Substrate processing method, method for producing semiconductor device, program, and substrate processing device

Abstract

A method according to the present invention includes: (a) a step for setting the supply amount of a modifier on the basis of a relationship between the supply amount of the modifier and the characteristic of saturated adsorption of a raw material to a substrate; and (b) a step for supplying the modifier to the substrate on the basis of the set supply amount.

Description

SUBSTRATE PROCESSING METHOD, SEMICONDUCTOR DEVICE MANUFACTURING METHOD, PROGRAM, AND SUBSTRATE PROCESSING METHOD

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

[0002] 2. Description of the Related Art One step in the manufacturing process of a semiconductor device is a substrate processing step in which a source gas and a reactive gas are supplied to a substrate to form a film on the substrate (see, for example, Patent Document 1).

[0003] JP 2014-135475 A

[0004] The present disclosure provides a technique that can improve the properties of a film formed on a substrate.

[0005] According to one aspect of the present disclosure, there is provided a technique comprising: (a) setting a supply amount of a modifier based on a relationship between the supply amount of the modifier and saturated adsorption characteristics of a raw material on a substrate; and (b) supplying the modifier to the substrate based on the set supply amount.

[0006] According to the present disclosure, it is possible to provide a technique that can improve the properties of a film formed on a substrate.

[0007] FIG. 1 is a longitudinal cross-sectional view showing an outline of a vertical processing furnace of a substrate processing apparatus 10 suitable for use in one embodiment of the present disclosure. FIG. 2 is a schematic configuration diagram of the vertical processing furnace of a substrate processing apparatus 10 suitable for use in one embodiment of the present disclosure, showing the processing furnace 202 portion in a cross-sectional view taken along line A-A in FIG. 1. FIG. 3 is a schematic configuration diagram of a controller 121 of a substrate processing apparatus suitable for use in one embodiment of the present disclosure, showing a control system of the controller 121 in a block diagram. FIG. 4 is a diagram showing an example of a processing sequence in one embodiment of the present disclosure. FIG. 5 is a diagram showing the relationship between the supply amount of a modifier and the adsorption characteristics of a raw material in one embodiment of the present disclosure. FIG. 6 is a diagram showing the relationship between the supply amount of a modifier and the saturated adsorption amount of a raw material in one embodiment of the present disclosure.

[0008] <One Aspect of the Present Disclosure> One aspect of the present disclosure will be described below with reference to Figures 1 to 6. Note that all drawings used in the following description are schematic, and the dimensional relationships between elements, the ratios of elements, and the like shown in the drawings do not necessarily match those in reality. Furthermore, the dimensional relationships between elements, the ratios of elements, and the like do not necessarily match between multiple drawings.

[0009] (1) Configuration of the Substrate Processing Apparatus The substrate processing apparatus 10 includes a processing furnace 202 provided with a heater 207 as a heating means (heating mechanism, heating system). The heater 207 has a cylindrical shape and is installed vertically by being supported by a heater base (not shown) as a holding plate.

[0010] An outer tube 203 constituting a reaction tube (reaction vessel, processing vessel) is disposed concentrically inside the heater 207. The outer tube 203 is made of a heat-resistant material such as stone or silicon carbide (SiC) and has a cylindrical shape with a closed upper end and an open lower end. A manifold 209 is disposed concentrically below the outer tube 203. The manifold 209 is made of a metal such as stainless steel and has a cylindrical shape with open upper and lower ends. An O-ring 220a is provided as a sealing member between the upper end of the manifold 209 and the outer tube 203. The manifold 209 is supported by a heater base, so that the outer tube 203 is installed vertically.

[0011] An inner tube 204 that constitutes a reaction vessel is disposed inside the outer tube 203. The inner tube 204 is made of a heat-resistant material such as quartz or SiC, and is formed in a cylindrical shape with a closed upper end and an open lower end. The outer tube 203, the inner tube 204, and the manifold 209 mainly constitute a processing vessel (reaction vessel). A processing chamber 201 is formed in the cylindrical hollow portion of the processing vessel (inside the inner tube 204).

[0012] The processing chamber 201 is configured to accommodate wafers 200 as substrates arranged in multiple stages in the vertical direction in a horizontal position on boats 217 as supports.

[0013] Nozzles 410, 420, and 430 are provided in the processing chamber 201 so as to penetrate the sidewall of the manifold 209 and the inner tube 204. Gas supply pipes 310, 320, and 330 are connected to the nozzles 410, 420, and 430, respectively. However, the processing furnace 202 of this embodiment is not limited to the above-mentioned configuration.

[0014] Mass flow controllers (MFCs) 312, 322, and 332, which are flow rate controllers (flow rate control parts), are respectively provided on the gas supply pipes 310, 320, and 330 in this order from the upstream side. Also, valves 314, 324, and 334, which are on-off valves, are respectively provided on the gas supply pipes 310, 320, and 330. Gas supply pipes 510, 520, and 530, which supply inert gas, are connected to the downstream sides of the valves 314, 324, and 334 of the gas supply pipes 310, 320, and 330, respectively. The gas supply pipes 510, 520, and 530, which are on-off valves, are respectively provided on the gas supply pipes 510, 520, and 530 in this order from the upstream side. MFCs 512, 522, and 532, which are flow rate controllers (flow rate control parts), and valves 514, 524, and 534, which are on-off valves, are respectively provided.

[0015] Nozzles 410, 420, and 430 are connected to the tips of the gas supply pipes 310, 320, and 330, respectively. The nozzles 410, 420, and 430 are configured as L-shaped nozzles, and their horizontal portions are provided so as to penetrate the side wall of the manifold 209 and the inner tube 204. The vertical portions of the nozzles 410, 420, and 430 are provided inside the channel-shaped (groove-shaped) pre-chamber 201a, which protrudes radially outward from the inner tube 204 and extends vertically. The vertical portions of the nozzles 410, 420, and 430 are provided inside the pre-chamber 201a, facing upward (upward in the arrangement direction of the wafers 200) along the inner wall of the inner tube 204.

[0016] The nozzles 410, 420, and 430 are provided to extend from a lower region of the processing chamber 201 to an upper region of the processing chamber 201. A plurality of gas supply holes 410a, 420a, and 430a are provided in the nozzles 410, 420, and 430 at positions facing the wafer 200. Thus, processing gas is supplied to the wafer 200 from the gas supply holes 410a, 420a, and 430a of the nozzles 410, 420, and 430, respectively. The gas supply holes 410a, 420a, and 430a are provided in plurality from the lower portion to the upper portion of the inner tube 204. The gas supply holes 410a, 420a, and 430a each have the same opening area. The gas supply holes 410a, 420a, and 430a are arranged at the same pitch. However, the gas supply holes 410a, 420a, and 430a are not limited to the above-described configuration. For example, the opening areas of the gas supply holes 410 a, 420 a, and 430 a may be gradually increased from the bottom to the top of the inner tube 204. This makes it possible to more uniform the flow rates of gas supplied to the wafer 200 from the gas supply holes 410 a, 420 a, and 430 a.

[0017] The gas supply holes 410a, 420a, 430a of the nozzles 410, 420, 430 are provided in plurality from the bottom to the top of the boat 217. Therefore, the process gas supplied into the process chamber 201 from the gas supply holes 410a, 420a, 430a of the nozzles 410, 420, 430 is supplied to the entire area of ​​the wafers 200 accommodated from the bottom to the top of the boat 217. The nozzles 410, 420, 430 may be provided so as to extend from the bottom region to the top region of the process chamber 201, but are preferably provided so as to extend to near the ceiling of the boat 217.

[0018] From the gas supply pipe 310, a raw material is supplied as a processing gas into the processing chamber 201 via an MFC 312, a valve 314, and a nozzle 410. In this disclosure, the raw material is also referred to as a raw material agent, a source, or a precursor.

[0019] A reactant is supplied as a processing gas from the gas supply pipe 320 into the processing chamber 201 via the MFC 322, the valve 324, and the nozzle 420. In this disclosure, the reactant is also referred to as a reactant or a reactant.

[0020] A process gas, namely, a modifier, which is different from a reactant and inhibits adsorption of elements contained in the raw material, is supplied from the gas supply pipe 330 into the process chamber 201 via the MFC 332, the valve 334, and the nozzle 430. In the present disclosure, the modifier is also referred to as an adjuster, an adsorption suppressant, a reaction inhibitor, or a surface adjuster.

[0021] In this disclosure, the term "agent" as used herein includes at least one of a gaseous substance and a liquid substance. Liquid substances include mist-like substances. That is, a modifying agent may contain a gaseous substance, a liquid substance such as a mist-like substance, or both. Furthermore, when a gaseous substance is contained, it can be referred to as a source gas, a reaction gas, or a modifying gas, respectively.

