Method for processing substrate and apparatus for processing substrate

Abstract

Provided is a technique for obtaining a SiO film having a low impurity content from a SiN film that contains a silicon compound having a nitrogen- and hydrogen-containing functional group. A first processing gas containing at least one of H2O2 or H2O is supplied to a substrate on which a SiN film that contains a silicon compound having a nitrogen- and hydrogen-containing functional group is formed, and the substrate is heated to replace the functional group with a hydroxy group. Then, a second processing gas containing at least one of O2 or O3 is supplied in a plasma state to the substrate, and the substrate is heated to separate hydrogen from the silicon compound and obtain a SiO film.

Description

METHOD FOR PROCESSING A SUBSTRATE AND APPARATUS FOR PROCESSING A SUBSTRATE - Patent application

[0001] The present disclosure relates to a method for processing a substrate and an apparatus for processing a substrate.

[0002] In the manufacturing process of a semiconductor device, a recess such as a via hole or a trench is formed in an insulator layer formed on a semiconductor wafer (hereinafter also referred to as a "wafer"), which is a substrate, and a conductor, which is a wiring material, is embedded in the recess. An insulator layer is then formed on top of the conductor embedded in the recess, and the process of forming the recess and embedding the conductor is repeated to form a multilayer wiring.

[0003] Patent Document 1 describes a technique for forming a polysilazane film by spin-coating a semiconductor substrate with a perhydrosilazane polymer, baking the resulting coating film, and evaporating the solvent. This polysilazane film is then heated for a predetermined time at different temperatures, 400°C and 700°C, in a water vapor atmosphere, and converted into a silicon oxide film.

[0004] Patent Document 2 describes a technique for obtaining a SiO film by an oxidation reaction in which a thin film of polysilazane is applied to a substrate by a spin coater, the substrate being heated to, for example, 40°C to 300°C and water vapor being supplied thereto, or the substrate being heated to 40°C to 100°C and a gas obtained by vaporizing hydrogen peroxide is supplied thereto. It also describes that for a substrate treated using water vapor, an annealing process may be performed in which the substrate treatment chamber is heated to, for example, 600°C to 1100°C in an atmosphere supplied with water vapor to remove impurities such as nitrogen and hydrogen and to densify the SiO film.

[0005] JP 2010-251598 A JP 2015-62254 A

[0006] The present disclosure provides a technique for obtaining a SiO film with a low impurity content and high film density from a SiN film containing a silicon compound having a functional group containing nitrogen and hydrogen.

[0007] The method for treating a substrate according to the present disclosure is a method for treating a substrate, the method comprising: treating a substrate on which a SiN film containing a silicon compound having a functional group containing nitrogen and hydrogen is formed with H ２ O２ or H ２ a step of supplying a first process gas containing at least one of O and O and heating the substrate to replace the functional group with a hydroxy group; ２ or O ３ and supplying a second process gas containing at least one of the above in a plasma state and heating the substrate to remove hydrogen from the silicon compound, thereby obtaining a SiO film.

[0008] According to the present disclosure, a SiO film with a low impurity content and high film density can be obtained from a SiN film containing a silicon compound having a functional group containing nitrogen and hydrogen.

[0009] 1 is a first explanatory diagram relating to a process for forming a SiN film; FIG. 2 is a second explanatory diagram relating to a process for forming a SiN film; and FIG. 3 is a third explanatory diagram relating to a process for forming a SiN film. An example of a longitudinal side view of the vicinity of a wafer surface on which a SiN film is stacked on a metal film. An example of a longitudinal side view of the vicinity of a wafer surface on which a process according to a comparative embodiment has been carried out. An example of a longitudinal side view of the vicinity of a wafer surface being processed in a first process module. An example of a longitudinal side view of the vicinity of a wafer surface being processed in a second process module. A schematic plan view showing an embodiment of an apparatus for processing a wafer on which a SiN film has been formed. A longitudinal side view of an example of a first process module provided in the apparatus. A longitudinal side view of an example of a second process module provided in the apparatus. A longitudinal side view of an example of a common process module having the functions of both the first and second process modules. Results of FTIR analysis of a film before and after a first process. Results of FTIR analysis of a film before and after a second process. A graph showing changes in wet etching rate as viewed along the thickness direction of a film after first and second processes.

[0010] <SiN film> First, an example of the structure of a SiN film to which the substrate processing method according to the present disclosure is applied will be described. For example, a SiN 902 film is embedded in a recess 901c formed in a metal film 901, which is a conductive material on the surface of a wafer W. The metal film 901 can be formed of silicon (Si), silicon germanium (SiGe), other metal materials, a nitride film containing a metal, or a laminate film of these materials.

[0011] The SiN film 902 contains a silicon compound having functional groups containing N (nitrogen) and H (hydrogen). A specific example of the SiN film 902 having such characteristics is the raw material polysilazane (for example, [-SiH ２ NH-] ｎ Another example is a coating film obtained by applying a solution containing trisilylamine (N(SiH ３ ) ３ An example of the SiN film is a film of an oligomer or polymer having fluidity formed by polymerizing two or more molecules of a silicon nitride (SiN) gas by a CVD method. The SiN film 902 may be formed not only from polysilazane or trisilylamine (TSA) but also from other materials that contain silicon compounds having functional groups containing N and H and that can be embedded in the recesses 901 formed on the surface of the wafer W.

[0012] 1A to 1C show an example of a process for forming a SiN film 902. In the example shown in these figures, a lower metal film 901a and an upper metal film 901b are laminated on the surface of a wafer W to form a metal film 901, and a recess 901c is formed in the upper metal film 901b. A polysilazane solution is supplied to this upper metal film 901b by spin coating as a raw material liquid 902a for the SiN film 902, or a TSA oligomer or polymer having fluidity is formed by CVD.

[0013] When the source liquid 902a is supplied to the surface of the wafer W, the source liquid 902a penetrates into the recess 901c in the upper metal film 901b, gradually filling the recess 901c (FIG. 1A). The source liquid 902a is then supplied so as to completely fill the recess 901c and further cover the entire upper surface of the upper metal film 901b. The wafer W is then heated, for example. This heating process evaporates the solvent contained in the polysilazane solution and polymerizes the TSA, forming a solid SiN film 902 (FIG. 1B). Subsequently, a planarization process is performed, such as etching or CMP (chemical mechanical polishing), to remove the SiN film 902 covering the upper surface of the upper metal film 901b, thereby obtaining the SiN film 902 filled in the recess 901c. 2 to 5, which will be described below, schematically show the structure in which the SiN film 902 is formed by the above-mentioned method, omitting the illustration of the recess 901c and showing a laminated structure in which the SiN film 902 and the like are laminated on the upper surface of the metal film 901.

