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

Abstract

To provide a technique capable of improving a characteristic of a film to be formed on a substrate.SOLUTION: A substrate processing method includes: (a) forming a layer containing a front surface terminated by an element X onto a front surface of a substrate by supplying an element X-containing gas to the substrate set at a first temperature; (b) changing a termination by the element X in the front surface of the layer to a termination of an element Y by supplying an element Y-containing gas to the substrate set at a second temperature; (c) detaching the element Y constructing the termination of the element Y in the front surface of the layer by setting the substrate at a third temperature; and (d) forming the film onto the layer from which the element Y is detached by supplying a deposition gas to the substrate set at a fourth temperature.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] BACKGROUND ART As one step in the manufacturing process of a semiconductor device, a process of forming a film on a substrate is sometimes performed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-068864 Summary of the Invention [Problem to be solved by the invention]

[0004] 2. Description of the Related Art As semiconductor devices become increasingly miniaturized, there is a strong demand for improvements in the properties of films formed on substrates.

[0005] The present disclosure provides a technique that can improve the properties of a film formed on a substrate. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, (a) supplying a gas containing element X to a substrate at a first temperature to form a layer on a surface of the substrate, the layer including a surface terminated with the element X; (b) supplying a gas containing element Y to the substrate at a second temperature to change the termination of element X on the surface of the layer to termination of element Y; (c) heating the substrate to a third temperature to desorb the element Y constituting the termination of the element Y on the surface of the layer; (d) supplying a film-forming gas to the substrate at a fourth temperature to form a film on the layer from which the element Y has been desorbed; Techniques for doing this are provided. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to improve the properties of a film formed on a substrate. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus suitably used in one embodiment of the present disclosure, showing a processing furnace 202 portion in vertical cross section. [Figure 2] FIG. 2 is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus suitably used in one embodiment of the present disclosure, and is a cross-sectional view of the processing furnace 202 taken along line AA in FIG. [Figure 3] FIG. 3 is a schematic configuration diagram of a controller 121 of a substrate processing apparatus suitably used in one embodiment of the present disclosure, and is a block diagram showing a control system of the controller 121. [Figure 4] FIG. 4 is a diagram showing a processing sequence according to one embodiment of the present disclosure. [Figure 5] 5(a) is a TEM image showing the surface portion of the wafer in evaluation sample 2 of example 2. FIG. 5(b) is a TEM image showing the surface portion of the wafer in evaluation sample 4 of comparative example 1. [Figure 6] FIG. 6 is a graph showing the evaluation results in Examples 1 to 3 and Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0009] <One aspect of the present disclosure> Hereinafter, one embodiment of the present disclosure will be described mainly with reference to Figures 1 to 4. Note that all drawings used in the following description are schematic, and the dimensional relationships, ratios, etc. of elements shown in the drawings do not necessarily match those of reality. Furthermore, the dimensional relationships, ratios, etc. of elements between multiple drawings do not necessarily match.

[0010] (1) Configuration of the substrate processing apparatus (substrate processing system) As shown in Fig. 1, the process furnace 202 has a heater 207 as a temperature regulator (heating unit). The heater 207 is cylindrical and is installed vertically by being supported by a holding plate. The heater 207 functions as an energy imparting unit that imparts energy to the gas, and also functions as an activation mechanism (excitation unit) when the gas is activated (excited) by heat.

[0011] A reaction tube 203 is disposed concentrically with the heater 207 inside 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. A manifold 209 is disposed concentrically with the reaction tube 203 below the reaction tube 203. The manifold 209 is made of a metal material such as stainless steel (SUS) and has a cylindrical shape with open upper and lower ends. 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. An O-ring 220a is provided between the manifold 209 and the reaction tube 203 as a sealing member. The reaction tube 203 is installed vertically, similar to the heater 207. The reaction tube 203 and the manifold 209 mainly constitute a processing vessel (reaction vessel). A processing chamber 201 is formed in the cylindrical hollow portion of the processing vessel. The processing chamber 201 is configured to be able to accommodate wafers 200 as substrates. In the processing chamber 201, processing of the wafers 200 is performed.

[0012] Nozzles 249a to 249c serving as first to third supply units are respectively provided in the processing chamber 201 so as to penetrate the sidewall of the manifold 209. The nozzles 249a to 249c are also referred to as first to third nozzles, respectively. The nozzles 249a to 249c are made of a heat-resistant material such as quartz or SiC. Gas supply pipes 232a to 232c are connected to the nozzles 249a to 249c, respectively. The nozzles 249a to 249c are different nozzles, and each of the nozzles 249a and 249c is provided adjacent to the nozzle 249b.

[0013] Gas supply pipes 232a-232c are provided with mass flow controllers (MFCs) 241a-241c, which are flow rate control devices (flow rate control parts), and valves 243a-243c, which are on-off valves, in order from the upstream side of the gas flow. Gas supply pipes 232d and 232f are connected to gas supply pipe 232a downstream of valve 243a. Gas supply pipes 232e and 232g are connected to gas supply pipe 232b downstream of valve 243b. Gas supply pipe 232h is connected to gas supply pipe 232c downstream of valve 243c. Gas supply pipes 232d-232h are provided with MFCs 241d-241h and valves 243d-243h, in order from the upstream side of the gas flow. Gas supply pipes 232a-232h are made of a metal material, such as SUS.

[0014] As shown in FIG. 2, the nozzles 249a to 249c are respectively provided in an annular space between the inner wall of the reaction tube 203 and the wafers 200 in a plan view, extending from the lower part to the upper part of the inner wall of the reaction tube 203 and rising upward in the arrangement direction of the wafers 200. That is, the nozzles 249a to 249c are respectively provided in regions horizontally surrounding the wafer arrangement region on the sides of the wafer arrangement region where the wafers 200 are arranged, and extending along the wafer arrangement region. In a plan view, the nozzle 249b is disposed so as to face an exhaust port 231a (described later) on a straight line across the center of the wafer 200 loaded into the processing chamber 201. The nozzles 249a and 249c are disposed so as to sandwich a line L passing through the nozzle 249b and the center of the exhaust port 231a along the inner wall of the reaction tube 203 (the outer periphery of the wafers 200) from both sides. The line L also passes through the nozzle 249b and the center of the wafer 200. In other words, the nozzle 249c can be said to be provided on the opposite side of the nozzle 249a across the line L. The nozzles 249a and 249c are arranged symmetrically with respect to the line L as the axis of symmetry. Gas supply holes 250a to 250c for supplying gas are provided on the side surfaces of the nozzles 249a to 249c, respectively. Each of the gas supply holes 250a to 250c opens to face (face) the exhaust port 231a in a plan view, and is able to supply gas toward the wafers 200. A plurality of the gas supply holes 250a to 250c are provided from the bottom to the top of the reaction tube 203.

[0015] A gas containing element X is supplied from the gas supply pipe 232a into the processing chamber 201 via the MFC 241a, the valve 243a, and the nozzle 249a.

[0016] A silicon (Si)-containing gas is supplied from the gas supply pipe 232b into the processing chamber 201 via the MFC 241b, the valve 243b, and the nozzle 249b.

[0017] A film forming gas is supplied from the gas supply pipe 232c into the processing chamber 201 via an MFC 241c, a valve 243c, and a nozzle 249c.

[0018] A gas containing element Y is supplied from the gas supply pipe 232d into the processing chamber 201 via the MFC 241d, the valve 243d, the gas supply pipe 232a, and the nozzle 249a.

[0019] A dopant gas is supplied from the gas supply pipe 232e into the processing chamber 201 via the MFC 241e, the valve 243e, the gas supply pipe 232b, and the nozzle 249b.

[0020] Inert gas is supplied from the gas supply pipes 232f to 232h through the MFCs 241f to 241h, the valves 243f to 243h, the gas supply pipes 232a to 232c, and the nozzles 249a to 249c into the processing chamber 201. The inert gas acts as a purge gas, a carrier gas, a dilution gas, etc.

[0021] An element X-containing gas supply system is mainly constituted by the gas supply pipe 232a, MFC 241a, and valve 243a. An Si-containing gas supply system is mainly constituted by the gas supply pipe 232b, MFC 241b, and valve 243b. A film formation gas supply system is mainly constituted by the gas supply pipe 232c, MFC 241c, and valve 243c. An element Y-containing gas supply system is mainly constituted by the gas supply pipe 232d, MFC 241d, and valve 243d. A dopant gas supply system is mainly constituted by the gas supply pipe 232e, MFC 241e, and valve 243e. An inert gas supply system is mainly constituted by the gas supply pipes 232f-232h, MFCs 241f-241h, and valves 243f-243h.