[0022] From the gas supply pipes 510, 520, and 530, an inert gas such as nitrogen (N ２ ) gases are supplied into the processing chamber 201 via MFCs 512, 522, and 532, valves 514, 524, and 534, and nozzles 410, 420, and 430, respectively. ２ An example using gas will be described. As an inert gas, N ２ In addition to gas, for example, a rare gas such as argon (Ar) gas, helium gas, neon gas, or xenon gas may be used.

[0023] When a raw material is flowed from the gas supply pipe 310, a raw material supply system (first gas supply system) is mainly composed of the gas supply pipe 310, the MFC 312, and the valve 314, but the nozzle 410 may be considered to be included in the raw material supply system. When a reactant is flowed from the gas supply pipe 320, a reactant supply system (third gas supply system) is mainly composed of the gas supply pipe 320, the MFC 322, and the valve 324, but the nozzle 420 may be considered to be included in the reactant supply system. When a modifying agent is flowed from the gas supply pipe 330, a modifying agent supply system (second gas supply system) is mainly composed of the gas supply pipe 330, the MFC 332, and the valve 334, but the nozzle 430 may be considered to be included in the modifying agent supply system. The raw material supply system, the reactant supply system, and the modifying agent supply system may also be referred to as a process gas supply system. The process gas supply system may include the nozzles 410, 420, and 430. The gas supply pipes 510, 520, and 530, the MFCs 512, 522, and 532, and the valves 514, 524, and 534 mainly constitute an inert gas supply system.

[0024] The gas supply pipe 310 may be provided with a reservoir 701 for storing the processing gas, and a valve 702 at the downstream side (processing chamber 201 ) of the reservoir 701 .

[0025] In this embodiment, gas is delivered into inner tube 204 via nozzles 410, 420, and 430 disposed in preliminary chamber 201a, which is an annular, vertically elongated space defined by the inner wall of inner tube 204 and the ends of multiple wafers 200. Gas is then ejected into inner tube 204 from multiple gas supply holes 410a, 420a, and 430a provided in nozzles 410, 420, and 430 at positions facing wafers 200. More specifically, raw material and the like are ejected in a direction parallel to the surfaces of wafers 200 from gas supply hole 410a of nozzle 410, gas supply hole 420a of nozzle 420, and gas supply hole 430a of nozzle 430.

[0026] The exhaust hole (exhaust port) 204a is a through-hole formed in the sidewall of the inner tube 204 at a position facing the nozzles 410, 420, and 430, and is, for example, a slit-shaped through-hole that is elongated in the vertical direction. Gas is supplied into the processing chamber 201 from the gas supply holes 410a, 420a, and 430a of the nozzles 410, 420, and 430 and flows over the surface of the wafer 200. The gas flows through the exhaust hole 204a into the gap (into the exhaust path 206) formed between the inner tube 204 and the outer tube 203. The gas that flows into the exhaust path 206 then flows into the exhaust pipe 231 and is discharged to the outside of the processing furnace 202.

[0027] The exhaust hole 204a is provided at a position facing the plurality of wafers 200. The gas supplied from the gas supply holes 410a, 420a, and 430a to the vicinity of the wafers 200 in the processing chamber 201 flows horizontally and then flows into the exhaust path 206 through the exhaust hole 204a. The exhaust hole 204a is not limited to being configured as a slit-shaped through-hole, and may be configured as a plurality of holes.

[0028] An exhaust pipe 231 for exhausting the atmosphere inside the processing chamber 201 is connected to an exhaust port 231a provided in the manifold 209. The exhaust pipe 231 is connected to, in order from upstream, a pressure sensor 245 serving as a pressure detector (pressure detection unit) for detecting the pressure inside the processing chamber 201, an APC (Auto Pressure Controller) valve 243, and a vacuum pump 246 serving as a vacuum exhaust device. The APC valve 243 can evacuate and stop the evacuation of the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating. Furthermore, the APC valve 243 can adjust the pressure inside the processing chamber 201 by adjusting the valve opening while the vacuum pump 246 is operating. An exhaust system is mainly composed of the exhaust port 204a, the exhaust path 206, the exhaust pipe 231, the APC valve 243, and the pressure sensor 245. The vacuum pump 246 may be included in the exhaust system.

[0029] 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. A rotation mechanism 267 is provided on the opposite side of the seal cap 219 from the process chamber 201 to rotate a boat 217 that accommodates wafers 200. 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 boat 217 to rotate the wafers 200. The seal cap 219 is configured to be raised and lowered in the vertical direction by a boat elevator 115 serving as an elevating mechanism installed vertically outside the outer tube 203. The boat elevator 115 is configured to be able to load and unload the boat 217 into and out of the processing chamber 201 by lifting and lowering the seal cap 219. The boat elevator 115 is configured as a transfer device (transfer mechanism, transfer system) that transfers the boat 217 and the wafers 200 accommodated in the boat 217 into and out of the processing chamber 201.

[0030] The boat 217 is configured to hold multiple wafers 200, for example, 25 to 200, arranged horizontally and with their centers aligned and spaced apart in the vertical direction. The boat 217 is made of a heat-resistant material such as quartz or SiC. Dummy substrates 218, also made of a heat-resistant material such as quartz or SiC, are supported horizontally 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 the above. For example, instead of providing the dummy substrates 218 at the bottom of the boat 217, a heat insulating cylinder, which is a cylindrical member made of a heat-resistant material such as quartz or SiC, may be provided.

[0031] 2, a temperature sensor 263 serving as a temperature detector is installed inside the inner tube 204. The substrate processing apparatus 10 is configured to adjust the amount of power supplied to the heater 207 based on temperature information detected by the temperature sensor 263, thereby achieving a desired temperature distribution inside the processing chamber 201. The temperature sensor 263 is configured in an L-shape, similar to the nozzles 410, 420, and 430, and is provided along the inner wall of the inner tube 204.

[0032] As shown in FIG. 3 , the controller 121, which is a control unit (control means), 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 connected to the CPU 121a via an internal bus so as to be able to exchange data. An input / output device 122, such as a touch panel, is connected to the controller 121. The substrate processing apparatus may be configured to include one or more control units. That is, control for performing the processing sequence described below may be performed using one control unit or multiple control units. Furthermore, the multiple control units may be configured as a control system connected to each other via a wired or wireless communication network, and control for performing the processing sequence described below may be performed by the entire control system. In this specification, when the term "control unit" is used, it may include one control unit, multiple control units, or a control system configured by multiple control units.

[0033] The storage device 121c is composed of, for example, a flash memory or an HDD (Hard Disk Drive). A control program for controlling the operation of the substrate processing apparatus and a process recipe describing the procedures and conditions of a semiconductor device manufacturing method (substrate processing method) described later are readably recorded and stored in the storage device 121c. The process recipe is a combination of processes (steps) in a semiconductor device manufacturing method (substrate processing method) described later that are executed by the controller 121 to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe and the control program are collectively referred to simply as a program. In this specification, the term "program" may refer to a process recipe alone, a control program alone, or a combination of a process recipe and a control program. The RAM 121b is configured as a memory area for temporarily storing programs, data, etc. read by the CPU 121a.

[0034] The I / O port 121d is connected to the above-mentioned MFCs 312, 322, 332, 512, 522, 532, valves 314, 324, 334, 514, 524, 534, 702, pressure sensor 245, APC valve 243, vacuum pump 246, heater 207, temperature sensor 263, rotation mechanism 267, boat elevator 115, etc.

[0035] The CPU 121 a is configured to read and execute a control program from the storage device 121 c, and also to read a process recipe or the like from the storage device 121 c in response to an input of an operation command from the input / output device 122 or the like. The CPU 121a is configured to be able to control, in accordance with the contents of the read process recipe, the flow rate adjustment operation of various gases by the MFCs 312, 322, 332, 512, 522, and 532, the opening and closing operation of the valves 314, 324, 334, 514, 524, 534, and 702, the gas storage operation in the storage section 701 by the valve 702, the opening and closing operation of the APC valve 243, the pressure adjustment operation by the APC valve 243 based on the pressure sensor 245, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the start and stop of the vacuum pump 246, the rotation and rotation speed adjustment operation of the boat 217 by the rotation mechanism 267, the raising and lowering operation of the boat 217 by the boat elevator 115, and the operation of storing the wafers 200 in the boat 217.

[0036] The controller 121 can be configured by installing the above-mentioned program recorded and stored in an external storage device 123 (for example, a magnetic disk such as a hard disk, an optical disk such as a CD or DVD, or a semiconductor memory such as a USB memory or a memory card) 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 simply as recording media. In this specification, the recording medium may include only the storage device 121c, only the external storage device 123, or both the storage device 121c and the external storage device 123. The program (program product) 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.

[0037] (2) Substrate Processing Step As one step in the manufacturing process of a semiconductor device, an example of a processing sequence for forming a silicon nitride (SiN) film, which is used as a charge trap film for 3D NAND, on a wafer 200 as a substrate will be described mainly with reference to FIGS. 4 and 5 . The above-described processing sequence example is performed using the processing furnace 202 of the substrate processing apparatus 10 described above. Note that in this embodiment, an example will be described in which the wafer 200 is a silicon substrate (silicon wafer) having recesses such as trenches and holes formed in its surface. In the following description, the operation of each component constituting the substrate processing apparatus 10 is controlled by a controller 121.