[0014] The SiN film 902 formed by these methods contains silicon compounds derived from the raw materials polysilazane and trisilylamine, and these silicon compounds have functional groups containing N and H. For example, the SiN film 902 in FIG. 2 is a coating film obtained by spin-coating polysilazane and then baking at 150° C. This SiN film 902 contains monosilylamine (SiH), an example of a silicon compound derived from the raw material polysilazane. ３ NH ２ ), and monosilylamine has an amino group, which is a functional group containing N and H.

[0015] <Conventional Process and Comparative Example> As described above, the SiN film 902 containing N and H has insufficient properties such as insulating properties, low density, and low etching resistance. Therefore, as described in Patent Document 1 exemplified in the background art, a conventional annealing process has been performed in which the wafer W is heated to approximately 400°C in a water vapor supply atmosphere to desorb NH and replace it with SiO, and then the heating temperature is increased to approximately 700°C to oxidize Si. The annealing process may be performed in the state shown in FIG. 1B before the planarization process or in the state shown in FIG. 1C after the planarization process. This annealing process desorbs H contained in the silicon compound, resulting in a dense SiO film. However, heating the wafer W at a temperature as high as 700°C may damage the underlying structure of the wafer W.

[0016] Here, the following are examples of damage caused by high-temperature heating. When the heating temperature is raised to about 700°C to replace the SiN film with a SiO film, the semiconductor substrate is exposed to a high-temperature oxidizing atmosphere. In this case, the conductive regions (the upper metal film 901 and the lower metal film 901a in contact with the SiN film 902 in Figures 1A to 1C) are oxidized, causing oxidation damage such as preventing the desired characteristics from being obtained or impairing the characteristics. This is not limited to the conductors described above, but also includes unintended oxidation damage such as oxidation of interfaces. Furthermore, similar oxidation damage is a concern not only on the outermost surface of the semiconductor substrate, but also when there is a structure in the lower layer that similarly poses a risk of oxidation.

[0017] Another example of damage is stress damage to a semiconductor pattern caused by volume expansion and contraction during compositional substitution from a SiN film to a SiO film at about 400° C., followed by high-temperature annealing to oxidize Si at about 700° C. In a coated film such as a polysilazane film, the volume expansion and contraction associated with temperature and composition changes are large, generating film stress and resulting in the risk of pattern collapse or pattern curvature.

[0018] Another example of damage is a shift in doping concentration in semiconductor devices. If there is a P-type or N-type doped Si substrate region below, high-temperature annealing can change the dopant concentration and distribution, which can lead to a shift in the semiconductor device characteristics.

[0019] Therefore, the inventors heated the wafer W to about 400°C and used water vapor plasma generated by microwave application as a processing gas to process the SiN film 902 (comparative example). The water vapor plasma contains active species such as oxygen radicals, oxygen ions, and electrons. In the comparative example, the inventors intended to form a SiO film without performing annealing at a high temperature of about 700°C by supplying these active species to the SiN film 902, thereby causing the desorption of NH and the oxidation of Si to proceed in parallel.

[0020] However, when a wafer W processed according to the comparative example was analyzed, it was found that the supply of active species caused the desorption of NH and the oxidation of Si to proceed, and the formation of SiO regions 904a remained near the surface of the SiN film 902 ( FIG. 3 ). On the other hand, it was found that even if NH desorbs from silicon compound molecules such as monosilylamine below the SiO region 904a, the released NH may recombine with the silicon compound molecules and not be removed from the SiN film 902. For this reason, as shown in FIG. 3 , with the method according to the comparative example, the SiN film 902 remains below the SiO region 904a, making it difficult to convert the entire SiN film 902 into a SiO film.

[0021] The inventors speculate that the reason for this phenomenon occurs is as follows: Water vapor plasma formed using microwaves in a temperature range of about 400°C contains not only mildly active radicals O1d (excited atomic oxygen) and O3p (ground state atomic oxygen), but also more active O ２＋ The highly active oxygen ions and electrons react quickly with silicon compound molecules on the surface side of the SiN film 902, and cause the elimination of NH and the oxidation of Si to proceed first in the surface region, forming a dense SiO region 904a.

[0022] On the other hand, activated species penetrate into the interior of the SiN film 902 at a later timing than into the surface of the SiN film 902. Therefore, the reaction of releasing NH and oxidizing Si in the SiN film 902 proceeds later than at the surface of the SiN film 902. As a result, dense SiO regions 904a are formed on the surface of the SiN film 902 before NH, N, and H are released from the interior of the SiN film 902. Furthermore, since the SiO regions 904a inhibit the release of NH and N from the interior of the SiN film 902, it is thought that these NH and N recombine with silicon compound molecules that have released NH and become more active. This phenomenon also occurs in SiN films 902 obtained by CVD using trisilylamine gas.

[0023] <Substrate Processing According to the Embodiment> The inventors have discovered a method for suppressing the formation of SiO regions 904a on the surface of the SiN film 902 and the recombination of released NH, etc., by dividing the process for converting the SiN film 902 into the SiO film 904 into two stages and using different process gases in each stage. It has been found that this method makes it possible to convert the entire SiN film 902 into the SiO film 904 at a relatively low temperature.

[0024] In the first step of the two-step process, functional groups containing N and H in the silicon compound contained in the SiN film 902, such as amino groups (NH ２ In the first process, the wafer W is irradiated with H. ２ O ２ or H ２ A first process gas containing at least one of O is supplied, and the wafer W is heated.

[0025] The second process is a process for obtaining a SiO film 904 by removing hydrogen (H) from the silicon compound contained in the SiOH film 903 obtained in the first process (FIG. 5). ２ or O ３ A second process gas containing at least one of the above is supplied in a plasma state, and the wafer W is heated.

[0026] When the wafer W including the stacked structure described with reference to FIG. 2 is heated and the first process gas is supplied, H contained in the first process gas is released when the first process gas comes into contact with the wafer W. ２ O ２ and H ２ The thermal decomposition of O generates active species such as OH radicals. These active species are taken into the SiN film 902 and converted into silicon compounds (monosilylamine (SiH) in the example described with reference to FIG. 2) contained in the SiN film 902. ３ NH ２ )) In this case, as shown in FIG. 4, the OH radical reacts with the NH ２ The functional groups containing nitrogen and hydrogen are substituted with hydroxyl groups, and NH radicals, N radicals, H radicals, etc. are released from the SiN film 902 (a process of substituting functional groups containing nitrogen and hydrogen with hydroxyl groups).

[0027] On the other hand, in the first process, the heating temperature of the wafer W is kept at a relatively low temperature of, for example, 100 to 400° C., and no plasma generating means is employed as a method for obtaining activated species of the first process gas. ２ The progress of the reaction in which H is released from the OH groups substituted for the groups to form SiO is suppressed. As a result, it is possible to suppress the formation of SiO regions 904 a on the surface of the SiN film 902, as in the comparative example described with reference to FIG.

