JP6836655B2 - Substrate processing equipment, semiconductor equipment manufacturing methods and programs - Google Patents

Description

The present invention relates to a substrate processing apparatus, a method for manufacturing a semiconductor apparatus, and a program.

As one step in the manufacturing process of a semiconductor device, a substrate processing step of processing a film formed on the surface of the substrate by supplying a processing gas containing hydrogen peroxide to the substrate may be performed (for example, a patent). Refer to Documents 1 and 2).

International Publication No. 2014/069826 International Publication No. 2013/070343

An object of the present invention is to provide a technique capable of facilitating the formation of a film having desired properties, densities, etc. in a substrate treatment performed using hydrogen peroxide.

According to one aspect of the present invention, a processing chamber for processing a substrate, a vaporizer for vaporizing a solution containing hydrogen peroxide and supplying vaporized gas to the processing chamber, and a concentration of hydrogen peroxide are the first concentration. A first liquid supply system configured to supply the above first solution to the vaporizer, and a second solution in which the concentration of hydrogen peroxide is lower than the first concentration and equal to or lower than the second concentration. A technique is provided that comprises a second liquid supply system configured to supply the vaporizer.

According to the present invention, it is possible to facilitate the formation of a film having desired characteristics, densities and the like in a substrate treatment performed using hydrogen peroxide.

It is a schematic block diagram of the vertical processing furnace of the substrate processing apparatus which concerns on 1st Embodiment of this invention, and is the figure which shows the processing furnace part in the vertical sectional view. It is a schematic vertical sectional view of the gas generator of the substrate processing apparatus which concerns on 1st Embodiment of this invention. It is a schematic block diagram of the controller of the substrate processing apparatus which concerns on 1st Embodiment of this invention, and is the figure which shows the control system of the controller by the block diagram. It is a flow chart which shows an example of the pretreatment process. It is a flow chart which shows an example of the substrate processing process which is carried out after a pre-processing process. It is a schematic block diagram of the vertical processing furnace of the substrate processing apparatus which concerns on 2nd Embodiment of this invention, and is the figure which shows the processing furnace part in the vertical sectional view. It is a schematic block diagram of the vertical processing furnace of the substrate processing apparatus which concerns on 3rd Embodiment of this invention, and is the figure which shows the processing furnace part in the vertical sectional view. It is a schematic block diagram of the vertical processing furnace of the substrate processing apparatus which concerns on 4th Embodiment of this invention, and is the figure which shows the processing furnace part in the vertical sectional view. It is a figure which shows the comparison result of the film density and the film shrinkage rate of the silicon oxide film formed by Comparative Example 1 to Comparative Example 3 and Example respectively. It is a figure which shows the measurement result of FT-IR (Fourier transform infrared spectroscopy) of the silicon oxide film formed by Comparative Example 1 and Example respectively.

<First Embodiment of the present invention>
Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 to 5.

(1) Configuration of Substrate Processing Device 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 the upper end and a furnace opening (opening) at the lower end. There is. A processing chamber 201 is formed in the hollow portion of the reaction tube 203. The processing chamber 201 is configured to accommodate a plurality of wafers 200 as substrates.

Below the reaction tube 203, a seal cap 219 is provided 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. An O-ring 220 is provided on the upper surface of the seal cap 219. A rotation mechanism 267 is installed below the seal cap 219. The rotation shaft 255 of the rotation mechanism 267 is connected to the boat 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the boat 217. The bearing portion 219s of the rotating shaft 255 provided on the rotating shaft 255 is configured as a fluid seal such as a magnetic seal. The seal cap 219 is configured to be vertically raised and lowered by a boat elevator 115 as an elevating mechanism.

The boat 217 as a substrate support supports a plurality of wafers, for example 25 to 200 wafers, in a horizontal position and vertically aligned with each other, that is, in multiple stages. It is configured to be arranged at intervals. 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 at the top and bottom. The heat insulating body 218 supported in multiple stages in a horizontal posture under the boat 217 is made of a heat-resistant material such as quartz or SiC.

A heater 207 as a heating unit is provided on the outside of the reaction tube 203. The heater 207 not only heats the wafer 200 housed in the wafer storage area to a predetermined temperature, but also functions as a liquefaction suppressing mechanism that applies heat energy to the gas supplied into the processing chamber 201 to suppress the liquefaction. , It functions as an excitation mechanism that activates this gas with heat. In the processing chamber 201, a temperature sensor 263 as a temperature detection unit is provided along the inner wall of the reaction tube 203.

A gas supply pipe 232a is connected to the gas supply port 203p provided at the upper end of the reaction pipe 203. The gas supply pipe 232a includes a gas generator 250a as a vaporizer, a mass flow controller (MFC) 241a as a flow rate controller (flow control unit), a valve 243a as an on-off valve, and a gas concentration meter 300a in order from the upstream side. It is provided.

A gas supply pipe 232b for supplying a carrier gas (dilution gas) is connected to the downstream side of the gas supply pipe 232a with respect to the valve 243a and upstream of the gas concentration meter 300. The gas supply pipe 232b is provided with an MFC 241b and a valve 243b. As the carrier gas, oxygen (O ₂₎ oxygen (O) containing gas or the like gas, nitrogen (N ₂₎ gas or an inert gas such as a noble gas, or can be used a mixture of these gases.

A liquid supply pipe 232c as a first supply pipe for supplying a liquid raw material as a first solution is connected to the gas generator 250a. As the liquid raw material as the first solution, a hydrogen peroxide solution having a hydrogen peroxide (H ₂ O ₂ ) content concentration of the first concentration or more is used. Here, the example of the first concentration is 30%, and as a typical example of a predetermined concentration equal to or higher than the first concentration, the concentration of the liquid raw material in the present embodiment is 31%. Here, the hydrogen peroxide solution is an aqueous solution obtained by dissolving H2O2, which is a liquid at room temperature, in water (H2O) as a solvent. The liquid supply pipe 232c is provided with a raw material tank 250t as a storage tank (reservoir tank) for storing the liquid raw material, a liquid MFC (LMFC) 241c, and a valve 243c.

