Oxide film etching method and substrate processing apparatus

Abstract

To suppress removal of a protective film containing silicon exposed on a surface of a substrate due to etching of a silicon-containing oxide film.SOLUTION: A method for etching an oxide film includes the steps of forming a protective film of a metal or metal nitride not containing silicon so as to cover a protected film from among an oxide film containing silicon and the protected film containing silicon exposed on a surface of a substrate, supplying a mixed gas containing hydrogen fluoride gas and ammonia gas to the substrate to react with the oxide film containing silicon, thereby transforming the oxide film and generating a reaction product, and sublimating and removing the reaction product.SELECTED DRAWING: Figure 2A

Description

[Technical field]

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

[0002] In the manufacturing process of semiconductor devices, a method is known in which a silicon oxide film, which is a natural oxide film present on the surface of a semiconductor wafer (hereinafter referred to as a "wafer") serving as a substrate, is dry-etched without using plasma. This dry-etching method is carried out, for example, by a COR (Chemical Oxide Removal) process that alters the silicon oxide film to generate reaction products, and a PHT (Post Heat Treatment) process that sublimates and removes the reaction products.

[0003] For example, Patent Document 1 describes a wafer structure on which these processes are performed. Specifically, an interlayer insulating film, HDP-SiO 2 , formed by a bias high-density plasma CVD (HDP-CVD) method, is provided on a Si layer. 2 The HDP-SiO 2 The film has a contact hole that reaches the Si layer. An insulating SiN film is provided on the sidewall of the contact hole, and the document describes how a sacrificial oxide film, which is a natural oxide film provided on the bottom of the contact hole, is removed by the above-mentioned process. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6161972 Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a technique for suppressing removal of a protected film containing silicon exposed on a surface of a substrate due to etching of a silicon-containing oxide film. [Means for solving the problem]

[0006] The oxide film etching method of the present disclosure includes: forming a protective film of a metal or metal nitride not containing silicon so as to cover the protective film of the silicon-containing protective film and the silicon-containing oxide film exposed on the surface of the substrate; supplying a mixed gas containing hydrogen fluoride gas and ammonia gas to the substrate to react with the silicon-containing oxide film, thereby transforming the oxide film and generating a reaction product; removing the reaction product by sublimation; Contains: Effect of the Invention

[0007] According to the present disclosure, it is possible to suppress removal of the silicon-containing protected film exposed on the surface of the substrate by etching the silicon-containing oxide film. [Brief description of the drawings]

[0008] [Figure 1A] FIG. 2 is a cross-sectional side view of a recess formed in a wafer according to an embodiment of the present disclosure. [Figure 1B] FIG. 11 is a vertical sectional side view of the recess in a comparative example. [Figure 2A] FIG. 4 is a first vertical cross-sectional side view of the recess according to the embodiment. [Figure 2B] FIG. 4 is a second vertical cross-sectional side view of the recess according to the embodiment. [Figure 2C] FIG. 11 is a third vertical cross-sectional side view of the recess according to the embodiment. [Figure 2D] FIG. 11 is a fourth vertical cross-sectional side view of the recess according to the embodiment. [Figure 2E] FIG. 13 is a fifth vertical cross-sectional side view of the recess according to the embodiment. [Diagram 3] 1 is a plan view of a substrate processing apparatus according to an embodiment of the present invention; [Figure 4] 2 is a vertical sectional side view showing a first processing module of the substrate processing apparatus. FIG. [Diagram 5] 4 is a vertical sectional side view showing a second processing module of the substrate processing apparatus. FIG. [Figure 6] 4 is a vertical sectional side view showing a third processing module of the substrate processing apparatus. FIG. [Figure 7] FIG. 13 is a graph showing experimental results of a preliminary test. [Figure 8] 1 is a SEM image showing the experimental results of an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Before describing an embodiment of an oxide film etching method according to the present disclosure, the configuration of a wafer W, which is a substrate to be processed by the method, will be described. FIG. 1A is a vertical cross-sectional side view showing a portion of a surface layer of a wafer W before processing. The base layer of the wafer W is a Si layer 10 made of, for example, silicon (Si). A SiOx (silicon oxide) layer 11 is formed on the Si layer 10. The SiOx layer 11 is used as an interlayer insulating layer.

[0010] In the SiOx layer 11, a plurality of elongated recesses 12 formed by etching are provided so as to open to the surface of the wafer W. Note that in Figs. 1A to 1B and 2A to 2E, only one recess 12 is illustrated. Each recess 12 is provided so as to reach the Si layer 10, and is formed in order to provide a contact metal film (hereinafter also simply referred to as a "contact film") and a wiring layer connected to the Si layer 10. The width of the recesses 12 is formed to be, for example, about 10 nm to 20 nm in order to meet the demand for miniaturization of semiconductor circuits in recent years, and these recesses 12 are formed at narrow intervals.