[0028] By suppressing the formation of the SiO region 904a, OH radicals can penetrate into the SiN film 902, and NH ２ The first treatment reacts with the silicon compound having a group, and the NH radicals and N radicals generated by the reaction can be released outside the film. As a result, the recombination of the NH radicals and N radicals that occurred in the comparative example of FIG. 3 can be suppressed, and the entire film can be made into a SiOH film 903 as shown in FIG. 4. As shown in the experimental results in FIG. 10 (to be described later), it has been confirmed that the composition of SiN can be replaced with SiO by performing the first treatment.

[0029] On the other hand, according to the reaction using the first process gas described above, H ２ O２ and H ２ The supply of O is performed by NH 3 of the silicon compound contained in the SiN film 902. ２ Therefore, as in the technique described in Patent Document 2 cited in the background art, the reaction is carried out at a low temperature of 40°C to 100°C by replacing functional groups such as H ２ O ２ It is considered that it is difficult to uniformly oxidize the entire SiN film 902 to generate a dense SiOH film 903 by the method of supplying steam. Therefore, in the wafer processing of this embodiment, the SiOH film 903 obtained in the first processing is oxidized in the second processing. ２ By supplying plasma of the second processing gas containing the above, a process for obtaining a dense SiO film 904 from the SiOH film 903 is performed.

[0030] Active species such as O1d contained in the plasma of the second processing gas are supplied to the surface of the wafer W and are taken into the SiOH film 903. Then, they react with the silicon compound constituting the SiN film 902 to form NH ２ The first process removes H from the OH groups substituted with the silicon compounds, as well as H that was originally present before the replacement. This reaction progresses throughout the SiOH film 903, converting the entire SiN film 902 into a dense SiO film 904, as shown in Figure 5 (a process for obtaining a SiO film by removing hydrogen from silicon compounds). Experimental results shown in Figure 12 (to be described later) confirm that a dense SiO film 904 with high etching resistance can be formed by performing the second process following the first process.

[0031] Furthermore, as a feature of the technology disclosed herein, by performing both the first and second treatments, even if the compositional substitution to SiO in the first treatment is insufficient, substitution and densification can be performed in the second treatment (as shown in FIG. 12 of the experimental results described below). As a result, even if SiN bonds remain partially after only the first treatment, oxygen is supplemented in the first treatment, making it possible to replace all of them with SiO bonds. The fact that the second treatment can also supplement the first treatment is a feature of the technology disclosed herein.

[0032] In addition, the plasma treatment of the second treatment ２ He / O may be added. ２H for oxidation plasma treatment of ２ By adding H, some OH radicals are formed, which can assist the oxidation process. ２ The flow rate is, for example, O ２ It is added at a ratio of about 0.1 to 1 with respect to gas 1. An example of the configuration of a wafer processing apparatus 1 that performs this processing will be described below with reference to FIGS.

[0033] <Wafer Processing Apparatus> Figure 6 is a schematic plan view showing an example of the configuration of a wafer processing apparatus 1 that performs a process of converting a SiN film 902 into a SiO film 904. The wafer processing apparatus 1 includes an atmospheric transfer module 2 that loads and unloads wafers W, load lock modules 31 and 32, a vacuum transfer module 4, and multiple, e.g., four, processing modules 5 and 6. The atmospheric transfer module 2 includes an atmospheric transfer mechanism 22 in an atmospheric transfer chamber 21. The atmospheric transfer chamber 21 is connected to, e.g., three carriers 20 that accommodate multiple wafers W, and the load lock modules 31 and 32, respectively, and the wafers W are transferred between these modules by the atmospheric transfer mechanism 22. In Figure 6, reference numeral 23 denotes a carrier placement section on which the carriers 20 are placed, and reference numeral 24 denotes an aligner chamber in which the wafers W are aligned.

[0034] The vacuum transfer module 4 is configured by providing a substrate transfer mechanism 42 inside a vacuum transfer chamber 41. The processing modules 5 and 6 and the load lock modules 31 and 32 are connected to the vacuum transfer chamber 41, respectively, and the substrate transfer mechanism 42 transfers wafers W between them. As described above, the two load lock modules 31 and 32 are connected to the atmospheric transfer chamber 21 and the vacuum transfer chamber 41, respectively, and are configured so that the interiors thereof can be switched between atmospheric pressure and vacuum pressure atmospheres.

[0035] The wafer processing apparatus 1 is provided with two first processing modules 5 and two second processing modules 6. These processing modules 5 and 6 each include a processing vessel 61 connected to a vacuum transfer chamber 41, and are configured so that vacuum processing is performed in each processing vessel 61. Furthermore, in each of the modules 31, 32, 4, 5, and 6 of the wafer processing apparatus 1, a gate valve GV is provided between each of the connected modules.

[0036] <First Processing Module 5> Next, a description will be given of an example of the configuration of the first and second processing modules 5 and 6. The first processing module 5 is a module that performs the first processing (processing for substituting the SiN film 902 with hydroxyl groups (OH groups) to obtain the SiOH film 903) described above. As described above, when performing this processing, the wafer W is irradiated with H ２ O ２ or H ２ The processing is performed by supplying a first processing gas containing at least one of H, O, and H O while heating the wafer W. ２ O ２ A case where processing is performed using a first processing gas containing the above will be described.

[0037] 7 is a longitudinal side view showing an example of the configuration of the first processing module 5. The first processing module 5 includes a processing vessel (first processing vessel) 61, the lower part of which is configured as an exhaust chamber 62. The processing vessel 61 and the exhaust chamber 62 are preferably made of, for example, metal, and have corrosion resistance against activated species generated from the first processing gas and the cleaning gas described below. From this perspective, the inner walls of the processing vessel 61 and the exhaust chamber 62 are preferably made of Al ２ O ２ , Y ２ O ３ Alternatively, the inner wall surfaces of the metal processing vessel 61 and the exhaust chamber 62 may be covered with a ceramic cover such as quartz. ２ O ２ , Y ２ O ３ , Si or the like may be coated.

[0038] Also, a first processing gas supply (H２ O ２ The piping from the supply device 651 to the process gas supply nozzle 64 of the first process module 5 may be metal piping coated with ceramics or the like as described above. Alternatively, these piping may be coated with resin such as Teflon (registered trademark). Coating the piping with ceramics or resin can prevent corrosion of the piping and avoid decomposition of the first process gas, allowing for more efficient processing.

[0039] The processing vessel 61 is connected to the vacuum transfer chamber 41 via a transfer port 60 for the wafer W, which is formed so as to be freely opened and closed by a gate valve GV, and the wafer W is transferred in and out by a substrate transfer mechanism 42. The exhaust chamber 62 is connected to a vacuum exhaust mechanism 623 via an exhaust pipe 621 provided with a pressure adjustment unit 622.

