Substrate processing method, semiconductor device manufacturing method, recording medium, and substrate processing apparatus

Abstract

The invention relates to a substrate processing method, a semiconductor device manufacturing method, a recording medium, and a substrate processing apparatus. The present invention provides a technique in which charge trapping characteristics can be improved by controlling the amount of Si-Si bonds (the amount of Si substitution) and the amount of Si-Si bonds in a film formed on a substrate. [Solution] The method comprises: (a) a step in which a decomposable processing gas containing silicon is supplied to a substrate, and a layer containing Si-Si-Si bonds is formed on the substrate; and (b) a step of supplying a reaction gas to the substrate to dissociate the Si-Si-Si bond.

Description

Technical Field

[0001] The present invention relates to a substrate processing method, a method for manufacturing a semiconductor device, a recording medium and a substrate processing apparatus. Background Art

[0002] One of the steps in the manufacturing process of a semiconductor device is to form an insulating film such as a silicon oxide film (SiO 2 ) or a silicon nitride film (Si 3 N 4 ) on a substrate (eg, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2010-153795 Summary of the invention

[0006] Problems to be solved by the invention

[0007] The present invention provides a technology capable of improving charge trapping characteristics by controlling the amount of Si-Si-Si bonds (Si substitution amount) and the amount of Si-Si bonds in a film formed on a substrate.

[0008] Means for solving problems

[0009] According to one embodiment of the present invention, a technology is provided, which comprises: (a) a process of supplying a processing gas containing silicon decomposition properties to a substrate to form a layer containing Si-Si-Si bonds on the substrate; and (b) a process of supplying a reaction gas to the substrate to dissociate the Si-Si-Si bonds.

[0010] Effects of the Invention

[0011] The present invention can improve the charge trapping characteristics by controlling the amount of Si-Si-Si bonds (Si substitution amount) and the amount of Si-Si bonds in a film formed on a substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 1 is a schematic diagram showing the structure of a substrate processing apparatus used in a substrate processing method according to an embodiment of the present invention.

[0013] Figure 2 A substrate processing apparatus used in a substrate processing method according to an embodiment of the present invention is shown. Figure 1 AA line cross-section diagram.

[0014] Figure 3 This is a block diagram for explaining a controller included in a substrate processing apparatus used in a substrate processing method according to an embodiment of the present invention.

[0015] Figure 4This is a diagram showing a flow in a substrate processing method (semiconductor manufacturing method) according to one embodiment of the present invention.

[0016] Figure 5 It is a schematic diagram of the Si-substituted and N-deficient structure of the present invention.

[0017] Description of Reference Numerals

[0018] 100 Substrate processing device

[0019] 200 wafers (substrate)

[0020] 207 Heater

[0021] 231 Exhaust pipe

[0022] 232a, 232b gas supply pipe

[0023] 250a, 250c Gas supply holes DETAILED DESCRIPTION

[0024] Hereinafter, the present invention will be described in detail.

[0025] The present invention is not limited to the following embodiments at all. The following embodiments can be appropriately modified within the scope of the purpose of the present invention.

[0026] In the present invention, a numerical range expressed using "to" means a range including the numerical values ​​described before and after "to" as the minimum value and the maximum value, respectively.

[0027] In the numerical ranges described stepwise in the present invention, the upper limit value or the lower limit value described in a certain numerical range may be replaced by the upper limit value or the lower limit value of the numerical range described in another stepwise manner.

[0028] In addition, in the numerical range described in the present invention, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the Examples.

[0029] In the present invention, the term "step" includes not only an independent step but also a step that cannot be clearly distinguished from other steps as long as the intended purpose is achieved.

[0030] The following mainly refers to Figure 1 and Figure 2 One embodiment of the present invention is described. It should be noted that the drawings used in the following description are schematic, and the relationship between the dimensions of the elements and the ratio of the elements in the drawings may not be consistent with the actual situation. In addition, the relationship between the dimensions of the elements and the ratio of the elements may not be consistent between multiple drawings.

[0031] <Substrate processing apparatus>

[0032] like Figure 1 As shown, the substrate processing apparatus 100 includes a processing furnace 202. A heater 207 as a temperature control unit is provided in the processing furnace 202. The heater 207 is cylindrical and is vertically mounted by being supported by a holding plate. The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) gas by heat.

[0033] A reaction tube 203 constituting a reaction container (processing container) is disposed inside the heater 207 concentrically with the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC) and has a cylindrical shape with a closed upper end and an open lower end.

[0034] A manifold 209 is disposed concentrically with the reaction tube 203 below the reaction tube 203. The manifold 209 is made of metal such as stainless steel (SUS) and has a cylindrical shape with an open upper end and a lower end.

[0035] The upper end of the manifold 209 engages with the lower end of the reaction tube 203 , and is configured to support the reaction tube 203 .

[0036] An O-ring 220a as a sealing member is provided between the manifold 209 and the reaction tube 203. The manifold 209 is supported on a heater base, whereby the reaction tube 203 is vertically installed. The reaction tube 203 and the manifold 209 constitute a processing container (reaction container). A processing chamber 201 is formed in the hollow portion of the cylinder of the processing container. The processing chamber 201 is configured to accommodate a plurality of wafers 200 as substrates. The wafers 200 are processed in the processing chamber 201.

[0037] In the processing chamber 201, nozzles 249a and 249b extending in the vertical direction are provided so as to penetrate the side wall of the manifold 209. Gas supply pipes 232a and 232b are connected to the nozzles 249a and 249b, respectively. In this way, two nozzles 249a and 249b and two gas supply pipes 232a and 232b are provided on the reaction tube 203, thereby being configured to be able to supply multiple gases, in this case two gases, into the processing chamber 201.

[0038] On the gas supply pipe 232a, a mass flow controller (MFC) 241a as a flow controller (flow control unit), a valve 243a as an on-off valve, a storage unit (gas storage unit) 240a configured to temporarily store gas, and a valve 242a are provided in order from the upstream side of the gas flow. In addition, an inert gas supply pipe 232c is connected to the gas supply pipe 232a on the downstream side of the valve 243a. On the inert gas supply pipe 232c, a mass flow controller 241c as a flow controller (flow control unit) and a valve 243c as an on-off valve are provided in order from the upstream side of the gas flow.