[0038] The processing sequence in this embodiment includes the following steps: (a) Step A: setting the supply amount of the modifier based on the relationship between the supply amount of the modifier and the saturated adsorption characteristics of the raw material on the wafer 200; and (b) Step B: supplying the modifier to the wafer 200 based on the set supply amount.

[0039] In this embodiment, an example is described in which, after performing step B, there is further included step C of (c) supplying a raw material to the wafer 200, and, after performing step C, there is further included step D of (d) supplying a reactant to the wafer 200.

[0040] 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, film, etc. formed on the wafer." In this specification, the term "substrate" is synonymous with the term "wafer."

[0041] 1, the boat 217 supporting the wafers 200 is lifted by the boat elevator 115 and loaded into the processing chamber 201. The boat 217 supporting the wafers 200 is then housed in the processing vessel. In this state, the seal cap 219 closes the lower end opening of the outer tube 203 via the O-ring 220.

[0042] (Pressure Regulation and Temperature Regulation) The processing chamber 201 is evacuated by the vacuum pump 246 so that the processing chamber 201, i.e., the space in which the wafer 200 is present, reaches a desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by the pressure sensor 245. Then, based on the pressure information measured by the pressure sensor 245, the APC valve 243 is feedback-controlled (pressure regulation). The vacuum pump 246 remains in a constantly operating state at least until the processing of the wafer 200 is completed. Furthermore, the processing chamber 201 is heated by the heater 207 so that the processing chamber 201 reaches a desired temperature. At this time, the amount of power supplied to the heater 207 is feedback-controlled based on temperature information detected by the temperature sensor 263 so that the processing chamber 201 achieves a desired temperature distribution (temperature regulation). Heating of the processing chamber 201 by the heater 207 continues at least until the processing of the wafer 200 is completed.

[0043] (Step A: Setting the Modifier Supply Amount) Next, the modifier supply amount (exposure amount) is set. First, the controller 121 reads data from the storage device 121c regarding the relationship between the modifier supply amount and the saturated adsorption characteristics of the source material to the wafers 200. Based on this data, the modifier supply amount to be supplied to the wafers 200 is set in step B, which will be described later. The modifier supply amount is set based on a predetermined cycle rate of the desired source material. This setting may be performed by an operator of the processing apparatus, or may be set via a network from a higher-level device (HOST), another device, or another terminal. The saturated adsorption characteristics of the source material refer to characteristics related to changes in the amount of adsorption of the source material to the wafers 200. Specifically, when the source material is supplied to the wafers 200, the adsorption amount of the source material increases as the source supply amount is increased until the adsorption amount of the source material reaches a predetermined critical value. After the adsorption amount of the source material reaches the predetermined critical value, the adsorption amount of the source material does not change (increase) even if the source supply amount is increased. Hereinafter, this critical value is also referred to as the saturated adsorption amount. If the modifying agent is supplied before the raw material is supplied, some of the molecules of the modifying agent are adsorbed onto the surface of the wafer 200, and the adsorption sites for the raw material are reduced, so the saturated adsorption amount of the raw material is reduced.

[0044] The above-mentioned data is data such as that shown in FIG. 5. FIG. 5 shows the relationship between the supply amount of the modifier and the adsorption characteristics of the source material. The horizontal axis of FIG. 5 represents the supply amount of the source material per cycle, and the vertical axis represents the cycle rate (thickness of the layer formed per cycle), which essentially represents the amount of source material adsorbed to the wafer 200 per cycle. Furthermore, M0, M1, M2, and M3 in FIG. 5 represent whether or not a modifier is supplied before the source material is supplied, and the supply amount of the modifier if supplied. M0 represents the case where the supply amount of the modifier is 0 (zero), i.e., the case where no modifier is supplied. M1, M2, and M3 represent the supply amount of the modifier when the modifier is supplied, and the supply amounts of the modifier are in the relationship M1<M2<M3. The curves shown near M0, M1, M2, and M3 represent the adsorption characteristics of the source material. Specifically, the curve corresponding to M0 indicates that the amount of raw material adsorbed to wafer 200 continues to increase as the raw material supply rate increases, i.e., the raw material adsorption rate is not saturated but unsaturated. The curves corresponding to M1, M2, and M3 indicate that the amount of raw material adsorbed to wafer 200 increases as the raw material supply rate increases until the raw material adsorption rate reaches points t1, t2, and t3, respectively. Furthermore, the curves corresponding to M1, M2, and M3 indicate that when the raw material adsorption rate reaches points t1, t2, and t3, the raw material adsorption rate saturates and does not change even if the raw material supply rate is increased. In other words, the curves corresponding to M1, M2, and M3 indicate the saturated adsorption characteristics of the raw material.

[0045] The curves corresponding to M1 to M3 also show that by increasing the supply rate of the modifier, the amount of raw material supplied can be reduced until the point t1 to t3 at which the amount of raw material adsorption saturates is reached. Specifically, in the curve corresponding to M3, the amount of raw material supplied until the point t3 at which the amount of raw material adsorption saturates is reached is less than the amount of raw material supplied until the point t2 at which the amount of raw material adsorption saturates is reached in the curve corresponding to M2. The curves corresponding to M1 to M3 also show that by increasing (decreasing) the supply rate of the modifier, the amount of raw material adsorbed to the wafer 200 per cycle decreases (increases). Note that, hereinafter, the points t1 to t3 at which the amount of raw material adsorption saturates may be referred to as saturation points t1 to t3.

[0046] 6 shows the relationship between the amount of modifier supplied and the saturated adsorption amount of raw material. In FIG. 6, the horizontal axis represents the amount of modifier supplied, and the vertical axis represents the saturation cycle rate, which is essentially the saturated adsorption amount of raw material per cycle. As shown in FIG. 6, the saturated adsorption amount of raw material per cycle can be reduced by increasing the amount of modifier supplied.

[0047] From the above, "setting the supply amount of the modifier based on the relationship between the supply amount of the modifier and the saturated adsorption characteristic of the raw material to the wafer 200" means, for example, that when it is desired to exhibit the characteristic that the adsorption amount of the raw material becomes saturated at the saturation point t2 in step C, the supply amount of the modifier is set to M2 based on the relationship shown in FIG.

[0048] The supply amount of the modifier set in this step is preferably an amount that allows the raw material to exhibit saturation adsorption characteristics, that is, an amount that allows the raw material to be saturated in the amount of adsorption onto the wafer 200. To ensure that this characteristic is exhibited, it is preferable to supply the raw material under conditions that do not cause the raw material to decompose in step C described below, or to use a material that does not cause deposition of the raw material due to physical adsorption.

[0049] The supply amount (exposure amount) of the modifier can be set by at least one of the supply flow rate of the modifier, the supply time of the modifier, and the treatment pressure (partial pressure) when the modifier is supplied. The supply amount of the modifier is preferably set by the supply flow rate of the modifier and the treatment pressure when the modifier is supplied. Also, it is preferably set by the supply flow rate of the modifier and the supply time of the modifier.

[0050] (Modifying Agent Supply Process: Step B) The controller 121 opens the valve 334 to flow the modifying agent into the gas supply pipe 330. The flow rate of the modifying agent is adjusted by the MFC 332 based on the flow rate setting set in step A, and then the modifying agent is supplied into the processing chamber 201 from the gas supply holes 430a of the nozzle 430. The modifying agent supplied into the processing chamber 201 is exhausted from the exhaust pipe 231. At this time, the modifying agent is supplied to the wafer 200. At this time, the controller 121 opens the valve 534 to supply N 2 into the gas supply pipe 530. ２ An inert gas such as N gas may be flowed through the gas supply pipe 530. ２ The gas is supplied into the processing chamber 201 together with the modifying agent after the flow rate is adjusted by the MFC 532. ２ The gas is exhausted from the exhaust pipe 231. At this time, in order to prevent the modifying agent from entering the nozzles 410 and 420, the controller 121 opens the valves 514 and 524 to supply N 2 into the gas supply pipes 510 and 520. ２ Gas may be flowed. ２ Gas is supplied into the processing chamber 201 through gas supply pipes 310 and 320 and nozzles 410 and 420 and is exhausted from an exhaust pipe 231 .

