber 201 from each of the gas supply pipes 232c and 232d and exhausted from the exhaust pipe 231. As a result, the processing chamber 201 is purged with the inert gas, and the reaction gas remaining in the processing chamber 201 is removed from the processing chamber 201 (inert gas purge). Thereafter, the atmosphere in the processing chamber 201 is replaced with the inert gas (inert gas replacement), and the pressure in the processing chamber 201 is restored to normal pressure (atmospheric pressure restoration: S8).

[0094] (Unloading step: S9) Thereafter, the seal cap 219 is lowered by the boat elevator 115 to open the lower end of the manifold 209, and the processed wafers 200 supported by the boat 217 are unloaded from the lower end of the manifold 209 to the outside of the reaction tube 203 (boat unloading). After boat unloading, the shutter 219s is moved, and the lower end opening of the manifold 209 is sealed by the shutter 219s via the O-ring 220c (shutter close). After being unloaded to the outside of the reaction tube 203, the processed wafers 200 are removed from the boat 217 (wafer discharging). After wafer discharging, an empty boat 217 may be loaded into the processing chamber 201.

[0095] (3) Plasma Control Processing Next, the plasma control processing performed for the example process of the above-described procedure will be described with reference to FIGS.

[0096] Among the above-described film forming steps (S3, S4, S5, S6), in the reactive gas supply steps (S5, S6), a process is performed using a plasma-excited reactive gas. This process is performed collectively on a plurality of wafers 200 stacked in multiple stages and loaded in the boat 217. Therefore, if the plasma generated in the reaction tube 203 has a variation or bias in plasma density in the vertical direction within the reaction tube 203, the process on the plurality of wafers 200 may result in non-uniform film quality on each wafer 200 in the stacking direction.

[0097] Therefore, in the substrate processing apparatus according to this embodiment, the following plasma control process is performed: In the following description, the operation of each component of the substrate processing apparatus is controlled by a controller 121 .

[0098] The plasma control process first uses the OES 500 to measure the emission intensity of plasma in the reaction tube 203. Specifically, as shown in FIG. 5 , the prism head 502 of the OES 500 is inserted into the protective tube 505, and the reflecting portion 502a of the prism head 502 is brought to a position corresponding to an area in the reaction tube 203 where a plurality of wafers 200 are held (hereinafter also referred to as the "substrate holding area"). Then, for one of the substrate holding areas, light emitted by the plasma is reflected by the reflecting portion 502a and detected by the detecting portion 501a via the optical cable 503, and spectral analysis is performed in the main body 501 of the OES 500, thereby measuring the emission intensity of the plasma. Thereafter, the prism head 502 is moved within the protective tube 505, and the emission intensity of plasma is similarly measured for another of the substrate holding areas. Such measurement of plasma emission intensity is carried out at least at two locations in the substrate holding area, preferably at three or more locations, namely, the upper, central and lower portions of the substrate holding area.

[0099] That is, by disposing the prism head 502 of the OES 500 movably within the protective tube 505, the plasma emission intensity is measured at at least two locations in the substrate holding area within the reaction tube 203 while the boat 217 holds a plurality of wafers 200 within the reaction tube 203. This makes it possible to recognize from the measurement results, if there is any variation or bias in the plasma density in the vertical direction within the reaction tube 203.

[0100] By measuring the plasma emission intensity at at least two locations in the substrate holding area, it is possible to control the plasma generating unit based on the measurement results so as to adjust the uniformity of the plasma generated in the substrate holding area.

[0101] 3 or 4, the high-frequency power supplied from the high-frequency power supplies 273, 373 to the rod-shaped electrodes 269, 271, 369, 371 (377-1) serving as power supply electrodes in the buffer structures 300, 400 is adjusted. The high-frequency power is adjusted based on the measurement results of the plasma emission intensity. This makes it possible to adjust the vertical plasma distribution in the substrate holding area in the processing chamber 201 by utilizing the difference in length between the rod-shaped electrodes 269, 271, 369, 371 (377-1).

[0102] For example, if the plasma emission intensity is measured at at least two locations in the substrate holding area and the emission intensity at the upper part of the substrate holding area is weaker than that at the lower part of the substrate holding area, the high frequency power supplies 273, 373 are controlled so that the high frequency power supplied from the high frequency power supply 373 to the rod-shaped electrode 371 (377-1) is stronger than the high frequency power supplied from the high frequency power supply 273 to the rod-shaped electrode 271. In this way, since the rod-shaped electrode 371 (377-1) is longer than the rod-shaped electrode 271, the density of the plasma generated at the upper part of the substrate holding area can be adjusted to be higher, and as a result, the plasma generated in the substrate holding area can be made more uniform.