[0011] The bottom surface of the recess 12 is composed of a Si layer 10. On the surface of the Si layer 10 facing the inside of the recess 12, a silicon oxide film 10a is formed which is naturally oxidized when the wafer W is transported in, for example, an air atmosphere. The silicon oxide film 10a corresponds to the "oxide film containing silicon" in the present disclosure. The side surface of the recess 12 is composed of a SiN (silicon nitride) layer 13 used as a stopper during the etching process. On the side surface of the SiN layer 13 facing the inside of the recess 12, a thin damaged film 13a is formed which is damaged by the etching process and an ashing process for removing the resist. The damaged film 13a has a thickness of, for example, about 1 nm to 2 nm, and contains, for example, silicon nitride which is oxidized during the transport process. In this way, the silicon oxide film 10a and the damaged film 13a are exposed to the surface of the wafer W through the recess 12.

[0012] For the wafer W having the above structure, the silicon oxide film 10a having a high electrical resistance is removed by the COR process and the PHT process described in the Background Art, and then a contact film and a cap film constituting a part of the wiring layer are formed. As shown in FIG. 2E described later, the cap film 16 may be a barrier metal that constitutes a part of the wiring layer, or may be removed without constituting the wiring layer. Hereinafter, the COR process and the PHT process are collectively referred to as an "oxide film removal process." Here, before describing the etching method of the present disclosure, a comparative etching method that is to be compared with the etching method of the present disclosure will be described.

[0013] A comparative etching method will be described with reference to FIG. 1A and FIG. 1B. In the comparative etching method, an oxide film removal process is first performed on a wafer W including the structure shown in FIG. 1A. As a result, the silicon oxide film 10a becomes a reaction product such as ammonia fluorosilicate (AFS) by a mixed gas described later supplied in the COR process, and the reaction product is sublimated and removed in the PHT process. However, as described above, the damaged film 13a contains oxidized silicon nitride, so the COR and PHT processes also act on the silicon oxide portion in the damaged film 13a. Therefore, as shown in FIG. 1B, there is a risk that the damaged film 13a containing silicon and oxygen will also be removed in the oxide film removal process.

[0014] If the damaged film 13a is removed, the width of the recess 12 may increase by about 2 to 4 nm, which is a significant increase in width for extremely thin semiconductor wiring on the nano-order. On the other hand, the removal of the damaged film 13a corresponds to the removal of a part of the SiOx layer 11 between adjacent recesses 12. As a result, the spacing between the wiring layers formed in the recesses 12 becomes narrow, which may cause inconveniences such as an increase in leakage current.

[0015] As a method for solving the problem that a part of the SiN layer 13 (damaged film 13a) described in the above comparative embodiment is removed, an oxide etching method according to the present disclosure and the resulting change in film shape will be described with reference to FIGS. 2A to 2E. In the oxide etching method according to the present disclosure, a step of forming a protective film for forming a protective film 14 on the damaged film 13a corresponding to the film to be protected ("protective film forming step") is performed before the oxide film removing step. By performing the oxide film removing step after covering the damaged film 13a with the protective film 14, it is possible to remove the silicon oxide film 10a while suppressing the removal of the damaged film 13a. After this oxide film removing step, a step of removing the protective film 14 ("cleaning step"), a contact film forming step for forming the contact film 15, and a cap film forming step for forming the cap film 16 are performed in this order.

[0016] The above series of processes of the present disclosure will be described in detail below with reference to Figs. 2A to 2E showing changes in the surface of the wafer W. During the series of processes, the environment surrounding the wafer W is a vacuum atmosphere. That is, the wafer W is not exposed to the atmosphere during the series of processes. For this reason, each process step is performed with the wafer W housed in a process container. Furthermore, when different process containers are used for the above-mentioned multiple process steps, the wafer W is vacuum-transferred via a vacuum transfer chamber to which these process containers are connected (vacuum transfer step).

[0017] In the protective film forming process, a film forming gas for forming a protective film (hereinafter also referred to as "protective film forming gas") is supplied to the wafer W shown in FIG. 1A. As the protective film, a material having etching resistance against the dry etching gas (mixed gas containing hydrogen fluoride gas and ammonia gas) supplied in the COR process is used. Examples of such materials include metals and metal nitrides. In the following example, a case where TiN, a metal nitride, is used as the protective film will be described.

[0018] The protective film forming gas is composed of a source gas containing the source material of the protective film and a reactive gas that reacts with the source gas. The source gas is, for example, a metal-containing gas, specifically a titanium (Ti)-containing gas, more specifically, TiCl 4 The reactive gas is a gas that precipitates the metal contained in the metal-containing gas, and is, for example, a gas that reacts with the titanium-containing gas, and more specifically, TiCl 4 NH gas reacts with Ti to nitride it. 3 (ammonia) gas. It is also an inert gas used as a purge gas together with the mixed gas, such as N 2 (Nitrogen) gas may be fed in parallel.

[0019] As shown in FIG. 2A, it is preferable that the protective film 14 is mainly formed on the damaged film 13a of the silicon oxide film 10a and the damaged film 13a exposed on the surface of the wafer W, and is hardly formed on the silicon oxide film 10a. Therefore, in a processing module described later that performs the protective film forming process, the film is formed without using plasma with high energy toward the substrate mounting table 55 on which the wafer W is mounted. The film is formed isotropically, for example, by a thermal atomic layer deposition method (ALD, Atomic Layer Deposition). This makes it possible to suppress the formation of TiN on the silicon oxide film 10a, which is a surface parallel to the substrate mounting table 55, and to preferentially form the protective film 14 on the damaged film 13a formed on a surface perpendicular to the substrate mounting table 55.