[0051] At this time, the controller 121 adjusts the APC valve 243 based on the setting of the supply rate of the modifying agent set in step A to set the pressure (process pressure) in the process chamber 201 to, for example, 1,000 Pa within a range of 1 to 3,990 Pa. The supply flow rate of the modifying agent controlled by the MFC 332 is, for example, within a range of 0.005 to 5.0 slm. The supply time of the modifying agent is, for example, 10 to 120 seconds. Here, the controller 121 adjusts the pressure in the process chamber 201 and the supply flow rate and supply time of the modifying agent into the process chamber 201 so that the exposure amount of the modifying agent to the wafer 200 becomes a first exposure amount. Note that the first exposure amount in the present disclosure is calculated, for example, by multiplying the partial pressure of the modifying agent in the process chamber 201 by the supply time of the modifying agent into the process chamber 201 (partial pressure x time). The first exposure amount is less than a second exposure amount, which will be described later. N controlled by MFC 512, 522, 532 ２ The gas supply flow rates are set to, for example, a range of 0.1 to 5.0 slm. At this time, the temperature of the heater 207 is set so that the temperature of the wafer 200 is, for example, 250 to 800°C, preferably 600 to 700°C. Note that in this disclosure, the expression of a numerical range such as "1 to 3990 Pa" means that the lower limit and upper limit are included in the range. Thus, for example, "1 to 3990 Pa" means "1 Pa or more and 3990 Pa or less." The same applies to other numerical ranges. The first supply amount (exposure amount) may be the product of the supply flow rate of the modifying agent into the processing chamber 201 and the supply time (supply flow rate × supply time), the product of the total pressure in the processing chamber 201 and the supply time of the modifying agent into the processing chamber 201 (total pressure × supply time), or the product of the partial pressure (total pressure) in the processing chamber 201 and the supply flow rate and supply time of the modifying agent into the processing chamber 201 (partial pressure (total pressure) × supply flow rate × supply time). The supply flow rate of the modifying agent into the processing chamber 201 is affected by the volume of the processing container, the pattern of the recesses formed on the wafer 200, etc. Therefore, it is preferable that the first exposure amount be the product of the partial pressure in the processing chamber 201 and the supply time of the modifying agent into the processing chamber 201.

[0052] Preferably, the exposure amount of the modifying agent to the wafer 200 (first exposure amount) is an amount that causes saturated adsorption of molecules of the modifying agent on the opening side of the recess (upper side of the recess) of the wafer 200 having recesses formed on the surface thereof. In other words, the exposure amount of the modifying agent to the wafer 200 is preferably an amount that causes saturated adsorption of molecules of the modifying agent on the opening side of the recess (upper side of the recess) of the wafer 200 having recesses formed on the surface thereof.

[0053] In the present disclosure, saturation does not necessarily mean that all of the adsorption sites on the wafer 200 are filled, but rather that the adsorption sites are substantially saturated. In other words, to improve productivity, a state that is not completely saturated is also acceptable, in other words, a state in which the reaction has not completely converged. For example, a state that is not completely saturated on the curves corresponding to M1, M2, and M3 described above may also be referred to as saturated adsorption in the present disclosure. A supply time on one of the above curves can achieve at least one of the effects of the present disclosure. Setting the supply time within a supply time range in which such a curve is obtained can also be referred to as supply utilizing saturated adsorption characteristics.

[0054] The modifying agent supplied to the wafer 200 is, for example, a halogen-containing agent. The halogen-containing agent is a substance containing at least one of Group 17 elements. Examples of such substances include hydrogen halide agents such as hydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen bromide (HBr), and hydrogen iodide (HI). The modifying agent may also be a substance composed of a halogen element, such as fluorine (F ２ ), chlorine (Cl ２ ), bromine (Br ２ ), and iodine (I ２ ) and the modifier may be nitrogen trifluoride (NF ３ ), and chlorine trifluoride (ClF ３) may be a substance containing two types of halogen elements. Preferably, the halogen element contains the same type of element as the halogen element contained in the raw material. Preferably, a highly polarizable substance is used as the modifier. Such a highly polarizable substance is, for example, a hydrogen halide, specifically HCl. Molecules of such a highly polarizable substance are easily adsorbed to the wafer 200. Furthermore, a highly polarizable substance can suppress the adsorption of the raw material itself, as described below, as well as the adsorption of decomposition products (decomposition products) generated by the decomposition of the raw material. When the adsorption to the wafer 200 is not taken into consideration, it is preferable to use a modifier containing Cl. ２ A substance such as the following can be used. ２ Although Cl has a smaller polarizability than the hydrogen halide, its molecular size is larger than that of the hydrogen halide. ２ The large molecular size of the SiO2 has the effect of preventing the adsorption of raw material molecules and decomposition products generated by the decomposition of the raw material. In other words, the adsorption inhibitors act as steric hindrance. The decomposition products of the raw material may be generated on the surface of the wafer 200 or in the space above the wafer 200.

[0055] By supplying such a modifying agent to the wafer 200, adsorption inhibitors are formed on the surface of the wafer 200. The adsorption inhibitors are molecules containing halogen elements or halogen elements themselves.

[0056] Furthermore, by exposing (supplying) the modifying agent to the wafer 200 at the first exposure amount, it is possible to adsorb the modifying agent molecules or a portion of the modifying agent molecules to the upper side of the recess formed on the surface of the wafer 200.

[0057] The modifier is not limited to the inorganic substances described above, but may be an organic modifier. An organic modifier is, for example, a substance containing an alkyl group (alkyl ligand). An example of the alkyl group is a methyl group. Methyl groups are electrically negative and repel negative source molecules, making them less likely to bond with the source molecules. For example, a methyl group (Me-) and a halogen (Cl-) contained in a source molecule are both electrically negative and therefore less likely to bond with each other. Here, Me means methyl. In other words, by adsorbing a substance containing an alkyl group to a specific location on the wafer 200, it is possible to prevent subsequently supplied source materials from being adsorbed to that specific location on the wafer 200. Examples of substances containing an alkyl group include hexamethyldisilazane, dimethylaminotrimethylsilane, trimethylsilanol, and triethylsilanol.

[0058] After a predetermined time has elapsed since the start of supply of the modifying agent, for example, 1 to 600 seconds, the controller 121 closes the valve 334 of the gas supply pipe 330 to stop the supply of the modifying agent. At this time, the controller 121 leaves the APC valve 243 of the exhaust pipe 231 open and causes the vacuum pump 246 to evacuate the processing chamber 201, thereby removing from the processing chamber 201 any unreacted modifying agent remaining in the processing chamber 201 or any modifying agent that has contributed to the formation of adsorption inhibitors.

[0059] (Source Material Supply Process: Step C) The controller 121 opens the valve 314 to flow the source material into the gas supply pipe 310. The source material is supplied into the processing chamber 201 from the gas supply holes 410a of the nozzle 410 after the flow rate is adjusted by the MFC 312. The source material supplied into the processing chamber 201 is exhausted from the exhaust pipe 231. In this way, the source material is supplied to the wafer 200. At this time, the controller 121 opens the valve 514 to supply N 2 into the gas supply pipe 510. ２ An inert gas such as N 2 gas is flowed through the gas supply pipe 510. ２ The gas is supplied into the processing chamber 201 together with the raw material after the flow rate is adjusted by the MFC 512. ２The gas is exhausted from the exhaust pipe 231. At this time, in order to prevent the raw material from entering the nozzles 420 and 430, the controller 121 opens the valves 524 and 534 to supply N 2 into the gas supply pipes 520 and 530. ２ Gas may be flowed. ２ The gas is supplied into the processing chamber 201 through the gas supply pipes 320 and 330 and the nozzles 420 and 430 , and then exhausted from the exhaust pipe 231 .

[0060] At this time, the controller 121 adjusts the APC valve 243 to set the pressure inside the processing chamber 201 within a range of, for example, 1 to 3990 Pa, for example, to 500 Pa. The supply flow rate of the raw material controlled by the MFC 312 is, for example, 0.1 to 5000 sccm, preferably 10 to 1000 sccm. The raw material supply time is, for example, 0.1 to 20 seconds. Here, the raw material may be supplied to the wafers 200 under conditions where the adsorption of the raw material to the wafers 200 is self-limited or non-self-limited. Supplying the raw material under conditions where the adsorption of the raw material to the wafers 200 is self-limited means supplying the raw material under conditions where the amount of adsorption of the raw material to the wafers 200 is saturated, specifically, means supplying the raw material to the wafers 200 in an amount equal to or greater than the saturated adsorption amount of the raw material. Furthermore, performing the process under conditions where the adsorption of the raw material onto the wafer 200 is non-self-limiting means performing the process under conditions where the amount of adsorption of the raw material onto the wafer 200 is unsaturated, and specifically means supplying the raw material to the wafer 200 in an amount less than the saturated adsorption amount of the raw material. The raw material supply amount is set to be less than the amount of raw material supplied when the modifying agent is not supplied in advance. As described above, by supplying the modifying agent in advance in step B, the amount of raw material required to saturate the adsorption amount can be reduced compared to when the modifying agent is not supplied in advance. Note that the raw material supply amount in the present disclosure is, for example, the product of the partial pressure of the raw material in the process chamber 201 and the time during which the raw material is supplied into the process chamber 201 (partial pressure x time). The N controlled by the MFCs 512, 522, and 532 ２The gas supply flow rates are set to, for example, a range of 0.1 to 20.0 slm. The temperature of the heater 207 is set so that the temperature of the wafer 200 is, for example, 250 to 850°C, preferably 600 to 700°C. The second exposure amount in the present disclosure may also be the product of the supply flow rate of the source material into the processing chamber 201 and the supply time (supply flow rate × supply time), the product of the total pressure in the processing chamber 201 and the supply time of the source material into the processing chamber 201 (total pressure × supply time), or the product of the partial pressure (total pressure) in the processing chamber 201, the supply flow rate of the source material into the processing chamber 201, and the supply time (partial pressure (total pressure) × supply flow rate × supply time). The supply flow rate of the source material into the processing chamber 201 is affected by the volume of the processing vessel, the pattern of the recesses formed on the wafer 200, and the like. Therefore, the second exposure amount is preferably the product of the partial pressure in the processing chamber 201 and the supply time of the source material into the processing chamber 201.