[0039] The nozzle 249a is connected to the front end of the gas supply pipe 232a. The nozzle 249a is arranged in the arc-shaped space between the inner wall of the reaction tube 203 and the wafer 200 in a manner of standing up from the bottom to the top of the inner wall of the reaction tube 203 toward the loading direction of the wafer 200. The nozzle 249a is configured as an L-shaped long nozzle. A gas supply hole 250a for supplying gas is provided on the side of the nozzle 249a. The gas supply hole 250a opens toward the center of the reaction tube 203. 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 further provided at the same opening pitch.

[0040] The storage part 240a is constituted as a gas storage tank or spiral piping having a larger gas capacity than a normal piping, for example. By opening and closing the valve 243a on the upstream side and the valve 242a on the downstream side compared with the storage part 240a, the gas supplied from the gas supply pipe 232a can be filled into the storage part 240a, and the gas filled in the storage part 240a can be supplied into the processing chamber 201. By closing the valve 242a and opening the valve 243a, the gas whose flow rate is adjusted by the MFC 241a can be filled into the storage part 240a. After the storage part 240a is filled with a predetermined amount of gas and the pressure in the storage part 240a reaches a predetermined pressure, the valve 243a is closed and the valve 242a is opened, thereby, the high-pressure gas filled in the storage part 240a can be suddenly (in a short time) supplied (flash supply) into the processing chamber 201 via the gas supply pipe 232a and the nozzle 249a. It should be noted that the valve 243a may be opened during flash supply.

[0041] Alternatively, when supplying the processing gas into the processing chamber 201 , the processing gas may be directly supplied into the processing chamber 201 (non-flash supply) without filling the storage portion 240 a with the processing gas.

[0042] On the supply pipe 232b, a mass flow controller (MFC) 241b as a flow controller (flow control unit) and a valve 243b as an on-off valve are sequentially provided from the upstream side of the gas flow. In addition, an inert gas supply pipe 232d is connected to the gas supply pipe 232b on the downstream side of the valve 243b. On the inert gas supply pipe 232d, an MFC 241d and a valve 243d are sequentially provided from the upstream side of the gas flow.

[0043] A nozzle 249b is connected to the front end of the gas supply pipe 232b. The nozzle 249b is provided in the buffer chamber 237 as a gas dispersion space.

[0044] like Figure 2 As shown, the buffer chamber 237 is provided in the arc-shaped space between the inner wall of the reaction tube 203 and the wafer 200, in the portion from the lower part to the upper part of the inner wall of the reaction tube 203, along the loading direction of the wafer 200. A gas supply hole 250c for supplying gas is provided at the end of the wall of the buffer chamber 237 adjacent to the wafer 200. The gas supply hole 250c opens toward the center of the reaction tube 203. The gas supply holes 250c are provided in plurality from the lower part to the upper part of the reaction tube 203, each having the same opening area, and further provided at the same opening pitch.

[0045] The nozzle 249b is provided at the end of the buffer chamber 237 on the opposite side to the end where the gas supply hole 250c is provided, so as to stand up from the bottom to the top of the inner wall of the reaction tube 203 toward the loading direction of the wafer 200. The nozzle 249b is configured as an L-shaped long nozzle. A gas supply hole 250b for supplying gas is provided on the side of the nozzle 249b. The gas supply hole 250b opens toward the center of the buffer chamber 237. The gas supply holes 250b are provided in plurality from the bottom to the top of the reaction tube 203, similarly to the gas supply holes 250c of the buffer chamber 237.

[0046] With respect to the respective opening areas of the plurality of gas supply holes 250b, when the pressure difference between the buffer chamber 237 and the processing chamber 201 is small, the same opening spacing can be formed with the same opening area from the upstream side (lower part) to the downstream side (upper part); and when the pressure difference is large, the opening area can be increased or the opening spacing can be decreased from the upstream side to the downstream side.

[0047] By adjusting the opening area and the opening pitch of the gas supply holes 250b of the nozzle 249b from the upstream side to the downstream side as described above, first, the gas with substantially equal flow rates is ejected from each of the gas supply holes 250b, although there is a flow rate difference. Furthermore, the gas ejected from each of the gas supply holes 250b is temporarily introduced into the buffer chamber 237, so that the flow rate difference of the gas can be made uniform in the buffer chamber 237.

[0048] The gases ejected from the gas supply holes 250b of the nozzle 249b into the buffer chamber 237 have their particle speeds moderated in the buffer chamber 237 before being ejected from the gas supply holes 250c of the buffer chamber 237 into the processing chamber 201. Thus, the gases ejected from the gas supply holes 250b of the second nozzle 249b into the buffer chamber 237 have uniform flow rates and flow speeds when ejected from the gas supply holes 250c of the buffer chamber 237 into the processing chamber 201.

[0049] Thus, in this embodiment, the gas is transported through the nozzles 249a, 249b and the buffer chamber 237 arranged in the annular longitudinal space defined by the inner wall of the reaction tube 203 and the ends of the plurality of wafers 200 loaded, that is, arranged in the cylindrical space.

[0050] Then, gas is ejected into the processing chamber 201 from the gas supply holes 250a to 250c opened in the nozzles 249a and 249b and the buffer chamber 237 respectively, near the wafer 200. In addition, the main flow of the gas in the processing chamber 201 is parallel to the surface of the wafer 200, that is, in the horizontal direction. The residual gas after the reaction flowing on the surface of the wafer 200 flows toward the exhaust pipe 231 described later. However, the flow direction of the residual gas is appropriately determined according to the position of the exhaust port.

[0051] (Processing Gas) A gas containing silicon (Si) (silicon-containing gas), for example, is supplied from the gas supply pipe 232a into the processing chamber 201 via the MFC 241a, the valve 243a, the storage portion 240a, the valve 242a, and the nozzle 249a.

[0052] (Reaction gas) A gas (nitrogen-containing gas) containing nitrogen (N), for example, is supplied from the gas supply pipe 232b through the MFC 241b, the valve 243b, and the nozzle 249b into the processing chamber 201. The reaction gas has a different molecular structure (chemical structure) from the processing gas.