[0020] In addition, in the thermal ALD, the above-mentioned source gas and reactive gas are alternately and repeatedly supplied through a purge gas to perform cyclic film formation. As a result, the titanium metal contained in the metal-containing gas attached to the surface of the wafer W is precipitated and nitrided, and a molecular layer of TiN (titanium nitride) is formed on the surface of the wafer W one layer per film formation cycle. At this time, the incubation time required for the precipitation of TiN constituting the protective film 14 is longer for the silicon oxide film 10a than for the SiN layer 13. It is understood that the incubation time is correlated with the number of film formation cycles as shown in the preliminary test described later. Hereinafter, the number of cycles until the precipitation of the film begins may be referred to as the incubation cycle. In this embodiment, the number of film formation cycles is set to be greater than the incubation cycle for the SiN layer 13 and to be approximately the same as or less than the incubation cycle for the silicon oxide film 10a. As a result, the protective film 14 is selectively formed on the damaged film 13a between the silicon oxide film 10a and the damaged film 13a.

[0021] In this embodiment, the TiN film thus formed is used as the protective film 14. The TiN protective film 14 is difficult for silicon and oxygen to diffuse from the damaged film 13a, and contains very little silicon and oxygen. In addition, the protective film 14 has good adhesion to the damaged film 13a because it contains nitrogen, and can effectively protect the damaged film 13a from the mixed gas during the COR process even if it is formed relatively thin.

[0022] As shown in FIG. 2A, the width of the recess 12 is narrowed by forming the protective film 14. The lower end of the protective film 14 covers the upper portions of the two ends of the silicon oxide film 10a in the width direction. The protective film 14 is preferably as thin as possible within a range in which the damaged film 13a can be protected in the oxide film removal process. By suppressing an increase in the thickness of the protective film 14 and not narrowing the width of the recess 12, an increase in contact resistance due to a decrease in the buried volume of the wiring material can be suppressed. In the present disclosure, the thickness of the protective film 14 is, for example, about 0.5 nm to 5 nm, and is preferably about 1 nm to 2 nm in order to protect the damaged film 13a and to selectively form a film on the damaged film 13a.

[0023] Next, an oxide film removing step is performed on the wafer W on which the protective film 14 is formed. The oxide film removing step includes a COR step (a step of generating a reaction product by altering the oxide film) in which the silicon oxide film 10a is altered to become a reaction product, and a PHT step (a step of sublimating and removing the reaction product) in which the reaction product is sublimated. In the etching method of the present disclosure, the protective film 14 is not altered by the COR step and is not removed by the oxide film removing step. The damaged film 13a covered with the protective film 14 is not easily altered to become a reaction product and is not easily removed by the oxide film removing step because the supply of the mixed gas supplied in the COR step is suppressed. By the above-mentioned protective film forming step and oxide film removing step, the damaged film 13a covered with the protective film 14 remains, while the silicon oxide film 10a is removed, as shown in FIG. 2B. The bottom of the recess 12 is exposed to the unoxidized Si layer 10.

[0024] Next, a cleaning gas is supplied to the wafer W from which the silicon oxide film 10a has been removed, and a cleaning process is performed to remove the protective film 14. As a result, the protective film 14 is removed and the damaged film 13a is exposed, as shown in FIG. 2C. The side surface of the recess 12 is formed by the damaged film 13a, and the width of the recess 12 becomes approximately the same as the width of the recess 12 before the protective film forming process. Through the above process, the width change of the recess 12 is suppressed, and the unoxidized Si layer 10 is exposed at the bottom surface.

[0025] Then, a contact film forming process is performed on the wafer W from which the protective film 14 has been removed, in which a contact film 15, for example a Ti (titanium) film, is formed. The contact film forming process is performed by plasma CVD, which supplies a gas for forming a contact film (hereinafter also referred to as a "contact film forming gas") described later to perform anisotropic film formation. As shown in FIG. 2D, the formed contact film 15 is provided so as to cover the damaged film 13a constituting the sidewall of the recess 12 and the Si layer 10 constituting the bottom. Although not shown in the drawing, the contact film 15 tends to be thicker on the bottom side than on the sidewall side of the recess 12. In addition, since the contact film 15 comes into contact with the damaged film 13a and the Si layer 10, Si is diffused and silicide is formed, becoming a TiSi film 15a. The TiSi film 15a comes into contact with the Si layer 10 over a wide range at the bottom of the recess 12, and is formed with good dimensional accuracy on the sidewall of the recess 12.