[0040] A susceptor (first mounting table) 63 for horizontally supporting a wafer W is provided within the processing vessel 61, supported from below by support columns 631. The susceptor 63 may be made of metal or a ceramic material. If the susceptor 63 is made of metal, it may be covered with a ceramic cover 633 as shown in FIG. 7 for the same reasons as the inner walls of the processing vessel 61 and the exhaust chamber 62. Alternatively, the surface of the susceptor 63 may be coated by ceramic spraying or the like. The need for such a cover or coating to protect the susceptor 63 from activated species generated from the first processing gas also applies to other components exposed to the interior of the processing vessel 61 (e.g., the sidewalls of the support columns 631 and the inner wall of the gate valve GV).

[0041] The susceptor 63 includes a heater (first heating unit) 632 and is configured to heat the wafer W to a preset temperature, for example, 200°C within a range of 100°C or higher and 400°C or lower.

[0042] The top surface of the processing vessel 61 is covered by a ceiling plate 611. A processing gas supply nozzle 64 is provided at a height position on the upper side of the sidewall of the processing vessel 61, discharging a first processing gas into the processing vessel 61 toward a region below the ceiling plate 611. In the example shown in FIG. 7 , the first processing gas is supplied using multiple processing gas supply nozzles 64. However, the processing vessel 61 may be provided with only one processing gas supply nozzle 64. The configuration for supplying the first processing gas into the processing vessel 61 is not limited to the processing gas supply nozzle 64. For example, a gas shower head may be used. A gas shower head enables more uniform gas supply, while a nozzle system reduces the contact area with the first processing gas, thereby reducing deactivation of activated species. In this way, the gas supply structure can be appropriately selected. In this example, a processing gas supply nozzle 64 with a small contact area with the first processing gas is used, which reduces the risk of deactivating activated species.

[0043] The processing gas supply nozzle 64 is supplied with H through a processing gas supply pipe 641 provided with a valve V1 and a mass flow controller M1. ２ O ２ A supply device 651 is connected. ２ O ２ The supply device 651 supplies H with a concentration of, for example, about 50,000 vol ppm. ２ O ２ Known high purity, high concentration H ２ O ２ It is also composed of a device that generates H ２ O ２ The gas generated by the supply device 651 contains, for example, H with a concentration of about 100,000 vol ppm. ２ O may be contained. ２ O ２ From the supply device 651, these H ２ O ２ and H ２ O is supplied together with a carrier gas. The carrier gas may be argon (Ar) gas, helium (He) gas, or nitrogen (N ２ ) gas, or an inert gas such as oxygen (O ２ ) gas.

[0044] H ２ O ２ H contained in the first process gas supplied from the supply device 651 ２ O ２ In order to suppress the adsorption and decomposition of H, a heater may be provided in the processing gas supply pipe 641 to heat the pipe to, for example, about 100° C. ２ O ２ High concentration H supplied from the supply device 651 ２ O ２ , H ２ The mixed gas of O and the carrier gas corresponds to the first process gas in this embodiment. ２ O ２ The supply device 651, the mass flow controller M1, the valve V1, the processing gas supply pipe 641, and the processing gas supply nozzle 64 constitute a first processing gas supply unit of this embodiment.

[0045] In the first treatment module 5, H ２ O ２ The polysilazane SiN film 902 is replaced with a SiOH film 903 using a silicon compound. ２ group) and an NH group, which is an amino group with one hydrogen atom removed, are H ２ O ２ The reaction with the gas causes the silicon dioxide to be substituted with hydroxyl groups (OH groups), forming the SiOH film 903 as shown in FIG. 4. The temperature used for this substitution is, for example, 100° C. to 500° C. A temperature of 300° C. or less is desirable. If the temperature is below this temperature, the silicon dioxide can be oxidized while the silicon dioxide can be oxidized. ２ O ２ The oxidizing power of the gas replaces the polysilazane SiN film 902 with a SiOH film 903. The processing pressure used is in the range of 13.3 kPa (100 Torr) to atmospheric pressure. If the pressure is too low, the gas concentration becomes insufficient and the replacement reaction efficiency drops, so it is better to apply a certain amount of pressure, preferably around 53.3 kPa (400 Torr).

[0046] 7, a remote plasma device 66 is provided on, for example, the top plate 611 of the processing vessel 61 to supply cleaning gas for cleaning the inside of the processing vessel 61. By-products generated from SiH, NH, etc. released from the SiN film 902 may accumulate on the inner walls of the processing vessel 61 and the exhaust chamber 62, the surface of the cover 633 of the susceptor 63, etc. A cleaning gas is supplied to remove these deposits. Specific examples of the cleaning gas include NF ３ , H ２ The cleaning gas may be a single gas or a mixture of gases that react with silicon compounds, such as HCl, HBr, etc. The cleaning gas may be argon (Ar) gas, helium (He) gas, nitrogen (N ２ ) gas or the like may be used after dilution as appropriate.

[0047] The remote plasma device 66 converts the cleaning gas into plasma and supplies it into the processing vessel 61 through a remote plasma supply port 612 provided in the top plate 611. At this time, a heater (not shown) may be provided in the processing vessel 61, and together with a heater 632 provided in the susceptor 63, the temperatures of the processing vessel 61, the exhaust chamber 62, and the susceptor 63 may be adjusted to temperatures suitable for cleaning during cleaning.

[0048] The remote plasma supplied from the remote plasma device 66 is not limited to being used only for cleaning the inside of the processing vessel 61. For example, the NH ２ When performing a treatment to replace a group (including an NH group; the same applies hereinafter) with an OH group, ２ Gas and H ２ The gas, Ar gas, or the like may be turned into plasma and supplied into the processing chamber 61 in parallel with the first processing gas. O radicals or OH radicals generated by the remote plasma may be converted into NH ２ This can assist the substitution of the OH group from the OH group, making it possible to carry out the substitution reaction more efficiently.

[0049] Also H ２ O ２A part of the first process gas supplied from the supply device 651 may be supplied to the remote plasma device 66, where it may be converted into plasma and then introduced into the process vessel 61. ２ O ２ By converting O into plasma and generating radicals, the substitution reaction can proceed more efficiently. ２ Gas and H ２ Gas, Ar gas, some H ２ O ２ The gas constitutes an auxiliary gas group in this embodiment. The auxiliary gas selected from the auxiliary gas group is not limited to one type, and two or more types may be supplied. In addition, the remote plasma device 66 corresponds to the auxiliary gas plasma generating unit in this embodiment.

[0050] However, if the amount of activated species supplied from the remote plasma device 66 is too large, an SiO region 904a may be formed on the surface of the SiN film 902, as in the comparative example described with reference to FIG. 3, and recombination of released NH and the like may occur inside the SiN film 902. Therefore, when processing the SiN film 902, H ２ O ２ The flow rate ratio of the first processing gas supplied from the supply device 651 to the remote plasma supplied from the remote plasma device 66 is kept at approximately 2:1 or less.