A liquid supply pipe 232d as a second supply pipe for supplying a liquid raw material for dilution, which is a second solution, on the downstream side of the liquid supply pipe 232c of the valve 243c and on the upstream side of the gas generator 250a. Is connected. As the diluting liquid raw material which is the second solution, a _{hydrogen peroxide solution having a concentration of H 2} O ₂ lower than the first concentration (30% in this case) and a second concentration or less is used. Here, an example of the second concentration is 2%, and as a typical example of a predetermined concentration equal to or lower than the second concentration, the concentration of the liquid raw material for dilution in the present embodiment is 0% (that is, pure water is used). .. Incidentally, the pure water containing a concentration of 0% H ₂ O ₂ also contains H ₂ O ₂ concentrations are included in the lower aqueous than the first concentration. The liquid supply pipe 232d is provided with an LMFC 241d and a valve 243d.

That is, by connecting the liquid supply pipe 232d to the liquid supply pipe 232c on the upstream side of the gas generator 250a, a solution in which the liquid raw material and the liquid raw material for dilution are mixed can be supplied to the gas generator 250a. It is composed. That is, the gas generator 250a is _{a solution in which hydrogen peroxide solution having a H 2} O ₂ content of 30% or more and pure water is mixed, for example, the H ₂ O ₂ content is about 5%. A diluted hydrogen peroxide solution can be supplied.

_{Here, the predetermined concentration of H 2} O ₂ equal to or higher than the first concentration (30%) of the hydrogen peroxide solution used as the liquid raw material diluted with pure water is particularly the hydrogen peroxide solution used industrially. As a general concentration of about 31%, it is generally desirable that H ₂ O ₂ in the solution is 35% or less, which is the upper limit concentration capable of maintaining a chemically stable state.

A pumping gas supply pipe 232f for supplying pumping gas into the raw material tank 250t is connected to the raw material tank 250t. The gas supply pipe 232f is provided with an MFC 241f and a valve 243f. The pumping gas is used to push the liquid raw material in the raw material tank 250t into the liquid supply pipe 232c, and for example, a gas similar to the carrier gas can be used. Further, the raw material tank 250t is provided with 232 g of a drain pipe for discharging the liquid raw material from the inside thereof. The drain pipe 232 g is provided with a valve 243 g.

A gas supply pipe 232e for supplying a carrier gas for vaporization is connected to the gas generator 250a. The gas supply pipe 232e is provided with an MFC 241e and a valve 243e. The vaporization carrier gas is used to atomize the solution supplied to the gas generator 250a from the liquid supply pipes 232c and 232d to facilitate vaporization. For example, a gas similar to the carrier gas can be used.

The gas concentration meter 300a measures (detects) the concentration of _{H 2} O ₂ and H ₂ O contained in the processing gas flowing through the gas supply pipe 232a. The gas concentration meter 300a measures the content concentration _{of H 2} O ₂ and H ₂ O in the processing gas by analyzing the spectral spectrum of infrared rays passing through the processing gas flowing in the cell.

The vaporized gas supply system (first supply system) is mainly composed of the gas supply pipe 232a, the MFC 241a, the valve 243a, and the gas concentration meter 300a. The carrier gas supply system (second supply system) is mainly composed of the gas supply pipe 232b, the MFC 241b, and the valve 243b. The first liquid supply system (third supply system) is mainly composed of the raw material tank 250t, the liquid supply pipe 232c, the LMFC241c, and the valve 243c. The second liquid supply system (fourth supply system) is mainly composed of the liquid supply pipe 232d, the LMFC241d, and the valve 243d. A carrier gas supply system for vaporization (fifth supply system) is mainly composed of a gas supply pipe 232e, an MFC 241e, and a valve 243e. The pumping gas supply system (sixth supply system) is mainly composed of the gas supply pipe 232f, the MFC241f, and the valve 243f.

An exhaust pipe 231 that exhausts the atmosphere in the processing chamber 201 is connected below the side wall of the reaction pipe 203. A vacuum pump 246 as an exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 as a pressure detector for detecting the pressure in the processing chamber 201 and an APC valve 244 as a pressure regulator. The exhaust system is mainly composed of an exhaust pipe 231, an APC valve 244, and a pressure sensor 245. The vacuum pump 246 may be included in the exhaust system.

FIG. 2 shows the configuration of the gas generator 250a. The gas generator 250a heats a mixed solution of a liquid raw material and a liquid raw material for dilution to a predetermined temperature (vaporization temperature) in the range of 120 to 200 ° C. under substantially atmospheric pressure, for example, to vaporize or mist the mixture. It is configured to generate vaporized gas by causing it. In the present embodiment, when the diluted hydrogen peroxide solution is vaporized or mistized, the diluted hydrogen peroxide solution is supplied to the gas generator 250a together with the diluted hydrogen peroxide solution. The water is atomizing.

The gas generator 250a gas supplies the vaporization container 101, the vaporization space 102 composed of the vaporization container 101, the vaporizer heater 103 for heating the vaporization container 101, and the vaporization gas generated by vaporizing the hydrogen peroxide solution. A temperature control controller that controls the temperature of the vaporizer heater 103 based on the exhaust port 104 that exhausts (supplies) to the pipe 232a, the thermocouple 105 that measures the temperature of the vaporizer container 101, and the temperature measured by the thermocouple 105. An atomizer 107 that atomizes the hydrogen peroxide solution and supplies it into the vaporization container 101, and a carrier gas introduction port 108 that supplies the carrier gas supplied from the carrier gas supply pipe 232e into the vaporization container 101. It is composed of a heat insulating material 109.

The vaporizer container 101 is heated by the vaporizer heater 103 so that the diluted hydrogen peroxide solution supplied in the form of mist is vaporized in the vaporizer container 101. The vaporization container 101 is made of quartz, SiC, or the like.