[0026] A cap film forming process is performed in which a film forming gas for a cap film (hereinafter, also referred to as a "film forming gas for a cap film") is supplied to the wafer W on which the TiSi film 15a is formed, and a cap film 16, for example, a TiN film, is formed. When a TiN film is used as the cap film 16, the film forming gas for the cap film can be the same as the protective film forming gas described above. The cap film forming process is performed, for example, by isotropic thermal ALD, similarly to the protective film forming process. As shown in FIG. 2E, the formed cap film 16 is formed so as to cover the TiSi film 15a constituting the sidewall and bottom of the recess 12. The cap film 16 has approximately the same thickness on the sidewall and bottom of the recess 12. Such a cap film 16 is formed on the TiSi film 15a formed with good dimensional accuracy, and therefore is formed approximately according to the design value.

[0027] A substrate processing apparatus 1 capable of carrying out the above-mentioned series of processes will be described with reference to the plan view of Fig. 3. The substrate processing apparatus 1 includes a loader module 21, a load lock module 25, first and second vacuum transfer modules 31 and 32, a connection module 33, and first to fourth process modules 41 to 44. In the following description, the first vacuum transfer module 31 and the second vacuum transfer module 32 may be collectively referred to as vacuum transfer modules 31 and 32. Also, the first to fourth process modules 41 to 44 may be simply referred to as process modules 41 to 44.

[0028] The loader module 21, the load lock module 25, the first vacuum transfer module 31, the connection module 33, and the second vacuum transfer module 32 are arranged linearly in the front-rear direction in this order. In the following description of the substrate processing apparatus 1, the side where the loader module 21 is located is referred to as the front side, and the side where the second vacuum transfer module 32 is located is referred to as the rear side.

[0029] The loader module 21 includes a housing whose interior is at atmospheric pressure, a transfer mechanism 22 for the wafer W provided in the housing, and a load port 23. In this example, four load ports 23 are provided in a row on the left and right side of the front side of the housing. A transfer container 24 for storing the wafer W, called a FOUP (Front Opening Unified Pod), is placed on each load port 23. The transfer mechanism 22 is formed of, for example, a multi-joint arm that can move left and right, and can transfer the wafer W between the transfer container 24 on each load port 23 and each load lock module 25.

[0030] In this example, three load lock modules 25 are provided side by side when viewed from the front side. Each load lock module 25 has a housing, and the housing is connected to the loader module 21 and the vacuum transfer module 31 via gate valves G provided on the front and rear sides, respectively. Each load lock module 25 is configured so that the pressure inside the housing can be freely changed between atmospheric pressure and vacuum pressure when the gate valves G on the front and rear sides of the housing are closed. A stage (not shown) on which the wafer W is placed is provided inside the housing, and the stage is configured so that the wafer W can be delivered to and from the transfer mechanism 22 and the vacuum transfer mechanism 34 described later, which access the load lock module 25, respectively.

[0031] The first and second vacuum transfer modules 31, 32 are configured similarly to each other, and each include a housing 31a, 32a, and a vacuum transfer mechanism 34 provided in the housing 31a, 32a. An exhaust port 35 is opened in each of the housings 31a, 32a, and one end of an exhaust pipe is connected to the exhaust port 35. The other end of the exhaust pipe is connected to an exhaust mechanism 36 constituted by, for example, a turbo molecular pump, and the inside of the housings 31a, 32a is maintained in a vacuum atmosphere by exhaust from the exhaust port 35 by the exhaust mechanism 36.

[0032] In this example, two connection modules 33 are provided side by side. Each connection module 33 includes a housing 33a, which is connected to the housings 31a and 32a of the vacuum transfer modules 31 and 32. The housing 33a of the connection module 33 is also made into a vacuum atmosphere of the same pressure as the housings 31a and 32a by exhausting the air by the exhaust mechanism 36. A wafer W is placed in the housing 33a, and a stage (not shown) configured to be able to transfer the wafer W between the housing 33a and a vacuum transfer mechanism 34 described later is provided. The housings 31a and 32a of the first and second vacuum transfer modules 31 and 32 and the housing 33a of the connection module 33, which are made into a vacuum atmosphere by the exhaust mechanism 36, correspond to a vacuum transfer chamber for the wafer W.

[0033] A second processing module 42 and a third processing module 43 arranged side by side in the front and rear are connected to both left and right sides of the housing 31a of the first vacuum transfer module 31 as viewed from the front side via gate valves G1. The second processing module 42 is arranged on the front side, and the third processing module 43 is arranged on the rear side. The transfer of the wafer W between the second processing module 42, the third processing module 43 and the load lock module 25 is performed by a vacuum transfer mechanism 34 constituted by, for example, an articulated arm that can move back and forth.

[0034] A fourth processing module 44 and a first processing module 41 arranged side by side in the front and rear are connected to both left and right sides of the housing 32a of the second vacuum transfer module 32 as seen from the front side via gate valves G1. The fourth processing module 44 is arranged on the front side, and the first processing module 41 is arranged on the back side. The transfer of the wafer W between the fourth processing module 44, the first processing module 41, and the connection module 33 is performed by, for example, a vacuum transfer mechanism 34.