[0061] In this step, N supplied to the wafer 200 together with the raw material ２ By adjusting the supply amount of an inert gas such as a gas, the thickness of the layer formed on the wafer 200 can be adjusted by performing this step. Since the inert gas supplied in this step acts as a dilution gas for the raw material, the thickness of the layer formed on the wafer 200 can be increased by decreasing the supply amount of the inert gas. Furthermore, the thickness of the layer formed on the wafer 200 can be decreased by increasing the supply amount of the inert gas.

[0062] Furthermore, the amount of gas exposed to (supplied) the wafer 200 in this disclosure can also be rephrased as the amount of gas molecules adsorbed on the surface of the wafer 200. As described above, this amount of adsorption can be adjusted by, for example, the product (partial pressure x time) of the partial pressure of the gas (modifier or raw material) in the processing chamber 201 and the supply time of the gas (modifier or raw material) into the processing chamber 201.

[0063] In the present disclosure, the second exposure amount (adsorption amount) can be made larger than the first exposure amount (adsorption amount) by adjusting at least one of the partial pressure, total pressure, supply flow rate, and supply time related to the second exposure amount to be larger than at least one of the partial pressure, total pressure, supply flow rate, and time related to the first exposure amount.

[0064] The raw material may be stored in the storage section 701 and supplied from the storage section 701 into the processing chamber 201. When the raw material stored in the storage section 701 is supplied into the processing chamber 201, the supply time of the raw material into the processing chamber 201 may be shorter than the supply time of the modifying agent into the processing chamber 201. In this case, for example, the exposure amounts (first exposure amount and second exposure amount) of the raw material and the modifying agent are adjusted so that the product of the partial pressure (total pressure) of the raw material in the processing chamber 201 and the supply time of the raw material into the processing chamber 201 is greater than the product of the partial pressure (total pressure) of the modifying agent in the processing chamber 201 and the supply time of the modifying agent into the processing chamber 201. In the raw material supply step (third step), the raw material may be supplied into the processing chamber 201 not only once but also multiple times. When the supply of the raw material into the processing chamber 201 is performed multiple times, the supply of the raw material into the processing chamber 201 is stopped between a predetermined supply and the next supply. Furthermore, when the supply of the raw material into the processing chamber 201 is performed multiple times, the raw material stored in the storage section 701 may be supplied into the processing chamber 201 at least once. For example, when the supply of the raw material into the processing chamber 201 is performed two or more times, the raw material stored in the storage section 701 is supplied into the processing chamber 201 the first time, and the raw material is supplied into the processing chamber 201 without being stored in the storage section 701 the second time. Note that the supply of the raw material into the processing chamber 201 is stopped between the first and second times. Furthermore, the processing chamber 201 may be evacuated (reduced in pressure) in accordance with the stop of the supply of the raw material into the processing chamber 201, or an inert gas may be supplied into the processing chamber 201 in accordance with the evacuation. The supply and stop of the raw material into the processing chamber 201 is controlled by, for example, opening and closing a valve 702 .

[0065] The raw material supplied to the wafer 200 includes, for example, a main element that constitutes (is contained in) the film formed on the wafer 200. The main element is, for example, Si. For example, a silane-based gas containing Si can be used as the raw material. For example, a gas containing Si and a halogen element, i.e., a halosilane gas can be used as the silane-based gas. Examples of halogen elements include chlorine (Cl), fluorine (F), bromine (Br), and iodine (I). For example, a chlorosilane gas containing Si and Cl can be used as the halosilane gas.

[0066] The raw material is, for example, monochlorosilane (SiH ３ Cl) gas, dichlorosilane (SiH ２ Cl ２ ) gas, trichlorosilane (SiHCl ３ ) gas, tetrachlorosilane (SiCl ４ ) gas, hexachlorodisilane gas (Si ２ Cl ６ , abbreviated as HCDS) gas and octachlorotrisilane (Si ３ Cl ８ As the raw material, one or more of these can be used. Preferably, Si ２ Cl ６ and Si ３ Cl ８ Materials containing two or more atoms of Group 14 elements such as Zn, Ni, NiFe, NiAl, NiO, NiAl ...

[0067] As the raw material, in addition to chlorosilane gas, for example, tetrafluorosilane (SiF ４ ) gas, difluorosilane (SiH ２ F ２ ) gas, tetrabromosilane (SiBr ４ ) gas, dibromosilane (SiH ２ Br ２ ) gas, bromosilane gas such as tetraiodosilane (SiI４ ) gas, diiodosilane (SiH ２ I ２ As the raw material, one or more of these can be used.

[0068] In addition to these, a gas containing Si and an amino group, i.e., an aminosilane gas, can also be used as a raw material. An amino group is a monovalent functional group formed by removing hydrogen (H) from ammonia, a primary amine, or a secondary amine, and is represented by -NH ２ , -NHR, -NR ２ where R represents an alkyl group, and —NR ２ The two R's may be the same or different.

[0069] The raw material is, for example, tetrakis(dimethylamino)silane (Si[N(CH ３ ) ２ ] ４ ) gas, tris(dimethylamino)silane (Si[N(CH ３ ) ２ ] ３ H) gas, bis(diethylamino)silane (Si[N(C ２ H ５ ) ２ ] ２ H ２ ) gas, bis(tert-butylamino)silane (SiH ２ [NH(C ４ H ９ )] ２ ) gas, and (diisopropylamino)silane (SiH ３ [N(C ３ H ７ ) ２ As the raw material, one or more of these can be used.

[0070] In this disclosure, an example using HCDS gas as a source material will be described. When HCDS gas is used as a source material, a silicon (Si)-containing layer containing chlorine (Cl) of a predetermined thickness can be formed as a first layer on the top surface of the wafer 200. The Cl-containing Si-containing layer can be formed on the top surface of the wafer 200 by physical adsorption or chemical adsorption of source material molecules, physical adsorption or chemical adsorption of molecules of a substance formed by decomposition of at least a portion of the source material molecules (also referred to as a decomposition product), or deposition of Si due to thermal decomposition of the source material. In this disclosure, the decomposition product is also referred to as a ligand of the source material or a portion of the ligand of the source material. When HCDS is used as a source material, the decomposition product is, for example, SiClx, where x is 2, 3, or 4. The Cl-containing Si-containing layer can be an adsorption layer (physical adsorption layer or chemical adsorption layer) of chlorosilane gas molecules or molecules of a substance formed by decomposition of a portion of the chlorosilane gas, or a deposition layer of Cl-containing Si. When the above-described chemical adsorption layer or the above-described deposition layer is formed on the outermost surface of the wafer 200, Si contained in the chlorosilane gas is adsorbed onto the outermost surface of the wafer 200. In the present disclosure, the Si-containing layer containing Cl is also simply referred to as the Si-containing layer.

[0071] Furthermore, before the supply of HCDS gas, a modifier is supplied, and adsorption inhibitors are formed on the surface of the wafer 200 by the modifier. When HCl gas is used as the modifier, adsorption inhibitors such as HCl and Cl, which is a part of HCl, are formed on the surface of the wafer 200. Such adsorption inhibitors suppress the adsorption of HCDS gas molecules and the adsorption of SiClx. In other words, the presence of adsorption inhibitors can suppress the adsorption of some of the ligands of the raw material. Note that the structure of the molecules (atoms) that make up the adsorption inhibitors can suppress the adsorption of a specific number x of SiClx among SiClx.

[0072] (Removal of Residual Gas) After a predetermined time has elapsed since the start of the supply of raw materials, for example, 1 to 60 seconds, the controller 121 closes the valve 314 of the gas supply pipe 310 to stop the supply of raw materials. That is, the time for supplying raw materials to the wafer 200 is set to, for example, a time within a range of 1 to 60 seconds. At this time, the controller 121 leaves the APC valve 243 of the exhaust pipe 231 open and causes the vacuum pump 246 to evacuate the processing chamber 201, thereby removing any raw materials remaining in the processing chamber 201 that have not reacted or that have contributed to layer formation. That is, the controller 121 evacuates the atmosphere in the processing chamber 201. At this time, the controller 121 leaves the valves 514, 524, and 534 open and causes the N ２ The supply of gas into the processing chamber 201 may be maintained. ２ The gas acts as a gas for suppressing the intrusion of gas into each of the nozzles 410, 420, and 430, and also acts as a purge gas. ２ When the gas is supplied, it is possible to enhance the effect of removing raw materials remaining in the processing chamber 201 that have not reacted or that have contributed to layer formation from the processing chamber 201 .