The gas obtained by vaporizing the hydrogen peroxide solution contains H2O2 and H2O at predetermined concentrations, respectively. Hereinafter, this gas is also referred to as an H2O2-containing gas. H2O2 contained in the treatment gas is a kind of active oxygen, which is unstable and easily releases oxygen (O), and generates hydroxyl radical (OH radical) having a very strong oxidizing power. Therefore, the H2O2-containing gas acts as a strong oxidizing agent in the substrate processing step described later.

As shown in FIG. 3, the controller 121, which is a control unit, is configured as a computer including a CPU 121a, a RAM 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 so that data can be exchanged with the CPU 121a via the internal bus 121e. An input / output device 122 configured as a touch panel or the like is connected to the controller 121.

The storage device 121c is composed of a flash memory, an HDD, and the like. In the storage device 121c, a control program for controlling the operation of the substrate processing apparatus, a process recipe in which the procedures and conditions for substrate processing described later are described, and the like are readablely stored. The process recipes are combined so that the controller 121 can execute each procedure described later and obtain a predetermined result, and functions as a program. Hereinafter, process recipes, control programs, etc. are collectively referred to simply as programs. In addition, a process recipe is also simply referred to as a recipe. When the term program is used in the present specification, it may include only a recipe alone, a control program alone, or both of them. The RAM 121b is configured as a memory area for temporarily holding programs, data, and the like read by the CPU 121a.

The I / O port 121d includes the above-mentioned MMC241a, 241b, 241e, 241f, LMFC241c, 241d, valves 243a to 243g, gas generator 250a, gas concentration meter 300a, pressure sensor 245, APC valve 244, vacuum pump 246, and heater 207. , Temperature sensor 263, rotation mechanism 267, boat elevator 115 and the like.

The CPU 121a is configured to read and execute a control program from the storage device 121c and read a recipe from the storage device 121c in response to input of an operation command from the input / output device 122 or the like. The CPU 121a has a gas generation operation by the gas generator 250a, a flow rate adjustment operation by the MFC 241a, 241b, 241e, 241f, the LMFC 241c, 241d based on the gas concentration meter 300a, and opening and closing of the valves 243a to 243g so as to follow the contents of the read recipe. Operation, opening / closing operation of APC valve 244 and pressure adjustment operation by APC valve 244 based on pressure sensor 245, start and stop of vacuum pump 246, temperature adjustment operation of heater 207 based on temperature sensor 263, rotation of boat 217 by rotation mechanism 267. It is configured to control the rotation speed adjusting operation, the ascending / descending operation of the boat 217 by the boat elevator 115, and the like.

The controller 121 installs the above-mentioned program stored in an external storage device (for example, a magnetic disk such as an HDD, an optical disk such as a CD, a magneto-optical disk such as an MO, or a semiconductor memory such as a USB memory) 123 in a computer. Can be configured by. The storage device 121c and the external storage device 123 are configured as a computer-readable recording medium. Hereinafter, these are collectively referred to simply as a recording medium. When the term recording medium is used in the present specification, it may include only the storage device 121c alone, it may include only the external storage device 123 alone, or it may include both of them. The program may be provided to the computer by using a communication means such as the Internet or a dedicated line without using the external storage device 123.

(2) Pretreatment Step Here, a pretreatment step performed before performing the substrate treatment step on the wafer 200 will be described with reference to FIG.

As shown in FIG. 4, in this step, the polysilazane (PHPS) coating step (S10) and the prebaking step (S11) are sequentially carried out on the wafer 200. In the PHPS coating step (S10), a coating liquid containing polysilazane (polysilazane solution) is coated on the surface of the wafer 200 by using a technique such as a spin coating method. In the prebaking step (S11), the solvent is removed from the film by heat-treating the wafer 200 on which the coating film is formed. By heat-treating the wafer 200 on which the coating film is formed at a treatment temperature (pre-baking temperature) in the range of, for example, 70 to 250 ° C., the solvent can be volatilized from the coating film. This heat treatment is preferably performed at about 150 ° C.

The coating film formed on the surface of the wafer 200 undergoes the prebaking step (S11) to become a film (polysilazane film) having a silazane bond (-Si-N-) as a silicon-containing film. In addition to silicon (Si), this film contains nitrogen (N) and hydrogen (H), and may further contain carbon (C) and other impurities. In the substrate processing step described later, the polysilazane film formed on the wafer 200 is modified (oxidized).

(3) Substrate Processing Step Next, an example of a substrate processing step carried out as one step of the manufacturing process of the semiconductor device using the above-mentioned substrate processing apparatus will be described with reference to FIG. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the controller 121.

(Board loading process, S20)
A plurality of wafers 200 having a polysilazane film formed on the surface thereof are loaded on the boat 217. After that, 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. In this state, the seal cap 219 is in a state of sealing the lower end of the reaction tube 203.

(Pressure / temperature adjustment process, S21)
After vacuum exhausting (vacuum purging) the inside of the processing chamber 201, that is, the space where the wafer 200 exists, by the vacuum pump 246 for a predetermined time, the valve 243b is opened and the O ₂ gas (carrier gas) into the processing chamber 201 is opened. Supply. At this time, the inside of the processing chamber 201 is continuously exhausted by the vacuum pump 246 so as to reach a predetermined pressure (reform pressure). The pressure in 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. At this time, the state of energization of the heater 207 is feedback-controlled based on the temperature information detected by the temperature sensor 263 so that the wafer 200 has a predetermined temperature. Further, the rotation mechanism 267 starts the rotation of the wafer 200. The operation of the vacuum pump 246 and the heating and rotation of the wafer 200 are all continuously performed until the processing on the wafer 200 is completed.