[0051] <Second Processing Module 6> Next, an example of the configuration of the second processing module 6 will be described with reference to Fig. 8. The second processing module 6 is a module that performs the second processing described above, which obtains a SiO film 904 by removing hydrogen (H) from silicon compounds contained in the SiOH film 903 obtained in the first processing module 5. In performing the second processing, O ２ or O ３ The second process gas containing at least one of the above is supplied in a plasma state, and the wafer W is heated. ２ 8, when the second processing module 6 can adopt the same configuration as the first processing module 5 described with reference to FIG. 7, the same reference numerals as those in FIG. 7 are used, and the individual description will be omitted.

[0052] 8 , the second process module 6 includes a process vessel 61 serving as a second process vessel and a susceptor 63 serving as a second mounting table housed within the process vessel 61. A heater 632 serving as a second heating unit provided in the susceptor 63 is configured to heat the wafer W to a predetermined temperature, for example, 300°C within a range of 200°C to 600°C. Furthermore, if the susceptor 63 is made of metal, a bias power supply 635 may be connected via a matching unit 634 to apply bias power that draws in activated species contained in the plasma-converted second process gas. The bias power supply 635 applies high-frequency power of, for example, 13.56 MHz.

[0053] The second processing module 6 shown in FIG. ２ The process gas supply nozzle 64 is configured to supply a mixed gas of an oxygen source 661 and a dilution gas into the process vessel 61. An inert gas is preferably used as the dilution gas, and FIG. 8 illustrates the case where He is supplied. Alternatively, Ar may be supplied as the dilution gas. In this example, a process gas supply pipe 641 equipped with a valve V2 is connected to the process gas supply nozzle 64. The process gas supply pipe 641 branches upstream of the valve V2. One of the branched process gas supply pipes 641 is connected to an oxygen supply source 661 via a mass flow controller M2, and the other is connected to a He supply source 671 via a mass flow controller M3.

[0054] For example, the oxygen supply source 661 and the He supply source 671 each contain high-purity (approximately 100%) O ２ The mass flow controllers M2 and M3 are configured by gas cylinders that supply O, He. ２ The flow rates of the second process gas (in this example, O 2 ) and the He gas are adjusted so that the flow rate ratio is, for example, 10 sccm:1000 sccm within a range of 1:1 to 1:200. ２The flow rate ratio of the oxygen supply source 661 to the diluent gas (He in this example) can be adjusted within a range of, for example, 1:1 to 1:200, more preferably 1:5 to 1:200. The oxygen supply source 661, the He supply source 671, the mass flow controllers M2 and M3, the valve V2, the process gas supply pipe 641, and the process gas supply nozzle 64 constitute a second process gas supply unit of this embodiment.

[0055] Furthermore, the second process module 6 includes a plasma generating unit for generating oxygen radicals, which are activated species, by converting the second process gas supplied to the process vessel 61 through the process gas supply nozzle 64 into plasma. The plasma generating unit preferably suppresses the generation of ions that may damage the wafer W and generates plasma rich in O1d radicals that are highly reactive with the SiOH film 903.

[0056] O1d radicals have an energy of 4.6 eV, which can provide higher reaction energy than the 2.6 eV bond energy of Si-Si bonds. Therefore, they easily react with Si, releasing hydrogen (H) to form SiO bonds. Furthermore, the reaction with radicals forms stable SiO bonds, which promotes film densification and improves film density. Microwave plasma is a method for generating plasma with these characteristics. Microwave plasma is a surface wave plasma that can provide a dissociation energy of approximately 8 to 12 eV in the plasma generation region. In other words, O1d radicals with an energy of 4.6 eV can be generated. Meanwhile, the susceptor 63 on which the wafer is processed is located in the diffusion plasma region, where high-density, low-electron-temperature plasma diffuses. This configuration makes it possible to supply high-density oxygen radicals, such as O1d radicals, to the wafer W with minimal damage. The above is a feature of the technology disclosed herein, which supplies highly transportable 1d radicals using microwave plasma. The microwave frequency is not limited to 2.45 GHz, but can be in the range of 700 MHz to 10 GHz, such as 860 MHz, 8.35 GHz, 5.8 GHz, 1.98 GHz, etc. Other plasma sources include ICP (Induced Coupling Plasma) plasma, which forms plasma using a high-frequency antenna, and VHF plasma.

[0057] 8 illustrates a case where a microwave supply mechanism 68 is used as the plasma generating unit. The microwave supply mechanism 68 is provided on the upper surface of the processing vessel 61, above the region where the second processing gas is supplied from the processing gas supply nozzle 64. In this example, the upper surface of the processing vessel 61 is covered with a dielectric plate 613. The dielectric plate 613 is made of a dielectric material that transmits microwaves, such as quartz. This dielectric material is made of Al ２ O ３ , Y ２ O ３Alternatively, a ceramic member such as a ceramic material may be used. A microwave propagation plate 685 is provided on the upper surface of the dielectric plate 613. A coaxial waveguide 684, a mode converter 683, a waveguide 682, and a microwave generation unit 681 are connected to this microwave propagation plate 685 in this order via a microwave introduction unit (not shown). In addition, a cover 614 is provided on the upper surface sides of the dielectric plate 613 and the microwave propagation plate 685 to prevent leakage of microwaves.

[0058] In the above configuration, microwaves supplied from the coaxial waveguide 684 via a microwave introduction part (not shown) propagate through the lower surface of the microwave propagation plate 685 and are supplied to the dielectric plate 613 on the lower surface side thereof. Then, the second process gas is converted into plasma by the microwaves introduced into the process vessel 61 via the dielectric plate 613. Here, although a single microwave supply mechanism is illustrated in Fig. 8, a plurality of microwave supply mechanisms may be provided, and the microwave generation mechanism may be selected from a magnetron type, a solid-state amplifier type, or the like.

[0059] Furthermore, the second processing module 6 may be provided with a remote plasma device 66 that supplies a cleaning gas for cleaning the inside of the processing vessel 61. When a microwave supply mechanism 68 is provided on the top surface of the processing vessel 61 as shown in FIG. 8 , a configuration may be adopted in which remote plasma of a cleaning gas is supplied from, for example, the sidewall side of the processing vessel 61. As an alternative form of cleaning, a cleaning gas line may be provided and cleaning may be performed using the same microwave plasma. Since the cleaning process can be performed using the same plasma source as the second process, SiO formation, equipment costs can be reduced.

[0060] On the other hand, the SiOH film 903 that is to undergo the process of removing H in the second processing module 6 has already been treated with NH ２A process is performed in which N-type N groups are replaced with OH groups. Therefore, the amount of SiH and NH released is small, which are likely to generate by-products that accumulate on the inner wall surfaces of the processing vessel 61 and the exhaust chamber 62 and on the surface of the susceptor 63 (cover 633). Therefore, the installation of a permanent remote plasma device 66 for the second processing module 6 may be omitted to reduce equipment costs. In this case, if cleaning becomes necessary due to long-term operation of the second processing module 6, for example, the module can be opened and wet cleaning performed by wiping the inside of the module with diluted hydrofluoric acid can be performed instead.