[0053] Inert gas is supplied from gas supply pipes 232c and 232d into the processing chamber 201 via MFCs 241c and 241d, valves 243c and 243d, gas supply pipes 232a and 232b, and nozzles 249a and 249b. The inert gas functions as a purge gas, a carrier gas, a dilution gas, and the like.

[0054] The gas supply pipe 232a, the MFC 241a, the valve 243a, the storage unit 240a, and the valve 242a constitute a processing gas supply system.

[0055] The gas supply pipe 232 b , the MFC 241 b , and the valve 243 b constitute a reaction gas supply system.

[0056] The gas supply pipes 232c and 232d, the MFCs 241c and 241d, and the valves 243c and 243d constitute an inert gas supply system.

[0057] like Figure 2 As shown, in the buffer chamber 237, two rod-shaped electrodes 269 and 270 having a long and thin structure are arranged from the bottom to the top of the reaction tube 203 along the stacking direction of the wafer 200. Each of the rod-shaped electrodes 269 and 270 is arranged in parallel with the nozzle 249b. Each of the rod-shaped electrodes 269 and 270 is protected by being covered by an electrode protection tube 275 from the top to the bottom. One of the rod-shaped electrodes 269 and 270 is connected to a high-frequency power supply 273 via a matching device 272, and the other is connected to a ground wire as a reference potential. By applying high-frequency (RF) power from the high-frequency power supply 273 to between the rod-shaped electrodes 269 and 270 via the matching device 272, plasma is generated in a plasma generation region 224 between the rod-shaped electrodes 269 and 270. The rod-shaped electrodes 269 and 270 and the electrode protection tube 275 constitute a plasma source as a plasma generator (plasma generation unit). It is also possible to include the matching device 272 and the high frequency power supply 273 in the plasma source. As described later, the plasma source functions as an activation mechanism (excitation unit) that activates (excites) the gas into a plasma state. It should be noted that the plasma generating unit may not be provided when the gas is not activated into a plasma state.

[0058] The electrode protection tube 275 is structured so that the rod-shaped electrodes 269 and 270 can be inserted into the buffer chamber 237 in a state of being isolated from the atmosphere in the buffer chamber 237. If the oxygen concentration inside the electrode protection tube 275 is about the same as the oxygen concentration of the outside air (atmosphere), the rod-shaped electrodes 269 and 270 respectively inserted into the electrode protection tube 275 are oxidized by the heat of the heater 207. By pre-filling the inside of the electrode protection tube 275 with an inert gas such as nitrogen (N2) gas, or by using an inert gas purge mechanism to purge the inside of the electrode protection tube 275 with an inert gas such as nitrogen (N2) gas, the oxygen concentration inside the electrode protection tube 275 can be reduced, thereby preventing the oxidation of the rod-shaped electrodes 269 and 270.

[0059] An exhaust pipe 231 for exhausting the atmosphere in the processing chamber 201 is connected to the reaction tube 203. One end of the exhaust pipe 231 is connected to the exhaust port at the lower end of the processing chamber 201. In addition, the exhaust pipe 231 is connected to a vacuum pump 246 as an exhaust device via a pressure sensor 245 as a pressure detector (pressure detection unit) for detecting the pressure in the processing chamber 201, an APC (Auto Pressure Controller) as an exhaust valve (pressure regulating unit), and a valve 244. The APC valve 244 is a valve configured as follows, that is, by opening and closing the valve in a state where the vacuum pump 246 is operated, the exhaust and exhaust stop in the processing chamber 201 can be performed, and further, in a state where the vacuum pump 246 is operated, the valve opening is adjusted based on the pressure information detected by the pressure sensor 245, so that the pressure in the processing chamber 201 can be adjusted. The exhaust system is mainly composed of the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. It should be noted that it is also conceivable to include the vacuum pump 246 in the exhaust system. The exhaust pipe 231 is not limited to being provided on the reaction tube 203, and may be provided on the manifold 209 similarly to the nozzles 249a and 294b.

[0060] A sealing cover 219 is provided below the manifold 209 as a furnace port cover capable of hermetically closing the lower end opening of the manifold 209 .

[0061] The sealing cover 219 is configured to abut against the lower end of the manifold 209 from the lower side in the vertical direction. An O-ring 220b as a sealing member abutting against the lower end of the manifold 209 is provided on the upper surface of the sealing cover 219. The rotating shaft 255 of the rotating mechanism 267 passes through the sealing cover 219 and is connected to the wafer boat 217 described later. The rotating mechanism 267 is configured to rotate the wafer 200 by rotating the wafer boat 217. The sealing cover 219 is configured to be lifted and lowered in the vertical direction by the wafer boat elevator 115 as a lifting mechanism vertically provided outside the reaction tube 203. The wafer boat elevator 115 is configured to move the wafer boat 217 into and out of the processing chamber 201 by lifting and lowering the sealing cover 219. The wafer boat elevator 115 is configured as a conveying device (conveying mechanism) that conveys the wafer boat 217 and the wafer 200 supported on the wafer boat 217 into and out of the processing chamber 201.

[0062] The wafer boat 217 as a substrate holder is configured to support a plurality of wafers 200, for example, 25 to 200 wafers 200, arranged in a horizontal position and in a state where the centers are aligned with each other in a vertical direction in multiple layers. The wafer boat 217 is made of a heat-resistant material such as quartz or SiC. A heat insulating member 218 made of a heat-resistant material such as quartz or SiC is provided at the bottom of the wafer boat 217, and is configured to prevent heat from the heater 207 from being easily transferred to the sealing cover 219 side.

[0063] A temperature sensor 263 as a temperature detector is provided in the processing chamber 201. The temperature in the processing chamber 201 is configured to have a desired temperature distribution 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 configured to be L-shaped like the nozzles 249a and 249b, and is provided along the inner wall of the reaction tube 203.

[0064] like Figure 3 As shown, the controller 121 as a control unit (control unit) is configured as a computer having a CPU (Central Processing Unit; Central Processing Unit) 121a, a RAM (Random Access Memory; 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. The controller 121 is connected to an input / output device 122 configured as a touch panel or the like.