[0035] Correspondence between the processes performed in each of the first to fourth process modules 41 to 44 and the series of processes described above is shown. The first process module 41 performs a protective film forming process and a cap film forming process. By performing the protective film forming process and the cap film forming process, which form the same TiN film, in the first process module 41, the number of process modules is reduced and the efficiency of these processes is improved. In the claims, the process module that performs the protective film forming process (process step of forming a protective film) is called the "first process module," and the process module that performs the cap film forming process (process step of forming a cap film) is called the "fifth process module." From this perspective, the process module 41 shown in FIG. 3 and FIG. 4 has a common configuration of the first process module and the fifth process module.

[0036] The second process module 42 performs a COR process (a process of generating a reaction product by altering an oxide film), the third process module 43 performs a PHT process (a process of sublimating and removing the reaction product), and the fourth process module 44 performs a contact film formation process. Each of the process modules 41 to 44 includes a process chamber 51 that is evacuated to create a vacuum atmosphere inside, and a substrate mounting table 55 that is provided in the process chamber 51 and on which a wafer W is mounted. Each process step is performed in the process chamber 51.

[0037] The substrate processing apparatus 1 includes a control unit 20, which is a computer, and the control unit 20 includes a program. The program includes instructions (steps) for carrying out the above-mentioned processing steps of the wafer W and the transport step of the wafer W. The program is stored in a storage medium, such as a compact disc, a hard disk, a DVD, a non-volatile memory, etc., and is read from the storage medium and installed in the control unit 20.

[0038] The control unit 20 outputs control signals to each unit of the substrate processing apparatus 1 according to the program, and controls the operation of each unit. Specifically, the control unit 20 controls the operation of the processing modules 41-44, the opening and closing of the gate valves G and G1, the operation of the transfer mechanism 22, the operation of the vacuum transfer mechanism 34, the operation of the exhaust mechanism 36, the switching of the pressure in the load lock module 25, and the like. The control of the operation of the processing modules 41-44 includes, for example, temperature control of the wafer W by supplying power to heaters 56A-56C, etc., which will be described later, control of supplying and cutting off each gas to the processing vessel 51, and control of plasma formation by turning on and off the high frequency power source, if a high frequency power source is provided. The control operations performed by the control unit 20 in the COR process, the PHT process, the protective film forming process, the cleaning process, the contact film forming process, and the cap film forming process correspond to the processing steps. In addition, the control operations for transferring the wafer W to each processing vessel 51 in order to perform these processes correspond to the transfer steps.

[0039] Regarding the transfer path of the wafer W in the substrate processing apparatus 1, the wafer W is first transferred in the order of the transfer container 24 → the loader module 21 → the load lock module 25 → the vacuum transfer module 31 → the second vacuum transfer module 32 → the first processing module 41. Then, the wafer W subjected to the protective film forming process in the first processing module 41 is transferred in the order of the first processing module 41 → the second vacuum transfer module 32 → the connection module 33 → the first vacuum transfer module 31 → the second processing module 42. The wafer W subjected to the COR process in the second processing module 42 is transferred in the order of the second processing module 42 → the first vacuum transfer module 31 → the third processing module 43.

[0040] Then, the wafer W that has been subjected to the PHT process in the third process module 43 is transferred in the order of the third process module 43 → the first vacuum transfer module 31 → the connection module 33 → the second vacuum transfer module 32 → the fourth process module 44. The wafer W that has been subjected to the contact film forming process in the fourth process module 44 is transferred in the order of the fourth process module 44 → the second vacuum transfer module 32 → the first process module 41, and is subjected to the cap film forming process. The wafer W that has been subjected to the cap film forming process is transferred in the order of the first process module 41 → the second vacuum transfer module 32 → the connection module 33 → the first vacuum transfer module 31 → the load lock module 25 → the loader module 21, and is returned to the transfer container 24.

[0041] Next, the first processing module 41 in which the protective film forming process and the cap film forming process are performed will be described with reference to the vertical cross-sectional side view of FIG. 4. The processing vessel 51 of the first processing module 41 is made of, for example, aluminum, and a transfer port for the wafer W is formed in the side wall of the processing vessel 51, and a gate valve G1 for opening and closing the transfer port is provided. An exhaust duct 52 having, for example, a circular ring shape with a rectangular cross section is disposed in the upper part of the side wall of the processing vessel 51. A slit 52a is provided along the inner peripheral surface of the exhaust duct 52, and an exhaust port 52b is formed in the outer wall of the exhaust duct 52. A top wall 54 is provided on the upper surface of the exhaust duct 52 so as to close the upper opening of the processing vessel 51 via an insulating member 53, and the space between the exhaust duct 52 and the insulating member 53 is airtightly sealed by a seal ring.

[0042] A substrate mounting table 55 for horizontally supporting a wafer W is provided inside the processing vessel 51, and this substrate mounting table 55 is formed in a disk shape from a ceramic material such as aluminum nitride (AlN) or a metal material such as an aluminum or nickel alloy. In this example, a heater 56A for heating the wafer W is embedded in the substrate mounting table 55, and the heater 56A heats the wafer W to, for example, 700°C to 1000°C in the protective film forming process and the contact film forming process. The outer peripheral region and side surfaces of the upper surface of the substrate mounting table 55 are covered with a cover member made of ceramics such as alumina.