[0022] Any or all of the various supply systems described above may be configured as an integrated supply system 248 in which the valves 243a-243h, MFCs 241a-241h, etc. are integrated. The integrated supply system 248 is connected to each of the gas supply pipes 232a-232h, and is configured so that the supply operation of various substances (various gases) into the gas supply pipes 232a-232h, i.e., the opening and closing operation of the valves 243a-243h and the flow rate adjustment operation by the MFCs 241a-241h, etc., are controlled by a controller 121, which will be described later. The integrated supply system 248 is configured as an integrated or separate integrated unit, and can be attached and detached to and from the gas supply pipes 232a-232h, etc., so that maintenance, replacement, expansion, etc. of the integrated supply system 248 can be performed on an integrated unit basis.

[0023] An exhaust port 231a for exhausting the atmosphere inside the processing chamber 201 is provided at the bottom of the sidewall of the reaction tube 203. As shown in FIG. 2, the exhaust port 231a is provided at a position facing (opposite) the nozzles 249a-249c (gas supply holes 250a-250c) across the wafer 200 in a plan view. The exhaust port 231a may be provided along the sidewall of the reaction tube 203 from the bottom to the top, i.e., along the wafer arrangement area. An exhaust pipe 231 is connected to the exhaust port 231a. A vacuum pump 246 serving as a vacuum exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 serving as a pressure detector (pressure detection unit) for detecting the pressure inside the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 serving as a pressure regulator (pressure adjustment unit). The APC valve 244 is configured to be able to evacuate and stop the evacuation of the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating, and further, to be able to adjust the pressure inside the processing chamber 201 by adjusting the valve opening based on pressure information detected by the pressure sensor 245 while the vacuum pump 246 is operating. An exhaust system is mainly configured by the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 may be included in the exhaust system.

[0024] Below the manifold 209, a seal cap 219 is provided as a furnace port cover capable of airtightly closing the lower end opening of the manifold 209. The seal cap 219 is made of a metal material 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. Below the seal cap 219, a rotation mechanism 267 is provided to rotate the boat 217 (described later). A rotation shaft 255 of the rotation mechanism 267 penetrates the seal cap 219 and is connected to the boat 217. The rotation mechanism 267 is configured to rotate the boat 217, thereby rotating the wafers 200. The seal cap 219 is configured to be vertically raised and lowered by a boat elevator 115 as a lifting mechanism installed outside the reaction tube 203. The boat elevator 115 is configured as a transfer device (transfer mechanism) that transfers the wafers 200 into and out of the processing chamber 201 by raising and lowering the seal cap 219.

[0025] A shutter 219s is provided below the manifold 209 as a furnace port cover that can airtightly close the lower end opening of the manifold 209 when the seal cap 219 is lowered and the boat 217 is removed from the processing chamber 201. The shutter 219s is made of a metal material such as SUS and has a disk shape. An O-ring 220c is provided on the upper surface of the shutter 219s as a sealing member that abuts against the lower end of the manifold 209. The opening and closing operation (lifting and lowering operation, rotating operation, etc.) of the shutter 219s is controlled by a shutter opening and closing mechanism 115s.

[0026] The boat 217 as a substrate support is configured to support a plurality of wafers 200, for example, 25 to 200 wafers 200, in a horizontal position and aligned vertically with their centers aligned, i.e., arranged at intervals, in multiple stages. The boat 217 is made of a heat-resistant material such as quartz or SiC. At the bottom of the boat 217, heat insulating plates 218, also made of a heat-resistant material such as quartz or SiC, are supported in multiple stages.

[0027] A temperature sensor 263 serving as a temperature detector is installed inside the reaction tube 203. By adjusting the power supply to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature inside the processing chamber 201 can be adjusted to a desired temperature distribution. The temperature sensor 263 is installed along the inner wall of the reaction tube 203.

[0028] 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 configured to be able to exchange data with the CPU 121a via an internal bus 121e. An input / output device 122 configured as, for example, a touch panel is connected to the controller 121. An external storage device 123 can also be connected to the controller 121.

[0029] The storage device 121c is configured with, for example, a flash memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. Control programs for controlling the operation of the substrate processing apparatus, process recipes describing procedures and conditions for substrate processing (described later), etc., are readably recorded and stored in the storage device 121c. The process recipe is a combination of procedures for substrate processing (described later) that are executed by the controller 121 in the substrate processing apparatus (substrate processing system) to obtain a predetermined result, and functions as a program. Hereinafter, the process recipes, control programs, etc. are collectively referred to simply as programs. The process recipes are also simply referred to as recipes. In this specification, the term "program" may refer to a recipe alone, a control program alone, or both. The RAM 121b is configured as a memory area (work area) for temporarily storing programs, data, etc. read by the CPU 121a.

[0030] The I / O port 121d is connected to the above-mentioned MFCs 241a to 241h, valves 243a to 243h, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, boat elevator 115, shutter opening / closing mechanism 115s, and the like.

[0031] The CPU 121a is configured to read and execute a control program from the storage device 121c, and to read a recipe from the storage device 121c in response to input of an operation command from the input / output device 122. The CPU 121a is configured to control, in accordance with the contents of the read recipe, the flow rate adjustment operation of various substances (various gases) by the MFCs 241a to 241h, the opening and closing operation of the valves 243a to 243h, the opening and closing operation of the APC valve 244 and the pressure adjustment operation by the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, the temperature adjustment operation of the heater 207 based on the temperature sensor 263, the rotation and rotation speed adjustment operation of the boat 217 by the rotation mechanism 267, the lifting and lowering operation of the boat 217 by the boat elevator 115, the opening and closing operation of the shutter 219s by the shutter opening and closing mechanism 115s, and the like.

[0032] The controller 121 can be configured by installing the above-mentioned program recorded and stored in the external storage device 123 into a computer. The external storage device 123 includes, for example, a magnetic disk such as an HDD, an optical disk such as a CD, a magneto-optical disk such as an MO, and a semiconductor memory such as a USB memory or an SSD. 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. When the term recording media is used in this specification, it may include only the storage device 121c alone, only the external storage device 123 alone, or both. Note that the program may be provided to the computer using a communication means such as the Internet or a dedicated line, without using the external storage device 123.

[0033] (2) Substrate processing process An example of a method for processing a substrate as one step in a semiconductor device manufacturing process (manufacturing method) using the above-described substrate processing apparatus, i.e., a processing sequence for forming a layer on the surface of a wafer 200 as a substrate and forming a film on this layer, will be described mainly with reference to Figure 4. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by a controller 121. Note that the layer formed on the surface of the wafer 200 is thinner than the film to be formed on this layer, and serves as a nucleus (seed) when forming (growing) a film on this layer, so hereinafter this layer will also be referred to as a seed layer.

[0034] In the processing sequence of this embodiment, (a) Step A of supplying a gas containing element X to a wafer 200 at a first temperature to form a seed layer on the surface of the wafer 200, the seed layer including a surface terminated with element X; (b) Step B of supplying a gas containing element Y to the wafer 200 at the second temperature to change the termination of element X on the surface of the seed layer to a termination of element Y; (c) Step C of desorbing element Y constituting the termination of element Y on the surface of the seed layer by heating the wafer 200 to a third temperature; (d) Step D of supplying a film forming gas to the wafer 200 at the fourth temperature to form a film on the seed layer from which the element Y has been desorbed; The seed layer may also be simply referred to as a layer.

[0035] 4, a case will be described in which an element X-containing gas and an Si-containing gas are alternately supplied to the wafer 200 in step A. In the example below, a seed layer is formed on the surface of the wafer 200 by performing a cycle including step A1 of supplying an element X-containing gas to the wafer 200 and step A2 of supplying an Si-containing gas to the wafer 200 a predetermined number of times (n times, where n is an integer of 1 or 2 or more).

[0036] In the following example, a germanium (Ge)-containing gas is supplied as a film forming gas to the wafer 200 in step D. In step D, a Ge-containing gas and a dopant gas can also be supplied together to the wafer 200.

[0037] In this specification, the above-described processing sequence may be expressed as follows for convenience: Similar notations will be used in the following explanations of modified examples and other aspects.

[0038] [Gas containing element X → Gas containing Si] × n → Gas containing element Y → Inert gas → Film-forming gas

[0039] 4, after step D is performed, step E of heat-treating wafer 200 is further performed. Note that step E may be omitted. This also applies to the following modified examples and other aspects.

[0040] [Gas containing element X → Gas containing Si] × n → Gas containing element Y → Inert gas → Film-forming gas → Heat treatment

[0041] In the following example, a case will be described in which the second temperature is higher than the first temperature, the third temperature is higher than the first temperature, and the fourth temperature is lower than the first temperature, as shown in Fig. 4. In the following example, a case will be described in which the second temperature and the third temperature are the same temperature, as shown in Fig. 4.