(Modification step, S22)
Subsequently, the valves 243c, 243d, and 243e were opened, and while the flow rate was controlled by the LMFC 241c, 241d, and MFC 241e, the supply of the diluted hydrogen peroxide solution as a mixed solution and the carrier gas for vaporization to the gas generator 250a was started. The gas generator 250a generates vaporized gas containing _{H 2} O ₂ gas and H _{2 O gas.} At this time, the flow rates of the liquid raw material and the liquid raw material for dilution (particularly, so that the concentration of _{H 2} O ₂ contained in the mixed solution supplied to the gas generator 250a is a predetermined value, for example, about 5%). Flow rate ratio) is adjusted. _{As a result, the ratio of the concentrations of H 2} O ₂ and H ₂ O contained in the vaporized gas is adjusted to a desired value. Specifically, the controller 121 controls at least one of the LMFC 241c and the LMFC 241d so that the concentration of the mixed solution supplied to the gas generator 250a becomes a predetermined value. Further, the concentration of _{H 2} O ₂ contained in the vaporized gas can be adjusted by adjusting the flow rate of the mixed solution. The hydrogen peroxide solution, which is a liquid raw material, is pushed out from the raw material tank 250t to the liquid supply pipe 232c by opening the valve 243f and supplying the pumping gas to the raw material tank 250t while controlling the flow rate by the MFC 241f.

When the amount and concentration of the vaporized gas are stabilized, the valve 243a is opened, and the supply of the vaporized gas as the processing gas into the processing chamber 201 via the gas supply port 203p is started while controlling the flow rate by the MFC 241a. At this time, the processing gas is supplied to the wafer 200. As a result, an oxidation reaction occurs on the surface of the wafer 200, and the polysilazane film on the wafer 200 is modified into a silicon oxide film (SiO film).

_{When supplying the processing gas into the processing chamber 201, the O 2} gas is continuously supplied from the gas supply pipe 232a into the processing chamber 201 while adjusting the flow rate by the MFC 241b. In the present specification, _{the processing gas diluted with O 2} gas may be simply referred to as a processing gas for convenience. By adjusting the flow rate of the O _{2 gas, the concentration of H 2} O ₂ contained in the processing gas can be adjusted to a predetermined value.

Here, in the present embodiment, _{the content concentrations of H 2} O ₂ and H ₂ O contained in the processing gas are measured by the gas concentration meter 300a, and the first liquid supply system is based on the measured content concentration values. And at least one of the second liquid supply systems can also be controlled. _{Specifically, the ratio of the content concentration of H 2} O ₂ and H ₂ O contained in the processing gas acquired by the gas concentration meter 300a is measured, and the value is set to a desired value (for example, about 5:95). The flow rate ratio between the liquid raw material and the liquid raw material for dilution is determined in advance. Then, at least one of the LMFC 241c and the LMFC 241d is controlled by the controller 121 so that the flow rate ratio of the liquid raw material and the diluting liquid raw material becomes a predetermined ratio, and the diluted liquid raw material supplied to the gas generator 250a. Adjust the concentration of. Further, the flow rate ratio of the liquid raw material and the liquid raw material for dilution is controlled by feedback at any time so that the measured ratio becomes a predetermined ratio based on the ratio of the content concentration in the processing gas acquired by the gas concentration meter 300a. You may.

Similarly, in the present embodiment, _{the content concentration of H 2} O ₂ contained in the processing gas is measured by the gas concentration meter 300a, and the first liquid supply system, the second, is based on the measured content concentration value. It is also possible to control at least one of the liquid supply system and the carrier gas supply system of the above. _{Specifically, the content concentration of H 2} O ₂ contained in the processing gas acquired by the gas concentration meter 300a is measured, and the concentration is a desired value (for example, 1.5 to 18.5 mol%, preferably 1.5 to 18.5 mol%). The flow rates of the liquid raw material, the liquid raw material for dilution, and the O _{2 gas so as to be 2.1 to 13.5 mol%) are predetermined.} Then, at least one of LMFC241c, LMFC241d, MFC241b and MFC241e is controlled by the controller 121 so that the flow rates thereof become a predetermined flow rate. Then, _{a processing gas having a desired concentration of H 2} O ₂ can be supplied to the wafer. Further, based on the content concentration value in the processing gas acquired by the gas concentration meter 300a, at least one of the flow rates of the _{liquid raw material, the diluting liquid raw material, and the O 2 gas is adjusted so that the measured value becomes a predetermined value.} Feedback control may be performed at any time.

When the predetermined time elapses and the modification of the polysilazane film to the SiO film is completed, the valve 243a is closed and the supply of the processing gas into the processing chamber 201 is stopped.

The following are examples of processing conditions in the reforming step.
Treatment temperature: 250 ° C or less, preferably 100 ° C or less Treatment pressure: 1100 hPa or less H ₂ O ₂ concentration of diluted hydrogen peroxide solution (mixed solution): less than 30%, preferably 5% or less diluted hydrogen peroxide Supply flow rate of water (mixed solution): 3 ccm
Supply flow rate of O ₂ gas (carrier gas for vaporization): 15000 ccm
Gas supply time: 180 minutes or less, preferably 15 minutes or less

_{Here, H 2} O ₂ contained in the vaporized gas has a very strong oxidizing power as described above. Therefore, when the polysilazane film is oxidized _{by supplying a vaporized gas generated by vaporizing a hydrogen peroxide solution having a H 2} O ₂ content of 30% or more as a processing gas, the film is reformed into an oxide film. Since the speed is relatively high, it is modified into a dense oxide film at a low temperature in a short time, and it is difficult to control the film density and the film characteristics. On the other hand, the oxidation process for the polysilazane film is subjected with steam, very slow the speed of modifying the oxide film at a low temperature compared with the case of using H ₂ O _2, than with H ₂ O ₂ Since it is necessary to perform the treatment at a high temperature or for a long time, there is a problem that the amount of membrane shrinkage increases.

In the present embodiment, containing H ₂ O ₂ concentrations containing concentrations and 31% hydrogen peroxide H ₂ O ₂ as the liquid raw material by mixing 0% deionized water, diluted to about 5% peracetic Hydrogen peroxide water is generated and vaporized to oxidize the polysilazane film. As a result, the reforming rate of the oxide film can be slowed down, and the oxide film can be formed so that the silazane bond remains in the film. That is, it is possible to control the film characteristics and modify the film into a dense oxide film. For example, it is possible to reduce the film density with respect to the polysilazane film, prevent heat shrinkage of the polysilazane film to be oxidized, and reduce the stress applied to the film.