[0073] (Reactant Supply: Step D) After removing the residual gas from the processing chamber 201, the controller 121 opens the valve 324 to flow the reactant into the gas supply pipe 320. The reactant is supplied into the processing chamber 201 from the gas supply hole 420a of the nozzle 420 after the flow rate is adjusted by the MFC 322. The reactant supplied into the processing chamber 201 is exhausted from the exhaust pipe 231. At this time, the reactant is supplied to the wafer 200. At this time, the controller 121 also controls the flow rate of N 2 gas into the gas supply pipes 510, 520, and 530 while keeping the valves 514, 524, and 534 open. ２ The gas supply is maintained. N2 flows through the gas supply pipes 510, 520, and 530. ２ The flow rates of the gases are adjusted by MFCs 512, 522, and 532. N ２ The gas is supplied into the processing chamber 201 together with the reactants through the gas supply pipe 320 and the nozzle 420, and then exhausted from the exhaust pipe 231. ２The gas is supplied into the processing chamber 201 through the gas supply pipe 330 and the nozzle 430, and then exhausted from the exhaust pipe 231. This prevents reactants from entering the nozzle 430. In addition, N ２ The gas is supplied into the processing chamber 201 through the gas supply pipe 310 and the nozzle 410, and then exhausted from the exhaust pipe 231. This prevents reactants from entering the nozzle 410.

[0074] At this time, the controller 121 adjusts the APC valve 243 to set the pressure inside the processing chamber 201 within a range of, for example, 1 to 13,300 Pa, for example, 5,000 Pa. The supply flow rate of the reactant controlled by the MFC 322 is set within a range of, for example, 1 to 50 slm, preferably 1 to 10 slm. The supply time of the reactant is set within a range of, for example, 1 to 120 seconds. The N controlled by the MFCs 512, 522, and 532 is set within a range of, for example, 1 to 50 slm, preferably 1 to 10 slm. ２ The supply flow rates of the gases are, for example, within a range of 0.1 to 5.0 slm. The supply amount of the reactant in the present disclosure is, for example, the product of the partial pressure of the reactant in the processing chamber 201 and the supply time of the reactant into the processing chamber 201 (partial pressure x time). The temperature of the heater 207 is set to a temperature such that the temperature of the wafer 200 is, for example, within a range of 250 to 850°C, preferably 600 to 700°C. The supply amount of the reactant in the present disclosure may also be the product of the supply flow rate of the reactant into the processing chamber 201 and the supply time (supply flow rate x supply time), the product of the total pressure in the processing chamber 201 and the supply time of the reactant into the processing chamber 201 (total pressure x supply time), or the product of the partial pressure (total pressure) in the processing chamber 201, the supply flow rate of the reactant into the processing chamber 201, and the supply time (partial pressure (total pressure) x supply flow rate x supply time). The flow rate of the reactant supplied into the processing chamber 201 is affected by the volume of the processing vessel, the pattern of the recesses formed on the wafer 200, etc. Therefore, it is preferable that the supply amount of the reactant be the product of the partial pressure in the processing chamber 201 and the supply time of the reactant into the processing chamber 201.

[0075] The amount of reactant supplied to the wafer 200 (exposure amount, adsorption amount) is preferably an amount that saturates the amount of reactant molecules adsorbed to the wafer 200. In other words, the amount of reactant supplied to the wafer 200 is preferably an amount that saturates the amount of reactant molecules adsorbed to the wafer 200.

[0076] In this step, the thickness of the layer formed on the wafer 200 can be adjusted by adjusting the supply amount of the reactants. For example, by increasing the supply amount of the reactants in this step, the thickness of the layer formed on the wafer 200 can be increased. Alternatively, by decreasing the supply amount of the reactants in this step, the thickness of the layer formed on the wafer 200 can be decreased.

[0077] The reactant supplied to the wafer 200 may be, for example, a nitrogen (N) and hydrogen (H) containing gas, which is a nitriding gas (nitriding agent). The N and H containing gas may be both an N containing gas and an H containing gas. The N and H containing gas preferably has an N-H bond.

[0078] The reactant may be, for example, ammonia (NH ３ ) gas, diazene (N ２ H ２ ) gas, hydrazine (N ２ H ４ ) gas, and N ３ H ８ A hydrogen nitride gas, such as a nitrogen-containing gas, can be used. One or more of these can be used as the reactant. When the reactant contains hydrogen, the reactant can be called a reducing agent. When the reducing agent is a gas, it can also be called a reducing gas.

[0079] In addition to these, gases containing nitrogen (N), carbon (C), and hydrogen (H) can also be used as reactants. Examples of gases containing N, C, and H include amine-based gases and organic hydrazine-based gases. The gas containing N, C, and H can be an N-containing gas, a C-containing gas, an H-containing gas, or an N- and C-containing gas.

[0080] The reactant may be, for example, monoethylamine (C ２ H ５ NH ２ ) gas, diethylamine ((C ２ H ５ ) ２ NH) gas, triethylamine ((C ２ H ５ ) ３ N) gas, and monomethylamine (CH ３ NH ２ ) gas, dimethylamine ((CH ３ ) ２ NH) gas, trimethylamine ((CH ３ ) ３ Methylamine-based gases such as monomethylhydrazine ((CH ３ ) HN ２ H ２ ) gas, dimethylhydrazine ((CH ３ ) ２ N ２ H ２ ) gas, trimethylhydrazine ((CH ３ ) ２ N ２ (CH ３ Organic hydrazine-based gases such as HCl, ...

[0081] (Removal of Residual Gas) After a predetermined time has elapsed since the start of the supply of the reactants, for example, 1 to 1200 seconds, the controller 121 closes the valve 324 of the gas supply pipe 320 to stop the supply of the reactants. Then, by a processing procedure similar to that of the second step described above, any unreacted reactants or reaction by-products remaining in the processing chamber 201 or that have contributed to the formation of a layer are removed from the processing chamber 201. That is, the controller 121 exhausts the atmosphere in the processing chamber 201.

[0082] (Performed a predetermined number of times) By performing the cycle of sequentially performing the above-described steps A, B, C, and D at least once (a predetermined number of times (n times, where n is an integer of 1 or 2 or more)), a film of the elements contained in the raw material having a predetermined thickness is formed on the wafer 200. For example, a silicon nitride film (SiN film) can be formed on the wafer 200. It is preferable to repeat the above-described cycle multiple times.

[0083] (Purge and atmospheric pressure return) The controller 121 supplies N ２ The gas is supplied into the processing chamber 201. ２ The gas is exhausted from the exhaust pipe 231. ２ The gas acts as a purge gas. As a result, the inside of the processing chamber 201 is purged with the inert gas, and gases and reaction by-products remaining in the processing chamber 201 are removed from the inside of the processing chamber 201. Thereafter, the atmosphere in the processing chamber 201 is replaced with the inert gas, and the pressure in the processing chamber 201 is returned to normal pressure (atmospheric pressure).

[0084] (Wafer Unloading) Thereafter, the seal cap 219 is lowered by the boat elevator 115 to open the lower end of the outer tube 203. Then, the processed wafers 200 are unloaded from the lower end of the outer tube 203 while being supported by the boat 217. Thereafter, the processed wafers 200 are removed from the boat 217.

[0085] (3) Effects of this Aspect According to this aspect, one or more of the following effects can be obtained.

[0086] (a) By performing steps A and B before performing step C, the source material can be more easily saturatedly adsorbed onto the wafer 200 in step C. This makes the amount of source material adsorbed uniform across the wafer surface, improving the uniformity of film thickness within the wafer surface. This also makes it possible to make film quality, such as film density, uniform across the wafer surface, thereby making the refractive index of the film within the wafer surface constant.

[0087] By performing steps A and B, a desired cycle rate (effectively the amount of raw material adsorbed to the wafer 200 per cycle) can be obtained in the next step C. For example, by supplying a modifier in step B, the cycle rate in step C can be reduced, thereby improving the step coverage and filling characteristics.

[0088] By supplying the modifying agent to the wafer 200 in step B, it is possible to prevent a large amount of raw material from being adsorbed to a specific location on the wafer 200. This prevents the film thickness at the specific location on the wafer 200 from increasing, while increasing the film thickness at other locations. Furthermore, it is possible to allow raw material molecules adsorbed to the specific location on the wafer 200 to reach other locations. In other words, it is possible to reduce the amount of raw material consumed at the specific location on the wafer 200 and increase the amount of raw material consumed at other locations on the wafer 200. Here, the specific location may be, for example, the following location: a location close to the nozzle of the wafer 200, or, if a recess is formed in the wafer 200, the upper side of the recess. When the specific location is close to the nozzle of the wafer 200, it is possible to improve the film thickness uniformity within the wafer 200 as a film characteristic. When the specific location is the upper side of the recess, it is possible to reduce the amount of raw material adsorbed (consumption) at the upper side of the recess and increase the amount of raw material adsorbed (consumption) at the bottom side of the recess. This improves the uniformity of the film thickness in the depth direction of the recess, for the film formed on the wall or bottom of the recess. That is, it improves the step coverage as a film characteristic. Here, the recess refers to a trench or a hole. The hole may also include a blind hole or a through hole.