[0042] The term "wafer" used in this specification may refer to the wafer itself or to a laminate of the wafer and a predetermined layer or film formed on its surface. The term "surface of a wafer" used in this specification may refer to the surface of the wafer itself or to the surface of a predetermined layer or the like formed on the wafer. When described in this specification, "forming a predetermined layer on a wafer" may mean forming a predetermined layer directly on the surface of the wafer itself or forming a predetermined layer on a layer or the like formed on the wafer. When used in this specification, the term "substrate" is synonymous with the term "wafer".

[0043] As used herein, the term "layer" includes continuous and / or discontinuous layers. For example, a seed layer may include a continuous layer, a discontinuous layer, or both.

[0044] (Wafer charge and boat load) When a plurality of wafers 200 are loaded into the boat 217 (wafer charge), the shutter 219s is moved by the shutter opening / closing mechanism 115s, and the lower end opening of the manifold 209 is opened (shutter open). Thereafter, as shown in FIG. 1 , the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115 and carried into the processing chamber 201 (boat load). In this state, the seal cap 219 seals the lower end of the manifold 209 via the O-ring 220b. In this manner, the wafers 200 are prepared in the processing chamber 201.

[0045] (pressure and temperature regulation) After the boat loading is completed, the processing chamber 201, i.e., the space in which the wafers 200 are present, is evacuated (reduced pressure exhausted) by the vacuum pump 246 so that the interior of the processing chamber 201 is at a desired pressure (vacuum level). At this time, the pressure inside the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on the measured pressure information. Furthermore, the wafers 200 inside the processing chamber 201 are heated by the heater 207 so that the processing temperature is at a desired processing temperature. At this time, the power supply to the heater 207 is feedback-controlled based on temperature information detected by the temperature sensor 263 so that the processing chamber 201 has a desired temperature distribution. Furthermore, the rotation mechanism 267 starts to rotate the wafers 200. The evacuation inside the processing chamber 201 and the heating and rotation of the wafers 200 are all continued at least until the processing of the wafers 200 is completed.

[0046] (Step A) Thereafter, a gas containing element X is supplied to the wafer 200 at the first temperature. Specifically, in this step, the following steps A1 and A2 are sequentially performed. As a result, a seed layer including a surface terminated with element X is formed on the surface of the wafer 200.

[0047] [Step A1] In this step, a gas containing element X is supplied to the wafer 200 at the first temperature.

[0048] Specifically, the valve 243a is opened to allow the element X-containing gas to flow into the gas supply pipe 232a. The flow rate of the element X-containing gas is adjusted by the MFC 241a, and the gas is supplied into the processing chamber 201 via the nozzle 249a and exhausted from the exhaust port 231a. At this time, the element X-containing gas is supplied to the wafer 200 from the side of the wafer 200 (supply of element X-containing gas). At this time, the valves 243f to 243h may be opened to supply an inert gas into the processing chamber 201 via the nozzles 249a to 249c, respectively.

[0049] The processing conditions for supplying the element X-containing gas in this step are as follows: Processing temperature (first temperature): 350-440℃ Processing pressure: 100~1000Pa Element X containing gas supply flow rate: 0.01~1slm Element X-containing gas supply time: 0.5 to 10 minutes Inert gas supply flow rate (per gas supply pipe): 0.01 to 10 slm is exemplified.

[0050] In this specification, when a numerical range such as "350 to 440°C" is expressed, both the lower limit and the upper limit are included in the range. For example, "350 to 440°C" means "350°C or higher and 440°C or lower." The same applies to other numerical ranges. In this specification, the processing temperature refers to the temperature of the wafer 200 or the temperature inside the processing chamber 201, and the processing pressure refers to the pressure inside the processing chamber 201. The processing time refers to the time the processing continues. In addition, when the supply flow rate includes 0 slm, 0 slm means that the gas is not supplied. These also apply to the following description.

[0051] After the supply of the gas containing element X to the wafer 200 is completed, the valve 243a is closed to stop the supply of the gas containing element X into the processing chamber 201. Then, the processing chamber 201 is evacuated to remove gaseous substances remaining in the processing chamber 201. At this time, the valves 243f to 243h are opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c. The inert gas supplied from the nozzles 249a to 249c acts as a purge gas, thereby purging the processing chamber 201.

[0052] The processing conditions for purging in this step are as follows: Processing pressure: 1 to 30 Pa Treatment time: 1 to 120 seconds, preferably 1 to 60 seconds Inert gas supply flow rate (per gas supply pipe): 0.5 to 20 slm The processing temperature when purging is performed is preferably the same as the processing temperature (first temperature) when the gas containing element X is supplied.

[0053] The element X-containing gas may be, for example, a gas containing Si and a halogen as the element X, i.e., a halosilane-based gas. The halogen as the element X includes chlorine (Cl), fluorine (F), bromine (Br), iodine (I), etc. The halosilane-based gas may be, for example, a silane-based gas having a Si-Cl bond, a Si-F bond, a Si-Br bond, or a Si-I bond, i.e., a chlorosilane-based gas, a fluorosilane-based gas, a bromosilane-based gas, or an iodosilane-based gas. Among these, it is preferable to use, for example, a chlorosilane-based gas as the halosilane-based gas. That is, the element X in the element X-containing gas preferably contains a halogen, and more preferably contains Cl.

[0054] Examples of gases that can be used as the element X-containing gas include monochlorosilane (SiH3Cl) gas, dichlorosilane (SiH2Cl2) gas, trichlorosilane (SiHCl3) gas, tetrachlorosilane (SiCl4) gas, hexachlorodisilane (Si2Cl6) gas, octachlorotrisilane (Si3Cl8) gas, etc. One or more of these can be used as the element X-containing gas.

[0055] As the inert gas, nitrogen (N2) gas or a rare gas such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, or xenon (Xe) gas can be used. One or more of these can be used as the inert gas. This also applies to each step described below.

[0056] [Step A2] After step A1 is completed, a Si-containing gas is supplied to the wafer 200 at the first temperature.

[0057] Specifically, the valve 243b is opened to allow the Si-containing gas to flow into the gas supply pipe 232b. The flow rate of the Si-containing gas is adjusted by the MFC 241b, and the Si-containing gas is supplied into the processing chamber 201 through the nozzle 249b and exhausted from the exhaust port 231a. At this time, the Si-containing gas is supplied to the wafer 200 from the side of the wafer 200 (Si-containing gas supply). At this time, the valves 243f to 243h may be opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c, respectively.

[0058] The processing conditions for supplying the Si-containing gas in this step are as follows: Processing temperature (first temperature): 350-440℃ Processing pressure: 100~1000Pa Si-containing gas supply flow rate: 0.01 to 1 slm Si-containing gas supply time: 0.5 to 10 minutes Inert gas supply flow rate (per gas supply pipe): 0.01 to 10 slm is exemplified.

[0059] After the supply of the Si-containing gas to the wafers 200 is completed, the valve 243b is closed to stop the supply of the Si-containing gas into the processing chamber 201. Then, gaseous substances remaining in the processing chamber 201 are removed (purged) from the processing chamber 201 by the same processing procedure and processing conditions as those for purging in step A1. Note that the processing temperature during purging is preferably the same as the processing temperature (first temperature) during supply of the Si-containing gas.

[0060] Examples of the Si-containing gas that can be used include a gas containing Si and hydrogen (H), i.e., a silicon hydride gas, and a gas containing Si and an amino group, i.e., an aminosilane gas, etc. Examples of the aminosilane gas that can be used include an aminosilane gas having a Si-N bond in which an amino group is directly bonded to Si.

[0061] Examples of the Si-containing gas include monosilane (SiH4) gas, disilane (Si2H6) gas, trisilane (Si3H8) gas, and tetrasilane (Si4H 10 ) gas, pentasilane (SiH 12 ) gas, hexasilane (Si6H 14 ) gas, etc. can be used. In addition, as the Si-containing gas, for example, tetrakis(dimethylamino)silane (Si[N(CH3)2]4) gas, tris(dimethylamino)silane (Si[N(CH3)2]3H) gas, bis(diethylamino)silane (Si[N(C2H5)2]2H2) gas, bis(tert-butyl)aminosilane (Si[NH(C4H9)]2H2) gas, (diisobutylamino)silane ((C4H9)2NSiH3) gas, (diisopropylamino)silane ((C3H7)2NSiH3) gas, etc. can be used. As the Si-containing gas, one or more of these can be used.

