Method for processing substrate and apparatus for processing substrate

Abstract

To provide a technique for obtaining a SiO film with a low impurity content from a SiN film containing a silicon compound having a functional group containing nitrogen and hydrogen.SOLUTION: A first process gas containing at least one of H2O2 and H2O is supplied to a substrate on which a SiN film containing a silicon compound having functional groups containing nitrogen and hydrogen is formed, and the substrate is heated to replace the functional groups with hydroxyl groups. Next, a second process gas containing at least one of O2 and O3 is supplied in a plasma state to the substrate, and the substrate is heated to desorb hydrogen from the silicon compound, thereby obtaining a SiO film.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] In the manufacturing process of a semiconductor device, a process is performed in which recesses such as via holes and trenches are 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 recesses. An insulator layer is then further formed on the upper surface side of the conductor embedded in the recess, and the formation of the recesses and the embedding of the conductor are repeated to form a multilayer wiring.

[0003] Patent Document 1 describes a technique in which a semiconductor substrate is spin-coated with a perhydrogenated silazane polymer, the resulting coating is baked, and the solvent is evaporated to form a polysilazane film. This polysilazane film is 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 also describes a technique for obtaining a SiO film by an oxidation reaction by heating a substrate to, for example, 40°C to 300°C and supplying water vapor to a thin film of polysilazane applied onto the substrate by a spin coater, or by heating the substrate to 40°C to 100°C and supplying a gas obtained by vaporizing hydrogen peroxide solution. 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 of water vapor supply to remove impurities such as nitrogen and hydrogen and to densify the SiO film. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-251598 A [Patent Document 2] JP 2015-62254 A Summary of the Invention [Problem to be solved by the invention]

[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. [Means for solving the problem]

[0007] A method of processing a substrate according to the present disclosure includes the steps of: A step of supplying a first process gas containing at least one of H2O2 and H2O to a substrate on which a SiN film containing a silicon compound having a functional group containing nitrogen and hydrogen is formed, and heating the substrate, thereby substituting the functional group with a hydroxyl group; Next, a second process gas containing at least one of O2 and O3 is supplied in a plasma state to the substrate, and the substrate is heated to remove hydrogen from the silicon compound, thereby obtaining a SiO film. Effect of the Invention

[0008] According to the present disclosure, a SiO film having 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. [Brief description of the drawings]

[0009] [Figure 1A] FIG. 1 is a first explanatory diagram relating to a process for forming a SiN film. [Figure 1B] FIG. 2 is a second explanatory diagram relating to the process of forming a SiN film. [Figure 1C] FIG. 11 is a third explanatory diagram relating to the process of forming a SiN film. [Diagram 2] 1 is an example of a vertical cross-sectional side view of the vicinity of a wafer surface in which a SiN film is laminated on a metal film. [Diagram 3]It is a longitudinal side view near the surface of a wafer on which processing related to a comparative form has been performed. [Figure 4] It is an example of a longitudinal side view near the surface of a wafer being processed by a first processing module. [Diagram 5] It is an example of a longitudinal side view near the surface of a wafer being processed by a second processing module. [Figure 6] It is a schematic plan view showing an embodiment of an apparatus for processing a wafer on which a SiN film is formed. [Figure 7] It is a longitudinal side view showing an example of a first processing module provided in the apparatus. [Figure 8] It is a longitudinal side view showing an example of a second processing module provided in the apparatus. [Figure 9] It is a longitudinal side view showing an example of a common processing module having the functions of both the first and second processing modules. [Figure 10] It is the result of FTIR analysis of the film before and after the first processing. [Figure 11] It is the result of FTIR analysis of the film before and after the second processing. [Figure 12] It is a graph showing the change in wet etching rate viewed along the thickness direction of the film after the first and second processes.

Embodiments for Carrying Out the Invention

[0010] <SiN film> First, a configuration example of a SiN film to which the method for processing a substrate according to the present disclosure is applied will be described. For example, the SiN902 film forms a recess 901c in a metal film 901 which is a conductive material on the surface of a wafer W, and is embedded in this recess 901c. The metal film 901 can be exemplified by being composed of silicon (Si), silicon germanium (SiGe), other metal materials, a nitride film containing a metal, or a laminated film of these materials.

[0011] The SiN film 902 contains a silicon compound having a functional group containing N (nitrogen) and H (hydrogen). A specific example of the SiN film 902 having such characteristics is the raw material polysilazane (e.g., [-SiH2NH-] n ) by spin coating. Another example is a film of oligomer or polymer having fluidity formed by polymerizing two or more molecules of trisilylamine (N(SiH3)3) gas by CVD. The SiN film 902 may be formed using other materials that contain silicon compounds having functional groups containing N and H and can be embedded in the recesses 901 formed on the surface of the wafer W, without being limited to using polysilazane or trisilylamine (TSA) as raw materials.