[0103] That is, at least two or more rod-shaped electrodes 269, 271, 369, 371 (377-1) are provided as power supply electrodes, and when the at least two rod-shaped electrodes 269, 271, 369, 371 (377-1) are of different lengths, the controller 121 controls the multiple high-frequency power supplies 273, 373 to adjust the high-frequency power supplied to each rod-shaped electrode 269, 271, 369, 371 (377-1) from the high-frequency power supplies 273, 373 based on the results of measurement of plasma emission intensity using the prism head 502 of the OES 500. In this way, the results of measurement of plasma emission intensity in the substrate holding region are reflected in the plasma generation in the substrate holding region, resulting in uniform plasma generation.

[0104] Although the example described here is a case where the high frequency power supplied from the multiple high frequency power supplies 273, 373 is adjusted, plasma uniformity may be achieved without relying on such a control mode. For example, even when one high frequency power supply selectively (e.g., in a time-sharing manner) supplies high frequency power to multiple plasma generating units having power supply electrodes of different lengths, it is possible to adjust the plasma distribution in the vertical direction of the substrate holding area by utilizing the difference in the lengths of the power supply electrodes, thereby achieving plasma uniformity.

[0105] This means that if power electrodes of different lengths are prepared in advance, the lengths of the power electrodes to which high-frequency power is supplied can be adjusted by selectively supplying high-frequency power. Here, "adjustable length of power electrode" may include not only selective supply of high-frequency power to power electrodes of different lengths, but also a case where the tip position of the power electrode is arranged to be movable in the vertical direction and the length of the power electrode is adjusted by utilizing the movement of the power electrode. In either case, by making the length of the power electrode adjustable based on the measurement results of plasma emission intensity at at least two locations in the substrate holding area, it is possible to achieve uniformity of the plasma generated in the substrate holding area.

[0106] The plasma control process described above may be performed in parallel with the reactive gas supply steps (S5, S6), for example. That is, for the plasma generated in the substrate holding area in the reactive gas supply step (S5), the plasma emission intensity is measured using the prism head 502 of the OES 500, and feedback control is performed to adjust the vertical plasma distribution in the substrate holding area based on the measurement results.

[0107] However, the plasma control process is not necessarily limited to being performed in parallel with the reactive gas supply steps (S5, S6), and may be performed in the manner described below. For example, during equipment maintenance or the like, plasma emission intensity is measured at at least two locations in the substrate holding area in the reaction tube 203 while multiple wafers 200 are held in the reaction tube 203. Then, while reflecting the measurement results, plasma control process is performed for the subsequent reactive gas supply steps (S5, S6) to uniformize the plasma generated in the substrate holding area.

[0108] Furthermore, in the above-described plasma control process, an adjustment is made based on the measurement results of plasma emission intensity at at least two locations in the substrate holding area to offset differences between the locations. However, this is not necessarily limited to this configuration, and the control process described below may also be performed. For example, normal values ​​for plasma emission intensity at at least two locations in the substrate holding area are determined in advance, and each normal value is stored and held in the memory device 121c of the controller 121. In other words, the memory device 121c functions as a memory unit that stores normal values ​​for plasma emission intensity at at least two locations in advance. The controller 121 then compares the measurement results of plasma emission intensity at at least two locations in the substrate holding area with the normal values ​​stored in the memory device 121c for each location, and if there is a discrepancy between the measured value and the normal value, performs plasma control process to bring the measured value closer to the normal value. Even when performing control process of this configuration, the discrepancy between the measured value and the normal value can be eliminated, thereby achieving uniformity of plasma generated in the substrate holding area.

[0109] (4) Effects of the Present Embodiment The present embodiment provides one or more of the following effects.

[0110] (a) In this embodiment, the plasma emission intensity is measured at at least two locations in the substrate holding area. Therefore, even if there is a variation or bias in plasma density, for example, in the vertical direction within the reaction tube 203, this can be recognized from the measurement results of the plasma emission intensity. Then, based on the measurement results of such plasma emission intensity, it becomes possible to perform plasma control processing on the plasma generated in the substrate holding area so as to homogenize the plasma. In other words, according to this embodiment, when performing plasma-based processing on multiple wafers 200 at the same time, non-uniform processing on each wafer 200 can be suppressed by measuring the plasma emission intensity at at least two locations in the substrate holding area.