[0062] [Perform the specified number of times] A cycle including the above-described steps A1 and A2, i.e., a cycle in which steps A1 and A2 are performed non-simultaneously (alternately) as shown in FIG. 4, is performed a predetermined number of times (n times, where n is an integer of 1 or greater than 1). This allows a seed layer including a surface terminated with element X to be formed on the surface of wafer 200. The above-described cycle is preferably repeated multiple times until the seed layer including a surface terminated with element X reaches a desired thickness.

[0063] For example, in this step, by using the above-mentioned element X-containing gas, a seed layer including a surface having Si-X termination can be formed on the surface of the wafer 200. As described above, the element X preferably includes a halogen, and more preferably includes Cl. Therefore, in this step, it is preferable to form a seed layer including a surface having Si-halogen termination on the surface of the wafer 200, and it is more preferable to form a seed layer including a surface having Si-Cl termination.

[0064] (heating) After a seed layer including a surface terminated with element X is formed on the surface of wafer 200, the output of heater 207 is adjusted to raise the processing temperature from the first temperature to a second temperature higher than the first temperature, as shown in Fig. 4. At this time, the processing chamber 201 is purged using the same processing procedure and processing conditions as those for the purge in step A1. Note that the purge is preferably continued until the temperature of wafer 200 reaches and stabilizes at the second temperature.

[0065] (Step B) After the temperature of the wafers 200 reaches the second temperature and stabilizes, a gas containing element Y is supplied to the wafers 200 at the second temperature.

[0066] Specifically, the valve 243d is opened to allow the element Y-containing gas to flow into the gas supply pipe 232d. The flow rate of the element Y-containing gas is adjusted by the MFC 241d, and the gas is supplied into the processing chamber 201 through the nozzle 249a and exhausted from the exhaust port 231a. At this time, the element Y-containing gas is supplied to the wafer 200 from the side of the wafer 200 (element Y-containing gas supply). At this time, the valves 243f to 243h may be opened to supply an inert gas into the processing chamber 201 through the nozzles 249a to 249c, respectively.

[0067] In this step, the second temperature is set to be higher than the first temperature, as shown in Fig. 4. Therefore, in this step, the output of the heater 207 is adjusted so that the processing temperature (second temperature) is maintained higher than the processing temperature (first temperature) in step A (step A1, step A2).

[0068] By supplying a gas containing element Y to the wafer 200 under processing conditions described below, a substitution reaction occurs in which element X on the surface of the seed layer is replaced (changed) to element Y, and terminations of element X on the surface of the seed layer can be changed to terminations of element Y. In particular, by setting the second temperature higher than the first temperature, it is possible to increase the conversion rate of terminations of element X on the surface of the seed layer to terminations of element Y, and to suppress the residue of terminations of element X on the surface of the seed layer. In this way, in this step, a state can be created in which a seed layer including a surface terminated with element Y is formed on the surface of the wafer 200.

[0069] The processing conditions for supplying the element Y-containing gas in this step are as follows: Treatment temperature (second temperature): 400 to 520°C, preferably 450 to 500°C Treatment pressure: 500 to 101325 Pa, preferably 800 to 10133 Pa Treatment time: 0.5 to 2 hours, preferably 0.5 to 1 hour Supply flow rate of element Y-containing gas: 1 to 5 slm, preferably 2 to 3 slm Inert gas supply flow rate (per gas supply pipe): 0.01 to 10 slm is exemplified.

[0070] After changing the termination of the surface of the seed layer from element X to element Y, the valve 243d is closed to stop the supply of the gas containing element Y into the processing chamber 201. Then, gaseous substances remaining in the processing chamber 201 are removed (purged) from the processing chamber 201 by the same processing procedure and processing conditions as those for purging in step A1. Note that the processing temperature during purging is preferably the same as the processing temperature (second temperature) during supply of the gas containing element Y.

[0071] The element Y-containing gas may be, for example, a reducing gas. For example, a gas containing hydrogen (H) or deuterium (D) as the element Y may be used as the reducing gas. Among them, a gas containing H is preferred as the reducing gas. That is, the element Y in the element Y-containing gas preferably contains H or D, and more preferably contains H.

[0072] The element Y-containing gas may be, for example, an H-containing gas such as hydrogen (H) gas. The element Y-containing gas may be, for example, a D-containing gas such as deuterium (D) gas. One or more of these gases may be used as the element Y-containing gas.

[0073] In addition, when a seed layer including a surface having Si-X termination is formed in step A, this step can change the Si-X termination on the surface of the seed layer to a Si-Y termination. As described above, the element Y preferably contains H or D, and more preferably contains H. Therefore, in this step, it is preferable to create a state in which a seed layer including a surface having Si-H termination or Si-D termination is formed on the surface of the wafer 200, and it is preferable to create a state in which a seed layer including a surface having Si-H termination is formed on the surface of the wafer 200.

[0074] Furthermore, the processing time in this step is preferably equal to or longer than the processing time in step C described below, and more preferably longer than the processing time in step C. This allows the processing in this step to be carried out effectively, increasing the conversion rate of terminations due to element X on the surface of the seed layer to terminations due to element Y, and making it possible to suppress the residue of terminations due to element X on the surface of the seed layer. In this case, the processing time in step C described below can be shortened, making it possible to improve throughput, i.e., productivity.

[0075] (Step C) After step B is performed, the wafer 200 is heated to a third temperature higher than the first temperature. As shown in FIG. 4, an example is shown in which the third temperature is set to the same temperature as the second temperature. Therefore, in this step, the output of the heater 207 is adjusted so that the processing temperature (third temperature) is maintained at the same temperature as the processing temperature (second temperature) in step B.

[0076] Also, as shown in FIG. 4, a case will be described in which an inert gas is supplied to the wafer 200 that has been set to the third temperature after step B has been performed.

[0077] Specifically, the valves 243f-243h are opened to allow the inert gas to flow into the gas supply pipes 232f-232h. The inert gas has its flow rate adjusted by the MFCs 241f-241h, is supplied into the processing chamber 201 via the nozzles 249a-249c, and is exhausted from the exhaust port 231a. At this time, the inert gas is supplied to the wafer 200 from the side of the wafer 200 (inert gas supply).

[0078] By supplying an inert gas to the wafer 200 under processing conditions described below, the element Y constituting the termination of the element Y on the surface of the seed layer can be thermally desorbed, thereby generating dangling bonds on the surface of the seed layer. In particular, by setting the third temperature higher than the first temperature, the desorption rate of the element Y on the surface of the seed layer can be increased, and more dangling bonds can be generated on the surface of the seed layer. In this way, in this step, a state can be created on the surface of the wafer 200 in which a seed layer including a surface in a state having dangling bonds, which is a state in which a film is easily grown during film formation, is formed.

[0079] The processing conditions for supplying the inert gas in this step are as follows: Treatment temperature (third temperature): 400 to 520°C, preferably 450 to 500°C Treatment pressure: 500 to 101325 Pa, preferably 800 to 10133 Pa Treatment time: 0.5 to 2 hours, preferably 0.5 to 1 hour Inert gas supply flow rate: 1 to 10 slm, preferably 2 to 5 slm is exemplified.

[0080] In addition, when the Si-X termination on the surface of the seed layer is changed to a Si-Y termination in step B, the Si-Y bond at the Si-Y termination on the surface of the seed layer can be broken in this step, and the element Y can be desorbed. This makes it possible to obtain a state in which Si has a dangling bond on the surface of the seed layer. As described above, when the surface of the seed layer has a Si-H termination as the Si-Y termination, H can be desorbed in this step to make the Si on the surface of the seed layer have a dangling bond. In this case, this step makes it possible to create a state in which a seed layer including a surface in which Si has dangling bonds is formed on the surface of the wafer 200.

[0081] 4 shows an example in which the third temperature is the same as the second temperature, but the third temperature may be different from the second temperature. By making the third temperature the same as the second temperature, it is not necessary to change the processing temperature between step B and this step, and the time required to change the temperature of wafer 200 and stabilize the temperature of wafer 200 can be shortened, making it possible to improve throughput, i.e., productivity.

[0082] In steps B and C, the second and third temperatures are preferably set to 400° C. or higher, and more preferably 450° C. or higher. In steps B and C, the second and third temperatures are preferably set to 520° C. or lower, and more preferably 500° C. or lower.

