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

Abstract

The present invention comprises: (a) a step of supplying a first fluid containing hydrogen peroxide to a substrate on which a silicon-containing film and a metal film are formed; and (b) a step of supplying a second fluid including a carboxy group to the substrate.

Description

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

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

[0002] 2. Description of the Related Art As one step in the manufacturing process of a semiconductor device, a process of modifying a film formed on a substrate may be performed (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2019-175920

[0004] The present disclosure provides a technique capable of selectively oxidizing a silicon-containing film, which is a film to be oxidized, among a silicon-containing film and a metal film formed on a substrate.

[0005] According to one aspect of the present disclosure, there is provided a technique including: (a) a step of supplying a first fluid containing hydrogen peroxide to a substrate having a silicon-containing film and a metal film formed thereon; and (b) a step of supplying a second fluid containing a carboxy group to the substrate.

[0006] According to the present disclosure, it is possible to selectively oxidize a silicon-containing film, which is a film to be oxidized, out of a silicon-containing film and a metal film formed on a substrate.

[0007] FIG. 1 is a schematic diagram of a vertical processing furnace of a substrate processing apparatus suitable for use in one embodiment of the present disclosure, showing a vertical cross-sectional view of a processing furnace 202. FIG. 2 is a schematic 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 block diagram form. FIG. 3 is a flow chart showing a substrate processing process performed in one embodiment of the present disclosure. FIG. 4( a) is a partially enlarged cross-sectional view of the surface of a wafer 200 having a Si-containing film 400 formed on its surface as a base and a metal film 500 formed in the Si-containing film 400. FIG. 4( b) is a partially enlarged cross-sectional view of the surface of a wafer 200 after a first fluid containing hydrogen peroxide is supplied to modify the Si-containing film 400 into a Si oxide-containing film 410 and modify the surface of the metal film 500 into a metal oxide film 510. FIG. 4C is an enlarged partial cross-sectional view of the surface of the wafer 200 after the film modified into the metal oxide film 510 has been reduced to the metal film 500 by supplying the second fluid containing a carboxy group.

[0008] <One Aspect of the Present Disclosure> One aspect of the present disclosure will be described below with reference to Figures 1 to 4. 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 As shown in Fig. 1, the processing furnace 202 includes a reaction tube 203. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC), and is configured as a cylindrical member having a gas supply port 203p at its upper end and a furnace port (opening) at its lower end. A processing chamber 201 is formed in the cylindrical hollow portion of the reaction tube 203. The processing chamber 201 is configured to be able to accommodate a plurality of wafers 200 as substrates.

[0010] A seal cap 219 is provided below the reaction tube 203 as a lid that can airtightly close the lower end opening of the reaction tube 203. The seal cap 219 is made of a non-metallic material such as quartz. A rotation mechanism 267 is provided below the seal cap 219. A rotation shaft 255 of the rotation mechanism 267 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 raised and lowered vertically by a boat elevator 115 that serves as a lifting mechanism.

[0011] The boat 217, which serves as a substrate support, is configured to support a plurality of wafers 200, for example, 25 to 200, in a horizontal position and aligned vertically in multiple stages, i.e., arranged with intervals between them. The boat 217 is made of a heat-resistant material such as quartz or SiC, and has a top plate 217a and a bottom plate 217b on the top and bottom. Insulators 218, which are supported in multiple stages in a horizontal position below the boat 217, are made of a heat-resistant material such as quartz or SiC.

[0012] A heater 207 serving as a heating unit is provided on the outside of the reaction tube 203. The heater 207 not only heats the wafers 200 accommodated in the wafer accommodation area to a predetermined temperature, but also functions as a liquefaction suppression mechanism that applies thermal energy to the gas supplied into the processing chamber 201 to suppress liquefaction, and as an excitation mechanism that thermally activates the gas. A temperature sensor 263 serving as a temperature detection unit is provided in the processing chamber 201 along the inner wall of the reaction tube 203.

[0013] A gas supply pipe 232a is connected to a gas supply port 203p provided at the upper end of the reaction tube 203. The gas supply pipe 232a is provided with a gas generator 250a as a first vaporizer, a mass flow controller (MFC) 241a as a flow rate controller (flow rate control part), a valve 243a as an on-off valve, and a gas concentration meter 300a.

[0014] A supply pipe 232c for supplying hydrogen peroxide solution is connected to the gas generator 250a.２ O ２ with water (H ２ The supply pipe 232c is provided with a tank 250t serving as a storage tank (reservoir tank) for storing hydrogen peroxide solution, an MFC 241c, and a valve 243c.

[0015] A gas supply pipe 232g is connected to the tank 250t, and supplies a first pressurized gas into the tank 250t. The supply pipe 232g is provided with an MFC 241g and a valve 243g. The first pressurized gas is used to push the hydrogen peroxide solution in the tank 250t to the supply pipe 232c. For example, the first pressurized gas may be a gas similar to the inert gas described below. The tank 250t is also provided with a drain pipe 232h, which discharges the hydrogen peroxide solution from the tank 250t. The drain pipe 232h is provided with a valve 243h.

[0016] A gas supply pipe 232d is connected to the gas generator 250a, and supplies a first vaporization carrier gas to the gas generator 250a. The gas supply pipe 232d is provided with an MFC 241d and a valve 243d. The first vaporization carrier gas is used to atomize the solution (hydrogen peroxide solution) supplied from the supply pipe 232c to the gas generator 250a, facilitating vaporization.