[0089] (b) By performing steps A and B in advance, even if a raw material that easily decomposes in the gas phase, such as a raw material containing two or more Group 14 elements, is used in step C, the uniformity of the film formed on the wafer 200, particularly the step coverage of the recesses, can be improved. Raw materials that easily decompose in the gas phase include, for example, chlorosilane-based gases, specifically HCDS gas. When HCDS is used, the decomposition of HCDS produces decomposition products such as SiCl ２ and SiCl ４ Among these, SiCl ２ A CVD reaction occurs for the above. The occurrence of a CVD reaction prevents the relationship between the time the source material is supplied to the wafer 200 and the increase in the film thickness of the wafer 200 (film thickness per cycle) from becoming saturated. In other words, an unsaturated characteristic is obtained. Note that the unsaturated characteristic means that the film thickness of the wafer 200 (film thickness per cycle) does not converge to a predetermined value even if the time the source material is supplied to the wafer 200 increases. If a film is formed on the wafer 200 under conditions that result in this unsaturated characteristic, the film thickness at a specific location on the wafer 200 increases, which may result in a deterioration in the film thickness uniformity of the wafer 200. The characteristic of the film formed in the recessed portion may result in a deterioration in step coverage. According to the technology disclosed herein, in step B, by supplying a modifier to the wafer 200, this SiCl ２ It is possible to suppress the adsorption of intermediates that cause unsaturated properties such as SiCl onto the wafer 200. As a result, it is possible to improve the film thickness uniformity of the wafer 200. Furthermore, when a wafer 200 having a recess is processed, it is possible to improve the step coverage of the film formed in the recess. Among such decomposition products, SiCl ２ The amount of SiCl produced is proportional to the time that HCDS gas is supplied to the wafer 200. That is, as the time that HCDS gas is supplied to the wafer 200 increases, the amount of SiCl produced increases. ２ The amount of SiCl produced increases. ２The increase in the amount of SiCl produced is due to the fact that the residence time of HCDS molecules in the processing chamber 201 increases with the increase in the supply time of HCDS to the wafer 200. That is, when the residence time of HCDS molecules in the processing chamber 201 increases, the time for which the HCDS molecules are heated in the processing chamber 201 increases, and the number of molecules that are thermally decomposed increases. ２ The amount of SiCl produced and the amount of SiCl ２ In order to reduce the amount of adsorption, it is preferable to reduce the supply time of HCDS gas to the wafer 200. In order to reduce the supply time of HCDS gas to the wafer 200, it is preferable to use the reservoir 701 to instantaneously supply (also called flush supply) HCDS gas to the wafer 200.

[0090] (c) The amount of the modifying agent supplied in step A is set to an amount that allows the source material to exhibit saturated adsorption characteristics on the wafers 200, thereby ensuring the above-mentioned effects.

[0091] (d) By adjusting the supply amount of the modifier, it is possible to adjust the curve corresponding to the supply amount of the modifier (the curve showing the saturated adsorption characteristics of the raw material, see FIG. 5). For example, by increasing (decreasing) the supply amount of the modifier, it is possible to change the above-mentioned curve and decrease (increase) the supply amount of the raw material until the adsorption amount of the raw material reaches saturation. It is possible to shorten the supply time of the raw material. In other words, it is possible to shorten the processing time of the wafer 200, and it is possible to improve the manufacturing throughput of semiconductor devices.

[0092] (e) In step A, the supply amount of the modifier is set based on at least one of the supply flow rate of the modifier, the supply time of the modifier, and the treatment pressure during the supply of the modifier. Specifically, for example, the supply amount of the modifier is set based on the supply flow rate of the modifier and the treatment pressure during the supply of the modifier, or based on the supply flow rate of the modifier and the supply time of the modifier. By setting the supply amount of the modifier in this manner, the above-mentioned effects can be reliably obtained.

[0093] (f) By using an inorganic modifier containing a halogen element, it is possible to reduce the increase in the amount of impurities caused by the modifier in the film formed on the wafer 200. Here, impurities are elements other than the main elements constituting the film formed on the wafer 200. On the other hand, the molecular size of organic modifiers is larger than that of inorganic modifiers. Therefore, when an organic modifier is used as the modifier, the effect of the modifier acting as a steric hindrance that inhibits the adsorption of raw materials onto the wafer 200 is greater than when an inorganic modifier is used as the modifier.

[0094] (g) In step C, the above-described effect can be reliably obtained by performing the step C under the condition that the adsorption of the raw material onto the wafer 200 is self-limited. Furthermore, in the present disclosure, since steps A and B are performed before performing step C, the amount of raw material required to saturate the adsorption amount can be reduced compared to when steps A and B are not performed.

[0095] (h) In step C, at least some of the above-described effects can be obtained even when the process is performed under conditions where the adsorption of the source material onto the wafer 200 is not self-limiting. Furthermore, by performing the process under conditions where the adsorption of the source material onto the wafer 200 is self-limiting, the thickness of the layer formed on the wafer 200 can be reduced (thinned), thereby further improving the step coverage and filling characteristics.

[0096] (i) In step C, an inert gas is supplied together with the raw material, and by adjusting the supply amount of the inert gas, the thickness of the layer formed on the wafer 200 can be adjusted by performing step C. In this way, in step C, the thickness of the layer formed on the wafer 200 can be adjusted not only by the supply amount of the raw material but also by the supply amount of the inert gas supplied together with the raw material. Since the inert gas supplied in this step acts as a dilution gas for the raw material, the thickness of the layer formed on the wafer 200 can be increased by performing step C by reducing the supply amount of the inert gas. Furthermore, the thickness of the layer formed on the wafer 200 can be decreased by performing step C by increasing the supply amount of the inert gas.

[0097] (j) The above-mentioned effect can also be obtained when the raw material contains a main element contained in the film formed on the wafer 200 and a halogen element.

[0098] (k) The above-mentioned effect can be obtained when the modifier contains a halogen element, or when both the raw material and the modifier contain a halogen element.

[0099] (l) In step D, the thickness of the layer formed on the wafer 200 can be adjusted by adjusting the supply rate of the reactants. For example, by increasing the supply rate of the reactants, the thickness of the layer formed on the wafer 200 can be increased by performing step D. Alternatively, by decreasing the supply rate of the reactants, the thickness of the layer formed on the wafer 200 can be decreased by performing step D.

[0100] As described above, the modifying agent not only inhibits the adsorption of source molecules to the wafer 200, but also promotes desorption of reactants from the wafer 200. In other words, it modifies the surface condition of the wafer 200. Therefore, the modifying agent used here is also referred to as a post-treatment gas, post-treatment gas, treatment gas, modifying gas, or desorption promoting gas. Furthermore, the modifying agent used when supplying source materials according to the present disclosure can also be referred to as a pre-treatment gas, pre-treatment gas, treatment gas, or modifying gas, since it changes the surface condition (surface characteristics, adsorption characteristics) of the wafer 200.

[0101] Other Aspects of the Present Disclosure The above describes specific aspects of the present disclosure. However, the present disclosure is not limited to the above aspects and can be modified in various ways without departing from the spirit and scope of the present disclosure.

[0102] For example, in the above embodiment, a gas containing Si element is used as a raw material, but the present disclosure is not limited thereto. For example, the present disclosure may be applicable to a process using a gas containing at least one element selected from the group 13, 14, 4, 6, and 8 elements as a raw material. This embodiment also provides the same effects as the above embodiment.

[0103] In the above embodiment, a gas containing nitrogen element is used as a reactant, but the present disclosure is not limited to this. For example, an oxide film may be formed on the wafer 200 using a gas containing oxygen element as a reactant. Examples of the gas containing oxygen include oxygen (O ２ ) gas, water (H ２ O), hydrogen peroxide (H ２ O ２ ) gas, nitrous oxide (dinitrogen oxide) (N ２ O) gas, nitric oxide (NO) gas, and ozone (O ３ ) gases. Furthermore, activated or excited gases of one or more of these gases may be used as reactants. In this embodiment, the same effects as those in the above embodiment can be obtained.