[0083] If the second temperature is set to less than 400°C, it may be difficult to change the termination of element X on the surface of the seed layer to a termination of element Y. That is, it may be difficult to cause a substitution reaction of element X with element Y on the surface of the seed layer. For example, when the surface of the seed layer includes a Si-X termination, it may be difficult to change the Si-X termination on the surface of the seed layer to a Si-Y termination. By setting the second temperature to 400°C or higher, it is possible to effectively change the termination of element X on the surface of the seed layer to a termination of element Y. That is, it is possible to effectively cause a substitution reaction of element X with element Y on the surface of the seed layer. For example, when the surface of the seed layer includes a Si-X termination, it is possible to effectively change the Si-X termination on the surface of the seed layer to a Si-Y termination. Furthermore, by setting the second temperature to 450°C or higher, it is possible to more effectively change the termination of element X on the surface of the seed layer to a termination of element Y. That is, it is possible to more effectively cause a substitution reaction of element X with element Y on the surface of the seed layer. For example, when the surface of the seed layer includes an Si-X termination, it becomes possible to more effectively change the Si-X termination on the surface of the seed layer to an Si-Y termination.

[0084] If the third temperature is set to less than 400°C, it may be difficult to desorb the element Y constituting the termination by the element Y on the surface of the seed layer. That is, the desorption reaction of the element Y on the surface of the seed layer may not occur sufficiently. For example, when the surface of the seed layer includes a Si-Y termination, it may be difficult to sever the Si-Y bond on the surface of the seed layer and create a state in which Si on the surface of the seed layer has a dangling bond. By setting the third temperature to 400°C or higher, it is possible to effectively desorb the element Y constituting the termination by the element Y on the surface of the seed layer. That is, it is possible to effectively cause the desorption reaction of the element Y on the surface of the seed layer. For example, when the surface of the seed layer includes a Si-Y termination, it is possible to effectively sever the Si-Y bond on the surface of the seed layer and create a state in which Si on the surface of the seed layer has a dangling bond. Furthermore, by setting the third temperature to 450°C or higher, it is possible to more effectively desorb the element Y constituting the termination by the element Y on the surface of the seed layer. That is, it is possible to more effectively cause the desorption reaction of the element Y on the surface of the seed layer. For example, when the surface of the seed layer includes a Si-Y termination, it becomes possible to more effectively cut the Si-Y bonds on the surface of the seed layer and make the Si on the surface of the seed layer have dangling bonds.

[0085] Furthermore, if the second and third temperatures exceed 520°C, aggregation of the main elements constituting the seed layer may occur, resulting in deterioration of the surface morphology, surface roughness, and other properties of the film formed on the seed layer. By setting the second and third temperatures to 520°C or less, aggregation of the main elements constituting the seed layer can be effectively suppressed, and as a result, deterioration of the surface morphology, surface roughness, and other properties of the film formed on the seed layer can be effectively suppressed. By setting the second and third temperatures to 500°C or less, aggregation of the main elements constituting the seed layer can be more effectively suppressed, and deterioration of the surface morphology, surface roughness, and other properties of the film formed on the seed layer can be more effectively suppressed.

[0086] Here, surface morphology and surface roughness both refer to the height difference on the surface of a film within a wafer surface or within an arbitrary target surface. Surface roughness, in particular, refers to the degree of height difference on the surface of a film (synonymous with surface roughness), with a smaller value indicating a smoother surface, and conversely, a larger value indicating a rougher surface. In this specification, improving surface morphology and surface roughness characteristics means that the height difference on the surface of the film becomes smaller, improving the surface smoothness. Conversely, deteriorating surface morphology and surface roughness characteristics means that the height difference on the surface of the film becomes larger, deteriorating the surface smoothness.

[0087] For the above reasons, the second and third temperatures are preferably set to 400°C or higher, and more preferably 450°C or higher. Furthermore, the second and third temperatures are preferably set to 520°C or lower, and more preferably 500°C or lower. Furthermore, the second and third temperatures are preferably set to 400°C or higher and 520°C or lower, and more preferably 450°C or higher and 500°C or lower. Here, the second and third temperatures may be the same or different.

[0088] In steps B and C, the pressure in the space where the wafer 200 exists, i.e., the pressure inside the processing chamber 201, is preferably set to 500 Pa or more, and more preferably 800 Pa or more. In steps B and C, the pressure in the space where the wafer 200 exists, i.e., the pressure inside the processing chamber 201, is preferably set to 101325 Pa or less, and more preferably 10133 Pa or less.

[0089] If the pressure in the space where the wafer 200 exists in steps B and C is less than 500 Pa, aggregation of the main elements constituting the seed layer occurs, which may result in deterioration of the properties of the film formed on the seed layer, such as surface morphology and surface roughness. By setting the pressure in the space where the wafer 200 exists in steps B and C to 500 Pa or more, aggregation of the main elements constituting the seed layer can be effectively suppressed, and as a result, deterioration of the properties of the film formed on the seed layer, such as surface morphology and surface roughness, can be effectively suppressed. Furthermore, by setting the pressure in the space where the wafer 200 exists in steps B and C to 800 Pa or more, aggregation of the main elements constituting the seed layer can be more effectively suppressed, and as a result, deterioration of the properties of the film formed on the seed layer, such as surface morphology and surface roughness, can be more effectively suppressed.

[0090] If the pressure in the space where the wafer 200 exists in steps B and C exceeds 101325 Pa, the processing time will be longer and throughput, i.e., productivity, may decrease. By setting the pressure in the space where the wafer 200 exists in steps B and C to 101325 Pa or less, the pressure adjustment time can be effectively shortened, and it is possible to effectively prevent a decrease in throughput, i.e., productivity. Furthermore, by setting the pressure in the space where the wafer 200 exists in steps B and C to 10133 Pa or less, it is possible to more effectively shorten the pressure adjustment time and it is possible to more effectively prevent a decrease in throughput, i.e., productivity.

[0091] For the above reasons, the pressure in the space where the wafer 200 exists in steps B and C is preferably 500 Pa or higher, and more preferably 800 Pa or higher. Furthermore, the pressure in the space where the wafer 200 exists in steps B and C is preferably 101325 Pa or lower, and more preferably 10133 Pa or lower. Furthermore, the pressure in the space where the wafer 200 exists in steps B and C is preferably 500 Pa or higher and 101325 Pa or lower, and more preferably 800 Pa or higher and 10133 Pa or lower. Here, the pressures in the spaces where the wafer 200 exists in steps B and C may be the same or different.

[0092] (Temperature fall) After the seed layer formed on the surface of the wafer 200 has dangling bonds, the output of the heater 207 is adjusted to lower the processing temperature from the third temperature to a fourth temperature that is equal to or lower than the first temperature, preferably to the fourth temperature that is lower than the first temperature, as shown in Fig. 4. At this time, the processing chamber 201 is purged using the same processing procedure and processing conditions as the purging in step A1. It is preferable that the purging be continued until the temperature of the wafer 200 reaches and stabilizes at the fourth temperature.

[0093] (Step D) After the temperature of the wafer 200 reaches the fourth temperature and stabilizes, a film formation gas is supplied to the wafer 200 at the fourth temperature. Here, a case will be described in which a Ge-containing gas is used as the film formation gas, and the Ge-containing gas and a dopant gas are supplied to the wafer 200 together.

[0094] Specifically, valves 243c and 243e are opened to allow a Ge-containing gas and a dopant gas to flow into gas supply pipes 232c and 232e, respectively. The Ge-containing gas and the dopant gas are adjusted in flow rate by MFCs 241c and 241e, respectively, and supplied into the processing chamber 201 via nozzles 249c and 249b. The gases are mixed in the processing chamber 201 and exhausted from the exhaust port 231a. At this time, the Ge-containing gas and the dopant gas are supplied onto the wafer 200 from the side of the wafer 200 (Ge-containing gas + dopant gas supply). At this time, valves 243f to 243h may be opened to supply an inert gas into the processing chamber 201 via nozzles 249a to 249c, respectively.

[0095] In the following example, the fourth temperature is set to a temperature lower than the first temperature, as shown in Fig. 4. Therefore, in this step, the output of the heater 207 is adjusted so that the processing temperature (fourth temperature) is maintained lower than the processing temperature (first temperature) in step A (step A1, step A2).

[0096] By supplying a Ge-containing gas as a film-forming gas to the wafer 200 under processing conditions described below, the Ge-containing gas is decomposed in the gas phase, and Ge is adsorbed (deposited) on the seed layer having dangling bonds, thereby forming a Ge film. Furthermore, by supplying a Ge-containing gas and a dopant gas together to the wafer 200, a Ge film doped with a dopant can be formed. Furthermore, under processing conditions described below, the crystalline structure of the Ge film becomes amorphous.

[0097] The processing conditions for supplying the Ge-containing gas in this step are as follows: Processing temperature (fourth temperature): 250-400℃, 280-320℃ Processing pressure: 30~400Pa Processing time: 1 to 300 minutes Ge-containing gas supply flow rate: 0.01 to 5 slm Dopant gas supply flow rate: 0 to 0.5 slm Inert gas supply flow rate (per gas supply pipe): 0.01 to 20 slm Here, a dopant gas supply flow rate of 0 slm means that no dopant gas is supplied. In other words, the supply of dopant gas can be omitted.