[0017] A gas supply pipe 232b is connected to the gas supply pipe 232a downstream of the valve 243a and upstream of the gas concentration meter 300a. The gas supply pipe 232b is provided with a gas generator 250b as a second vaporizer, an MFC 241b, and a valve 243b.

[0018] A supply pipe 232e that supplies a liquid containing a carboxy group (-COOH) (hereinafter, sometimes referred to as the "second liquid") is connected to the gas generator 250b. The supply pipe 232e is provided with a tank 250u that serves as a storage tank for storing the second liquid, an MFC 241e, and a valve 243e. The second liquid will be described in detail later.

[0019] A supply pipe 232i that supplies a second pressurized gas into the tank 250u is connected to the tank 250u. The gas supply pipe 232i is provided with an MFC 241i and a valve 243i. The second pressurized gas is used to push the second liquid in the tank 250u to the supply pipe 232e. For example, a gas similar to the inert gas described below can be used as the second pressurized gas. The tank 250u is also provided with a drain pipe 232j that discharges the second liquid from the tank 250u. The drain pipe 232j is provided with a valve 243j.

[0020] A gas supply pipe 232f is connected to the gas generator 250b, and supplies a second vaporization carrier gas to the gas generator 250b. The gas supply pipe 232f is provided with an MFC 241f and a valve 243f. The second vaporization carrier gas is used to atomize the solution (second liquid) supplied from the supply pipe 232e to the gas generator 250b, facilitating vaporization.

[0021] Gas generator 250a is configured to generate a first fluid, which is a vaporized gas of hydrogen peroxide, by, for example, heating hydrogen peroxide to a predetermined temperature under approximately atmospheric pressure and vaporizing or misting it. In this embodiment, when vaporizing or misting hydrogen peroxide or the like, a first vaporization carrier gas is supplied to gas generator 250a together with the hydrogen peroxide or the like, thereby atomizing the hydrogen peroxide or the like.

[0022] The gas generator 250b is configured to generate a second fluid, which is a vaporized gas of the second liquid, by, for example, heating the second liquid to a predetermined temperature under approximately atmospheric pressure and vaporizing or misting it. In this aspect, when vaporizing or misting the second liquid, a second vaporization carrier gas is supplied to the gas generator 250b together with the second liquid, thereby atomizing the second liquid.

[0023] A gas supply pipe 232k for supplying an inert gas is connected to the gas supply pipe 232b downstream of the valve 243b. The gas supply pipe 232k is provided with an MFC 241k and a valve 243k. The inert gas acts as a purge gas, a carrier gas, a dilution gas, etc.

[0024] The gas concentration meter 300a measures the H in the first fluid flowing through the gas supply pipe 232a. ２ O ２ The gas concentration meter 300a measures (detects) the concentration of —COOH in the first fluid and the second fluid. For example, the gas concentration meter 300a measures (detects) the concentration of —COOH in the first fluid by analyzing the spectrum of infrared light that has passed through the first fluid and the second fluid flowing in the cell. ２ O ２ The present invention is configured to measure the concentration of —COOH contained in the first fluid and the second fluid.

[0025] A first fluid supply system is mainly composed of gas supply pipe 232a, MFC 241a, valve 243a, and gas generator 250a. A second fluid supply system is mainly composed of gas supply pipe 232b, MFC 241b, valve 243b, and gas generator 250b. A hydrogen peroxide solution supply system is mainly composed of tank 250t, supply pipe 232c, MFC 241c, and valve 243c. A first vaporization carrier gas supply system is mainly composed of gas supply pipe 232d, MFC 241d, and valve 243d. A second liquid supply system is mainly composed of tank 250u, supply pipe 232e, MFC 241e, and valve 243e. A second vaporization carrier gas supply system is mainly composed of gas supply pipe 232f, MFC 241f, and valve 243f. A first compressed gas supply system is mainly composed of a gas supply pipe 232g, an MFC 241g, and a valve 243g. A second compressed gas supply system is mainly composed of a gas supply pipe 232i, an MFC 241i, and a valve 243i. An inert gas supply system is mainly composed of a gas supply pipe 232k, an MFC 241k, and a valve 243k.

[0026] An exhaust pipe 231 that exhausts the atmosphere inside the processing chamber 201 is connected to the lower sidewall of the reaction tube 203. A vacuum pump 246 serving as an exhaust device is connected to the exhaust pipe 231 via a gas concentration meter 300b serving as a gas concentration detector that detects the concentration of gas inside the processing chamber 201, a pressure sensor 245 serving as a pressure detector that detects the pressure inside the processing chamber 201, and an APC valve 244 serving as a pressure regulator. An exhaust system is mainly configured by the exhaust pipe 231 and the APC valve 244. The vacuum pump 246 may be considered to be included in the exhaust system.

[0027] The gas concentration meter 300b measures the H in the first fluid flowing through the exhaust pipe 231. ２ O ２ The gas concentration meter 300b measures (detects) the concentration of —COOH in the first fluid and the second fluid. For example, the gas concentration meter 300b measures (detects) the concentration of H in the first fluid by analyzing the spectrum of infrared light that has passed through the first fluid and the second fluid flowing in the cell. ２ O ２ The present invention is configured to measure the concentration of —COOH contained in the first fluid and the second fluid.