[0061] <Controller> The wafer processing apparatus 1 includes a controller 100 that controls the operation of each component of the wafer processing apparatus 1, such as the transfer of the wafer W and the processing of the wafer W in each of the processing modules 5 and 6. The controller 100 is, for example, a computer having a CPU and a storage unit (not shown). ２ The program stores a program that includes a group of steps (commands) for control required to execute a process of substituting the OH groups for the OH groups and a process of eliminating H from the SiOH film 903 to obtain the SiO film 904. The program is stored in a storage medium such as a hard disk, a compact disk, a magnetic optical disk, a memory card, or a nonvolatile memory, and is installed into a computer from there.

[0062] <Operation> The operation of the wafer processing apparatus 1 having the above-described configuration will be described below. In the wafer processing apparatus 1 shown in Figure 6, the atmospheric transfer mechanism 22 removes the wafer W housed in the carrier 20. Next, after alignment in the aligner chamber 24, the wafer W is loaded into the load lock module 31, which is in an atmospheric pressure atmosphere, and the load lock module 31 is adjusted to a vacuum pressure atmosphere. Thereafter, the substrate transfer mechanism 42 transfers the wafer W from the load lock module 31 to the first processing module 5.

[0063] 7, after the wafer W is placed on the susceptor 63 of the first processing module 5, the substrate transfer mechanism 42 is withdrawn and the gate valve GV is closed. Thereafter, the processing vessel 61 is evacuated to a vacuum while the pressure adjusting unit 622 is operated, and the pressure is adjusted to 53.3 kPa (400 Torr) within the range of 133.3 Pa to 101.3 kPa (1 to 760 Torr). By adjusting the pressure to a higher level compared to the processing in the second processing module 6 described later, the NH ２ It has been found that this can efficiently promote the substitution of OH groups with OH groups. The wafer W is heated to 200° C. by the heater 632, which is within the range of 100 to 400° C.

[0064] And H ２ O ２ From the supply device 651, H ２ O ２ A first process gas containing H is supplied at a flow rate of, for example, 5,000 sccm in the range of 100 to 10,000 sccm. ２ O ２ The first process gas supplied from the supply device 651 flows into the process vessel 61 through the process gas supply nozzle 64. When the first process gas that has flowed into the process vessel 61 comes into contact with the wafer W that is heated by the heater 632, H contained in the first process gas is released. ２ O ２ and H ２ Thermal decomposition of O generates active species such as OH radicals.

[0065] These active species are taken into the SiN film 902, and as explained above with reference to FIG. 4, the OH radicals are converted into NH ２ The functional groups containing nitrogen and hydrogen are substituted with hydroxyl groups, and the entire film can be made into an SiOH film 903 (step of substituting functional groups containing nitrogen and hydrogen with hydroxyl groups, FIG. 4).

[0066] Returning to the explanation of the operation of the wafer processing apparatus 1, after processing with the first processing gas is performed for a preset time in the first processing module 5, the supply of the first processing gas and heating of the wafer W are stopped, and the pressure inside the processing vessel 61 is adjusted. Thereafter, the gate valve GV is opened, and the substrate transfer mechanism 42 is allowed to enter and unload the processed wafer W.

[0067] Next, the substrate transfer mechanism 42 transfers the wafer W from the first process module 5 to the second process module 6 via the vacuum transfer module 4. After the wafer W is placed on the susceptor 63 of the second process module 6 shown in FIG. 8 , the substrate transfer mechanism 42 is withdrawn and the gate valve GV is closed. Thereafter, the pressure adjustment unit 622 is operated to evacuate the process vessel 61 and adjust the pressure to 133 Pa (1 Torr) within a range of 20 Pa to 1.3 kPa (0.15 to 10 Torr). In the second process module 6, which generates microwave plasma, the pressure inside the process vessel 61 is adjusted to a lower pressure than in the first process module 5, thereby allowing the plasma to spread over the entire surface of the wafer W. The wafer W is heated to 300°C within a range of 200 to 600°C by the heater 632.

[0068] After that, H ２ O ２ From the supply device 651 ２ and He are supplied at a flow rate of, for example, 1000 sccm in the range of 100 to 10000 sccm. Microwaves are supplied from the microwave supply mechanism 68 into the processing chamber 61, and bias power for attracting activated species is applied to the susceptor 63 from the bias power supply unit 635.

[0069] The second process gas supplied into the process vessel 61 through the process gas supply nozzle 64 is converted into plasma by microwaves, and O ２ On the other hand, in the microwave plasma, the generation of ions that damage the wafer W is suppressed.

[0070] Then, activated species such as O1d contained in the microwave plasma are carried by the flow of the second process gas in the process vessel 61 and are supplied to the surface of the wafer W by the action of the bias power applied to the susceptor 63, and are incorporated into the SiOH film 903. As a result, as described with reference to FIG. 5 , the entire SiN film 902 can be converted into a dense SiO film 904 (a process of obtaining an SiO film by desorbing hydrogen from a silicon compound).

[0071] Returning to the explanation of the operation of the wafer processing apparatus 1, after processing with the second processing gas is performed for a preset time in the second processing module 6, the supply of the first processing gas, the supply of microwaves, and heating of the wafer W are stopped, and the pressure inside the processing vessel 61 is adjusted. Thereafter, the gate valve GV is opened, and the substrate transfer mechanism 42 is allowed to enter and unload the processed wafer W. After processing is completed, the wafer W unloaded from the second processing module 6 is transferred to the load lock module 32 by the substrate transfer mechanism 42. Next, the atmosphere inside the load lock module 32 is switched to an atmospheric pressure atmosphere, and the processed wafer W is returned to the carrier 20 by the atmospheric transfer mechanism 22.

[0072] <Effects> According to the wafer processing apparatus 1 of the present embodiment described above, a SiO film with a low impurity content can be obtained from a SiN film containing a silicon compound having functional groups containing N and H. Furthermore, in the first processing module 5 and the second processing module 6, processing is performed at a heating temperature lower than 700° C., thereby suppressing damage to the underlying structure of the SiN film 902.

[0073] 9 is configured to share the processing vessel 61 (first processing vessel and second processing vessel), the susceptor 63 (first mounting table and second mounting table), and the heater 632 (first heating section and second heating section), and is capable of processing the SiN film 902 with the first processing gas and then processing the SiOH film 903 with the second processing gas. ２ O ２ 9, a microwave supply mechanism 68 is provided on the top surface of the processing vessel 61, and a matching box 634 for applying bias power is connected to the susceptor 63. Although not shown in FIG. 9, a remote plasma device 66 may be provided to supply plasma of a cleaning gas from, for example, the sidewall of the processing vessel 61.