[0043] The substrate mounting table 55 is connected to a lifting mechanism 57 provided below the processing vessel 51 via a support member, and is configured to be freely raised and lowered between a processing position shown by a solid line in FIG. 4 and a transfer position for the wafer W shown by a dashed line below the processing position. In FIG. 4, reference numeral 52c denotes a partition member for partitioning the inside of the processing vessel 51 into upper and lower parts together with the substrate mounting table 55 raised to the processing position. Three support pins 58 (only two are shown) are provided below the substrate mounting table 55 in the processing vessel 51 so as to be freely raised and lowered by the lifting mechanism provided below the processing vessel 51. The support pins 58 are inserted into through holes in the substrate mounting table 55 at the transfer position, and are configured to be able to protrude and retract from the upper surface of the substrate mounting table 55, and are used for transferring the wafer W between the vacuum transfer mechanism 34 of the first vacuum transfer module 31 and the substrate mounting table 55 shown in FIG. 3. Reference numeral 59 in the figure denotes a bellows that separates the atmosphere inside the processing chamber 51 from the outside air and expands and contracts in accordance with the vertical movements of the substrate placement table 55 and the support pins 58, respectively.

[0044] A shower head 61 for supplying various gases into the processing vessel 51 in a shower-like manner is provided in the processing vessel 51 so as to face the substrate mounting table 55. The shower head 61 includes a main body portion fixed to the ceiling wall 54 of the processing vessel 51 and a shower plate 62 connected below the main body portion, and the interior thereof forms a gas diffusion space 63. A ring-shaped protrusion protruding downward is formed on the periphery of the shower plate 62, and gas discharge holes 64 are formed on the inner flat surface of the ring-shaped protrusion. A gas inlet hole communicating with the gas diffusion space 63 is formed in the ceiling wall 54 and the main body portion of the shower head 61, and a gas supply mechanism 6A for forming a protective film is connected to the gas inlet hole.

[0045] The gas supply mechanism 6A includes a source gas supply unit 71A configured to supply a source gas containing a source material of the protective film 14 to the processing vessel 51, and a reactive gas supply unit 72A configured to supply a reactive gas that reacts with the source gas. The gas supply mechanism 6A further includes two purge gas supply units 73A configured to supply a purge gas. The source gas supply unit 71A includes a source gas supply source 74A and a supply path 75A, and the supply path 75A is provided with a flow rate adjustment unit M1A, a storage tank T1A, and a valve V1A from the upstream side.

[0046] The reactive gas supply unit 72A includes a reactive gas supply source 76A and a supply path 77A, and the supply path 77A is provided with a flow rate adjustment unit M2A, a storage tank T2A, and a valve V2A from the upstream side. Each purge gas supply unit 73A includes a purge gas supply source 78A and a supply path 79A, and each supply path 79A is provided with a flow path adjustment unit M3A and a valve V3A. The supply path 79A of one purge gas supply unit 73A is connected to the supply path 75A of the raw material gas to purge the raw material gas, and the supply path 79A of the other purge gas supply unit 73A is connected to the supply path 77A of the raw material gas to purge the reactive gas. As described above, the raw material gas supply unit 71A, the reactive gas supply unit 72A, and the purge gas supply unit 73A are configured to supply the raw material gas, the reactive gas, and the purge gas into the processing vessel 51 individually, respectively.

[0047] The processing vessel 51 is connected to a vacuum exhaust path 66 via exhaust port 52b, and a vacuum exhaust unit 67 made of, for example, a vacuum pump, is provided downstream of the vacuum exhaust path 66 and configured to evacuate the gas inside the processing vessel 51. In the vacuum exhaust path 66, a pressure control valve, for example, an APC valve (not shown), is provided between the processing vessel 51 and the vacuum exhaust unit 67.

[0048] Next, the second processing module 42 for performing the COR process will be described with reference to the vertical cross-sectional side view of Fig. 5, focusing on the differences from the first processing module 41. A vacuum exhaust unit 67, for example, is connected to the lower part of the processing vessel 51 via a vacuum exhaust path 66 equipped with an opening and closing valve. The processing vessel 51 is equipped with a heater 56B provided inside the substrate mounting table 55. The heater 56B is configured to adjust the temperature of the upper surface of the substrate mounting table 55 by, for example, circulating and supplying a temperature control fluid to a pipe line, and further to heat the wafer W mounted on the substrate mounting table 55 to a heating temperature of 60°C or higher.

[0049] The gases supplied by the mixed gas supply mechanism 6B for the COR process connected to the shower head 61 are HF (hydrogen fluoride) gas, NH 3 gas, and inert gas. The mixed gas supply mechanism 6B includes an HF gas supply unit 71B, an NH 3 The HF gas supply unit 71B includes an HF gas supply source 74B and a supply path 75B, and the supply path 75B is provided with a flow rate regulator M1B. 3 The gas supply unit 72B includes a reactive gas supply source 76B and a supply path 77B, and the supply path 77B is provided with a flow rate adjustment unit M2B. The inert gas supply unit 73B supplies argon (Ar) gas and N 2 The supply path 79B includes a supply source 78B for supplying a gas, and a flow path adjustment unit M3B is provided in the supply path 79B. The downstream ends of the supply paths 75B, 77B, and 79B are connected to the shower head 61.