[0028] As shown in FIG. 2 , 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 exchange data with the CPU 121a via an internal bus 121e. An input / output device 122, such as a touch panel, is connected to the controller 121. An external storage device 123 can also be connected to the controller 121. The substrate processing apparatus may be configured to include one control unit or multiple control units. That is, the 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 the control for carrying out the processing sequence described below may be performed by the entire control system. When the term "control unit" is used in this specification, it may include not only one control unit but also multiple control units or a control system configured by multiple control units.

[0029] The storage device 121c is composed of, for example, a flash memory, a hard disk drive (HDD), a solid state drive (SSD), 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 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 241g, 241k, valves 243a to 243k, gas generators 250a, 250b, gas concentration meters 300a, 300b, 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, etc.

[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 gas generation operation by the gas generators 250a and 250b, the flow rate adjustment operation by the MFCs 241a to 241g and 241k based on the gas concentration meter 300a, the opening and closing operation of the valves 243a to 243k, 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 raising 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 as recording media. When the term recording medium 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 Step A method for processing a substrate using the substrate processing apparatus described above as one step in the manufacturing process of a semiconductor device, specifically, an example of a processing sequence for oxidizing a wafer 200 as a substrate having a silicon (Si)-containing film 400 and a metal film 500 formed on its surface, will be described primarily with reference to FIGS. 3 and 4(a) to 4(c). More specifically, an example of a processing sequence for selectively oxidizing the Si-containing film 400, which is the film to be oxidized, of the Si-containing film 400 and the metal film 500 formed on the wafer 200 will be described. In this embodiment, as an example, a wafer 200 will be described in which a Si-containing film 400, such as a Si film, is formed on its surface as a base layer, and a metal film 500 is formed within the Si-containing film 400 as wiring (see FIG. 4(a)). In the following description, the operation of each component constituting the substrate processing apparatus is controlled by a controller 121.

[0034] In the process sequence shown in FIG. 3, the wafer 200 is mainly subjected to H ２ O ２ A step of supplying a first fluid containing —COOH (first fluid supply step: S3) and a step of supplying a second fluid containing —COOH to the wafer 200 (second fluid supply step: S5) are performed. In this embodiment, as an example, the first fluid is H ２ O ２ and the case where the second fluid is a gas containing —COOH will be described.

[0035] (Substrate Loading Step: S1) A plurality of wafers 200 having a Si-containing film 400 and a metal film 500 formed on their surfaces are loaded into a boat 217. Thereafter, as shown in Fig. 1 , the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115 and loaded into the processing chamber 201. In this state, the seal cap 219 seals the lower end of the reaction tube 203.

[0036] (Pressure / Temperature Adjustment Step: S2) The processing chamber 201, i.e., the space in which the wafer 200 is present, is evacuated (reduced pressure exhausted) by the vacuum pump 246 so as to reach 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 this measured pressure information. The wafer 200 is also heated by the heater 207 so as to reach 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 as to achieve a desired temperature distribution inside the processing chamber 201. The rotation mechanism 267 also starts to rotate the wafer 200. The evacuation inside the processing chamber 201 and the heating and rotation of the wafer 200 are all continued at least until the processing of the wafer 200 is completed.

[0037] (First fluid supply step: S3) In this step (S3), H ２ O ２ In this embodiment, the gas generator 250a starts generating a vaporized gas to supply the first fluid containing H to the wafer 200. ２ O ２ A vaporized gas containing

[0038] Specifically, first, valves 243c and 243d are opened, and while controlling the flow rates with MFCs 241c and 241d, supply of hydrogen peroxide solution and a first vaporization carrier gas to gas generator 250a is initiated, causing gas generator 250a to generate a vaporized hydrogen peroxide solution (first fluid). At this time, controller 121 controls MFC 241c to adjust the flow rate and concentration of the first fluid generated by gas generator 250a. Note that the hydrogen peroxide solution stored in tank 250t is forced out of tank 250t and into supply pipe 232c by opening valve 243g and supplying a first compressed gas to tank 250t while controlling the flow rate with MFC 241g. Note that although FIG. 3 discloses that this step (S3) is initiated after the pressure / temperature adjustment step (S2), S3 may be initiated during or before S2 is performed.

[0039] When the amount and concentration of the first fluid generated are stabilized, the valve 243a is opened, and H is introduced into the processing chamber 201 via the MFC 241a, the gas supply pipe 232a, and the gas supply port 203p. ２ O ２ Then, the supply of the first fluid containing the hydrogen peroxide vapor is started.

[0040] The first fluid supplied into the processing chamber 201 flows downward within the processing chamber 201 and is discharged to the outside of the processing chamber 201 via the exhaust pipe 231. At this time, the first fluid is supplied to the wafer 200. At this time, the valve 243k may be opened, and an inert gas may be supplied into the processing chamber 201 via the gas supply pipes 232b and 232a and the gas supply port 203p while adjusting the flow rate by the MFC 241k.