[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 an oligomer or polymer of TSA having fluidity is formed by CVD.

[0013] When the raw material liquid 902a is supplied to the surface of the wafer W, the raw material liquid 902a penetrates into the recess 901c of the upper metal film 901b, and the recess 901c is filled with the raw material liquid 902a (FIG. 1A). Then, the raw material liquid 902a is filled into the entire recess 901c, and the raw material liquid 902a is supplied so as to cover the entire upper surface of the upper metal film 901b, and then, for example, the wafer W is heated. This heating causes evaporation of the solvent contained in the polysilazane solution and polymerization of TSA to proceed, and a solid SiN film 902 is formed (FIG. 1B). Thereafter, a planarization process is performed by 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. In the following Figures 2 to 5, which are schematic diagrams showing the structure in which the SiN film 902 is formed by the above-mentioned method, the illustration of the recess 901c is omitted and a layered structure in which the SiN film 902 and the like are layered on the upper surface of the metal film 901 is shown.

[0014] The SiN film 902 formed by these methods contains silicon compounds resulting 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 (SiH3NH2) as an example of a silicon compound resulting from the raw material polysilazane, and monosilylamine has an amino group, which is a functional group containing N and H.

[0015] <Conventional treatment and comparative form> Thus, the SiN film 902 containing N and H has insufficient characteristics such as insulation, low density, and low etching resistance. Therefore, as described in Patent Document 1 exemplified in the background art, conventionally, an annealing process has been performed in which the wafer W is heated to about 400° C. in a water vapor supply atmosphere to desorb NH and replace it with SiO, and then the heating temperature is increased to about 700° C. to oxidize Si. The annealing process may be performed in the state of FIG. 1B before the planarization process, or in the state of FIG. 1B before the planarization process, or in the state of FIG. 1C after the planarization process. This annealing process causes H contained in the silicon compound to be desorbed, and a dense SiO film is obtained. However, if the wafer W is heated at a high temperature of 700° C., the structure of the wafer W on the underside may be damaged.

[0016] Here, examples of damage caused by high-temperature heating include the following. 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. At this time, the conductive region (upper metal film 901 and lower metal film 901a in contact with the SiN film 902 in FIGS. 1A to 1C) is oxidized, causing oxidation damage such as failure to obtain desired characteristics or loss of characteristics. This is not limited to the above-mentioned conductive material, but also includes unintended oxidation damage such as oxidation of the interface. In addition, there is a concern of similar oxidation damage not only on the outermost surface of the semiconductor substrate, but also when there is a structure in the lower layer that similarly includes an oxidation risk.

[0017] Another example of damage is stress damage to semiconductor patterns caused by volume expansion and contraction during compositional replacement 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 coated films such as polysilazane films, the volume expansion and contraction caused by temperature and compositional changes is large, generating film stress, which can lead to the risk of pattern collapse or pattern curvature.

[0018] Another example of damage is the shift in doping concentration of semiconductor elements. When 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 risk of shifting the semiconductor element characteristics.

[0019] Therefore, the inventors heated the wafer W to about 400°C and applied microwaves to generate plasma water vapor to process the SiN film 902 (comparative embodiment). Water vapor plasma contains active species such as oxygen radicals, oxygen ions, and electrons. In the comparative embodiment, the inventors intended to supply these active species to the SiN film 902 to cause the desorption of NH and the oxidation of Si to proceed in parallel, thereby forming a SiO film without performing annealing at a high temperature of about 700°C.

[0020] However, when the wafer W processed according to the comparative embodiment 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 SiO region 904a was formed only 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 on the lower side of the SiO region 904a, the released NH recombines with the silicon compound molecules and is not removed from the SiN film 902. For this reason, as shown in FIG. 3, in the method according to the comparative embodiment, the SiN film 902 remains on the lower side of the SiO region 904a, and it was found that it is difficult to convert the entire SiN film 902 into a SiO film.

[0021] The inventors speculate that the reason why such an event occurs is as follows. Water vapor plasma formed using microwaves in the 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 release 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, active species enter the interior of the SiN film 902 at a later timing than the surface of the SiN film 902. Therefore, the reaction of releasing NH and oxidizing Si in the SiN film 902 proceeds later than the surface of the SiN film 902. As a result, before NH, N, and H are released from the interior of the SiN film 902, a dense SiO region 904a is formed on the surface of the SiN film 902. Furthermore, since the SiO region 904a inhibits the release of NH and N from the interior of the SiN film 902, it is thought that the silicon compound molecules that have released NH and become highly active may recombine with these NH and N. This phenomenon also occurs in the SiN film 902 obtained by CVD from trisilylamine gas.