[0050] Next, the third process module 43 performing the PHT process will be described with reference to Fig. 6, focusing on the differences from the first process module 41. The heater 56C of the third process module 43 is made of a heater that uses, for example, resistance heat for heating, and is configured to heat the wafer W placed in the third process module 43 to a temperature higher than the temperature of the wafer W placed in the second process module 42.

[0051] The third processing module 43 is, for example, 2The inert gas supply unit 73C is provided for supplying an inert gas such as N 2 The third process module 43 has a gas supply source 78C and a supply path 79C with a flow rate adjustment unit M3C interposed therebetween. By using such an inert gas supply unit 73C, the reaction products sublimated in the processing vessel 51 can be quickly purged, and the pressure in the processing vessel 51 can be adjusted. The reaction products are sublimated by adjusting at least one of the temperature of the wafer W and the pressure in the processing vessel 51. From this point of view, the heater 56C and the vacuum exhaust unit 67 provided in the third process module 43 correspond to the sublimation processing unit of this embodiment.

[0052] A fourth process module 44 that performs the contact film forming process and the cleaning process will be described. The fourth process module 44 of this embodiment is configured to form a Ti film as the contact film 15. The fourth process module 44 is configured similarly to the first process module 41 described with reference to FIG. 3. On the other hand, the fourth process module 44 differs from the first process module 41 in the type of gas supplied from the gas supply mechanism and in that the fourth process module 44 is provided with a configuration related to plasma formation. In the following description, the components common to the first process module 41 described with reference to FIG. 3 are given the reference numerals shown in the figure.

[0053] The gas supply mechanism (not shown) of the fourth process module 44 is configured to supply a source gas and a reactive gas for forming the contact film, a cleaning gas, and a purge gas into the process chamber 51. The source gas for forming the contact film is a gas containing a source of the contact film, for example, a Ti-containing gas, specifically, TiCl 4 The reactive gas for forming the contact film is a gas that reacts with the source gas, for example, a gas that reacts with a Ti-containing gas, specifically, TiCl 4 H reacts with gas 2 (Hydrogen) gas.

[0054] The cleaning gas is a gas for removing the protective film 14, and is, for example, a gas containing a halogen compound gas, specifically, ClF 3 The purge gas is an inert gas that can purge various gases supplied in the fourth processing module 44 and dilute the cleaning gas, specifically, Ar gas. The dilution gas is ClF 3 It is provided as needed to adjust the concentration of gas.

[0055] The gas supply mechanism is TiCl 4 Gas supply unit, H 2 The first processing module 41 includes a gas supply unit, a purge gas supply unit, and a cleaning gas supply unit. Similar to the first processing module 41, these supply units each include a supply source and a supply path for each of the various gases, and each supply path is provided with a flow rate regulator. The downstream side of each supply path is connected to a shower head individually, for example, without merging.

[0056] The fourth processing module 44 forms a contact film by plasma CVD, and thus constitutes a capacitively coupled plasma processing apparatus with a shower head 61 serving as an upper electrode and a substrate mounting table 55 serving as a lower electrode. A high frequency power supply that supplies high frequency power for plasma generation is connected to the shower head 61 serving as the upper electrode via a matching box, and the substrate mounting table 55 serving as the lower electrode is grounded (both not shown).

[0057] In the contact film formation process, when high frequency power is applied to the shower head 61, the TiCl 4 Gas, H 2 The gas and Ar gas are ionized to generate plasma, whereby a contact film 15 is formed on the wafer W placed in the space between the shower head 61 and the substrate placement table 55 by plasma CVD.

[0058] In the contact film forming process, the pressure inside the processing vessel 51 is adjusted to a set value, for example, 666 Pa (5 Torr), and the temperature of the substrate mounting table 55 is adjusted to, for example, 400° C. In the cleaning process, the pressure inside the processing vessel 51 is adjusted to a set value, for example, 266 Pa (2 Torr), and the temperature of the substrate mounting table 55 is adjusted to, for example, 300° C.

[0059] Using the substrate processing apparatus 1 having the above-described configuration, the operation of performing a series of processes on a wafer W will be described with reference to Figs. 3 to 6 showing the apparatus 1 and Figs. 2A to 2E showing film changes. First, the vacuum transfer mechanism 34 in the vacuum transfer module 31 receives the wafer W to be processed from the load lock module 25 shown in Fig. 3, and transfers the wafer W toward the first processing module 41 located at the innermost position. Thereafter, the gate valve G1 of the first processing module 41 shown in Fig. 4 is opened, and the wafer W is caused to enter the processing vessel 51 from the entrance by the vacuum transfer mechanism 34. Then, the wafer W is transferred from the vacuum transfer mechanism 34 to the substrate placement table 55 using the support pins 58, and the vacuum transfer mechanism 34 is caused to leave the processing vessel 51, and the gate valve G1 is closed.