[0041] Examples of processing conditions in the first fluid supplying step include: processing temperature: 150 to 500°C, preferably 200 to 400°C processing pressure: 700 to 1000 hPa, preferably 800 to 980 hPa first fluid supply flow rate: 5 to 20 ccm, preferably 10 to 15 ccm first fluid supply time: 100 to 250 minutes, preferably 120 to 180 minutes first vaporization carrier gas supply flow rate: 3 to 10 slm inert gas supply flow rate: 0 to 10 slm

[0042] In this specification, when a numerical range such as "150 to 500°C" is expressed, both the lower and upper limits are included in the range. For example, "150 to 500°C" means "150°C or higher and 500°C or lower." The same applies to other numerical ranges. In this specification, the term "processing temperature" refers to the temperature of the wafer 200 or the temperature inside the processing chamber 201, and the term "processing pressure" refers to the pressure inside the processing chamber 201, in other words, the pressure in the space in which the wafer 200 is present. Furthermore, the term "processing time" refers to the time the processing continues. Furthermore, when the supply flow rate includes 0 slm, 0 slm means that the substance is not supplied. These terms also apply to the following description.

[0043] H contained in the first fluid ２ O ２is a type of active oxygen, which is unstable and easily releases oxygen (O), generating hydroxyl radicals (OH radicals) with very strong oxidizing power. ２ O ２ The first fluid, which is a gas containing gas, acts as a strong oxidizing agent in this step (S3).

[0044] Supplying the first fluid to the wafer 200 under the above-described conditions oxidizes both the Si-containing film 400 and the metal film 500 formed on the wafer 200. Specifically, supplying the first fluid to the wafer 200 under the above-described conditions not only oxidizes the Si-containing film 400, which is the film to be oxidized, but also oxidizes the metal film 500, which is not the film to be oxidized.

[0045] By supplying the first fluid to the wafer 200 under the above-described conditions, the O component contained in the first fluid can penetrate not only the surface of the Si-containing film 400 formed on the wafer 200 but also into the film (in the thickness direction). In this way, the Si-containing film 400 is oxidized not only on the surface but also deep inside (see FIG. 4(b)). On the other hand, by supplying the first fluid to the wafer 200 under the above-described conditions, -OH is formed on the surface of the metal film 500 formed on the wafer 200. In this way, the surface of the metal film 500 is oxidized (see FIG. 4(b)).

[0046] As described above, by supplying the first fluid to the wafer 200, not only is the Si-containing film 400, which is the film to be oxidized, modified into a Si-containing oxide film 410, but also the surface of the metal film 500, which is not the film to be oxidized, is modified into a metal oxide film 510 (see FIGS. 4(a) and 4(b)).

[0047] In order to obtain a modification effect over the entire thickness of the Si-containing film 400, it is preferable to continue performing this step (S3) over at least the entire thickness of the Si-containing film 400, that is, until the O component and the like reach a deep portion of the film. The processing time of S3 is preferably increased as the thickness of the Si-containing film 400 increases.

[0048] If the treatment temperature is less than 150° C., it may be difficult to oxidize the Si-containing film 400 at a practical rate. If the treatment temperature is 150° C. or higher, it becomes possible to oxidize the Si-containing film 400 at a practical rate. If the treatment temperature is 200° C. or higher, it becomes easy to oxidize the Si-containing film 400 at a practical rate.

[0049] If the processing temperature exceeds 500° C., the metal film 500 may be excessively oxidized or altered. By setting the processing temperature to 500° C. or less, it is possible to avoid excessive oxidation or alteration of the metal film 500. By setting the processing temperature to 400° C. or less, it is easy to avoid excessive oxidation or alteration of the metal film 500.

[0050] In this embodiment, the time for which the first fluid is retained in the processing chamber 201 is set to a time during which the first fluid is not liquefied, specifically, the time during which the H contained in the first fluid is not liquefied. ２ O ２ This time is set so that the components do not liquefy, which prevents the first fluid from becoming a liquid (hydrogen peroxide solution) in the processing chamber 201, thereby enabling the Si-containing film 400 formed on the wafer 200 to be uniformly oxidized.

[0051] The inert gas is nitrogen (N ２ Inert gases that can be used include rare gases such as argon (Ar) gas, helium (He) gas, neon (Ne) gas, and xenon (Xe) gas. One or more of these gases can be used as the inert gas. This also applies to the processes described below.

[0052] As the first vaporization carrier gas, for example, a gas similar to the inert gas described above can be used.

[0053] (First Purge Step: S4) After a predetermined time has elapsed and the oxidation process of the Si-containing film 400 or the like using the first fluid has been completed, the valve 243a is closed to stop the supply of the first fluid to the wafer 200. Then, the vacuum pump 246 is used to discharge (purge) the first fluid, by-products, and the like remaining in the processing chamber 201 to the outside of the processing chamber 201. At this time, the valve 243k is opened to supply an inert gas as a purge gas into the processing chamber 201, and the first fluid, by-products, and the like remaining in the processing chamber 201 to the outside of the processing chamber 201. If an inert gas was supplied from the gas supply pipe 232k in the first fluid supply step (S3), the valve 243k may be left open to continue the supply of the inert gas. If inert gas is not being supplied from the gas supply pipe 232k in S3, the valve 243k is opened to supply inert gas as a purge gas into the processing chamber 201, and the first fluid, by-products, etc. remaining in the processing chamber 201 are discharged (purged) outside the processing chamber 201.

[0054] (Concentration detection process) Thereafter, the H in the first fluid remaining in the processing chamber 201 is detected by the gas concentration meter 300b. ２ O ２ The concentration of the detected H ２ O ２ If the concentration of is equal to or greater than a predetermined value, H ２ O ２ The first purge step (S4) is continued until the concentration of H becomes less than a predetermined value, or the operation of the substrate processing apparatus is stopped. ２ O ２ If the concentration is less than a predetermined value, the process proceeds to a second fluid supply step (S5) described below. Note that this step (concentration detection step) may be unnecessary by adjusting the processing time of the first fluid supply step (S3) or S4. In such a case, this step can be omitted. This step may also be performed in parallel with S4.