[0111] (b) In this embodiment, the plasma measurement unit (OES) 500, which serves as a measurement unit for measuring the emission intensity of plasma, is configured to include a reflecting unit 502a, which reflects the light emitted by the plasma so as to change the direction of the optical axis of the light. As a result, even when the boat 217 supports multiple wafers 200 in multiple stages in the vertical direction, the plasma emission intensity of the substrate holding region, which is the region where multiple wafers 200 are held, can be measured while effectively utilizing the space within the reaction tube 203 (i.e., while realizing space saving within the reaction tube 203).

[0112] (c) In this embodiment, the prism head 502 of the plasma measurement unit (OES) 500 is disposed so as to be located inside a protective tube 505 provided inside the reaction tube 203. This makes it possible to measure the emission intensity of plasma generated in the substrate holding area inside the reaction tube 203 using the prism head 502 of the OES 500. If the OES 500 can be used in this way, it becomes possible to measure the plasma emission intensity appropriately and reliably.

[0113] (d) In this embodiment, the prism head 502 of the OES 500 is movable along the tube axis direction (e.g., up and down) within the protective tube 505. This allows the plasma emission intensity to be measured at least at two locations in the substrate holding area using a single prism head 502. In other words, even when measuring the plasma emission intensity at at least two locations in the substrate holding area, it is possible to prevent the device configuration from becoming complicated and the device size from becoming large.

[0114] (e) In this embodiment, the plasma generating unit includes rod-shaped electrodes 269, 271, 369, 371 (377-1) as power supply electrodes and rod-shaped electrodes 270, 370 as ground electrodes. Based on the measurement results of plasma emission intensity at at least two locations in the substrate holding area, the length of the power supply electrodes is adjustable or the high-frequency power supplied from the high-frequency power source is adjusted to achieve uniformity of the plasma generated in the substrate holding area. In this way, by using the power supply electrodes and the ground electrode and adjusting the length of the power supply electrodes or the high-frequency power supplied, it is possible to prevent the device configuration from becoming complicated or the device size from increasing in order to achieve plasma uniformity. In particular, by providing multiple plasma generating units as in this embodiment and individually adjusting the high-frequency power for each plasma generating unit using multiple high-frequency power sources, it is possible to easily and reliably achieve uniformity of the plasma within the reaction tube 203.

[0115] (f) As described in this embodiment, if the plasma control process is performed in parallel with the reactive gas supply step, feedback control for plasma uniformity is performed in real time, resulting in extremely excellent responsiveness of the plasma control process. On the other hand, if the plasma control process is performed by comparing with information stored in the storage device 121c that functions as a storage unit, excessive processing load on the controller 121, OES 500, etc. can be suppressed. Furthermore, by utilizing the normal values ​​stored in the storage device 121c, the reliability of the plasma control process can be improved.

[0116] Another Aspect of the Present Disclosure Next, a substrate processing apparatus according to another aspect of the present disclosure will be described.

[0117] In the above-described embodiment, the plasma generating unit is provided inside the reaction tube 203. However, in another embodiment described here, the plasma generating unit is provided outside the reaction tube 203. The other configurations are the same as in the above-described embodiment, and therefore will not be described here.

[0118] (Plasma Generation Unit) In a substrate processing apparatus according to another embodiment described herein, a plurality of plasma generation units are provided outside the reaction tube 203, i.e., outside the processing vessel (processing chamber 201). More specifically, an electrode 600 constituting one plasma generation unit and an electrode 700 constituting another plasma generation unit are provided outside the reaction tube 203. By applying power to the electrodes 600 and 700, it is possible to convert and excite a gas into plasma inside the reaction tube 203, i.e., inside the processing vessel (processing chamber 201), that is, to excite the gas into a plasma state.

[0119] 8, an electrode 600 and an electrode fixture 601 for fixing the electrode 600 are disposed between the heater 207 and the reaction tube 203. The electrode fixture 601 is disposed inside the heater 207, the electrode 600 is disposed inside the electrode fixture 601, and the reaction tube 203 is disposed inside the electrode 600.