[0065] The storage device 121c is composed of, for example, a flash memory, a HDD (Hard Disk Drive), etc. A control program for controlling the operation of the substrate processing device, a process recipe recording the steps and conditions of substrate processing such as film formation described later, etc. are stored in the storage device 121c in a readable manner. The RAM 121b is configured as a memory area (work area) for temporarily holding programs, data, etc. read by the CPU 121a.

[0066] The I / O port 121d is connected to the above-mentioned MFC241a~241d, valves 242a, 243a~243d, storage unit 240a, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotating mechanism 267, wafer boat elevator 115, matcher 272, high-frequency power supply 273, etc.

[0067] The CPU 121a is configured to read the control program from the storage device 121c and execute it, and read the process recipe from the storage device 121c according to the input of the operation command from the input / output device 122. The CPU 121a is configured to control the flow rate adjustment operation of various gases by the MFCs 241a to 241d, the opening and closing operation of the valves 242a, 243a to 243d, the storage operation of the processing gas by the storage unit 240a, the opening and closing operation of the APC valve 244 and the pressure adjustment operation of the APC valve 244 by the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment operation of the heater 207 by the temperature sensor 263, the rotation and rotation speed adjustment operation of the wafer boat 217 by the rotation mechanism 267, the lifting operation of the wafer boat 217 by the wafer boat elevator 115, the impedance adjustment operation by the matching unit 272, the power supply of the high frequency power supply 273, etc. in a manner according to the content of the read process recipe. Here, the process recipe is a combination of steps in a substrate processing step such as a film formation step described later that causes the controller 121 to execute so as to obtain a predetermined result, and functions as a program.

[0068] The controller 121 is not limited to being configured as a dedicated computer, but may also be configured as a general-purpose computer. For example, an external storage device (e.g., a semiconductor memory such as a USB memory, a memory card, etc.) 123 storing the above-mentioned program is prepared, and the program is installed on a general-purpose computer using the external storage device 123, so that the controller 121 of the present embodiment can be configured. However, the means for supplying the program to the computer is not limited to the case where it is supplied via the external storage device 123. For example, a communication unit such as the Internet or a dedicated line may also be used to supply the program without passing through the external storage device 123. The storage device 121c and the external storage device 123 are configured as a computer-readable recording medium. Hereinafter, they are collectively referred to as recording media. When the term recording medium is used in the present invention, sometimes only the storage device 121c is included alone, sometimes only the external storage device 123 is included alone, or sometimes both are included. It should be noted that the program may also be provided to the computer using a communication unit such as the Internet or a dedicated line instead of the external storage device 123.

[0069] <Substrate processing step>

[0070] As one of the steps in the manufacturing process of a semiconductor device (ie, a substrate processing method according to the present invention), referring to Figure 4 An example of a process of forming a thin film on the wafer 200 will be described. In the following description, the operations of the various components constituting the substrate processing apparatus are controlled by the controller 121.

[0071] In the substrate processing method (semiconductor device manufacturing method) of the present invention, a layer containing Si-Si bonds and Si is formed on the chip 200 by performing (a) a process of supplying a decomposable processing gas containing silicon to the chip 200 to form a layer containing Si-Si-Si bonds on the chip 200 and (b) a process of supplying a reaction gas to the chip 200 to dissociate the Si-Si-Si bonds.

[0072] It is presumed that the charge trapping characteristics of the layer formed on the wafer 200 are improved by the above-mentioned substrate processing method (semiconductor device manufacturing method) because the amount of Si-Si bonds (N deficiencies) contained in the layer can be easily controlled.

[0073] That is, in the step (a), a layer including Si-Si-Si bonds (Si substitution) which are the basis for the generation of N defects is formed.

[0074] Then, in step (b), the dissociation of Si-Si-Si bonds is adjusted by supplying a reaction gas, thereby controlling the amount of Si-Si bonds (N deficiency).

[0075] When the term "wafer" is used in the present invention, it may refer to "the wafer itself" or "a laminate of a wafer and a predetermined layer or film formed on the surface thereof". When the term "surface of a wafer" is used in the present invention, it may refer to "the surface of the wafer itself" or "the surface of a predetermined layer or film formed on the wafer". In the present invention, when the term "substrate" is used, it has the same meaning as when the term "wafer" is used.

[0076] In the present invention, Figure 5 As shown in FIG. 1 , “Si—Si—Si bond” means that three or more silicon atoms are directly bonded to one silicon atom.

[0077] Figure 5 "X" in represents each independently one selected from the group consisting of a hydrogen atom, an alkyl group, an amine, a halogen atom and a dangling bond (unbonded).

[0078] In the present invention, "Si-Si-Si bond" may also be expressed as "Si substitution (Si dB defect (Si dangling bond defect))".

[0079] In the present invention, Figure 5 As shown in FIG. 1 , “Si—Si bond” means that one silicon atom is directly bonded to one silicon atom.

[0080] Figure 5 The "X" in is the same as above.

[0081] In addition, in the present invention, "Si-Si bond" may be expressed as "N defect (Si-H defect)".

[0082] In the present invention, "-Si-" means that a silicon atom is not directly bonded to a silicon atom. Figure 5 As shown, X is bonded to Si.

[0083] In the present invention, "processing temperature" refers to the temperature of the wafer 200 or the temperature in the processing chamber 201, and "processing pressure" refers to the pressure in the processing chamber 201. In addition, "processing time" refers to the time during which the processing is continued.

[0084] (Wafer filling and wafer boat loading)

[0085] When a plurality of wafers 200 are loaded (wafer filling) in the wafer boat 217, the wafer boat 217 is lifted by the wafer boat elevator 115 and carried (wafer loading) into the processing chamber 201. At this time, the sealing cap 219 is in a state of hermetically closing (sealing) the lower end of the reaction tube 203 via the O-ring 220b.

[0086] (Pressure regulation and temperature regulation)

[0087] The vacuum pump 246 performs vacuum exhaust (decompression exhaust) to make the space in the processing chamber 201, that is, the space where the wafer 200 exists, to have a desired pressure (vacuum degree). At this time, the pressure of the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled (pressure regulated) based on the measured pressure information. The vacuum pump 246 is always operated until at least the processing of the wafer 200 is completed.