[0023] <Substrate Processing According to the Embodiment> Therefore, the inventors discovered a method for suppressing the formation of SiO regions 904a on the surface of the SiN film 902 and the recombination of emitted NH, etc., by dividing the process of converting the SiN film 902 into the SiO film 904 into two steps and using different processing gases for each step. It was 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] Of the two-stage process, the first process is a process for substituting functional groups containing N and H in the silicon compound contained in the SiN film 902, such as amino groups (NH2 groups) and NH groups in which one H has been removed from an amino group, with hydroxyl groups (OH groups) to obtain a SiOH film 903 (FIG. 4). In carrying out the first process, a first process gas containing at least one of H2O2 and H2O is supplied to the wafer W, 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). In carrying out the second process, a second process gas containing at least one of O2 and O3 is supplied in a plasma state to the wafer W, and the wafer W is heated.

[0026] When the wafer W including the laminated structure described with reference to Fig. 2 is heated and the first process gas is supplied, active species such as OH radicals are generated by thermal decomposition of H2O2 and H2O contained in the first process gas when the first process gas comes into contact with the wafer W. These active species are taken into the SiN film 902 and react with the silicon compound (monosilylamine (SiH3NH2) in the example described with reference to Fig. 2) contained in the SiN film 902. At this time, as also shown in Fig. 4, the OH radicals are replaced with the NH2 groups of the silicon compound, and NH radicals, N radicals, H radicals, etc. are released from the SiN film 902 (a process of replacing 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 adopted as a method for obtaining activated species of the first process gas. This suppresses the progress of the reaction in which H is released from the OH group substituted for the NH group to form SiO. As a result, it is possible to suppress the formation of a SiO region 904a 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 to react with silicon compounds having NH groups, and NH radicals and N radicals generated by the reaction can be released to the outside of the film. As a result, the recombination of NH radicals and N radicals that occurs 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 described later, it has been confirmed that the composition of SiN can be replaced with SiO by performing the first process.

[0029] On the other hand, according to the reaction using the first process gas described above, the supply of H2O2 or H2O under heating conditions at a relatively low temperature of 100 to 400°C mainly results in a reaction of replacing functional groups such as NH2 groups of silicon compounds contained in the SiN film 902 with OH groups. For this reason, it is considered difficult to uniformly oxidize the entire SiN film 902 to produce a dense SiOH film 903 by a method of supplying H2O2 vapor at a low temperature of 40°C to 100°C, as in the technique described in Patent Document 2 listed in the background art. Therefore, in the wafer processing of this embodiment, a process of obtaining a dense SiO film 904 from the SiOH film 903 is performed by supplying plasma of a second process gas containing O2 to the SiOH film 903 obtained in the first process.

[0030] Active species such as O1d contained in the plasma of the second process 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, and H from the OH group substituted for the NH2 group and H originally contained before the substitution are desorbed. In this way, the above reaction proceeds throughout the entire SiN film 903, and the entire SiN film 902 can be changed into a dense SiO film 904 as shown in FIG. 5 (a process of obtaining a SiO film by desorbing hydrogen from the silicon compound). As shown in the experimental results in FIG. 12 described later, it has been confirmed that a dense SiO film 904 with high etching resistance can be formed by performing the second process subsequent to the first process.

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

[0032] In addition, H2 may be added to the plasma processing of the second process. By adding H2 to the He / O2 oxidation plasma processing, some OH radicals are formed, which can assist the oxidation processing. The flow rate of H2 is added at a ratio of about 0.1 to 1 to 1 O2 gas. Hereinafter, a configuration example of a wafer processing apparatus 1 that performs this process will be described with reference to FIGS.

[0033] <Wafer processing equipment> 6 is a schematic plan view showing a configuration example of a wafer processing apparatus 1 that performs processing to convert a SiN film 902 into a SiO film 904. The wafer processing apparatus 1 includes an atmospheric transfer module 2 that loads and unloads a wafer W, load lock modules 31 and 32, a vacuum transfer module 4, and a plurality of, for example, four processing modules 5 and 6. The atmospheric transfer module 2 includes an atmospheric transfer mechanism 22 in an atmospheric transfer chamber 21. To the atmospheric transfer chamber 21, for example, three carriers 20, each of which accommodates a plurality of wafers W, and load lock modules 31 and 32 are connected, and the wafers W are transferred between them by the atmospheric transfer mechanism 22. In Fig. 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 in a vacuum transfer chamber 41. The vacuum transfer chamber 41 is connected to the processing modules 5 and 6 and the load lock modules 31 and 32, respectively, and is configured to transfer the wafer W between them by the substrate transfer mechanism 42. As described above, the two load lock modules 31, 32 are connected to the atmospheric transfer chamber 21 and the vacuum transfer chamber 41, respectively, and are configured so that their interiors can be switched between atmospheric pressure and vacuum pressure.