[0098] After the Ge film is formed on the seed layer, the valves 243c and 243e are closed to stop the supply of the Ge-containing gas and the dopant gas into the processing chamber 201. Then, gaseous substances remaining in the processing chamber 201 are removed (purged) from the processing chamber 201 using the same processing procedure and conditions as those for purging in step A1.

[0099] As the Ge-containing gas, for example, a germanium hydride gas (germane-based gas) containing Ge and H can be used. As the Ge-containing gas, for example, monogermane (GeH4) gas, digermane (Ge2H6) gas, trigermane (Ge3H8) gas, etc. can be used. As the Ge-containing gas, one or more of these can be used.

[0100] As the dopant gas, for example, a phosphorus (P)-containing gas, a boron (B)-containing gas, or an arsenic (As)-containing gas can be used. As the dopant gas, for example, a phosphine (PH) gas, a diborane (BH) gas, a trichloroborane (BCl) gas, an arsine (AsH) gas, or the like can be used. As the dopant gas, one or more of these can be used.

[0101] As described above, Fig. 4 shows an example in which the fourth temperature is lower than the first temperature, but the fourth temperature may be set to a temperature equal to or lower than the first temperature. By setting the fourth temperature equal to or lower than the first temperature, preferably lower than the first temperature, it is possible to lower the film formation temperature. Note that in Fig. 4, the second and third temperatures are set to temperatures higher than the first temperature, as described above, and therefore the fourth temperature is the lowest temperature among the first, second, third, and fourth temperatures.

[0102] As described above, the supply of the dopant gas can be omitted in this step, and by omitting the supply of the dopant gas, a Ge film not doped with a dopant, i.e., a non-doped Ge film, can be formed on the seed layer.

[0103] (heating) After the Ge film is formed on the seed layer, purging is performed as described above. In parallel with the purging, the output of the heater 207 is adjusted to raise the processing temperature from the fourth temperature to a fifth temperature higher than the fourth temperature, as shown in FIG. 4. It is preferable to continue purging until the temperature of the wafer 200 reaches the fifth temperature and stabilizes.

[0104] (Step E) After the temperature of the wafer 200 reaches the fifth temperature and stabilizes, the wafer 200 is subjected to a heat treatment (annealing treatment) at the fifth temperature. In the following example, as also shown in FIG. 4, an example is shown in which the treatment temperature (fifth temperature) of the heat treatment is set to a temperature higher than the fourth temperature. Therefore, in this step, the output of the heater 207 is adjusted so that the treatment temperature (fifth temperature) is maintained higher than the treatment temperature (fourth temperature) in step D.

[0105] This step may be performed with the valves 243f to 243h open and the inert gas being supplied into the processing chamber 201 through the nozzles 249a to 249c, respectively. Alternatively, this step may be performed with the valves 243f to 243h closed and the supply of the inert gas into the processing chamber 201 stopped.

[0106] The seed layer and the Ge film can be polycrystalline (polycrystallized) by performing a heat treatment (annealing treatment) under the processing conditions described below. The seed layer before the heat treatment can be in an amorphous state, a mixed crystal state of amorphous (non-crystalline) and poly (polycrystalline), or a poly state. In any case, the seed layer is polycrystalline, and after the seed layer is polycrystalline, the Ge film can be polycrystalline. This allows the Ge film to be polycrystalline using the crystal grains of the previously polycrystalline seed layer as nuclei. If polycrystalline seed layer and Ge film are not required, the heat treatment, i.e., step E, can be omitted.

[0107] The processing conditions for the heat treatment (annealing treatment) in this step are as follows: Processing temperature (5th temperature): 600~1000℃ Processing pressure: 0.1 to 100,000 Pa Processing time: 1 to 300 minutes Inert gas supply flow rate (each gas supply pipe): 0 to 20 slm is exemplified.

[0108] (After purging and atmospheric pressure recovery) After step E is completed, an inert gas is supplied as a purge gas from each of the nozzles 249a to 249c into the processing chamber 201 and exhausted from the exhaust port 231a. This purges the processing chamber 201, and gases and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201 (after-purge). Thereafter, the atmosphere in the processing chamber 201 is replaced with the inert gas (inert gas replacement), and the pressure in the processing chamber 201 is returned to normal pressure (atmospheric pressure return).

[0109] (Boat unloading and wafer discharge) Thereafter, the seal cap 219 is lowered by the boat elevator 115, and the lower end of the manifold 209 is opened. Then, the processed wafers 200, supported by the boat 217, are unloaded from the lower end of the manifold 209 to the outside of the reaction tube 203 (boat unloading). After the boat unloading, the shutter 219s is moved, and the opening at the lower end of the manifold 209 is sealed by the shutter 219s via the O-ring 220c (shutter close). After being unloaded to the outside of the reaction tube 203, the processed wafers 200 are removed from the boat 217 (wafer discharge).

[0110] (3) Effects of this mode According to this aspect, one or more of the following effects can be obtained.

[0111] By performing Step A followed by Steps B and C, the surface of the seed layer formed on the surface of the wafer 200 can be modified from a surface terminated with element X to a surface having dangling bonds. A surface having dangling bonds is a surface that is favorable for film growth during film formation. Therefore, supplying a film formation gas to the wafer 200 having a seed layer having such a surface in Step D can suppress non-uniform film growth. As a result, it is possible to improve the properties of the film formed on the surface of the seed layer, such as surface morphology, surface roughness, and step coverage. Furthermore, it is possible to shorten the incubation time during film formation, thereby improving throughput, i.e., productivity.

[0112] Furthermore, the surface of the seed layer having dangling bonds described above is obtained by converting the surface terminated with element X formed in step A into a surface terminated with element Y in step B, and then desorbing element Y constituting the termination with element Y in step C. By doing so, for example, compared to the case where element X constituting the termination with element X on the surface of the seed layer is desorbed, the surface having dangling bonds can be obtained at a lower temperature. This makes it possible to suppress the aggregation of the main elements constituting the seed layer due to heat, and as a result, it becomes possible to suppress deterioration of the properties such as surface morphology and surface roughness of the film formed on the seed layer.

[0113] In step A, a seed layer including a surface having an Si-X termination is preferably formed, and in step B, the Si-X termination on the surface of the seed layer is preferably changed to an Si-Y termination. Furthermore, in step C, the Si-Y bond in the Si-Y termination on the surface of the seed layer is preferably broken, so that the Si on the surface of the seed layer has a dangling bond. This makes it possible to obtain the above-mentioned effects more efficiently.

[0114] It is preferable that the second temperature in step B is higher than the first temperature in step A, and the third temperature in step C is higher than the first temperature in step A. This makes it possible to more efficiently obtain the above-mentioned effects.

[0115] The element X in the element X-containing gas, X termination, and Si-X termination preferably contains a halogen, more preferably chlorine. The element Y in the element Y-containing gas, Y termination, and Si-Y termination preferably contains hydrogen or deuterium. This allows the reactions in steps A, B, and C to occur efficiently and effectively, and the above-mentioned effects can be more significantly achieved.

[0116] In step A, it is preferable to supply a halosilane-based gas as the element X-containing gas to the wafer 200, and it is more preferable to supply a chlorosilane-based gas as the element X-containing gas. Also, in step A, it is preferable to further supply a silicon hydride-based gas to the wafer 200. Furthermore, it is preferable to further supply a halosilane-based gas and a silicon hydride-based gas alternately to the wafer 200 in step A. In addition, it is preferable to further supply at least one of hydrogen gas and deuterium gas as the element Y-containing gas to the wafer 200 in step B. This makes it possible to efficiently and effectively cause the reactions in steps A and B, and the above-mentioned effects can be more significantly achieved.

[0117] In step C, it is preferable to supply an inert gas to the wafer 200. This allows the reaction in step C to occur efficiently and effectively, and the above-mentioned effects can be obtained more significantly.

[0118] (4) Variations The processing sequence in this embodiment can be modified as shown in the following modified examples. These modified examples can be combined as desired. Unless otherwise specified, the processing procedures and processing conditions in each step of each modified example can be the same as the processing procedures and processing conditions in each step of the above-described processing sequence.

[0119] (Variation 1) As in the processing sequence shown below, in step A, the supply of Si-containing gas to the wafer 200 may be omitted. In step A of this modification, only a gas containing element X is supplied as a reactive gas to the wafer 200 at a first temperature, thereby forming a seed layer including a surface terminated with element X on the surface of the wafer 200. At this time, an inert gas may be supplied to the wafer 200, as in the above embodiment. In this modification, the same effects as those in the above embodiment can be obtained.