[0055] After the first fluid supply step (S3), the heater 207 is controlled to adjust the temperature of the wafer 200 to a predetermined temperature in the subsequent second fluid supply step (S5). In this embodiment, the temperature of the wafer 200 may be increased so that the temperature of the wafer 200 in S5 is higher than the temperature of the wafer 200 in S3.

[0056] (Second fluid supplying step: S5) In this step (S5), generation of vaporized gas is started in the gas generator 250b to supply the second fluid containing —COOH to the wafer 200. In this embodiment, the liquid containing —COOH (second liquid) is vaporized to generate the vaporized gas containing —COOH as the second fluid.

[0057] Specifically, first, valves 243e and 243f are opened, and the supply of the second liquid and the second vaporization carrier gas to gas generator 250b is started while the flow rates are controlled by MFCs 241e and 241f, and a vaporized gas (second fluid) of the second liquid containing —COOH is generated by gas generator 250b. At this time, the flow rate and concentration of the second fluid generated by gas generator 250b are adjusted by controlling MFC 241e by controller 121. Note that the second liquid stored in tank 250u is forced out of tank 250u and into supply pipe 232e by opening valve 243i and supplying a second compressed gas to tank 250u while the flow rate is controlled by MFC 241i.

[0058] When the amount and concentration of the second fluid generated are stabilized, the valve 243b is opened, and the supply of the second fluid containing --COOH into the processing chamber 201 begins via the MFC 241b, the gas supply pipes 232b and 232a, and the gas supply port 203p.

[0059] The second fluid supplied into the processing chamber 201 flows downward within the processing chamber 201 and is discharged to the outside of the processing chamber 201 via the exhaust pipe 231. In this step (S5), an inert gas may be supplied into the processing chamber 201, as in the first fluid supply step (S3).

[0060] Examples of processing conditions in the second fluid supplying step include: processing temperature: 200 to 550°C, preferably 250 to 500°C processing pressure: 700 to 1000 hPa, preferably 800 to 980 hPa second fluid supply flow rate: 5 to 20 ccm, preferably 10 to 15 ccm second fluid supply time: 100 to 250 minutes, preferably 120 to 180 minutes second vaporization carrier gas supply flow rate: 3 to 10 slm inert gas supply flow rate: 0 to 10 slm

[0061] By supplying the second fluid to the wafer 200 under the above-described processing conditions, it is possible to reduce the metal oxide film 510 of the Si oxide-containing film 410 and the metal oxide film 510 formed on the wafer 200. More specifically, by supplying the second fluid to the wafer 200 under the above-described processing conditions, it is possible to reduce the metal oxide film 510 while maintaining the Si oxide-containing film 410 in an oxidized state without reducing it (see FIG. 4(c)).

[0062] By supplying the second fluid to the wafer 200 under the above-described processing conditions, the -COOH contained in the second fluid reacts with the -OH formed on the metal oxide film 510 in the above-described first-fluid supplying step (S3), thereby cleaving the -OH. In this way, the second fluid containing -COOH acts as a reducing agent, and can reduce the metal oxide film 510 on the wafer 200 to the metal film 500 (see FIGS. 4(b) and 4(c)).

[0063] In this manner, of the Si-containing film 400 and the metal film 500 formed on the wafer 200, the Si-containing film 400, which is the film to be oxidized, can be selectively oxidized.

[0064] As described above, by setting the processing temperature (temperature of wafer 200) in this step (S5) to a temperature higher than the temperature of wafer 200 in the first fluid supply step (S3) described above, the reduction action of the second fluid can be enhanced.

[0065] If the treatment temperature is less than 200° C., it may be difficult to reduce the metal oxide film 510 at a practical rate. If the treatment temperature is 200° C. or higher, it becomes possible to reduce the metal oxide film 510 at a practical rate. If the treatment temperature is 250° C. or higher, it becomes easy to reduce the metal oxide film 510 at a practical rate.

[0066] If the treatment temperature exceeds 550° C., the metal film 500 and the metal oxide film 510 may be altered. By setting the treatment temperature to 550° C. or less, it is possible to avoid alteration of the metal film 500 and the metal oxide film 510. By setting the treatment temperature to 500° C. or less, it is easy to avoid alteration of the metal film 500 and the metal oxide film 510.

[0067] The second liquid may be a formic acid (HCOOH) solution or an acetic acid (CH ３ Here, the formic acid aqueous solution is a solution of HCOOH, which is a liquid at room temperature, in a solvent such as HCOOH. ２ The aqueous solution of acetic acid is obtained by dissolving it in CH4O, which is a liquid at room temperature. ３ COOH in H as a solvent ２ The second liquid is an aqueous solution obtained by dissolving the compound in O. One or more of these can be used as the second liquid.