[0088] The wafer 200 in the processing chamber 201 is heated by the heater 207 to a predetermined temperature. At this time, the amount of current supplied to the heater 207 is feedback-controlled (temperature-regulated) based on the temperature information detected by the temperature sensor 263 so that the processing chamber 201 reaches the predetermined temperature. The heating in the processing chamber 201 by the heater 207 is continuously performed at least until the processing of the wafer 200 is completed.

[0089] (Film forming treatment)

[0090] In the film forming process, the following steps 1 and 2 are performed in sequence.

[0091] [Process 1]

[0092] This process includes (a) supplying a processing gas containing silicon-degradable properties (hereinafter referred to as "processing gas") to the chip 200 to form a layer having Si-Si-Si bonds, and may also include a process of removing (exhausting) residual gas in the processing chamber 201.

[0093] Specifically, valve 243a is opened to allow the processing gas to flow in the gas supply pipe 232a. For the processing gas, flow management is performed by MFC241a, and the processing gas stored in the storage portion 240a is flash-supplied to the processing chamber 201 from the gas supply hole 250a of the nozzle 249a, and exhausted from the exhaust pipe 231. It should be noted that in this process, the processing gas may not be stored in the storage portion 240a, but the processing gas may be directly supplied to the processing chamber 201 (non-flash supply). At this time, valve 243c is opened at the same time to allow inactive gases such as nitrogen (N2) to flow into the gas supply pipe 232c. The inactive gas flowing in the gas supply pipe 232c is flow-regulated by MFC241c. The flow-regulated inactive gas is supplied to the processing chamber 201 together with the processing gas and discharged from the exhaust pipe 231.

[0094] The processing conditions of this step when the Si-containing gas of the present invention is used as the processing gas can be exemplified as follows:

[0095] Treatment temperature: 500-1000°C, preferably 600-800°C, more preferably 650-750°C Treatment pressure: 1-2666Pa, preferably 10-1333Pa

[0096] Processing gas supply flow rate: 1-2000sccm, preferably 10-1000sccm

[0097] Processing gas supply time: 1 to 120 seconds, preferably 1 to 60 seconds.

[0098] It should be noted that the expression of a numerical range such as "500-1000°C" in the present invention means that the lower limit and the upper limit are included in the range. Therefore, for example, "500-1000°C" means "above 500°C and below 1000°C". The same applies to other numerical ranges. In addition, the processing temperature in the present invention refers to the temperature of the wafer 200 or the temperature in the processing chamber 201, and the processing pressure refers to the pressure in the processing chamber 201. In addition, when the supply flow rate includes 0 sccm, 0 sccm means a case where the gas is not supplied. These are also the same in the following descriptions.

[0099] The above (a) is preferably performed under conditions where decomposition of the processing gas is suppressed, thereby reducing the amount of Si substitution and improving the charge trapping characteristics.

[0100] Conditions under which the decomposition of the processing gas is suppressed include, for example: (1) the temperature of the chip 200 is below the decomposition temperature of the processing gas (preferably lower than the decomposition temperature of the processing gas); (2) the flow rate of the processing gas is faster than the flow rate of the reaction gas described later; and (3) the passage time of the processing gas in the processing chamber 201 (the space where the chip 200 exists, the space on the chip 200) is shorter than the decomposition time of the processing gas.

[0101] In the present invention, “decomposition of the processing gas is suppressed” means that dissociation (cutting) of Si—Si—Si bonds is suppressed.

[0102] As for the above (1), for example, when the Si-containing gas of the present invention is used as the processing gas (decomposition temperature: varies depending on the gas used, preferably 300° C., for example), the temperature of the wafer 200 is preferably set to a temperature lower than the decomposition temperature of the processing gas used. Thus, the uniformity of the film formed on the wafer 200 is improved.

[0103] As for the above (2), for example, when the flow rate of the processing gas is set to 0.5 to 30 m / s, the flow rate of the reaction gas is preferably set to 0.1 to 3.0 m / s, and more preferably to 0.5 to 1.5 m / s.

[0104] The supply of the reaction gas is preferably carried out by the above-mentioned flash supply. As a result, the time that the reaction gas exists in the processing chamber 201 can be reduced, and the decomposition of the processing gas caused by heat or the like can be suppressed. By suppressing the decomposition of the processing gas, the amount of Si substitution can be reduced. It should be noted that when processing at such a flow rate, it is not necessary to set the temperature of the wafer 200 to a temperature lower than the decomposition temperature of the processing gas, and the processing can also be carried out at a temperature above the decomposition temperature. The temperature of the wafer 200 higher than the decomposition temperature is, for example, in the range of 500 to 800°C, more preferably in the range of 600 to 800°C, and further preferably in the range of 650 to 750°C. By setting it to such a temperature range, the reactivity of the reaction gas can be improved while suppressing the decomposition of the processing gas, and the characteristics of the film formed on the wafer 200 can be improved. It should be noted that the temperature above the decomposition temperature includes the same temperature as the decomposition temperature and the temperature higher than the decomposition temperature.

[0105] As for the above (3), for example, when the Si-containing gas of the present invention is used as the processing gas, the time for passing through the processing chamber 201 is preferably in the range of 0.01 to 0.5 seconds, and more preferably in the range of 0.05 to 0.1 seconds. This can suppress the decomposition of the processing gas and reduce the amount of Si substitution.

[0106] In the present invention, it is also preferable to carry out (a) under the condition that the processing gas is decomposed, thereby increasing the amount of Si substitution and increasing the amount of N deficiency caused by the supply of the reaction gas.

[0107] As a condition for decomposing the processing gas, for example, the pressure applied to the processing gas is higher than the pressure applied to the reaction gas.

[0108] Specifically, when the pressure applied to the reaction gas is 1 to 1333 Pa, the pressure applied to the process gas is 10 to 2666 Pa.

[0109] After the layer containing Si-Si-Si bonds is formed on the wafer 200, the valve 243a is closed to stop the supply of the processing gas. Then, the processing chamber 201 is evacuated to remove the processing gas remaining in the processing chamber 201 that has not reacted or has contributed to the formation of the layer containing Si-Si-Si bonds from the processing chamber 201. At this time, the valve 243e is kept open to maintain the supply of the inactive gas to the processing chamber 201. Thus, the effect of removing (purging) the processing gas remaining in the processing chamber 201 that has not reacted or has contributed to the formation of the layer containing Si-Si-Si bonds from the processing chamber 201 can be improved.