[0120] Gas containing element X → Gas containing element Y → Inert gas → Film-forming gas Gas containing element X → Gas containing element Y → Inert gas → Film-forming gas → Heat treatment

[0121] (Variation 2) As shown in the processing sequence below, in step C, the processing chamber 201, i.e., the space in which the wafer 200 exists, may be evacuated without supplying an inert gas to the wafer 200. In step C of this modification, the wafer 200 is set to a third temperature, and the space in which the wafer 200 exists is evacuated (reduced pressure exhaust, vacuum exhaust, vacuum drawing), thereby desorbing element Y that constitutes the termination of element Y on the surface of the seed layer. Note that the processing conditions in this modification can be the same as the processing conditions in step C of the above-described embodiment, except that the supply flow rate of the inert gas is set to 0 slm.

[0122] [Gas containing element X → Gas containing Si] × n → Gas containing element Y → Exhaust → Film-forming gas [Gas containing element X → Gas containing Si] × n → Gas containing element Y → Exhaust → Film forming gas → Heat treatment Gas containing element X → Gas containing element Y → Exhaust → Film-forming gas Gas containing element X → Gas containing element Y → Exhaust → Film-forming gas → Heat treatment

[0123] In this modification, the same effects as those of the above-described embodiment can be obtained. As described in the above-described embodiment and this modification, in step C, by supplying an inert gas to the wafer 200 and / or evacuating the space in which the wafer 200 exists, the element Y constituting the termination of the element Y on the surface of the seed layer can be efficiently and effectively desorbed.

[0124] (Variation 3) In step D, a Si-containing gas may be supplied to the wafer 200 at the fourth temperature. In step D of this modification, a Si-containing gas is supplied to the wafer 200 at the fourth temperature under processing conditions described below, instead of the Ge-containing gas in the above-described embodiment. This allows the element Y to be desorbed, and a Si film can be formed on the seed layer that now has dangling bonds. Furthermore, by supplying a Si-containing gas and a dopant gas together to the wafer 200, a dopant-doped Si film can be formed. Note that in step D of this modification, the fourth temperature is set to a temperature higher than the first temperature.

[0125] In this modification, the processing conditions for supplying the Si-containing gas are as follows: Processing temperature (fourth temperature): 450~650℃ Processing pressure: 30~400Pa Processing time: 1 to 300 minutes Si-containing gas supply flow rate: 0.01 to 5 slm Dopant gas supply flow rate: 0 to 0.5 slm Inert gas supply flow rate (per gas supply pipe): 0.01 to 20 slm is exemplified.

[0126] In this modification, the same effects as those of the above-described embodiment can be obtained. Furthermore, according to this modification, at least one of a Si film not doped with a dopant (non-doped Si film) and a Si film doped with a dopant can be formed on the seed layer.

[0127] (Variation 4) In step D, a Ge-containing gas and a Si-containing gas may be supplied to the wafer 200 at the fourth temperature. In step D of this modification, a Si-containing gas is supplied to the wafer 200 in addition to the Ge-containing gas in the above-described embodiment. That is, in step D of this modification, a Si-containing gas and a Ge-containing gas are supplied together to the wafer 200. This allows element Y to be desorbed, and a SiGe film can be formed on the seed layer that has dangling bonds. Furthermore, by supplying a Si-containing gas, a Ge-containing gas, and a dopant gas together to the wafer 200, a dopant-doped SiGe film can be formed. Note that in step D of this modification, the fourth temperature can be set to a temperature equal to or lower than the first temperature, or can be set to a temperature higher than the first temperature.

[0128] In this modification, the processing conditions for supplying the Si-containing gas and the Ge-containing gas are as follows: Processing temperature (fourth temperature): 280~520℃ Processing pressure: 30~400Pa Processing time: 1 to 300 minutes Si-containing gas supply flow rate: 0.01 to 5 slm Ge-containing gas supply flow rate: 0.01 to 5 slm Dopant gas supply flow rate: 0 to 0.5 slm Inert gas supply flow rate (per gas supply pipe): 0.01 to 20 slm is exemplified.

[0129] In this modification, the same effects as those of the above-described embodiment can be obtained. Furthermore, according to this modification, at least one of a SiGe film not doped with a dopant (non-doped SiGe film) and a SiGe film doped with a dopant can be formed on the seed layer.

[0130] As described in the above-described embodiment, Modification 3, and Modification 4, in step D, at least one of a Ge-containing gas and a Si-containing gas can be supplied to the wafer 200 as a film formation gas. This allows element Y to be desorbed, and at least one of a Ge film, a Si film, and a SiGe film, i.e., a film containing at least one of Ge and Si, can be formed on the seed layer having dangling bonds. Furthermore, as described above, these films may be doped with a dopant, or may be undoped with a dopant (non-doped film). In either case, the same effects as those of the above-described embodiment can be obtained.

[0131] The Si-containing gas in Modifications 3 and 4 may be, for example, any of the various silane-based gases, preferably any of the various silicon hydride-based gases exemplified in step A2 of the above-described embodiment. The dopant gas in Modifications 3 and 4 may be, for example, any of the various dopant gases exemplified in step D of the above-described embodiment.

[0132] <Other Aspects of the Present Disclosure> 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.

[0133] For example, in the above-described embodiment, a series of steps from step A to step E are performed in the same processing chamber 201 (in-situ). However, the present disclosure is not limited to this embodiment. For example, a series of steps from step A to step D may be performed in the same processing chamber, and then step E may be performed in another processing chamber (ex-situ). For example, a substrate processing system including multiple standalone substrate processing apparatuses (e.g., a first substrate processing apparatus, a second substrate processing apparatus, a third substrate processing apparatus, etc.) may be used, and each step may be performed in a different processing chamber of each of the different substrate processing apparatuses, i.e., in a different processing unit. Furthermore, a substrate processing system including a cluster-type substrate processing apparatus in which multiple processing chambers (e.g., a first processing chamber, a second processing chamber, a third processing chamber, etc.) are arranged around a transfer chamber may be used, and each step may be performed in a different processing chamber of the same substrate processing apparatus, i.e., in a different processing unit. In these cases, the same effects as those of the above-described embodiment can be obtained.

[0134] Furthermore, for example, after performing step D and before performing step E, step F may be performed to form a film other than a Ge film, a Si film, or a SiGe film (such as a silicon oxide film or a silicon nitride film). In this case, a series of steps from step A to step E, i.e., a series of steps including step F, may be performed in the same processing chamber (first processing chamber). Alternatively, a series of steps from step A to step D may be performed in the same processing chamber (first processing chamber), and a series of steps from step F to step E may be performed in another processing chamber (second processing chamber). Alternatively, a series of steps from step A to step D may be performed in the same processing chamber (first processing chamber), step F may be performed in another processing chamber (second processing chamber), and step E may be performed in yet another processing chamber (third processing chamber) or the first processing chamber. In these cases, the same effects as those of the above-described embodiment can be obtained.

[0135] In the various cases described above, if a series of steps are performed in-situ, the wafer 200 is not exposed to the atmosphere during the process, and the wafer 200 can be processed consistently while being kept under vacuum, allowing for stable substrate processing. Also, if some steps are performed ex-situ, the temperature inside each processing chamber can be set in advance to, for example, the processing temperature for each step or a temperature close to that temperature, thereby shortening the time required for temperature adjustment and enabling an improvement in throughput, i.e., productivity.

[0136] It is preferable that the recipes used for each process are individually prepared according to the process content and recorded and stored in the storage device 121c via an electric communication line or the external storage device 123. Then, when starting each process, it is preferable that the CPU 121a appropriately selects an appropriate recipe according to the process content from the multiple recipes recorded and stored in the storage device 121c. This makes it possible to form films with various film types, composition ratios, film qualities, and film thicknesses with good reproducibility using a single substrate processing apparatus. It also reduces the burden on the operator, prevents operational errors, and enables each process to be started quickly.

[0137] The above-mentioned recipes do not necessarily have to be newly created, but may be prepared by modifying an existing recipe already installed in the substrate processing apparatus, for example. When modifying a recipe, the modified recipe may be installed in the substrate processing apparatus via an electric communication line or a recording medium on which the modified recipe is recorded. Alternatively, an existing recipe already installed in the substrate processing apparatus may be directly modified by operating the input / output device 122 provided in the existing substrate processing apparatus.

[0138] In the above-described embodiment, an example of forming a film using a batch-type substrate processing apparatus that processes multiple substrates at a time has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied, for example, to a case where a film is formed using a single-wafer substrate processing apparatus that processes one or several substrates at a time. Furthermore, in the above-described embodiment, an example of forming a film using a substrate processing apparatus having a hot-wall processing furnace has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied to a case where a film is formed using a substrate processing apparatus having a cold-wall processing furnace.