<Modified example of this embodiment>
In the above-described embodiment, _{hydrogen peroxide solution having a H 2} O ₂ content diluted to about 5% is supplied to the gas generator 250a and vaporized, and hydrogen peroxide gas is used as the vaporized processing gas. _{The configuration of supplying H 2} O ₂ into the processing chamber 201 has been described, but the step of supplying a liquid raw material having a high concentration of H 2 O 2 (for example, the first concentration or more) to the gas generator 250a and H ₂ O ₂ The first liquid supply system and the second liquid are alternately performed a predetermined number of times with the step of supplying the liquid raw material for dilution having a low concentration of hydrogen peroxide (for example, equal to or less than the second concentration) to the gas generator 250a. The supply system may be controlled. That is, the step of supplying the vaporized gas of the liquid raw material having a high concentration of _{H 2} O ₂ into the processing chamber 201 and the vaporization gas of the liquid raw material for dilution having a low concentration of _{H 2} O _{2 in the processing chamber.} The step of supplying into 201 may be alternately performed a predetermined number of times. At this time, the step of supplying the vaporized gas of the high-concentration liquid raw material into the processing chamber 201 is shorter than the step of supplying the vaporized gas of the low-concentration liquid raw material for dilution into the processing chamber 201, whereby the polysilazane film is formed. It is advisable to fine-tune the degree of oxidation of. _{For example, the vaporized gas (hydrogen peroxide gas) of hydrogen peroxide solution having a H 2} O ₂ content of 31% is supplied to a 50 μm polysilazane film for 5 minutes, and the vaporized gas (water vapor) of pure water is supplied. May be alternately supplied for 10 minutes.

(Drying step, S23)
When the reforming step is completed, the heater 207 is controlled to heat the wafer 200 to a predetermined temperature (drying temperature) equal to or lower than the prebaking temperature. The drying temperature can be, for example, a temperature in the range of 120 to 160 ° C. After the temperature is raised, the wafer 200 and the inside of the processing chamber 201 are gently dried by maintaining this temperature. The processing pressure in the drying step is, for example, the same as the processing pressure in the reforming step. By performing the drying treatment, by-products and the like separated from the polysilazane film can be removed from the SiO film and its surface.

(Temperature lowering / atmospheric pressure restoration process, S24)
After the drying step is completed, the inside of the processing chamber 201 is evacuated. _{After that, an inert gas such as N 2} gas is supplied into the processing chamber 201 to restore the inside to atmospheric pressure. After a lapse of a predetermined time, the temperature inside the processing chamber 201 is lowered to a predetermined unloadable temperature.

(Board unloading process, S25)
The boat elevator 115 lowers the seal cap 219 to open the lower end of the reaction tube 203. Then, the processed wafer 200 is carried out of the reaction tube 203 from the lower end of the reaction tube 203 while being supported by the boat 217.

(4) Effects of the present embodiment According to the present embodiment, one or more of the following effects can be obtained.
(A) Since the content concentration of _{H 2} O ₂ contained in the treatment gas _{, particularly the ratio of the content concentration of H 2} O ₂ and H ₂ O can be easily adjusted to a desired value, the polysilazane film is oxidized. The degree of modification of hydrogen peroxide can be controlled to form an oxide film so that a silazane bond remains in the film. That is, it is possible to control the film characteristics and form a film according to the application.
(B) For example, impurities such as N and H may form a film in which impurities such as N and H remain in the film, or the density and shrinkage rate of the film may be set within a desired range so as to reduce the film density and reduce the thermal conductivity. Therefore, a film suitable for the intended use can be formed.
(C) In particular, by reducing the film density of the polysilazane film that has been oxidized, the thermal shrinkage of the polysilazane film that is the target of the oxidation treatment is prevented, the thermal conductivity is lowered, and the stress applied to this film is reduced. It becomes possible to do.

<Second Embodiment of the present invention>
Subsequently, a second embodiment of the present invention will be described with reference to FIG. In the following, detailed description of the same configurations and steps as those in the above-described embodiment will be omitted.

In the substrate processing apparatus of the present embodiment, a second liquid supply system (liquid supply pipe 232d, LMFC241d, valve 243d) for supplying the liquid raw material for dilution is connected to the raw material tank 250t. That is, the diluting liquid raw material supplied from the liquid supply pipe 232d is mixed with the liquid raw material in the raw material tank 250t.

Further, a liquid supply pipe 232k provided with an LMFC 241k and a valve 243k is connected to the raw material tank 250t. The undiluted liquid raw material sent from the external liquid raw material supply source is supplied into the raw material tank 250t via the liquid supply pipe 232k. In the present embodiment, the liquid supply pipe 232k, the LMFC 241k, and the valve 243k form a first liquid supply system.

Here, in the first embodiment, the liquid raw material and the liquid raw material for dilution are mixed at the connection portion between the liquid supply pipe 232c and the liquid supply pipe 232d, and _{the concentration of H 2} O ₂ contained in the mixed solution is a predetermined value. While each liquid supply system was controlled so as to be, in the present embodiment, the content concentration of _{H 2} O ₂ contained in the diluted hydrogen peroxide solution which is a mixed solution stored in the raw material tank 250t. Each liquid supply system is controlled so that is also a predetermined value. _{Specifically, the controller 121 makes the content concentration of H 2} O ₂ contained in the mixed solution stored in the raw material tank 250t at least one of the LMFC 241d and the LMFC 241k a predetermined value (for example, about 5%). To control. The concentration of the mixed solution in the raw material tank 250t is adjusted in advance before the supply of the mixed solution to the gas generator 250a is started.

In this concentration adjustment, for example, after opening the valve 243 g and discharging all the solution in the raw material tank 250t, the LMFC241d and the LMFC241k are controlled respectively, and the liquid raw material and the liquid raw material for dilution are each controlled by a predetermined amount (at a predetermined ratio). By supplying the raw material tank to 250 tons, a mixed solution having a predetermined concentration can be stored. Either one of the liquid raw material and the liquid raw material for dilution may be first supplied into the raw material tank 250t and then mixed.