[0120] 9, an electrode 700 and an electrode fixture 701 for fixing the electrode 700 are disposed between the heater 207 and the reaction tube 203. The electrode fixture 701 is disposed inside the heater 207, the electrode 700 is disposed inside the electrode fixture 701, and the reaction tube 203 is disposed inside the electrode 700.

[0121] In either configuration, the electrodes 600, 700 and the electrode fixtures 601, 701 are provided in a circular space between the inner wall of the heater 207 and the outer wall of the reaction tube 203 in a plan view, extending from the bottom to the top of the outer wall of the reaction tube 203 in the arrangement direction of the wafers 200. The electrodes 600, 700 are provided parallel to the nozzles 249a, 249b. The electrodes 600, 700 and the electrode fixtures 601, 701 are arranged and disposed concentrically with the reaction tube 203 and the heater 207 in a plan view, but are not in contact with the heater 207. The electrode fixtures 601, 701 are made of an insulating material (insulator) and are provided so as to cover at least a portion of the electrodes 600, 700 and the reaction tube 203. Therefore, the electrode fixtures 601 and 701 can also be called covers (quartz covers, insulating walls, insulating plates) or arc-shaped cross-section covers (arc-shaped cross-section bodies, arc-shaped cross-section walls).

[0122] A plurality of electrodes 600, 700 are provided, and these plurality of electrodes 600, 700 are fixed and installed on the inner wall of the electrode fixing device 601, 701. More specifically, the inner wall surface of the electrode fixing device 601, 701 is provided with protrusions (hooks) 610, 710 onto which the electrodes 600, 700 can be hooked, and the electrodes 600, 700 are provided with openings 605, 705 which are through holes into which the protrusions 610, 710 can be inserted. By hooking the electrodes 600, 700 onto the protrusions 610, 710 provided on the inner wall surface of the electrode fixing device 601, 701 via the openings 605, 705, the electrodes 600, 700 can be fixed to the electrode fixing device 601, 701.

[0123] As shown in FIG. 8 , the electrodes 600 include a first-type electrode 600-1, a second-type electrode 600-2, and a zero-type electrode 600-0. The first-type electrode 600-1 and the second-type electrode 600-2 are connected to a high-frequency power supply (RF power supply) via a matching box, and an arbitrary potential is applied to them. The zero-type electrode 600-0 is grounded and serves as a reference potential (0 V). In other words, the first-type electrode 600-1 and the second-type electrode 600-2 function as power supply electrodes, and the zero-type electrode 600-0 functions as a ground electrode. Therefore, when high-frequency power is supplied to the first-type electrode 600-1, plasma is generated in the region between the first-type electrode 600-1 and the zero-type electrode 600-0. Similarly, when high-frequency power is supplied to the second-type electrode 600-2, plasma is generated in the region between the second-type electrode 600-2 and the zero-type electrode 600-0.

[0124] The first-type electrode 600-1, the second-type electrode 600-2, and the zeroth-type electrode 600-0 are each configured as a plate-like member when viewed from the front, and are arranged along the vertical direction (vertical direction, the direction in which substrates are stacked) in which the reaction tube 203 extends. However, the first-type electrode 600-1 and the second-type electrode 600-2 have different vertical lengths. Specifically, their upper end positions in the vertical direction are different from each other, and the second-type electrode 600-2 is shorter than the first-type electrode 600-1. Therefore, by utilizing the different lengths of these power supply electrodes, it is possible to adjust the plasma distribution in the vertical direction of the processing chamber 201. In other words, the length of the power supply electrode to which high-frequency power is supplied can also be adjusted in the electrode 600.

[0125] 9, the electrode 700 includes a third-type electrode 700-3 in addition to the first-type electrode 700-1, the second-type electrode 700-2, and the zeroth-type electrode 700-0. The third-type electrode 700-3 is connected to a high-frequency power supply (RF power supply) via a matching box and functions as a power supply electrode. Therefore, when high-frequency power is supplied to the first-type electrode 700-1, plasma is generated in the region between the first-type electrode 700-1 and the zeroth-type electrode 700-0. Similarly, when high-frequency power is supplied to the second-type electrode 700-2, plasma is generated in the region between the second-type electrode 700-2 and the zeroth-type electrode 700-0. Similarly, when high-frequency power is supplied to the third-type electrode 700-3, plasma is generated in the region between the third-type electrode 700-3 and the zeroth-type electrode 700-0.