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

[0036] <First Processing Module 5> Next, an example of the configuration of the first and second processing modules 5 and 6 will be described. The first process module 5 is a module that performs the first process described above (process of obtaining a SiOH film 903 by replacing the SiN film 902 with a hydroxyl group (OH group)). As described above, in carrying out this process, a first process gas containing at least one of H2O2 and H2O is supplied to the wafer W, and the wafer W is heated, thereby carrying out the process. In the following example, a case where the process is carried out mainly using a first process gas containing H2O2 will be described.

[0037] 7 is a vertical cross-sectional side view showing a configuration example of the first processing module 5. The first processing module 5 includes a processing vessel (first processing vessel) 61, and a lower part of the processing vessel 61 is configured as an exhaust chamber 62. The processing vessel 61 and the exhaust chamber 62 are preferably made of, for example, a metal and have corrosion resistance against active species generated from the first processing gas and a cleaning gas described later. From this viewpoint, the inner walls of the processing vessel 61 and the exhaust chamber 62 may be covered with a cover made of ceramics such as Al2O2, Y2O3, and quartz. In addition, the inner wall surfaces of the metal processing vessel 61 and the exhaust chamber 62 may be coated with Al2O2, Y2O3, Si, etc. by ceramic spraying or the like.

[0038] Furthermore, the piping from the first process gas supplier (H2O2 supplier 651 described below) 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 with ceramics or resin can prevent piping corrosion and prevent decomposition of the first process gas, allowing the process to be carried out more efficiently.

[0039] The processing vessel 61 is connected to the vacuum transfer chamber 41 via a transfer port 60 for the wafer W formed so as to be freely opened and closed by a gate valve GV, and is configured so that 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] In the processing vessel 61, a susceptor (first mounting table) 63 for horizontally supporting a wafer W is provided in a state supported from below by a support pillar 631. The susceptor 63 may be made of metal or a ceramic material. When the susceptor 63 is made of metal, it may be covered with a ceramic cover 633 as shown in FIG. 7 for the same reason as the inner walls of the processing vessel 61 and the exhaust chamber 62. The surface of the susceptor 63 may be coated by ceramic spraying or the like. The necessity of protection from active species generated from the first processing gas by such a cover or coating is also the same for other devices exposed to the inside of the processing vessel 61 (for example, the side wall of the support pillar 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 upper surface of the processing vessel 61 is closed by a top plate 611. At a height position on the upper side of the side wall of the processing vessel 61, a processing gas supply nozzle 64 is provided to discharge a first processing gas into the processing vessel 61 toward a region below the top plate 611. In the example shown in FIG. 7, a plurality of processing gas supply nozzles 64 are used to supply the first processing gas, but 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, and may be, for example, a gas shower head. A gas shower head allows for more uniform gas supply, while the nozzle method can reduce the contact area with the first processing gas, thereby reducing the deactivation of active species. In this way, the gas supply structure can be appropriately selected. In this example, an example is shown in which a processing gas supply nozzle 64 is used that has a small contact area with the first processing gas and is less likely to deactivate active species.

[0043] The process gas supply nozzle 64 is connected to an H2O2 supply device 651 via a process gas supply pipe 641 provided with a valve V1 and a mass flow controller M1. The H2O2 supply device 651 is configured by a known device that generates high purity and high concentration H2O2 and supplies H2O2 gas with a concentration of, for example, about 50,000 volppm. The gas generated by the H2O2 supply device 651 may contain H2O with a concentration of, for example, about 100,000 volppm. The H2O2 and H2O are supplied from the H2O2 supply device 651 together with a carrier gas. The carrier gas may be an inert gas such as argon (Ar) gas, helium (He) gas, or nitrogen (N2) gas, or may be oxygen (O2) gas.

[0044] In order to suppress adsorption or decomposition of H2O2 contained in the first process gas supplied from the H2O2 supply device 651, a heater may be provided in the process gas supply pipe 641 to heat the pipe to, for example, about 100°C. The mixed gas of high concentration H2O2, H2O and carrier gas supplied from the H2O2 supply device 651 corresponds to the first process gas in this embodiment. The H2O2 supply device 651, the mass flow controller M1, the valve V1, the process gas supply pipe 641 and the process gas supply nozzle 64 constitute the first process gas supply unit in this embodiment.