Further, a concentration sensor for measuring _{the H 2} O ₂ content concentration of the solution in the raw material tank 250t may be further provided. Based on the concentration measured by the concentration sensor, the flow rate of at least one of LMFC241d and LMFC241k is controlled so that the concentration of the solution in the raw material tank 250t becomes a predetermined value, and at least one of the liquid raw material and the liquid raw material for dilution is controlled. By supplying one of them into the raw material tank 250t, a mixed solution having a predetermined concentration can be stored.

_{Then, in the reforming step (S22), the valve 243f is opened in a state where the content concentration of H 2} O ₂ contained in the mixed solution in the raw material tank 250t is a predetermined value, and the pumping gas is supplied to the raw material tank 250t. As a result, the mixed solution is extruded from the raw material tank 250t into the liquid supply pipe 232c and supplied to the gas generating unit 250a via the LMFC 241c and the valve 243c. That is, it is possible to stably supply the mixed solution having _{a constant H 2} O _{2 content concentration to the gas generator 250a.} Then, when the amount and concentration of the vaporized gas are stabilized, the valve 243a is opened, and the supply of the vaporized gas as the processing gas into the processing chamber 201 is started while controlling the flow rate by the MFC 241a.

<Third Embodiment of the present invention>
Subsequently, the third embodiment of the present invention will be described with reference to FIG.

The substrate processing apparatus of the present embodiment includes two, a gas generator 250a as a first vaporizer for vaporizing the liquid raw material and a gas generator 250b as a second vaporizer for vaporizing the liquid raw material for dilution. .. Then, the first vaporized gas generated by the gas generator 250a and the second vaporized gas generated by the gas generator 250b are supplied into the processing chamber 201 via the gas supply ports 203p and 203q, respectively.

Specifically, the gas supply pipe 232j is connected to the gas supply port 203q provided at the upper end of the reaction pipe 203. The gas supply pipe 232j is provided with a gas generator 250b, an MFC241j, a valve 243j, and a gas concentration meter 300b.

A gas supply pipe 232i for supplying a carrier gas for vaporization is connected to the gas generator 250b. The gas supply pipe 232i is provided with an MFC 241i and a valve 243i. A gas supply pipe 232h for supplying carrier gas is connected to the gas supply pipe 232j. The gas supply pipe 232h is provided with an MFC 241h and a valve 243h. The gas concentration meter 300b measures (detects) the contents of _{H 2} O ₂ and H ₂ O contained in the second vaporized gas flowing through the gas supply pipe 232j.

In the present embodiment, the gas supply pipe 232h, the MFC 241h, and the valve 243h mainly constitute a second carrier gas supply system (seventh supply system). Mainly, the gas supply pipe 232i, the MFC 241i, and the valve 243i form a second vaporization carrier gas supply system (eighth supply system). A second vaporized gas supply system (9th supply system) is mainly composed of a gas supply pipe 232j, an MFC241j, a valve 243j, a gas generator 250b, and a gas concentration meter 300b.

In the reforming step (S22) in the present embodiment, the first vaporized gas supply system and the first vaporized gas supply system and the first vaporization gas supply system are based on the contents of _{H 2} O ₂ and H ₂ O measured by the gas concentration meter 300a and the gas concentration meter 300b, respectively. Control at least one of the vaporized gas supply systems of 2.

Specifically, the ratio of the content concentration of _{H 2} O ₂ and H ₂ O contained in the processing gas supplied into the processing chamber 201, that is, the mixed gas of the processing gas supplied from the gas supply ports 203p and 203q, respectively. The flow rate of at least one of MFC241a and MFC241j is controlled by the controller 121 so that That is, each of the processing and the vaporized gas of the liquid material, a vaporized gas dilution liquid source having a constant H ₂ O ₂ and H ₂ O concentration ratios with a constant H ₂ O ₂ and H ₂ O concentration ratio The gas is supplied into the processing chamber 201 via the gas supply ports 203p and 203q.

Further, by controlling the flow rate of at least one of the LMFC241c and the LMFC241d, the supply amount of at least one of the liquid raw material supplied to the gas generator 250a and the liquid raw material for dilution supplied to the gas generator 250b is adjusted. _{Then, the contents concentrations of H 2} O ₂ and H ₂ O in the processing gas supplied from the first vaporization gas supply system and the second vaporization gas supply system may be adjusted, respectively.

_{Instead of the gas concentration meter 300a and the gas concentration meter 300b, the content of H 2} O ₂ and H ₂ O in the processing gas measured by a gas concentration meter (not shown) provided in the processing chamber 201 or the exhaust pipe 231 is provided. Based on the concentration, the first vaporized gas supply system and the second vaporized gas so that the ratio of the contents of _{H 2} O ₂ and H ₂ O contained in the mixed gas in the processing chamber 201 becomes a predetermined ratio. The supply system may be controlled.

Further, the LMFC 241c is set so that the flow rates of the liquid raw material, the diluting liquid raw material, and the diluting carrier gas supplied to the gas generators 250a and 250b are set to preset values without using the gas concentration meters 300a and 300b. , LMFC241d, MFC241e, MFC241i, etc. so that the ratio of the content concentration of _{H 2} O ₂ and H _{2 O in the processing gas in the processing chamber 201 and the content concentration of H 2} O ₂ become desired values. It may be. In this case, the set value of each flow rate can be determined based on, for example, a prior experiment.

<Fourth Embodiment of the present invention>
Subsequently, a fourth embodiment of the present invention will be described with reference to FIG.

In the third embodiment described above, an example in which the first vaporized gas supply system and the second vaporized gas supply system are independently connected to the processing chamber 201 has been described, but the substrate processing apparatus of the present embodiment has been described. The difference is that the first vaporized gas supply system and the second vaporized gas supply system are connected (merged) upstream of the processing chamber 201. That is, the processing gases supplied from each of the first vaporized gas supply system and the second vaporized gas supply system are mixed in the gas supply pipe 232a and supplied into the processing chamber 201.