[0074] 9 is used, for example, four common processing modules 7 are connected to the vacuum transfer module 4 in the wafer processing apparatus 1 of FIG. 6, and processing using the first processing gas and the second processing gas is performed in this order in each common processing module 7. The content of each processing is substantially the same as the content of the processing performed in the first processing module 5 and the second processing module 6 described with reference to FIGS.

[0075] However, in the above example, the heating temperature of the wafer W during processing with the first process gas is set to 200°C within a range of 100 to 400°C, and the heating temperature during processing with the second process gas is set to 300°C within a range of 200 to 600°C. However, when the processing temperatures for each process gas are made different in this manner, time is required to adjust the temperature of the wafer W. Therefore, the heating temperature of the wafer W during processing with each process gas may be fixed to, for example, 300°C within a common temperature range (200 to 400°C), and the processing with the first and second process gases may be performed consecutively without the time for temperature adjustment.

[0076] On the other hand, when the first and second process modules 5, 6 are configured separately as described with reference to FIGS. 7 and 8 , it is not essential that both modules 5, 6 be provided on a common platform (carrier placement unit 23, atmospheric transfer chamber 21, load lock modules 31, 32, and vacuum transfer module 4) shown in FIG. 6 . For example, a wafer processing apparatus may be configured in which only a plurality of first process modules 5 are connected to the platform, and a wafer processing apparatus may be configured in which only a plurality of second process modules 6 are connected to another platform. In this case, wafers W are processed using the first process gas in the wafer processing apparatus connected to the first process module 5. Thereafter, wafers W accommodated in carriers 20 are atmospherically transferred to the wafer processing apparatus connected to the second process module 6, where they are processed using the second process gas.

[0077] 6, when the SiN film 902 is formed by the CVD method using trisilylamine gas as a raw material, a processing vessel (film formation processing vessel) of a film formation module that performs film formation by the CVD method on the wafer W may be connected to the platform of Fig. 6. In this case, in the wafer processing apparatus 1, while the substrate is being transported to each processing vessel, the deposition of the SiN film 902 by the film formation module and processing by the first and second processing modules 5 and 6 are sequentially performed.

[0078] Furthermore, by utilizing these connected modules, the transfer of wafers W between each module (film-forming module, first and second processing modules 5 and 6), the formation of the SiN film 902, and the processing by the first and second processing modules 5 and 6 can be considered as one cycle, and this cycle can be repeated. By dividing the film-forming, oxidation, and densification processes into multiple stages and repeatedly performing them, compared to performing these processes all at once, the embeddability can be improved, and the film thickness per cycle can be reduced by dividing them. As a result, oxidation and densification can be performed more easily, and stable film quality can be obtained. Furthermore, by adjusting the conditions in each cycle, the degree of oxidation and densification can be selected as desired for each cycle relative to the film thickness.

[0079] In the first treatment module 5 described with reference to FIG. ２ O ２ A first process gas containing NH ２ The first process gas for this process is H ２ O ２ It is not limited to the above. For example, water vapor (H ２ O) may be supplied. ２ O ２ Compared to H ２ Since O has low activity, the heating temperature of the wafer W is adjusted to about 200 to 400° C. within the range of 100 to 400° C. described above.

[0080] In the second processing module 6 described with reference to FIG. ２The case where a second process gas containing O and a dilution gas is supplied to perform a process of desorbing H contained in the silicon compound that constitutes the SiOH film 903 has been described. ２ It is not limited to the above. For example, ozone (O ３ A mixture of the oxygen gas and a dilution gas may be supplied. ２ Compared to O ３ Since the activity of is high, the heating temperature of the wafer W is adjusted to about 200 to 400°C within the range of 200 to 600°C mentioned above.

[0081] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0082] (Experiment 1) A first process and a second process were sequentially performed on a SiN film 902 formed on a wafer W, and the structure of the film was analyzed before and after each process. A. Experimental Conditions A polysilazane solution was supplied to the surface of a bare silicon wafer W, a coating film was formed by spin coating, and then the wafer was baked at 150°C in an air atmosphere to form a SiN film 902 with a thickness of 300 nm. The wafer W was heated to 200°C in an atmosphere of 53.3 kPa (400 Torr), and H ２ O ２ A first process gas, H2O2 with a concentration of about 50,000 vol ppm, is supplied from a supply device 651. ２ O ２ The first process was performed by supplying the gas at a flow rate of 5,000 sccm. Then, the wafer W after the first process was heated to 300° C. under a pressure atmosphere of 133 Pa (1 Torr). The second process gas, O 2 , which was plasma-converted by microwaves in the microwave supply mechanism 68, was supplied. ２ A mixed gas of He and SiO 2 (flow rate ratio 10 sccm:1000 sccm) was supplied to carry out the second process.

[0083] The structure of the film formed on the surface of the wafer W before and after the first and second treatments was analyzed using a Fourier transform infrared spectrophotometer (FTIR). In addition, the composition of the film after the first treatment was evaluated using transmission electron microscope-energy dispersive X-ray spectroscopy (TEM-EDX).

[0084] B. Experimental Results Figure 10 shows the FTIR analysis results before and after the first treatment, and Figure 11 shows the FTIR analysis results before and after the second treatment. The horizontal axis of these figures represents the wave number of infrared light [cm －１ ], and the vertical axis represents absorbance [a.u. (arbitrary units)]. In FIG. 10, the analysis results of the membrane before the first treatment are shown by a dashed line, and the analysis results of the membrane after the first treatment are shown by a solid line. In FIG. 11, the analysis results of the membrane before the second treatment (described as "first treatment only") are shown by a dashed line, and the analysis results of the membrane after the second treatment (described as "first treatment + second treatment") are shown by a solid line.

[0085] 10 shows the results of evaluation by FTIR of the compositional substitution of the SiN bond to the SiO bond before and after the first treatment. The analysis result before the first treatment shown by the dashed line has SiN, SiH, and NH bonds, while the H ２ O ２ It is clear that after the first treatment using the gas, all of the bonds are replaced with SiO bonds.

[0086] After the first process, the composition of a 300 nm thick film was evaluated in the cross-sectional direction by TEM-EDX (not shown). Oxygen components were detected uniformly in the film thickness direction, but no nitrogen components were detected. This confirms that the process has been successful in uniformly substituting SiO into the polysilazane SiN film 902.

[0087] 11 shows the FTIR analysis results for the first treatment alone and for the first and second treatments. ２ Even if some of the O bonds (Si—NH or Si—NH) remain, by supplying the second processing gas plasmatized by microwaves in the second processing, the O bonds are complemented and all of them are replaced with SiO bonds. The fact that the second processing can also complement the first processing is a feature of the technology disclosed in this application.

[0088] (Experiment 2) An etching resistance test was performed on a film after only the first treatment and a film after both the first treatment and the second treatment. A. Experimental Conditions Wafers W on which films after only the first treatment and films after both the first treatment and the second treatment were formed were immersed in 0.5% hydrofluoric acid, and the etching rates were measured.