[0068] By using a formic acid solution, an acetic acid solution, or the like as the second liquid, the -COOH contained therein reacts with the -OH formed on the metal oxide film 510 in the first fluid supplying step (S3) described above, and the -OH can be easily cleaved. Incidentally, an acetic acid solution contains a large amount of C (carbon) components. In cases where there is a possibility that this C component may unintentionally affect the metal oxide film 510 formed on the wafer 200, it is preferable to use a formic acid solution with a lower C component than acetic acid as the second liquid. By using a formic acid solution as the second liquid, the -COOH contained in the second liquid reacts with the -OH formed on the surface of the metal oxide film 510, and the -OH can be easily cleaved without leaving any impurities.

[0069] As the second vaporization carrier gas, for example, a gas similar to the inert gas described above can be used.

[0070] (Second Purge Step: S6) After a predetermined time has elapsed and the reduction process of the metal oxide film 510 using the second fluid has been completed, the valve 243b is closed to stop the supply of the second fluid to the wafers 200. If an inert gas was supplied from the gas supply pipe 232k in the second fluid supply step (S5), the valve 243k is left open for a predetermined time (e.g., 30 to 60 minutes) to continue the supply of the inert gas. If an inert gas was not supplied from the gas supply pipe 232k in S5, the valve 243k is opened to supply the inert gas as a purge gas into the processing chamber 201 for a predetermined time (e.g., 30 to 60 minutes), and the second fluid, by-products, and the like remaining in the processing chamber 201 are discharged (purged) out of the processing chamber 201.

[0071] (Temperature reduction and atmospheric pressure return process: S7) Thereafter, the processing chamber 201 is evacuated by the vacuum pump 246. Then, an inert gas is supplied into the processing chamber 201 to return the interior to atmospheric pressure, thereby increasing the heat capacity within the processing chamber 201. This allows the wafers 200 and components within the processing chamber 201 to be uniformly heated, and makes it possible to remove particles, impurities, outgassing, etc. that could not be removed by the vacuum evacuation from within the processing chamber 201. After a predetermined time has elapsed, the temperature within the processing chamber 201 is reduced to a predetermined temperature at which the processing chamber 201 can be removed.

[0072] (Substrate Unloading Process: S8) The boat elevator 115 lowers the seal cap 219 to open the bottom end of the reaction tube 203. Then, the processed wafers 200, supported by the boat 217, are unloaded from the bottom end of the reaction tube 203 to the outside of the reaction tube 203. After being unloaded to the outside of the reaction tube 203, the processed wafers 200 are taken out of the boat 217.

[0073] (3) Effects of this Aspect According to this aspect, one or more of the following effects can be obtained.

[0074] (a) A wafer 200 having a Si-containing film 400 and a metal film 500 formed on its surface is treated with H ２ O ２ and a step (S5) of supplying a second fluid containing —COOH. This makes it possible to selectively oxidize the Si-containing film 400, which is the film to be oxidized, among these films.

[0075] Specifically, in the first fluid supply step (S3), not only the Si-containing film 400, which is the film to be oxidized, but also the metal film 500, which is not the film to be oxidized, is oxidized. However, in the second fluid supply step (S5), the metal oxide film 510 can be reduced while maintaining the oxidized state of the Si-containing film 410 (see FIGS. 4(a) to 4(c)). As a result, the Si-containing film 400, which is the film to be oxidized, can be selectively oxidized.

[0076] Furthermore, according to this embodiment, the Si-containing film 400, which is the film to be oxidized, can be selectively oxidized through a relatively simple process without performing a complicated process such as covering the metal film 500, which is not the film to be oxidized, with a hard mask.

[0077] Furthermore, if the metal film 500 is oxidized in the first fluid supply step (S3), the resistivity of the metal film increases, which may result in a deterioration in device characteristics. However, by reducing the oxidized metal film 510 in the second fluid supply step (S5), the resistivity of the metal film can be reduced, and the device characteristics can be restored.

[0078] Generally, when performing oxidation treatment on a specific film, O ２ gas, or hydrogen (H ２ ) Gas and O ２ However, these gases may contain H ２ O ２ Therefore, in the first fluid supply step, the gas containing H ２ O ２ When these gases are used instead of the first fluid containing H, the processing temperature is set to a relatively high temperature (for example, 500 to 700°C) in order to increase the oxidizing power of these gases. In this case, it is considered unavoidable that the metal film 500 formed on the wafer 200 will be excessively oxidized or altered. As a result, even if the oxidized metal film is reduced in the second fluid supply step, the recovery of the metal film's function as, for example, wiring may be insufficient. In contrast, when the H supplied in the first fluid supply step (S3) is used, the processing temperature is set to a relatively high temperature (for example, 500 to 700°C). In this case, the metal film 500 formed on the wafer 200 will be excessively oxidized or altered. As a result, even if the oxidized metal film is reduced in the second fluid supply step, the recovery of the metal film's function as, for example, wiring may be insufficient. ２ O ２The first fluid containing the metal oxide film 510 acts as a strong oxidizing agent, making it possible to carry out the oxidation treatment at a relatively low temperature as described above. This prevents the metal film 500 from being excessively oxidized or altered. Therefore, by reducing the oxidized metal film 510 in the second fluid supplying step (S5), the metal film 500 can regain its functionality as, for example, a wiring.

[0079] In addition, H supplied in the first fluid supply step (S3) ２ O ２ The first fluid containing O acts as a strong oxidizer, ２ Gas, or H ２ Gas and O ２ Compared with an oxidizing agent such as a mixed gas of an oxygen gas and a silicon dioxide gas, the oxygen component can penetrate deep into the Si-containing film 400. This allows oxidation to occur relatively easily deep into the Si-containing film 400.