Specifically, the second vaporized gas supply system is connected to the downstream side of the gas concentration meter 300a of the first vaporized gas supply system. A first carrier gas supply system (gas supply pipe 232b, MFC241b, valve 243b) is connected to the downstream side of the connection portion between the first vaporization gas supply system and the second vaporization gas supply system. A gas concentration meter 300c is provided on the downstream side of the connection portion between the first vaporized gas supply system and the first carrier gas supply system. The gas concentration meter 300c measures the content concentration of _{H 2} O ₂ and H ₂ O contained in the mixed gas of the first vaporized gas and the second vaporized gas.

Then, in the reforming step (S22) according to the present embodiment, the first vaporization gas supply system and the second vaporization are based on _{the H 2} O ₂ and H _{2 O content concentrations measured by the gas concentration meter 300c.} Control at least one of the gas supply systems. Specifically, at least one of MFC241a and MFC241j is operated by the controller 121 so that the ratio of the _{H 2} O ₂ and the H ₂ O content in the mixed gas measured by the gas concentration meter 300c becomes a predetermined ratio. Flow rate control.

Further, by controlling the flow rate of at least one of the LMFC 241c and the LMFC 241d, the supply amount of at least one of the liquid raw material supplied to the gas generator 250a and the liquid raw material for dilution supplied to the gas generator 250b is adjusted, and the first supply amount is adjusted. _{The content concentrations of H 2} O ₂ and H ₂ O in the processing gas supplied from the vaporized gas supply system and the second vaporized gas supply system, respectively, may be adjusted.

It should be noted that, without providing the gas concentration meter 300c, the gas is supplied into the processing chamber 201 based on the contents _{of H 2} O ₂ and H ₂ O in the processing gas measured by the gas concentration meter 300a and the gas concentration meter 300b, respectively. The first vaporization gas supply system and the second vaporization gas supply system may be controlled so that the ratio of the contents of _{H 2} O ₂ and H ₂ O contained in the mixed gas to be mixed gas becomes a predetermined ratio. ..

Further, as in the third embodiment, the liquid raw material, the diluting liquid raw material, and the diluting carrier gas supplied to the gas generators 250a and 250b, respectively, without using any of the gas concentration meters 300a, 300b, and 300c. By controlling the LMFC241c, LMFC241d, MFC241e, MFC241i, etc. so that the flow rate becomes a preset value, the ratio of the content concentration of _{H 2} O ₂ and H _{2 O in the processing gas in the processing chamber 201 and H 2} The O ₂ content may be set to a desired value.

In the third embodiment and the fourth embodiment described above, the configuration in which the first vaporized gas vaporized from the liquid raw material and the second vaporized gas vaporized from the liquid raw material for dilution are simultaneously supplied has been described. , The step of supplying the first vaporized gas and the step of supplying the second vaporized gas may be alternately performed a predetermined number of times as in the modified example of the first embodiment. At this time, the step of supplying the first vaporized gas may be shorter than the step of supplying the second vaporized gas. In the third embodiment and the fourth embodiment, since the gas generators 250a and 250b are provided, respectively, the supply of the liquid raw material and the liquid raw material for dilution is switched and the vaporization temperature in the gas generator is changed for each step. It is not necessary and is more suitable for carrying out this modification.

<Other Embodiments of the Present Invention>
Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist thereof.

In the above-described embodiment, an example of processing a substrate on which a polysilazane film is formed has been shown, but the present invention is not limited thereto. That is, even if the film to be treated is not a polysilazane film, the same effect as that of the above-described embodiment can be obtained.

In the above-described embodiment, an example of treating the polysilazane film formed by performing the PHPS coating step and the prebaking step has been described, but the present invention is not limited thereto. For example, even when a silicon-containing film such as a polysilazane film formed by the Flowable CVD method and not prebaked is treated, the same effect as that of the above-described embodiment can be obtained.

In the above-described embodiment, the configuration in which the liquid supply system for supplying the liquid raw material for dilution does not include the raw material tank has been described, but the liquid supply system for supplying the liquid raw material for dilution may also have a configuration in which the raw material tank is provided. In particular, when a solution containing hydrogen peroxide is used as the liquid raw material for dilution, it is desirable to provide a raw material tank.

The above-described embodiments and modifications can be used in combination as appropriate. Further, the processing procedure and processing conditions at this time can be, for example, the same processing procedure and processing conditions as those in the above-described embodiment.

<Example>
Hereinafter, examples of the present invention will be described.

In this embodiment, the 200 nm-thick polysilazane film coated on the wafer was oxidized under the respective conditions using the substrate processing apparatus shown in FIG. 1 to form a silicon oxide film on the wafer. .. Except for the points shown below, the treatment was carried out under the same steps and conditions as the treatment step shown in the first embodiment.

In the reforming step (S22) in the above-described embodiment, as Comparative Example 1, _{hydrogen peroxide gas obtained by vaporizing a hydrogen peroxide solution having a H 2} O ₂ content of 30% is supplied at 100 ° C. for 15 minutes for oxidation treatment. Was done. Further, as Comparative Example 2, steam obtained by vaporizing pure water was supplied at 200 ° C. for 60 minutes to perform an oxidation treatment. Further, as Comparative Example 3, steam obtained by vaporizing pure water was supplied at 250 ° C. for 60 minutes to perform an oxidation treatment. Further, as an example of this embodiment, hydrogen peroxide gas obtained by vaporizing a hydrogen peroxide solution diluted to a _{H 2} O _{2 content concentration of 5% is supplied at 100 ° C. for 15 minutes upstream of the gas generator 250a for oxidation treatment.} went.

FIG. 9 is a diagram showing a comparison result of the film density and the film shrinkage rate of the silicon oxide film formed by Comparative Examples 1 to 3 and Examples, respectively. The vertical axis of FIG. 9 shows the film density (g / cm ³ ), and the horizontal axis shows the film shrinkage rate (%). The film density was measured using XRR (X-ray reflectivity method). According to FIG. 9, it can be seen that the film formed by this example had a lower film density and a lower film shrinkage rate than the film formed by Comparative Examples 1 to 3. That is, it can be said that the film shrinkage rate could be reduced by using _{H 2} O ₂ as the processing gas, and the film density could be reduced by reducing the _{H 2} O _{2 content concentration to less than 30%.} ..