[0139] When using these substrate processing apparatuses, each process can be performed using the same processing procedures and conditions as in the above-described embodiments and modifications, and the same effects as in the above-described embodiments and modifications can be obtained.

[0140] The above-described embodiments and modifications may be used in combination as appropriate. The processing procedures and processing conditions in such a case may be the same as those of the above-described embodiments and modifications, for example. [Example]

[0141] Example 1 A seed layer was formed on the surface of a wafer using a process sequence similar to that shown in FIG. 4 , and a Ge film was then formed on the seed layer to produce Evaluation Sample 1 of Example 1. The process conditions for each step in producing Evaluation Sample 1 were set to predetermined conditions within the range of the process conditions for each step in the above-described embodiment. When producing Evaluation Sample 1, a Si wafer having a SiO film on its surface was used as the wafer, the chlorosilane-based gas exemplified in the above-described embodiment was used as the element X-containing gas, the silicon hydride-based gas exemplified in the above-described embodiment was used as the Si-containing gas, the H-containing gas exemplified in the above-described embodiment was used as the element Y-containing gas, and the germanium hydride-based gas exemplified in the above-described embodiment was used as the Ge-containing gas. The second temperature in Step B and the third temperature in Step C were both set within the range of 500 to 520°C.

[0142] <Example 2> Evaluation sample 2 of Example 2 was prepared in the same manner as evaluation sample 1 of Example 1, except that the second temperature in step B and the third temperature in step C were both set within the range of 460 to 490°C.

[0143] Example 3 Evaluation sample 3 of Example 3 was prepared in the same manner as evaluation sample 1 of Example 1, except that the second temperature in step B and the third temperature in step C were both set within the range of 400 to 440°C.

[0144] <Comparative Example 1> Evaluation sample 4 of Comparative Example 1 was prepared in the same manner as evaluation sample 1 of Example 1, except that steps B and C were not performed.

[0145] For each of the prepared evaluation samples, the surface portion of the wafer was observed with a transmission electron microscope (TEM) to obtain images (TEM images). Figure 5(a) is a TEM image showing the surface portion of the wafer in evaluation sample 2 of Example 2, and Figure 5(b) is a TEM image showing the surface portion of the wafer in evaluation sample 4 of Comparative Example 1.

[0146] Furthermore, for each evaluation sample fabricated, the thickness of the Ge film formed on the seed layer was measured for each supply time of the film-forming gas (Ge-containing gas) in step D, and the time until the film-forming reaction occurred, i.e., the incubation time, was evaluated. The evaluation results for each evaluation sample are shown in Figure 6. In the graph of Figure 6, the horizontal axis represents the supply time (seconds) of the film-forming gas (Ge-containing gas), and the vertical axis represents the thickness (Å) of the Ge film.

[0147] 5(a) and 5(b), it was confirmed that Evaluation Sample 2 of Example 2 had a smoother Ge film surface, improved surface morphology characteristics and surface roughness characteristics, and also excellent step coverage characteristics, compared to Evaluation Sample 4 of Comparative Example 1. Furthermore, according to FIG. 6, it was confirmed that Evaluation Samples 1 to 3 of Examples 1 to 3 all had significantly shorter incubation times during film formation, compared to Evaluation Sample 4 of Comparative Example 1. [Explanation of symbols]

[0148] 200 wafers (substrates)

Claims

1. (a) supplying an element X-containing gas containing a halogen as the element X to a substrate at a first temperature, thereby forming a layer on a surface of the substrate, the layer including a surface terminated with the element X; (b) supplying a gas containing element Y, which contains hydrogen or deuterium as element Y, to the substrate at a second temperature, thereby changing the termination of element X on the surface of the layer to a termination of element Y; (c) heating the substrate to a third temperature to desorb the element Y constituting the termination of the element Y on the surface of the layer; (d) supplying a film-forming gas to the substrate at a fourth temperature to form a film on the layer from which the element Y has been desorbed; A substrate processing method comprising:

2. 2. The substrate processing method according to claim 1, wherein (a) forming the layer includes a surface having Si—X termination, and (b) converting the Si—X termination on the surface of the layer to Si—Y termination.

3. 3. The substrate processing method according to claim 2, wherein in step (c), Si--Y bonds at Si--Y terminations on the surface of the layer are cut off, so that Si on the surface of the layer has dangling bonds.

4. 2. The substrate processing method according to claim 1, wherein the second temperature is higher than the first temperature, and the third temperature is higher than the first temperature.

5. The substrate processing method according to claim 4 , wherein the fourth temperature is set to a temperature equal to or lower than the first temperature.

6. The substrate processing method according to claim 4 , wherein the fourth temperature is higher than the first temperature.

7. 7. The substrate processing method according to claim 1, wherein the element X includes chlorine.

8. 7. The substrate processing method according to claim 1, wherein in step (a), a halosilane-based gas is supplied to the substrate as the gas containing element X.

9. 7. The substrate processing method according to claim 1, wherein in (a), a chlorosilane-based gas is supplied to the substrate as the gas containing element X.

10. 9. The substrate processing method according to claim 8, wherein in (a), a silicon hydride-based gas is further supplied to the substrate.

11. 11. The substrate processing method according to claim 10, wherein in (a), the halosilane-based gas and the silicon hydride-based gas are alternately supplied to the substrate.

12. 7. The substrate processing method according to claim 1, wherein in (b), at least one of hydrogen gas and deuterium gas is supplied to the substrate as the element Y-containing gas.

13. 7. The substrate processing method according to claim 1, wherein in (c), at least one of supplying an inert gas to the substrate and evacuating a space in which the substrate exists is carried out.

14. 7. The substrate processing method according to claim 1, wherein in (d), at least one of a germanium-containing gas and a silicon-containing gas is supplied to the substrate as the film forming gas.

15. 7. The substrate processing method according to claim 1, wherein the second temperature and the third temperature are set to 400° C. or higher and 520° C. or lower.

16. 7. The substrate processing method according to claim 1, wherein the pressure in the space in which the substrate exists in (b) and (c) is set to 500 Pa or more.

17. 7. The substrate processing method according to claim 1, wherein the processing time in (b) is equal to or longer than the processing time in (c).

18. (a) supplying an element X-containing gas containing a halogen as the element X to a substrate at a first temperature, thereby forming a layer on a surface of the substrate, the layer including a surface terminated with the element X; (b) supplying a gas containing element Y, which contains hydrogen or deuterium as element Y, to the substrate at a second temperature, thereby changing the termination of element X on the surface of the layer to a termination of element Y; (c) heating the substrate to a third temperature to desorb the element Y constituting the termination of the element Y on the surface of the layer; (d) supplying a film-forming gas to the substrate at a fourth temperature to form a film on the layer from which the element Y has been desorbed; A method for manufacturing a semiconductor device having the above structure.

19. an element X-containing gas supply system for supplying an element X-containing gas containing a halogen as the element X to the substrate; an element Y-containing gas supply system for supplying an element Y-containing gas containing hydrogen or deuterium as the element Y to the substrate; a deposition gas supply system for supplying a deposition gas to the substrate; a temperature adjusting unit that adjusts the temperature of the substrate; a control unit configured to be able to control the element X-containing gas supply system, the element Y-containing gas supply system, the film formation gas supply system, and the temperature adjustment unit to perform the following processes: (a) supplying the element X-containing gas to a substrate at a first temperature to form a layer including a surface terminated with the element X on the surface of the substrate; (b) supplying the element Y-containing gas to the substrate at a second temperature to change the termination of the element X on the surface of the layer to a termination of the element Y; (c) desorbing the element Y that constitutes the termination of the element Y on the surface of the layer by heating the substrate to a third temperature; and (d) supplying the film formation gas to the substrate at a fourth temperature to form a film on the layer from which the element Y has been desorbed; A substrate processing apparatus having:

20. (a) supplying an element X-containing gas containing a halogen as the element X to a substrate at a first temperature, thereby forming a layer on a surface of the substrate, the layer including a surface terminated with the element X; (b) supplying a gas containing element Y, which contains hydrogen or deuterium as element Y, to the substrate at a second temperature, thereby changing the termination of element X on the surface of the layer to a termination of element Y; (c) heating the substrate to a third temperature to desorb the element Y constituting the termination of the element Y on the surface of the layer; (d) supplying a film-forming gas to the substrate at a fourth temperature to form a film on the layer from which the element Y has been desorbed; A program that causes a computer to execute the above in a substrate processing apparatus.

Images