[0110] The processing conditions of this step when using N2 gas as the inert gas can be exemplified as follows:

[0111] Inert gas supply flow rate: 100-1000 sccm, preferably 300-500 sccm

[0112] Inert gas supply time: 1 to 60 seconds, preferably 2 to 20 seconds.

[0113] The other processing conditions are the same as those during the supply of the processing gas in this step.

[0114] Examples of the process gas containing decomposability of silicon in the present invention include inorganic process gases and organic process gases.

[0115] Examples of inorganic processing gases include halogen-containing silicon-based gases such as dichlorosilane (H2SiCl2) gas, hexachlorodisilane (Si2Cl6, abbreviated as HCDS) gas, and tetrachlorosilane (SiCl4) gas, and halogen-free silicon-based gases such as SiH4, Si2H6, and Si3H8.

[0116] As organic processing gases, for example, there can be mentioned: aminosilane-based tetrakisdimethylaminosilane (Si(N(CH3)2))4) gas, trisdimethylaminosilane (Si(N(CH3)2))3H) gas, bisdiethylaminosilane (Si(N(C2H5)2)2H2) gas, and bis-tert-butylaminosilane (SiH2(NH(C4H9))2) gas.

[0117] As the processing gas, one of these may be used alone, or two or more of them may be used in combination.

[0118] Among them, from the viewpoint of the ease of forming a layer containing Si-Si-Si bonds, inorganic processing gases such as HCDS gas, Si2H6 gas, Si2I6 gas, Si2Br6 gas having Si-Si bonds, and organic processing gases such as SiH2(NH(C4H9))2 gas having Si-Si bonds are preferred.

[0119] By supplying the Si-containing gas of the present invention to the wafer 200 under the conditions of the present invention, a layer including Si—Si—Si bonds can be formed on the wafer 200 .

[0120] The formation mechanism of the layer including Si-Si-Si bonds is not clear, but is presumed as follows.

[0121] First, the Si-Si bonds of the gas molecules having Si-Si bonds supplied into the processing chamber 201 are cut. By cutting the Si-Si bonds, SiR X ("X" is an integer greater than 1, indicating a gas smaller than R contained in the raw material.) X By using other SiR X The Si-Si-Si bonds are bonded to form Si-Si-Si bonds. It is speculated that the Si-Si-Si bonds are physically adsorbed and / or chemically adsorbed on the wafer 200 to form a layer containing Si-Si-Si bonds. It should be noted that, here, R is a ligand contained in the Si raw material of the present invention. For example, it is hydrogen (H), chlorine (Cl), amino, alkylamino, etc. In the case where the processing gas is HCDS, for example, R is Cl, X is an integer from 1 to 3, and SiR X SiCl X .

[0122] As the inert gas, for example, rare gases such as nitrogen (N2), argon (Ar), helium (He), neon (Ne), and xenon (Xe) can be used. The inert gas can be used alone or in combination of two or more. This also applies to each step described later.

[0123] [Process 2]

[0124] After step 1, this step includes (b) supplying a reaction gas to the wafer 200 to dissociate Si-Si-Si bonds in a layer including Si-Si-Si bonds formed on the wafer 200. In addition, it is preferable to include a step of removing (exhausting) residual gas in the processing chamber 201.

[0125] Thereby, a layer including Si—Si bonds generated by dissociation of Si—Si—Si bonds and Si can be formed.

[0126] Specifically, valve 243b is opened to allow the reaction gas to flow into the gas supply pipe 232b. The reaction gas is flow-regulated by MFC241b. The reaction gas with the regulated flow rate is supplied from nozzle 249b to the buffer chamber 237. At this time, high-frequency power is applied between the first rod-shaped electrode 269 and the second rod-shaped electrode 270 from the high-frequency power supply 273 via the matching device 272, so that the reaction gas supplied to the buffer chamber 237 is excited by plasma, and is supplied to the processing chamber 201 from the gas supply hole 250c as an active species and is discharged from the gas exhaust pipe 231. At this time, valve 243d is opened at the same time to allow the inactive gas to flow in the inactive gas supply pipe 232d. The inactive gas is supplied to the processing chamber 201 together with the reaction gas and is discharged from the gas exhaust pipe 231.

[0127] The treatment conditions of this step include:

[0128] Treatment temperature: 500-1000°C, preferably 600-800°C, more preferably 650-750°C Treatment pressure: 1-4000 Pa, preferably 10-10000 Pa

[0129] Reaction gas supply flow rate: 10-10000sccm, preferably 100-5000sccm

[0130] Reaction gas supply time: 1 to 120 seconds, preferably 10 to 60 seconds

[0131] High frequency power applied between the rod-shaped electrodes: 0~1000W.

[0132] In addition, when the reaction gas is supplied, plasma excitation is not performed, and the APC valve 244 is appropriately adjusted to set the pressure in the processing chamber 201 to a pressure in the range of, for example, 50 to 3000 Pa, thereby activating the reaction gas thermally in a non-plasma manner. It should be noted that, in comparison, when the reaction gas is activated by heat and supplied, a gentle reaction can be generated, and the nitridation described later can be performed gently. It should be noted that, when the reaction gas is not plasma excited, a configuration for generating plasma may not be provided in the substrate processing apparatus.

[0133] Then, the valve 243b of the supply pipe 232b is closed to stop the supply of the reaction gas. At this time, the APC valve 244 of the gas exhaust pipe 231 remains open, and the processing chamber 201 is vacuum-exhausted by the vacuum pump 246 to remove the reaction gas remaining in the processing chamber 201 from the processing chamber 201. It should be noted that at this time, the valve 243d remains open to maintain the supply of the inert gas to the processing chamber 201. As a result, the effect of removing (purging) the reaction gas remaining in the processing chamber 201 from the processing chamber 201 can be improved.

[0134] The processing conditions of this step when using N2 gas as the inert gas can be exemplified as follows:

[0135] Inert gas supply flow rate: 100-1000 sccm, preferably 300-500 sccm

[0136] Inert gas supply time: 1 to 60 seconds, preferably 2 to 20 seconds.