FIG. 10 is a diagram showing the measurement results of FT-IR of the silicon oxide film formed by Comparative Example 1 and Example, respectively. The vertical axis of FIG. 10 shows the absorbance, and the horizontal axis shows the wave number. As shown in FIG. 10, in the oxide film formed by this example, peaks indicating the presence of Si—OH, Si—N, and N—H remain, and OH groups and N are present in the film. , O, etc. remain at a significant concentration. On the other hand, it can be seen that the oxide film formed in Comparative Example 1 has an almost complete Si—O structure. That is, it can be said that the film characteristics can be controlled by controlling the amount of components such as OH groups and N, O in the film by adjusting the content concentration of _{H 2} O _2.

200 wafers (board)
201 processing room

Claims (15)

A processing room for processing the substrate and
A vaporizer that vaporizes a solution containing hydrogen peroxide and supplies vaporized gas to the processing chamber.
A first liquid supply system configured to supply a first solution having a hydrogen peroxide concentration equal to or higher than the first concentration to the vaporizer.
A second liquid supply system configured to supply the vaporizer with a second solution in which the concentration of hydrogen peroxide is lower than the first concentration and equal to or lower than the second concentration.
Have a,
A substrate processing apparatus in which a solution obtained by mixing the first solution and the second solution is supplied to the vaporizer. The substrate processing apparatus according to claim 1, wherein the first solution and the second solution are aqueous solutions. The substrate processing apparatus according to claim 2, wherein the second solution is pure water. The first liquid supply system has a first supply pipe for supplying the first solution.
The second liquid supply system has a second supply pipe for supplying the second solution.
It said first supply pipe and the second supply pipe is a substrate processing apparatus according to claim 1, characterized in that connected upstream of the evaporator. It also has a storage tank to store the solution supplied to the vaporizer.
The first liquid supply system has a first supply pipe for supplying the first solution.
The second liquid supply system has a second supply pipe for supplying the second solution.
The first and the second supply pipe and the supply pipe of the substrate processing apparatus according to claim 1, wherein connected to each of the storage tank. The first liquid supply system and the second liquid supply system so that the concentration of hydrogen peroxide contained in the mixed solution of the first solution and the second solution becomes a predetermined value. configured control unit to control at least one substrate processing apparatus according to claim 1, further comprising a. The first liquid supply system and the above so that the concentration of hydrogen peroxide contained in the mixed solution of the first solution and the second solution stored in the storage tank becomes a predetermined value. The substrate processing apparatus according to claim 5 , further comprising a control unit configured to control at least one of the second liquid supply systems. Control configured to control at least one of the first liquid supply system and the second liquid supply system so that the ratio of the concentration of hydrogen peroxide and water contained in the vaporized gas becomes a predetermined value. The substrate processing apparatus according to claim 2, further comprising a unit. Further having a gas concentration meter for measuring the concentration of hydrogen peroxide and water contained in the vaporized gas,
The control unit is configured to control at least one of the first liquid supply system and the second liquid supply system based on the values of the concentrations of hydrogen peroxide and water measured by the gas concentration meter. The substrate processing apparatus according to claim 8. It has a control unit configured to control at least one of the first liquid supply system and the second liquid supply system so that the concentration of hydrogen peroxide contained in the vaporized gas becomes a predetermined value. The substrate processing apparatus according to claim 1. Further having a gas densitometer for measuring the concentration of hydrogen peroxide contained in the vaporized gas,
The control unit is configured to control at least one of the first liquid supply system and the second liquid supply system based on the value of the concentration of hydrogen peroxide measured by the gas concentration meter. The substrate processing apparatus according to claim 10. A processing room for processing the substrate and
A vaporizer that vaporizes a solution containing hydrogen peroxide and supplies vaporized gas to the processing chamber.
A first liquid supply system configured to supply a first solution having a hydrogen peroxide concentration equal to or higher than the first concentration to the vaporizer.
A second liquid supply system configured to supply the vaporizer with a second solution in which the concentration of hydrogen peroxide is lower than the first concentration and equal to or lower than the second concentration.
The first liquid supply system and the second liquid supply system so that the step of supplying the first solution to the vaporizer and the step of supplying the second solution to the vaporizer are alternately performed a predetermined number of times. a control unit configured to control the liquid supply system,
Board processor that have a. The substrate processing apparatus according to claim 1, wherein a film containing a silazane bond is formed on the substrate. The process of bringing the substrate into the processing chamber and
A first liquid supply system configured to supply a first solution having a hydrogen peroxide concentration equal to or higher than the first concentration to the vaporizer, and a second liquid having a hydrogen peroxide concentration lower than the first concentration. A mixed solution of the first solution and the second solution, which are supplied from the second liquid supply system configured to supply the second solution having a concentration equal to or less than the above-mentioned vaporizer to the vaporizer. The process of supplying to the vaporizer and
A step of vaporizing the first solution and the second solution by the vaporizer to generate a vaporized gas, and
A step of supplying the vaporized gas to the processing chamber to modify the silicon-containing film formed on the substrate, and a step of modifying the silicon-containing film.
A method for manufacturing a semiconductor device having. The procedure for bringing the board into the processing chamber of the board processing device and
A first liquid supply system configured to supply a first solution having a hydrogen peroxide concentration equal to or higher than the first concentration to the vaporizer, and a second liquid having a hydrogen peroxide concentration lower than the first concentration. A mixed solution of the first solution and the second solution, which are supplied from the second liquid supply system configured to supply the second solution having a concentration equal to or less than the above-mentioned vaporizer to the vaporizer. The procedure for supplying the vaporizer and
A procedure for vaporizing the first solution and the second solution by the vaporizer to generate a vaporized gas, and
The procedure of supplying the vaporized gas to the processing chamber to modify the silicon-containing film formed on the substrate, and
A program that causes the board processing apparatus to execute the above.