[0104] Alternatively, a gas containing hydrogen may be used as a reactant to form a film containing the element as a main component on the wafer 200. Examples of the gas containing hydrogen include hydrogen (H ２ Gases composed of hydrogen elements such as silane-based gases, borane-based gases, phosphane-based gases, and germane-based gases, as well as mononuclear parent hydride gases, may be used as reactants. Examples of silane-based gases include monosilane (SiH ４ ) gas, disilane (Si ２ H ６ ) gas, and trisilane (Si ３ H ８ ) gases. Borane-based gases include monoborane (BH ３ ) gas, and diborane (B ２ H ６ ) gases. Phosphine gases include phosphine (PH ３ ) gas, and diphosphine (P ２ H ６ ) gases. Germane-based gases include monogermane (GeH ４ ) gas, digermane (Ge ２ H ６ ) gas, and trigermane (Ge ３ H ８) gas, etc. In this embodiment, the same effects as in the above embodiment can be obtained.

[0105] In the above embodiment, the reactants are supplied from the gas supply pipe 320 and the nozzle 420. However, the present disclosure is not limited to this. The reactants may be supplied from the gas supply pipe 330 and the nozzle 430 in addition to the gas supply pipe 320 and the nozzle 420. To supply the reactants in this manner, for example, a connection pipe 703 connecting the gas supply pipe 320 and the gas supply pipe 330 and a valve 704 are provided on the connection pipe 703. When the reactants are supplied from both the gas supply pipe 330 and the gas supply pipe 320, the valve 334 is closed and the valve 704 is opened. This configuration allows the reactants to be supplied from both sides of the gas supply pipe 310 and the nozzle 410 that supply the raw materials. This configuration makes it possible to uniformize the amount of reactants supplied within the surface of the wafer 200. As a result, the film thickness uniformity within the surface of the wafer 200 of the film formed on the wafer 200 can be improved. Furthermore, the film thickness uniformity within multiple recesses formed in the wafer 200 can also be improved.

[0106] In the above embodiment, the modifying agent is supplied from the gas supply pipe 330 and the nozzle 430. However, the present disclosure is not limited to this. The modifying agent may be supplied from the gas supply pipe 320 and the nozzle 420 in addition to the gas supply pipe 330 and the nozzle 430. To supply the modifying agent in this manner, for example, a connection pipe 703 connecting the gas supply pipe 320 and the gas supply pipe 330 and a valve 704 are provided on the connection pipe 703. When the modifying agent is supplied from both the gas supply pipe 330 and the gas supply pipe 320, the valve 324 is closed and the valve 704 is opened. This configuration supplies the modifying agent from both the gas supply pipe 310 and the nozzle 410 that supply the raw material. This configuration makes it possible to uniformize the amount of the modifying agent supplied within the surface of the wafer 200. As a result, the film thickness uniformity within the surface of the wafer 200 can be improved. Furthermore, the uniformity of the film thickness within the plurality of recesses formed in the wafer 200 can also be improved.

[0107] In the above-described embodiment, an example of film formation using a substrate processing apparatus that is a batch-type vertical apparatus that processes multiple substrates at a time has been described. However, the present disclosure is not limited to this and can also be suitably applied to film formation using a single-wafer substrate processing apparatus that processes one or several substrates at a time. In the above-described embodiment, an example of film formation 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 also be suitably applied to film formation using a substrate processing apparatus having a cold-wall processing furnace. When using these substrate processing apparatuses, film formation can be performed using the same sequence and processing conditions as in the above-described embodiment.

[0108] In the above-described embodiment, the processing sequence is performed in the same processing chamber of the same processing apparatus (in-situ). The present disclosure is not limited to the above-described embodiment, and for example, one step and another step of the processing sequence may be performed in different processing chambers of different processing apparatuses (ex-situ), or may be performed in different processing chambers of the same processing apparatus.

[0109] It is preferable that process recipes (programs describing processing procedures, processing conditions, etc.) used to form these various thin films are individually prepared (prepared in multiple numbers) depending on the content of substrate processing (such as the type, composition ratio, film quality, film thickness, processing procedure, or processing conditions of the thin film to be formed). Then, when starting substrate processing, it is preferable to appropriately select an appropriate process recipe from the multiple process recipes depending on the content of substrate processing. Specifically, it is preferable that the multiple process recipes individually prepared depending on the content of substrate processing are pre-stored (installed) in the storage device 121c of the substrate processing apparatus via an electric communication line or a recording medium (external storage device 123) on which the process recipes are recorded. Then, when starting substrate processing, it is preferable that the CPU 121a of the substrate processing apparatus appropriately selects an appropriate process recipe from the multiple process recipes recorded and stored in the storage device 121c depending on the content of substrate processing. This configuration makes it possible to versatilely and reproducibly form thin films of various film types, composition ratios, film qualities, and film thicknesses using a single substrate processing apparatus. Furthermore, the burden on the operator (such as the burden of inputting processing procedures and processing conditions) can be reduced, so that substrate processing can be started promptly while avoiding operational errors by the operator.

[0110] The present disclosure can also be realized, for example, by changing the process recipe of an existing substrate processing apparatus. When changing the process recipe, the process recipe according to the present disclosure can be installed in the existing substrate processing apparatus via an electric communication line or a recording medium on which the process recipe is recorded, or the process recipe itself can be changed to the process recipe according to the present disclosure by operating an input / output device of the existing substrate processing apparatus.

[0111] The above-described embodiments and modifications may be used in combination as appropriate. The processing procedures and conditions in such a case may be the same as those of the above-described embodiments and modifications.

[0112] Although the embodiments of the present disclosure have been specifically described above, the present disclosure is not limited to the above embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure.

[0113] 200...wafer (substrate)

Claims

1. A substrate processing method comprising: (a) a step of setting a supply amount of a modifier based on a relationship between the supply amount of the modifier and the saturation adsorption characteristics of a raw material on a substrate; and (b) a step of supplying the modifier to the substrate based on the set supply amount.

2. The substrate processing method according to claim 1, wherein the supply amount set in (a) is an amount that enables the source material to exhibit the saturated adsorption characteristics on the substrate.

3. The substrate processing method according to claim 2, wherein in (a), the supply amount is set by at least one of the supply flow rate of the modifying agent, the supply time of the modifying agent, and the processing pressure when the modifying agent is supplied.

4. The substrate processing method according to claim 2, wherein in (a), the supply amount is set based on the supply flow rate of the modifying agent and the processing pressure when the modifying agent is supplied.

5. The substrate processing method according to claim 1, wherein in (a), the supply amount is set based on a supply flow rate of the modifying agent and a supply time of the modifying agent.

6. The method for processing a substrate according to claim 1, further comprising the step of: (c) supplying the source material to the substrate.

7. The substrate processing method according to claim 6, wherein (c) is performed under a condition where adsorption of the source material onto the substrate is self-limiting.

8. The substrate processing method according to claim 6, wherein (c) is performed under conditions in which adsorption of the source material onto the substrate is non-self-limiting.

9. The substrate processing method according to claim 6, wherein in (c), an inert gas is supplied together with the raw material, and the amount of the inert gas supplied is adjusted to adjust the thickness of the layer formed on the substrate by performing (c).

10. The substrate processing method of claim 9, wherein in (c), the amount of the inert gas supplied is reduced, thereby increasing the thickness of the layer formed on the substrate by performing (c).

11. The substrate processing method according to claim 9, wherein in (c), the supply amount of the inert gas is increased to thereby reduce the thickness of the layer formed on the substrate.

12. The method of claim 6, further comprising the step of (d) supplying a reactant to the substrate, wherein in (d), the amount of reactant supplied is increased to thereby increase the thickness of the layer formed on the substrate by performing (d).

13. The method of claim 6, further comprising the step of: (d) supplying a reactant to the substrate, wherein in (d), a rate of supply of the reactant is decreased to thereby reduce a thickness of a layer formed on the substrate by performing (d).

14. The substrate processing method according to claim 1, wherein the source material contains a main element contained in the film formed on the substrate and a halogen element.

15. The substrate processing method according to claim 1, wherein the source material contains two or more atoms of a Group 14 element in each molecule.

16. The substrate processing method according to claim 1, wherein the modifying agent contains a halogen element.

17. The substrate processing method according to claim 1, wherein the source material and the modifier each contain a halogen element.

18. A method for manufacturing a semiconductor device, comprising: (a) a step of setting a supply amount of a modifier based on the relationship between the supply amount of the modifier and the saturation adsorption characteristics of the raw material on a substrate; and (b) a step of supplying the modifier to the substrate based on the set supply amount.

19. A program that causes a substrate processing apparatus to execute, via a computer, the steps of: (a) setting a supply amount of the modifier based on the relationship between the supply amount of the modifier and the saturated adsorption characteristics of the raw material on the substrate; and (b) supplying the modifier to the substrate based on the set supply amount.

20. A substrate processing apparatus comprising: a modifier supply system which supplies a modifier to a substrate; and a control unit configured to be capable of controlling the modifier supply system to perform the following: (a) a process for setting a supply amount of the modifier based on a relationship between the supply amount of the modifier and the saturated adsorption characteristics of the raw material on the substrate; and (b) a process for supplying the modifier to the substrate based on the set supply amount.

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