[0045] In the first processing module 5, a process of replacing the polysilazane SiN film 902 with a SiOH film 903 is performed using H2O2 with high oxidizing power. Functional groups containing N and H in the silicon compound contained in the SiN film 902, such as amino groups (NH2 groups) and NH groups with one H removed from an amino group, are replaced with hydroxyl groups (OH groups) by reaction with H2O2 gas, and the SiOH film 903 is formed as shown in FIG. 4. The temperature used for this replacement is, for example, 100°C to 500°C. The temperature is preferably 300°C or less, and if the temperature is less than this temperature, Si oxidation is prevented while the polysilazane SiN film 902 is replaced with the SiOH film 903 by the oxidizing power of the H2O2 gas. The processing pressure is in the range of 13.3 kPa (100 Torr) to normal pressure. If the pressure is too low, the gas concentration will be insufficient and the substitution reaction efficiency will decrease, 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 a 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 a single gas or a mixed gas of gases that react with silicon compounds, such as NF3, H2, HCl, and HBr. The cleaning gas may be appropriately diluted with argon (Ar) gas, helium (He) gas, nitrogen (N2) gas, etc.

[0047] The remote plasma device 66 converts the above-mentioned cleaning gas into plasma and supplies it into the processing vessel 61 through a remote plasma supply port 612 provided on 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 on 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] Moreover, the remote plasma supplied from the remote plasma device 66 is not limited to be used only for cleaning the inside of the processing vessel 61. For example, when performing a process of replacing NH2 groups (including NH groups; the same applies below) in the SiN film 902 with OH groups, O2 gas, H2 gas, or Ar gas may be turned into plasma and supplied into the processing vessel 61 in parallel with the above-mentioned first processing gas. O radicals or OH radicals generated by the remote plasma can assist in replacing the NH2 groups in the SiN film 902 with OH groups, making it possible to perform the replacement reaction more efficiently.

[0049] In addition, a part of the first process gas supplied from the H2O2 supply device 651 may be supplied to the remote plasma device 66, turned into plasma, and then introduced into the process vessel 61. By converting the highly reactive H2O2 into plasma and generating radicals, the substitution reaction can proceed more efficiently. O2 gas, H2 gas, Ar gas, and some H2O2 gas constitute the auxiliary gas group of 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 of this embodiment.

[0050] However, if the amount of active species supplied from the remote plasma device 66 is too large, a 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, during processing of the SiN film 902, the flow rate ratio of the first processing gas supplied from the H2O2 supply device 651 to the remote plasma supplied from the remote plasma device 66 is suppressed to approximately 2:1 or less.

[0051] <Second Processing Module 6> Next, a configuration example of the second process module 6 will be described with reference to Fig. 8. The second process module 6 is a module that performs the above-mentioned second process in which hydrogen (H) is removed from the silicon compound contained in the SiOH film 903 obtained in the first process module 5 to obtain a SiO film 904. In performing the second process, a second process gas containing at least one of O2 and O3 is supplied in a plasma state to the wafer W, and the wafer W is heated. In the following example, a case in which a second process gas containing O2 is supplied will be described. In addition, in the case where the second processing module 6 shown in Figure 8 can adopt a configuration common to the first processing module 5 described using Figure 7, the same symbols as those in Figure 7 may be used, and individual explanations may be omitted.

[0052] 8, the second processing module 6 includes a processing vessel 61 which is a second processing vessel, and a susceptor 63 which is a second mounting table housed in the processing vessel 61. A heater 632 which is a second heating unit provided in the susceptor 63 is configured to heat the wafer W to a preset temperature, for example, 300°C within a range of 200°C to 600°C. When the susceptor 63 is made of metal, a bias power supply unit 635 may be connected via a matching unit 634 to apply a bias power that draws in active species contained in the plasmatized second processing gas. A high-frequency power of, for example, 13.56 MHz is applied from the bias power supply unit 635.

[0053] The second process module 6 shown in FIG. 8 is configured to supply a mixed gas of O2 and a diluent gas as a second process gas to a process vessel 61. An inert gas is preferably used as the diluent gas, and FIG. 8 illustrates a case where He is supplied. Alternatively, Ar may be supplied as the diluent gas. In this example, a process gas supply pipe 641 provided 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, and 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 are each composed of a gas cylinder that supplies high purity (about 100%) O2 and He. The mass flow controllers M2 and M3 adjust the flow rate so that the flow rate ratio of O2 to He is, for example, 10 sccm:1000 sccm within a range of 1:1 to 1:200. The flow rate ratio of the second process gas (O2 in this example) to the dilution gas (He in this example) can be adjusted within a range of 1:1 to 1:200, more preferably within a range of 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 active 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 generation of ions that may damage the wafer W and generates plasma that is rich in O1d radicals that are highly reactive with the SiOH film 903.