[0126] The first-type electrode 700-1, the second-type electrode 700-2, the third-type electrode 700-3, and the zeroth-type electrode 700-0 are each configured as a plate-like member when viewed from the front, and are arranged along the vertical direction (vertical direction, the direction in which substrates are stacked) of the reaction tube 203. However, the first-type electrode 700-1, the second-type electrode 700-2, and the third-type electrode 700-3 have different vertical lengths. Specifically, their upper end positions in the vertical direction are different from one another, and the second-type electrode 700-2 is shorter than the first-type electrode 700-1, and the third-type electrode 700-3 is shorter than the second-type electrode 700-2. Therefore, by utilizing the different lengths of these power supply electrodes, it is possible to more precisely adjust the plasma distribution in the vertical direction of the processing chamber 201. In other words, the length of the power supply electrode to which high-frequency power is supplied can also be adjusted in the electrode 700.

[0127] The electrodes 600, 700 as described above constitute a plasma generating unit (plasma excitation unit, plasma activation mechanism) that excites (activates) the gas into a plasma state. The electrode fixtures 601, 701, a matching box, and an RF power supply may also be included in the plasma generating unit. Plasma is generated in the processing chamber 201 by such a plasma generating unit. Then, by performing plasma control processing using the respective electrodes 600, 700, the generated plasma can be made uniform.

[0128] The substrate processing apparatus according to the other aspect described above has one or more of the following effects in addition to the effects obtained in the above-described aspect.

[0129] (g) In another embodiment of the substrate processing apparatus, a power supply electrode and a ground electrode are used, and the plasma generated in the substrate holding area can be made uniform by adjusting the length of the power supply electrode and the supplied high-frequency power, for example.

[0130] (h) In the above-described embodiment, since a plasma generating unit is provided inside the reaction tube 203, plasma can be generated directly in the substrate holding area. Moreover, since the plasma is generated using a rod-shaped electrode, the generation of plasma can be prevented from becoming directional. Meanwhile, in the substrate processing apparatus according to the above-described embodiment, the plasma generating unit is provided outside the reaction tube 203, which facilitates simplifying the configuration inside the reaction tube 203 and also prevents particle generation inside the reaction tube 203, which is preferable for improving the processing environment inside the reaction tube 203. Furthermore, since the plasma generating unit provided outside the reaction tube 203 is configured using a plate-shaped electrode, the configuration around the reaction tube 203 can be prevented from becoming large.

[0131] <Modifications, etc.> Although the embodiments of the present disclosure have been specifically described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present disclosure.

[0132] For example, in the above-described embodiment, a case where a film is formed on a substrate using a source gas and a reactive gas in a film formation process performed by a substrate processing apparatus is exemplified, but this aspect is not limited to this. That is, other types of gases may be used as the process gas used in the film formation process to form other types of thin films. Furthermore, this aspect can be applied even when three or more types of process gases are used, as long as the film formation process is performed by alternately supplying these gases.

[0133] In the above-described embodiment, an example in which the reactant gas is supplied after the raw material is supplied has been described. However, the present disclosure is not limited to this example, and the order in which the raw material and the reactant gas are supplied may be reversed. In other words, the raw material may be supplied after the reactant gas is supplied. By changing the supply order, it is possible to change the film quality and composition ratio of the formed film.

[0134] Furthermore, in the above-described embodiments, a film formation process is exemplified as a process performed by the substrate processing apparatus, but this aspect is not limited thereto. That is, this aspect can be applied to the film formation processes exemplified in each embodiment as well as film formation processes other than the thin film formation processes exemplified in each embodiment. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is also possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0135] In the above-described embodiment, an example of forming a film using a batch-type substrate processing apparatus that processes multiple substrates at a time has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied, for example, to a case where a film is formed using a single-wafer substrate processing apparatus that processes one or several substrates at a time. Furthermore, in the above-described embodiment, an example of forming a film using a substrate processing apparatus having a hot-wall processing furnace has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied to a case where a film is formed using a substrate processing apparatus having a cold-wall processing furnace.

[0136] When using these substrate processing apparatuses, each process can be performed using the same processing procedures and conditions as in the above-described embodiments and modifications, and the same effects as in the above-described embodiments and modifications can be obtained.

[0137] Furthermore, it is preferable that recipes used for film formation and etching processes are individually prepared according to the process content and stored in the storage device 121c via an electric communication line or the external storage device 123. When starting various processes, it is preferable that the CPU 121a appropriately selects an appropriate recipe according to the process content from among the multiple recipes stored in the storage device 121c. This makes it possible to form thin films of various film types, composition ratios, film qualities, and film thicknesses in a versatile and reproducible manner using a single substrate processing apparatus. It also reduces the burden on the operator, avoids operational errors, and enables various processes to be started quickly.