[0137] As the reaction gas of the present invention, for example, there can be mentioned: a gas containing nitrogen element (N) and hydrogen element (H). It should be noted that a gas containing N and deuterium (D) can also be used instead of a gas containing N and H. As these gases, for example, there can be mentioned: N2 gas + H2 gas; ammonia (NH3) gas, diazine (N2H2) gas, hydrazine (N2H4) gas, N3H8 gas, ND3 gas and other hydrogen nitride gas. These reaction gases can be used alone or in combination of two or more.

[0138] It should be noted that the description of two gases such as "N2 gas + H2 gas" in the present invention refers to a mixed gas of H2 gas and N2 gas. When supplying a mixed gas, the two gases can be mixed (pre-mixed) in a supply pipe and then supplied to the processing chamber 201, or the two gases can be supplied to the processing chamber 201 from different supply pipes to mix (post-mixed) in the processing chamber 201.

[0139] Among them, from the viewpoint of increasing the amount of N deficiency, it is preferred to use N2 gas + H2 gas; NH3 gas, N2H2 gas, N2H4 gas, N3H8 gas, ND3 gas and other hydrogen nitride-based gases.

[0140] A layer including Si-Si bonds and Si is formed by supplying the reaction gas of the present invention to the wafer 200. In addition, Si and Si in the Si-Si bonds in the layer partially react with the reaction gas and are nitrided to form a silicon nitride layer (SiN layer).

[0141] The mechanism of formation of the layer including the above-mentioned Si-Si bonds and Si is not yet clear, but is presumed as follows.

[0142] The nitrogen atoms in the reaction gas enter between the Si-Si-Si bonds of the layer having Si-Si-Si bonds formed in step (a). As a result, it is estimated that the Si-Si-Si bonds are dissociated into Si-Si bonds and Si, and are modified into a layer containing Si-Si bonds and Si.

[0143] Preferably, Si in the Si-Si bond dissociated into Si-Si bond and Si by the reaction gas is bonded to the nitrogen element.

[0144] It is preferred that Si is bonded to the nitrogen element and to other ligands.

[0145] As the element to which Si and Si are bonded in the Si-Si bond, nitrogen is particularly preferred. Thus, at least a portion of the layer including Si-Si bonds and Si formed on the wafer 200 can be modified (nitrided) to form a SiN layer. In addition, the amount of N defects can be increased, and the charge trapping characteristics can be improved.

[0146] As the above-mentioned other ligands, each independently is at least one of a hydrogen atom, an alkyl group, an amine, a halogen atom, and a dangling bond (not bonded), etc. The other ligands may also include elements contained in the molecules of the raw material gas, ligands contained in the molecules of the raw material gas, and dangling bonds not bonded to them.

[0147] (Implementation of the prescribed number of times)

[0148] The cycle including the above steps 1 and 2 may be performed a predetermined number of times (n times, where n is an integer greater than 1 or 2). From the viewpoint of being able to easily adjust the refractive index, thickness and / or composition of the layer formed on the surface of the wafer 200, the above cycle is preferably performed a plurality of times.

[0149] When the cycle including step 1 and step 2 is performed a predetermined number of times, supply conditions of the processing gas and the reaction gas are preferably set based on the refractive index (RI) of the layer and the amount of Si-Si-Si bonds in the layer.

[0150] Furthermore, when a cycle including step 1 and step 2 is performed a predetermined number of times, the supply conditions of the processing gas and the reaction gas are more preferably set based on the RI of the layer, the amount of Si-Si-Si bonds in the layer, and the amount of Si-Si bonds in the layer (N deficiency amount). Thus, the charge trapping characteristics can be easily controlled.

[0151] When setting the supply conditions of the processing gas and the reaction gas, the RI of the layer formed on the surface of the wafer 200 is preferably 2.0 to 2.10, and more preferably 2.02 to 2.07. By setting the RI of the layer to 2.0 to 2.10, the required characteristics of the semiconductor device can be satisfied.

[0152] When the RI of the layer is less than 2.0, the amount of N defects decreases and the charge trapping characteristics deteriorate. When the RI of the layer is greater than 2.10, the leakage current may increase due to the increase in the amount of Si substitution, and the required characteristics of the semiconductor device may not be satisfied.

[0153] The RI of a layer can be measured using, for example, an apparatus such as a spectroscopic ellipsometer.

[0154] In addition, it is preferred to set either or both of the supply conditions of the processing gas and the supply conditions of the reaction gas based on the relationship between the Si substitution amount and the N defect amount of the layer formed on the surface of the wafer 200. Here, the so-called relationship between the Si substitution amount and the N defect amount refers to the relationship represented by a graph with the horizontal axis being the Si substitution amount and the vertical axis being the N defect amount. Preferably, the Si substitution amount is less than 1E+18 and the N defect amount is greater than 2.5E+18. By setting it to this range, the required characteristics of the semiconductor device can be met. It is more preferred to set the supply conditions in a manner such that the Si substitution amount is less than 5E+17 and the N defect amount is greater than 3.0E+18. It is more preferred to set the supply conditions in a manner such that the Si substitution amount is less than 1E+17 and the N defect amount is greater than 3.5E+18. When the Si substitution amount is greater than 1E+18, there is a situation where the leakage current increases, and sometimes it becomes impossible to meet the required characteristics of the semiconductor device. When the amount of N defects is less than 2.5E+18, the charge trapping characteristics may be reduced, and the required characteristics of the semiconductor device may not be satisfied. It should be noted that, as for the amount of Si substitution, the smaller the amount, the lower the leakage current can be, but it is preferably adjusted in such a way that it falls within the above-mentioned RI range. In addition, as for the amount of N defects, the larger the amount, the greater the charge trapping amount can be, but it is preferably adjusted in such a way that it falls within the above-mentioned RI range.

[0155] The Si substitution amount and the N deficiency amount can be calculated from the amount of dangling bonds contained in the layer using, for example, an ESR (Electron Spin Resonance) method.

[0156] (Purge and atmospheric pressure recovery)

[0157] After the film formation on the wafer 200 is completed, an inert gas is supplied into the processing chamber 201 and exhausted from the exhaust pipe 231. The inert gas acts as a purge gas, and thus the processing chamber 201 is purged with the inert gas, and the gas and reaction by-products remaining in the processing chamber 201 are removed (purged) from the processing chamber 201. Then, 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 recovery).