[0089] B. Experimental Results The effect of the second treatment following the first treatment, which is a feature of the technology disclosed in this application, is shown in Figure 12. The horizontal axis represents the film thickness of the polysilazane under consideration, with 0 representing the outermost surface and increasing values ​​representing deeper positions within the film along the film thickness direction. The location of approximately 2500 Å is the interface with the wafer W. The vertical axis represents the wet etching rate using diluted hydrofluoric acid, and the most stable thermally oxidized SiO2 prepared for reference was used. ２ This is a value normalized by the wet etching rate of the film. In other words, the higher the value on the vertical axis, the faster the wet etching rate and the lower the film quality. The smaller this value, the more densified the film and the better the film quality.

[0090] Solid line is H ２ O ２ This is the case where only the SiN is replaced with SiO, and the thermally oxidized SiO ２ In contrast, as shown by the dashed line in FIG. 12, the etching rate of the film subjected to the substitution process from SiN to SiO and the densification process by plasma, which are characteristics of the technology disclosed in the present application, is about 9.6 times higher than that of the thermally oxidized SiO film. ２ The actual effect is that the etching rate is 1.0 to 2.0 times faster than the film, and the effect obtained by the device disclosed in the present application is clear.

[0091] 1 wafer processing apparatus 5 first processing module 6 second processing module 63 susceptor 632 heater 651 H ２ O ２ Supply device 902 SiN film 903 SiOH film 904 SiO film

Claims

1. A method for treating a substrate, comprising: treating a substrate on which a SiN film containing a silicon compound having a functional group containing nitrogen and hydrogen is formed with H ２ O ２ Or H ２ supplying a first process gas containing at least one of O and a hydroxyl group to the substrate while heating the substrate; and ２ Or O ３ and supplying a second process gas containing at least one of the above in a plasma state and heating the substrate to remove hydrogen from the silicon compound to obtain a SiO film.

2. The method according to claim 1, wherein the SiN film is formed by spin coating using polysilazane as a raw material, or by CVD using trisilylamine as a raw material.

3. In the step of replacing the functional group with a hydroxy group, O ２ , H ２ , Ar or H ２ O ２ 2. The method according to claim 1, further comprising supplying to the substrate in a plasma state at least one auxiliary gas selected from the group consisting of:

4. The method according to claim 1, wherein the heating temperature of the substrate in the step of substituting the functional group with a hydroxy group is within the range of 100° C. or higher and 400° C. or lower.

5. The method according to claim 1, wherein the heating temperature of the substrate in the step of obtaining the SiO film is within the range of 200° C. or more and 600° C. or less.

6. The method according to claim 1, wherein the step of obtaining the SiO film uses any one of microwave plasma, ICP plasma, and high-frequency plasma obtained by applying power having a frequency within the range of 700 MHz to 10 GHz.

7. The second process gas contains at least one of He and Ar as a diluent gas, and the O ２ Or O ３ 2. The method according to claim 1, wherein a mixing ratio of at least one of the above and the dilution gas is within a range of 1:1 to 1:

200.

8. An apparatus for processing a substrate, comprising: a first processing vessel having a first stage on which a substrate is placed; ２ O ２ Or H ２ a first processing module including a first processing gas supply unit for supplying a first processing gas containing at least one of O and O to the first processing vessel and a first heating unit for heating the substrate; a second processing vessel including a second mounting table on which the substrate is mounted; ２ Or O ３ a second processing module including a second processing gas supply unit for supplying a second processing gas containing at least one of the above to the second processing vessel, a plasma forming unit for generating oxygen radicals by converting the second processing gas into plasma, and a second heating unit for heating the substrate; and a control unit, wherein the control unit is configured to output control signals for executing the steps of: placing a substrate, on which a SiN film containing a silicon compound having a functional group containing nitrogen and hydrogen, in the first processing vessel, supplying the first processing gas and heating the substrate to replace the functional group with a hydroxy group, and then placing the substrate in the second processing vessel, supplying the second processing gas in a plasma state, and heating the substrate to desorb hydrogen from the silicon compound to obtain a SiO film.

9. The apparatus described in claim 8, comprising: a vacuum transfer chamber to which the first processing vessel and the second processing vessel are connected; and a substrate transfer mechanism disposed within the vacuum transfer chamber, wherein the control unit is configured to output a control signal for performing a step of transferring the substrate by the substrate transfer mechanism between the first mounting table of the first processing vessel and the second mounting table of the second processing vessel via the vacuum transfer chamber, between performing the step of replacing the functional group with a hydroxy group and performing the step of obtaining the SiO film.

10. The apparatus described in claim 9, wherein the vacuum transfer chamber constitutes a film formation module for forming the SiN film by a CVD method using trisilylamine as a raw material, and a film formation processing vessel in which the film is formed on the substrate is connected, and the control unit is configured to output a control signal for carrying out the steps of placing the substrate in the film formation processing vessel and forming the SiN film before carrying out the step of replacing the functional group with a hydroxy group, and then transporting the substrate from the film formation processing vessel to the first processing vessel via the vacuum transfer chamber by the substrate transport mechanism.

11. The apparatus described in claim 10, wherein, when the steps of forming the SiN film, transporting the substrate from the film formation processing vessel to the first processing vessel, substituting the functional group with a hydroxy group, transporting the substrate between the first processing vessel and the second processing vessel, and obtaining the SiO film are regarded as one cycle, the control unit is configured to output a control signal to repeat the cycle a plurality of times.

12. The apparatus of claim 8, further comprising a common processing module having the functions of both the first processing module and the second processing module, wherein the first processing container and the second processing container, the first mounting table and the second mounting table, and the first heating section and the second heating section are common to each other.

13. The apparatus according to claim 8, wherein the SiN film is formed by spin coating using polysilazane as a raw material, or by CVD using trisilylamine as a raw material.

14. The first processing module includes: ２ , H ２ , Ar or H ２ O ２ and an auxiliary gas plasma forming unit for supplying the auxiliary gas in a plasma state to the first processing vessel.

15. The apparatus according to claim 8, wherein in the step of substituting the functional group with a hydroxy group, the first heating unit heats the substrate to a temperature in the range of 100° C. or more and 400° C. or less.

16. The apparatus according to claim 8, wherein in the step of obtaining the SiO film, the second heating section heats the substrate to a temperature in the range of 200° C. or more and 600° C. or less.

17. The apparatus according to claim 8, wherein the plasma forming section is configured to form either a microwave plasma, an ICP plasma, or a high-frequency plasma obtained by applying power having a frequency within a range of 700 MHz to 10 GHz.

18. The second process gas contains at least one of He and Ar as a diluent gas, and the O ２ Or O ３ The apparatus according to claim 8, wherein a mixing ratio of at least one of the above and the dilution gas is within a range of 1:1 to 1:

200.

19. The apparatus according to claim 8, wherein a bias power supply unit for applying bias power is connected to the second mounting table.

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