[0080] (b) By performing the second fluid supplying step (S5) after the first fluid supplying step (S3), the metal oxide film 510 that has been oxidized in S3 can be reduced to the oxide film 500 in S5.

[0081] (c) Because the first fluid is a liquid, it is possible to uniformly oxidize the Si-containing film 400 and the metal film 500 formed on the wafer 200. Because the second fluid is a liquid, it is possible to uniformly reduce the metal oxide film 510 formed on the wafer 200.

[0082] (d) The first fluid supply step (S3) and the second fluid supply step (S5) are not performed simultaneously, so that H ２ O ２ This prevents the first fluid containing —COOH from mixing with the second fluid containing —COOH, thereby suppressing the generation of peracid in the processing chamber 201. As a result, it is possible to prevent the progression of unintended reactions caused by the generation of peracid in the processing chamber 201.

[0083] (e) After the first fluid supply step (S3) and before the second fluid supply step (S5), the first fluid remaining in the processing chamber 201 is discharged (purged) to the outside of the processing chamber 201. As a result, the H 2 ２ O ２ This can reliably prevent the first fluid containing —COOH from mixing with the second fluid containing —COOH supplied in S5. Accordingly, it is possible to reliably suppress the generation of peracid in the processing chamber 201. As a result, it is possible to reliably prevent the progression of unintended reactions caused by the generation of peracid in the processing chamber 201.

[0084] (f) After the first fluid supply step (S3) and before the second fluid supply step (S5), an inert gas is supplied into the processing chamber 201, and the first fluid and the like remaining in the processing chamber 201 are discharged (purged) to the outside of the processing chamber 201. As a result, the H 2 supplied in S3 is discharged into the processing chamber 201. ２ O ２ This can reliably prevent the first fluid containing —COOH from mixing with the second fluid containing —COOH supplied in S5. Accordingly, it is possible to reliably suppress the generation of peracid in the processing chamber 201. As a result, it is possible to reliably prevent the progression of unintended reactions caused by the generation of peracid in the processing chamber 201.

[0085] (g) After the first fluid supply step (S3) and before the second fluid supply step (S5), H in the first fluid in the processing chamber 201 ２ O ２ The concentration of the detected H ２ O ２ If the concentration of is equal to or greater than a predetermined value, H ２ O ２ The first purge step (S4) is continued until the concentration of H2 becomes less than a predetermined value, or the operation of the substrate processing apparatus is stopped. ２ O ２This more reliably prevents the first fluid containing —COOH from mixing with the second fluid containing —COOH supplied in S5. Accordingly, it is possible to reliably suppress the generation of peracid in the processing chamber 201. As a result, it is possible to reliably prevent the progression of unintended reactions caused by the generation of peracid in the processing chamber 201.

[0086] (h) The processing temperature (temperature of the wafer 200) in the second fluid supply step (S5) is set to a temperature higher than the temperature of the wafer 200 in the first fluid supply step (S3). This enhances the reducing action of the second fluid, thereby improving throughput.

[0087] (i) A gas generator 250a is provided in the first fluid supply system that supplies the first fluid, and a gas generator 250b different from the gas generator 250a is provided in the second fluid supply system that supplies the second fluid. ２ O ２ This can reliably prevent the first fluid containing —COOH from mixing with the second fluid containing —COOH. Accordingly, it is possible to reliably suppress the generation of peracid within the gas generator. As a result, it is possible to reliably avoid the progression of unintended reactions caused by the generation of peracid within the gas generator.

[0088] 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.

[0089] For example, in the above-described embodiment, the first fluid is H ２ O ２ However, the present disclosure is not limited to this embodiment. ２ O ２ The vapor containing hydrogen peroxide or hydrogen peroxide solution (liquid) may be used. In this embodiment, the same effects as those in the above-mentioned embodiment can be obtained.

[0090] For example, in the above-described embodiment, when the second fluid is a gas containing —COOH, specifically, when the second fluid is HCOOH or CH ３The second fluid is a gas containing COOH, but the present disclosure is not limited to this. ３ It may be a vapor or liquid containing COOH, for example, HCOOH or CH ３ The vapor containing COOH may be a gas or vapor containing formic acid or a gas or vapor containing acetic acid. ３ The liquid containing COOH may be a liquid such as a formic acid solution or an acetic acid solution. In this embodiment, the same effects as those in the above embodiment can be obtained.

[0091] For example, in the above-described embodiment, the Si-containing film 400 formed on the surface of the wafer 200 is a Si film. However, the present disclosure is not limited to this embodiment. The Si-containing film 400 may be, for example, an oxide film such as a SiO film or a nitride film such as a SiN film. This embodiment also provides the same effects as the above-described embodiment.

[0092] For example, although not described in the above embodiment, the metal material constituting the metal film 500 may be, for example, cobalt (Co), copper (Cu), tungsten (W), or ruthenium (Ru). It is preferable to set the processing time of the first fluid supply step (S3) and the processing time of the second fluid supply step (S5) depending on the type of metal material constituting the metal film 500. It is also preferable to determine the upper limit of the processing temperature in S3 or S5 depending on the type of metal material constituting the metal film 500. This embodiment also achieves the same effects as the above embodiment. Furthermore, this embodiment can achieve appropriate reduction while suppressing excessive oxidation and modification of the metal film 500.