[0056] O1d radicals have an energy of 4.6 eV, which is a higher reaction energy than the 2.6 eV bond energy of the Si-Si bond, so they easily react with Si, releasing hydrogen (H) to form SiO bonds. In addition, stable SiO bonds are formed by reaction with radicals, so the film becomes denser and the film density improves. Microwave plasma is a method for generating plasma with such characteristics. Microwave plasma is a surface wave plasma, and can provide a dissociation energy of about 8 to 12 eV in the plasma generation region. In other words, O1d radicals with an energy of 4.6 eV can be generated. On the other hand, the susceptor 63 on which the wafer is processed is located in the diffusion plasma region, and in this region, plasma with high density and low electron temperature diffuses. With this configuration, it is possible to supply oxygen radicals such as O1d radicals with high density to the wafer W with low damage. The above is a feature of the technology disclosed in the present application that supplies 1d radicals with high transportability using microwave plasma. The microwave frequency is not limited to 2.45 GHz, but may be in the range of 700 MHz to 10 GHz, such as 860 MHz, 8.35 GHz, 5.8 GHz, or 1.98 GHz. Other examples of plasma sources include ICP (Induced Coupling Plasma) plasma, which is formed by using a high frequency antenna, and VHF plasma.

[0057] FIG. 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 side of the processing vessel 61, which is 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 closed by a dielectric plate 613. The dielectric plate 613 is made of a dielectric material that transmits microwaves, such as quartz. This dielectric material may also be a ceramic material, such as Al2O3 or Y2O3. 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 generating unit 681 are connected to this microwave propagation plate 685 in this order via a microwave introduction unit (not shown). A cover 614 is provided on the upper surface side of the dielectric plate 613 and the microwave propagation plate 685 to prevent leakage of microwaves.

[0058] In the above configuration, the microwaves supplied from the coaxial waveguide 684 through 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 of the microwave propagation plate 685. Then, the second processing gas is turned into plasma by the microwaves introduced into the processing vessel 61 through the dielectric plate 613. Although FIG. 8 illustrates an example of a single microwave supply mechanism, a plurality of microwave supply mechanisms may be provided, and the microwave generation mechanism may be selected from magnetron type, solid state amplifier type, and the like.

[0059] Furthermore, the second processing module 6 may be provided with a remote plasma device 66 for supplying a cleaning gas for cleaning the inside of the processing vessel 61. In the case where a microwave supply mechanism 68 is provided on the upper surface side 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 another form of cleaning, a cleaning gas line may be installed and cleaning may be performed with the same microwave plasma. Since the cleaning process can be performed with the same plasma source as the second process of forming SiO, the cost of the equipment can be reduced.

[0060] On the other hand, the SiOH film 903, which is to be subjected to the process of removing H in the second processing module 6, has already been subjected to the process of replacing NH2 groups with OH groups in the first processing module 5. Therefore, the amount of SiH and NH released, 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), is small. Therefore, the installation of the permanent remote plasma device 66 may be omitted for the second processing module 6 to reduce the cost of the device. In this case, when cleaning is required due to the long-term operation of the second processing module 6, for example, the module can be opened and the inside of the module can be wiped with diluted hydrofluoric acid to substitute for wet cleaning.

[0061] <Control unit> The wafer processing apparatus 1 includes a control unit 100 that controls the operation of each unit constituting the wafer processing apparatus 1, such as the transportation of the wafer W and the processing of the wafer W in each of the processing modules 5 and 6. The control unit 100 is, for example, a computer including a CPU and a storage unit (not shown), and the storage unit stores a program including a group of steps (instructions) for control required for executing a process of replacing the NH2 group in the SiN film 902 with an OH group and a process of removing 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 magnet optical disk, a memory card, or a nonvolatile memory, and is installed in the computer from the storage medium.

[0062] <effect> The operation of the wafer processing apparatus 1 having the above-mentioned configuration will be described below. In the wafer processing apparatus 1 shown in Fig. 6, the atmospheric transfer mechanism 22 takes out the wafer W accommodated in the carrier 20. Next, after alignment in the aligner chamber 24, the wafer W is carried 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 in the load lock module 31 to the first processing module 5.

[0063] As shown in FIG. 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 adjustment 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). It is understood that by adjusting the pressure to a higher value than the processing in the second processing module 6 described later, the replacement of NH2 groups in the SiN film 902 with OH groups can be efficiently promoted. In addition, the wafer W is heated to 200°C within the range of 100 to 400°C by the heater 632.