[0158] (Wafer boat unloading and wafer removal)

[0159] The sealing cover 219 is lowered by the wafer boat elevator 115 to open the lower end of the reaction tube 203. Then, the processed wafer 200 is carried out (wafer boat unloading) to the outside of the reaction tube 203 while being supported on the wafer boat 217. After the processed wafer 200 is carried out to the outside of the reaction tube 203, it is taken out from the wafer boat 217 (wafer taking out).

[0160] <Other Implementation Methods>

[0161] The embodiments of the present invention have been specifically described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

[0162] For example, as described above, a series of processes may be performed continuously (in-situ) in the same processing chamber (processing container) 201. In addition, at least one of the above-mentioned processes may be performed ex-situ in different processing chambers (processing containers). In either case, the same effect as the above-mentioned method can be obtained. It should be noted that when the above-mentioned processes are performed in-situ, contamination of the wafer 200, changes in the surface state of the wafer 200, etc. that may be caused by the wafer 200 being carried out of or into the processing room during the process can be suppressed. In addition, when these processes are performed in-situ, the migration time between processes can be shortened. On the other hand, when these processes are performed ex-situ, each process can be performed in parallel in different processing chambers, which can improve productivity.

[0163] In the above-mentioned method, an example of forming a film using a batch-type substrate processing device that processes a plurality of substrates at a time is described. The present invention is not limited to the above-mentioned method, and for example, it can also be appropriately applied to a case where a film is formed using a single-sheet substrate processing device that processes one or more substrates at a time. In addition, in the above-mentioned method, an example of forming a film using a substrate processing device having a hot-wall type processing furnace is described. The present invention is not limited to the above-mentioned method, and it can also be appropriately applied to a case where a film is formed using a substrate processing device having a cold-wall type processing furnace.

[0164] When these substrate processing apparatuses are used, each process can be performed with the same processing steps and processing conditions as those of the above-mentioned embodiment and modified example, and the same effects as those of the above-mentioned embodiment and modified example can be obtained.

Claims

1. A substrate processing method, comprising: (a) supplying a processing gas containing silicon decomposition properties to a substrate to form a layer containing Si-Si-Si bonds on the substrate; and (b) A step of supplying a reaction gas to the substrate to dissociate the Si-Si-Si bonds.

2. The substrate processing method according to claim 1, wherein: The process gas is a process gas having a Si-Si bond.

3. The substrate processing method according to claim 1, wherein: In (b), the Si-Si-Si bond is dissociated into a Si-Si bond and -Si-, A layer including the Si-Si bonds and the -Si- is formed.

4. The substrate processing method according to claim 1 or 3, wherein: The reaction gas is a gas containing nitrogen and hydrogen elements.

5. The substrate processing method according to claim 3, wherein: The reaction gas is a gas containing nitrogen element, In (b), Si in the Si-Si bond in the layer including the Si-Si bond and the -Si- is bonded to a nitrogen element, The Si is bonded to the nitrogen element and other ligands.

6. The substrate processing method according to claim 1, wherein: (a) is performed under conditions that suppress decomposition of the treatment gas.

7. The substrate processing method according to claim 1, wherein: (a) is performed under the condition that the temperature of the substrate is lower than the decomposition temperature of the processing gas.

8. The substrate processing method according to claim 1, wherein: (a) is performed under the condition that the flow rate of the processing gas is faster than the flow rate of the reaction gas.

9. The substrate processing method according to claim 1, wherein: (a) is performed under the condition that the time for the process gas to pass through the space where the substrate exists is shorter than the time for the process gas to decompose.

10. The substrate processing method according to claim 1, wherein: (a) is carried out under conditions where the treatment gas decomposes.

11. The substrate processing method according to claim 1, wherein: (a) is performed under the condition that the pressure in the space where the substrate exists is higher than the pressure in the space where the substrate exists when (b) is performed.

12. The substrate processing method according to claim 1, wherein: (c) (a) and (b) are performed a predetermined number of times to form a layer containing Si on the substrate.

13. The substrate processing method according to claim 12, wherein: Supply conditions of the processing gas and the reaction gas are set based on the refractive index of the layer and the amount of Si-Si bonds in the layer.

14. The substrate processing method according to claim 12, wherein: Supply conditions of the processing gas and the reaction gas are set based on the refractive index of the layer, the amount of Si-Si-Si bonds in the layer, and the amount of Si-Si bonds in the layer.

15. The substrate processing method according to claim 14, wherein: Supply conditions of the processing gas and the reaction gas are set so that the amount of Si-Si-Si bonds in the layer is 1E+18 or less and the amount of Si-Si bonds in the layer is 2.5E+18 or more.

16. The substrate processing method according to claim 13, wherein: Supply conditions of the processing gas and the reaction gas are set so that the refractive index of the layer becomes 2.0 to 2.

10.

17. The substrate processing method according to claim 13, wherein: Supply conditions of the processing gas and the reaction gas are set so that the refractive index of the layer is 2.02 to 2.

07.

18. A method for manufacturing a semiconductor device, comprising: (a) supplying a processing gas containing silicon decomposition properties to a substrate to form a layer containing Si-Si-Si bonds on the substrate; and (b) A step of supplying a reaction gas to the substrate to dissociate the Si-Si-Si bonds.

19. A computer-readable recording medium having a program recorded thereon for causing a substrate processing apparatus to execute the following steps via a computer: (a) supplying a silicon-decomposable processing gas to a substrate to form a layer containing Si-Si-Si bonds on the substrate; and (b) A step of supplying a reaction gas to the substrate to dissociate the Si-Si-Si bonds.

20. A substrate processing device comprising: a process gas supply system for supplying a process gas containing a decomposable property of silicon to the substrate; a reaction gas supply system that supplies a reaction gas to the substrate; and A control unit is configured to control the following processes: (a) supplying a processing gas containing silicon decomposition properties to a substrate to form a layer containing Si-Si-Si bonds on the substrate; and (b) supplying a reaction gas to the substrate to dissociate the Si-Si-Si bonds.

Images