[0093] For example, although not specifically described in the above embodiment, the processing time of the first fluid supply step (S3) and the processing time of the second fluid supply step (S5) may be different. Specifically, the processing time of S3 and the processing time of S5 may be different depending on the properties and constituent materials of the Si-containing film 400 and the metal film 500 formed on the wafer 200. For example, if the oxidation rate of the Si-containing film 400 in S3 is higher than the reduction rate of the metal oxide film 510 in S5, the processing time of S3 may be shorter than the processing time of S5. If the oxidation rate of the Si-containing film 400 in S3 is lower than the reduction rate of the metal oxide film 510 in S5, the processing time of S3 may be longer than the processing time of S5. This embodiment also achieves the same effects as the above embodiment. Furthermore, this embodiment can prevent excessive oxidation of the metal film 500 while allowing the O component to penetrate deep into the Si-containing film 400.

[0094] For example, although not specifically described in the above embodiment, the Si-containing film 400, which is the film to be oxidized, can be selectively oxidized by performing a cycle of the above-described first fluid supply step (S3) to second purge step (S6) asynchronously, i.e., in this order, once. However, the above-described cycle may be repeated multiple times depending on the film thickness of the Si-containing film 400. This embodiment also achieves the same effects as the above embodiment. Furthermore, this embodiment can prevent excessive oxidation of the metal film 500 while allowing the O component to penetrate deep into the Si-containing film 400.

[0095] 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 among the multiple recipes recorded and stored in the storage device 121c. This makes it possible to reproducibly form films with various film types, composition ratios, film qualities, and film thicknesses using a single substrate processing apparatus. It also reduces the burden on the operator, avoids operational errors, and enables each process to be started quickly.

[0096] 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. 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 200 wafers (substrates)

Claims

1. A substrate processing method comprising: (a) a step of supplying a first fluid containing hydrogen peroxide to a substrate having a silicon-containing film and a metal film formed thereon; and (b) a step of supplying a second fluid containing a carboxy group to the substrate.

2. The substrate processing method according to claim 1, wherein the first fluid is an oxidizing agent and the second fluid is a reducing agent.

3. The substrate processing method according to claim 1, wherein the first fluid is a gas or vapor containing hydrogen peroxide.

4. The substrate processing method according to claim 1, wherein the second fluid is a gas or vapor containing formic acid.

5. The substrate processing method according to claim 1, wherein the second fluid is a gas or vapor containing acetic acid.

6. The method of claim 1, wherein (b) is performed after (a).

7. The substrate processing method according to claim 1, further comprising the step of: (c) purging the first fluid from within the processing chamber in which the substrate is present, after (a) and before (b).

8. The substrate processing method according to claim 7, wherein in (c), an inert gas is supplied into the processing chamber to purge the first fluid.

9. The substrate processing method according to claim 7 or 8, further comprising the step of: (d) detecting a concentration of hydrogen peroxide in the first fluid in the processing chamber in which the substrate is present, after (a) and before (b).

10. The substrate processing method of claim 9, further comprising: if the concentration of hydrogen peroxide detected in (d) is equal to or greater than a predetermined value, continuing with (c) or stopping operation of the substrate processing apparatus in which the substrate is processed; and if the concentration of hydrogen peroxide detected in (d) is less than a predetermined value, proceeding to (b).

11. The method of claim 1, further comprising performing a cycle including (a) and (b) one or more times.

12. The substrate processing method according to claim 3, wherein in (a), the time for which the first fluid is retained in the processing chamber in which the substrate is present is set to a time for which the first fluid does not become liquid.

13. The substrate processing method according to claim 1, wherein the temperature of the substrate in (b) is higher than the temperature of the substrate in (a).

14. The substrate processing method according to claim 1, wherein the processing time of (a) is made different from the processing time of (b).

15. The substrate processing method of claim 1, wherein in (a), the first fluid oxidizes the silicon-containing film and the metal film, and in (b), the second fluid reduces the metal film that was oxidized in (a).

16. The substrate processing method of claim 1, wherein in (a), the first fluid penetrates the silicon-containing film with an oxygen component and forms a hydroxyl group on the metal film, and in (b), a carboxyl group contained in the second fluid reacts with a hydroxyl group on the metal film to cleave the hydroxyl group on the metal film.

17. A method for manufacturing a semiconductor device, comprising: (a) a step of supplying a first fluid containing hydrogen peroxide to a substrate having a silicon-containing film and a metal film formed thereon; and (b) a step of supplying a second fluid containing a carboxy group to the substrate.

18. A substrate processing apparatus comprising: a first fluid supply system that supplies a first fluid containing hydrogen peroxide to a substrate; a second fluid supply system that supplies a second fluid containing a carboxy group to the substrate; and a control unit configured to be capable of controlling the first fluid supply system and the second fluid supply system so as to perform: (a) a process of supplying the first fluid to a substrate having a silicon-containing film and a metal film formed thereon; and (b) a process of supplying the second fluid to the substrate.

19. The substrate processing apparatus according to claim 18, wherein the first fluid supply system is provided with a first vaporizer, and the second fluid supply system is provided with a second vaporizer different from the first vaporizer.

20. A program for causing a substrate processing apparatus to execute, by a computer, the steps of: (a) supplying a first fluid containing hydrogen peroxide to a substrate having a silicon-containing film and a metal film formed thereon; and (b) supplying a second fluid containing a carboxy group to the substrate.

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