[0064] Then, the H2O2 supply device 651 supplies a first process gas containing H2O2 at a flow rate of, for example, 5,000 sccm in the range of 100 to 10,000 sccm. The first process gas supplied from the H2O2 supply device 651 flows into the process vessel 61 through the process gas supply nozzle 64. When the first process gas flowing into the process vessel 61 comes into contact with the wafer W heated by the heater 632, active species such as OH radicals are generated by thermal decomposition of H2O2 and H2O contained in the first process gas.

[0065] These active species are incorporated into the SiN film 902, and as explained above with reference to FIG. 4, the OH radicals are substituted with the NH groups of the silicon compound, and the entire film can be turned into a SiOH film 903 (the process 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 processing module 5 to the second processing module 6 via the vacuum transfer module 4. After the wafer W is placed on the susceptor 63 of the second processing 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 processing vessel 61 and adjust the pressure to 133 Pa (1 Torr) within the range of 20 Pa to 1.3 kPa (0.15 to 10 Torr). In the second processing module 6 that forms microwave plasma, the pressure in the processing vessel 61 is adjusted to a lower pressure than that in the first processing module 5, so that the plasma can be spread over the entire surface of the wafer W. In addition, the wafer W is heated to 300° C. within the range of 200 to 600° C. by the heater 632.

[0068] Thereafter, a second process gas containing O and He is supplied from the H2O2 supply device 651 at a flow rate of, for example, 1000 sccm in the range of 100 to 10000 sccm. In addition, a microwave is supplied from the microwave supply mechanism 68 into the process vessel 61, and a bias power for attracting active species is applied from the bias power supply unit 635 to the susceptor 63.

[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 a large amount of highly active radicals, O1d, is generated from O2. On the other hand, in the microwave plasma, the generation of ions that may 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 taken into the SiOH film 903. As a result, as described with reference to Fig. 5, the entire SiN film 902 can be changed into a dense SiO film 904 (a process of obtaining a 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 the 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 the processing is completed, the wafer W is transferred from the second processing module 6 to the load lock module 32 by the substrate transfer mechanism 42. Next, the atmosphere in the load lock module 32 is switched to an atmospheric pressure atmosphere, and then 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 structure on the underlying side of the SiN film 902.

[0073] <Variations> 9, the common processing module 7 is configured to commonize 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. For this purpose, the processing vessel 61 is connected to both the first processing gas supply section (H2O2 supply device 651, mass flow controller M1, valve V1) and the second processing gas supply section (oxygen supply source 661, He supply source 671, mass flow controllers M2, M3, valve V2). A microwave supply mechanism 68 is provided on the upper surface of the processing vessel 61, and a matching box 634 for applying bias power is connected to the susceptor 63. Furthermore, although not shown in FIG. 9, a remote plasma device 66 may be provided to supply plasma of a cleaning gas from, for example, a 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 almost 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 FIG 7 and FIG 8.

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

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

[0077] As described above, when the SiN film 902 is formed by a 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 a CVD method on the wafer W may be connected to the platform of Fig. 6. In this case, in the wafer processing apparatus 1, the film formation 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 while the substrate is transported to each processing vessel.

[0078] In addition, by using these connected modules, the transfer of the wafer W between each module (film-forming module, first and second processing modules 5, 6), the formation of the SiN film 902, and the processing by the first and second processing modules 5, 6 may be regarded as one cycle, and this cycle may be repeated. By dividing the film-forming, oxidation, and densification processes into multiple steps and repeating them, compared to the case where these processes are performed all at once, the embedding property is improved, and the film thickness per cycle is reduced by dividing them. As a result, oxidation and densification become easier, and there is an effect of obtaining a stable film quality. In addition, by adjusting the conditions in each cycle, the degree of oxidation and the degree of densification can be arbitrarily selected for each cycle with respect to the film thickness.

[0079] In the first processing module 5 described with reference to FIG. 7, a first processing gas containing a high concentration of H2O2 is supplied to replace NH2 groups with OH groups. However, the first processing gas for carrying out this processing is not limited to one containing H2O2. For example, water vapor (H2O) may be supplied. Since H2O has a lower activity than H2O2, 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 first process module 5 described with reference to FIG. 8, the second process gas containing O2 and a diluent gas is supplied to perform a process of desorbing H contained in the silicon compound constituting the SiOH film 903. On the other hand, the second process gas for performing this process is not limited to one containing O2. For example, a mixed gas of ozone (O3) and a diluent gas may be supplied. Since O3 has a higher activity than O2, the heating temperature of the wafer W is adjusted to about 200 to 400°C within the above-mentioned range of 200 to 600°C.