[0138] The above-described recipe need not necessarily be newly created, but may be prepared by modifying an existing recipe already installed in the substrate processing apparatus. When modifying a recipe, the modified recipe may be installed in the substrate processing apparatus via an electric communication line or a recording medium on which the modified recipe is recorded. Alternatively, an existing recipe already installed in the substrate processing apparatus may be directly modified by operating the input / output device 122 provided in the existing substrate processing apparatus.

[0139] Furthermore, in the above embodiment, the substrate processing apparatus has been described, but the present invention can be applied to semiconductor manufacturing apparatuses in general.

[0140] 200...wafer, 201...processing chamber, 269, 271, 369, 371, 371-1...rod-shaped electrode (power supply electrode), 270, 370...rod-shaped electrode (ground electrode), 273, 373...high frequency power supply, 500...OES (plasma measurement unit), 600, 700...electrode, 600-1, 600-2...electrode (power supply electrode), 600-0...electrode (ground electrode), 700-1, 700-2, 700-3...electrode (power supply electrode), 700-0...electrode (ground electrode)

Claims

1. A substrate processing apparatus comprising: a processing chamber for processing a plurality of substrates; a plasma generation unit for generating plasma within the processing chamber; and a measurement unit for measuring the emission intensity of the plasma at at least two locations in an area where the plurality of substrates are held.

2. The substrate processing apparatus according to claim 1, wherein the measurement section includes a reflecting section that reflects light emitted by plasma so as to change the direction of the optical axis of the light.

3. The substrate processing apparatus according to claim 1, wherein the measurement unit is disposed within the processing chamber.

4. The substrate processing apparatus according to claim 3, wherein the measuring unit is disposed in a protective tube provided in the processing chamber.

5. The substrate processing apparatus according to claim 4, wherein the measuring unit is movable within the protective tube along the tube axis direction.

6. The substrate processing apparatus according to claim 1, wherein the measurement unit is configured as an optical emission spectrometer.

7. The substrate processing apparatus according to claim 1, wherein the plasma generating section comprises a power electrode and a ground electrode.

8. The substrate processing apparatus according to claim 7, wherein the length of the power supply electrode is adjustable based on the measurement result of the measurement unit.

9. The substrate processing apparatus according to claim 7, comprising a plurality of the plasma generating units.

10. The substrate processing apparatus according to claim 9, further comprising a plurality of high frequency power supplies for supplying high frequency power to a plurality of said plasma generating parts.

11. The substrate processing apparatus according to claim 10, wherein at least two or more power supply electrodes are provided in the plasma generating section, and the at least two power supply electrodes have different lengths.

12. A substrate processing apparatus according to claim 11, further comprising a control unit configured to control the plurality of high frequency power sources so as to adjust the high frequency power supplied from the plurality of high frequency power sources to the plurality of plasma generating units based on the measurement results of the measurement unit.

13. The substrate processing apparatus according to claim 9, wherein the plasma generating unit is provided within the processing chamber.

14. The substrate processing apparatus according to claim 13, wherein the power supply electrode and the ground electrode are rod-shaped electrodes.

15. The substrate processing apparatus according to claim 9, wherein the plasma generating unit is provided outside the processing chamber.

16. The substrate processing apparatus according to claim 15, wherein the power supply electrode and the ground electrode are plate-shaped electrodes.

17. A substrate processing apparatus as described in claim 1, comprising: a memory unit that stores normal values ​​of the plasma emission intensity at said at least two locations in advance; and a control unit configured to be able to compare the measurement results measured by said measurement unit with the normal values ​​stored in said memory unit.

18. A substrate processing method comprising: generating plasma in a processing chamber; measuring the emission intensity of the plasma at at least two locations in an area where a plurality of substrates are held; and processing the plurality of substrates.

19. A method for manufacturing a semiconductor device, comprising the steps of: manufacturing a semiconductor device using a substrate processed by the substrate processing method according to claim 18; 20. A program that causes a substrate processing apparatus to execute, by a computer, the steps of: generating plasma in a processing chamber; measuring the emission intensity of the plasma at at least two locations in an area where a plurality of substrates are held; and processing the plurality of substrates.

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