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

[0082] (Experiment 1) The SiN film 902 formed on the wafer W was subjected to the first process and the second process in that order, and the structure of the film before and after each process was analyzed. 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 300 nm thick SiN film 902. The wafer W was heated to 200°C under a pressure of 53.3 kPa (400 Torr), and a first process was performed by supplying a first process gas, H2O2 gas with a concentration of about 50,000 volppm, at a flow rate of 5,000 sccm, from the H2O2 supply device 651. Next, the wafer W after the first process was heated to 300°C under a pressure of 133 Pa (1 Torr), and a second process was performed by supplying a second process gas, a mixed gas of O2 and He (flow rate ratio 10 sccm:1000 sccm) plasmatized by microwaves from the microwave supply mechanism 68.

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

[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 is the wave number of infrared light [cm -1 ], and the vertical axis indicates absorbance [au (arbitrary unit)]. In Fig. 10, the analysis result of the membrane before the first treatment is shown by a dashed line, and the analysis result of the membrane after the first treatment is shown by a solid line. In Fig. 11, the analysis result of the membrane before the second treatment (indicated as "first treatment only") is shown by a dashed line, and the analysis result of the membrane after the second treatment (indicated as "first treatment + second treatment") is shown by a solid line.

[0085] Figure 10 shows an FTIR evaluation of the compositional replacement of the above-mentioned SiN bonds to SiO bonds before and after the first treatment. The analysis results before the first treatment, shown by the dashed line, show SiN, SiH, and NH bonds, whereas after the first treatment using H2O2 gas, all of these have been replaced with SiO bonds.

[0086] After the first process, the composition of the 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. In other words, it was confirmed that the process above was able to uniformly replace the polysilazane SiN film 902 with SiO.

[0087] Fig. 11 shows the FTIR analysis results when only the first treatment is performed and when both the first treatment and the second treatment are performed. It can be seen that even if SiN bonds (Si-NH2 and Si-NH) remain partially after only the first treatment, O is supplemented and all are replaced with SiO bonds by supplying the second treatment gas that has been plasmatized by microwaves in the second treatment. The fact that the second treatment can also supplement the first treatment is a feature of the technology disclosed in this application.

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

[0089] B. Experimental Results The effect of the second treatment subsequent to the first treatment, which is a feature of the technology disclosed in this application, is shown in Additional Figure 12. The horizontal axis is the film thickness of the polysilazane under consideration, with 0 being the outermost surface and increasing values ​​indicating deeper positions within the film along the film thickness direction. The interface with the wafer W is at approximately 2500 Å. The vertical axis indicates the wet etching rate using diluted hydrofluoric acid, a value normalized by the wet etching rate of the most stable thermally oxidized SiO2 film prepared as a reference. 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 is and the better the film quality is.

[0090] The dashed line is for the case where only the H2O2 SiN to SiO substitution process is performed, and the etching rate is about 9.6 times faster than the thermally oxidized SiO2 film. In contrast, as shown by the solid line in Fig. 12, the actual effect is that the film that has been subjected to the SiN to SiO substitution process, which is also a feature of the technology disclosed in this application, and the plasma densification process, has an etching rate that is 1.0 to 2.0 times faster than the thermally oxidized SiO2 film, and the effect obtained by the device disclosed in this application is clear. [Explanation of symbols]

[0091] 1 Wafer processing equipment 5. First Processing Module 6 Second Processing Module 63 Susceptor 632 Heater 651 H2O2 supply equipment 902 SiN film 903 SiOH film 904 SiO film

Claims

1. 1. A method for processing a substrate, comprising: A substrate having a SiN film formed thereon, which contains a silicon compound having a functional group containing nitrogen and hydrogen, is subjected to H ２ O ２ Or H ２ supplying a first process gas containing at least one of O and H while heating the substrate, thereby replacing the functional group with a hydroxy group; Next, the substrate is 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. 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 a range of 100° C. or more and 400° C. or less.

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

6. 2. 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 a 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 including a first mounting table on which a substrate is mounted; 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 generating unit for generating oxygen radicals by generating plasma from the second processing gas, and a second heating unit for heating the substrate; A control unit, The control unit is configured to output a control signal to execute the steps of: placing a substrate, on which a SiN film containing a silicon compound having functional groups including nitrogen and hydrogen, in the first processing vessel, supplying the first processing gas and heating the substrate to replace the functional groups with hydroxy groups; 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 and obtain a SiO film.

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

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

11. 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 apparatus of claim 10 , wherein the control unit is configured to output a control signal to perform the cycle repeatedly a number 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, by commonizing the first processing container and the second processing container, the first mounting table and the second mounting table, and the first heating unit and the second heating unit.

13. 9. 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 the first heating unit heats the substrate to a temperature in the range of 100° C. or more and 400° C. or less in the step of substituting the functional group with a hydroxy group.

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

17. The apparatus according to claim 8 , wherein the plasma forming unit is configured to form any one of microwave plasma, ICP plasma, and 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. 9. 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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