[0060] As described above, the first processing module 41 can perform both the protective film forming process and the cap film forming process, but first performs the protective film forming process. The pressure inside the processing vessel 51 and the temperature of the wafer W are adjusted according to the recipe for the protective film forming process. Next, as described above, various gases for forming the protective film are repeatedly supplied to the processing vessel 51 in a predetermined order. This film forming cycle may be performed, for example, within a range of about 30 to 60 times, taking into account the incubation cycle described above, and specifically, is performed 30 times. As a result, the protective film 14, which is a TiN film, is formed on the damaged film 13a, while being prevented from being formed on the silicon oxide film 10a (FIG. 2A).

[0061] After the protective film forming process is completed, the wafer W on which the protective film 14 is formed is unloaded from the first process module 41 in the reverse order of the loading process. The wafer W is then transported toward the second process module 42, which is the frontmost one. Thereafter, the wafer W is loaded into the second process module 42 in the same order as the loading process into the first process module 41, and the COR process is performed. The pressure and temperature in the process vessel 51 are adjusted according to the recipe settings for the COR process. Next, a mixed gas for the COR process is supplied to the process vessel 51, for example, at the same time. This allows the silicon oxide film 10a to be modified while avoiding the modification of the damaged film 13a covered with the protective film 14, thereby forming a reaction product.

[0062] After the COR process is completed, the wafer W on which the reaction products have been formed is transferred out of the second process module 42 in the same manner as in the first process module 41, and transferred into the third process module 43, which is the second from the front, for the PHT process. The pressure and temperature in the process vessel 51 are adjusted according to the recipe for the PHT process, and an inert gas is supplied to heat-treat the wafer W. The reaction products of the heat-treated wafer W are sublimated, and the silicon oxide film 10a is removed (FIG. 2B).

[0063] After the PHT process is completed, the wafer W from which the silicon oxide film 10a has disappeared is carried out from the third process module 43 and carried into the fourth process module 44, which is the third from the front. When the wafer W is carried from the third process module 43 to the fourth process module 44, it is carried through the first vacuum transfer module 31, the second vacuum transfer module 32, and the connection module 33, which are transfer paths in a vacuum atmosphere, so that the wafer W is not exposed to the air atmosphere. Therefore, it is possible to prevent the surface of the Si layer 10 exposed in the recess 12 from being re-oxidized by the air atmosphere. A cleaning process is performed on the wafer W from which the silicon oxide film 10a has been removed and carried into the fourth process module 44. In the cleaning process, the pressure and temperature in the process container 51 are adjusted according to the recipe setting for the process, and a cleaning gas with an adjusted flow rate is simultaneously supplied. As a result, the protective film 14 on the wafer W is removed (FIG. 2C).

[0064] After the cleaning process is completed, the contact film forming process is performed without being carried out from the third process module 43. Since the contact film forming process is performed in the vacuum atmosphere processing vessel 51 in which the cleaning process was performed, the efficiency of the entire process is high and the number of processing modules can be reduced. In the fourth process module 44, the pressure and temperature in the processing vessel 51 are adjusted according to the recipe setting in the contact film forming process, contact film forming gas is supplied, for example, simultaneously, and high frequency power is supplied to the shower head 61 by the power supply unit. By such plasma CVD, a contact film 15 is formed on the surface of the wafer W from which the silicon oxide film 10a and the protective film 14 have been removed (FIG. 2D). The contact film 15 in the recess 12 becomes a TiSi film 15a due to the diffusion of Si from the damaged film 13a and the Si layer 10.

[0065] When the contact film forming process is completed, the wafer W having the TiSi film 15a (contact film 15) formed on the surface thereof is carried out from the fourth process module 44 in the same manner, and is carried into the first process module 41 at the innermost side again. As described above, the first process module 41 can perform both the protective film forming process and the cap film forming process, but performs the cap film forming process at this timing. Since the recipe of the pressure, temperature, and film forming gas in the cap film forming process is almost the same as the recipe in the protective film forming process, the fourth process module 44 can be used in common for the protective film forming process and the contact film forming process. The film forming cycle in this process is performed, for example, about 30 to 90 cycles. As a result, the cap film 16 is formed on the TiSi film 15a (contact film 15) (FIG. 2E).

[0066] The wafer W on which the cap film 16 is formed is loaded into the load lock module 25, and then returned to the transfer container 24 via the loader module 21. As described above, according to the substrate processing apparatus 1 and the oxide film etching method of the present disclosure, the silicon oxide film 10a can be effectively removed in the oxide film removal step for removing the silicon oxide film 10a, and the recess 12 can be prevented from widening in the oxide film removal step.

[0067] (Modification) The protective film forming process in the embodiment of the present disclosure is not limited to thermal ALD, and may be performed by other film forming methods such as chemical vapor deposition (CVD) other than ALD that does not use plasma. In the case of adjusting the film thickness by film formation time like CVD, for example, selective film formation on the damaged film 13a can be performed by utilizing the difference in incubation time by adjusting the film formation gas supply time. In addition, the various gas mixtures and temperature adjustments in the above series of processes are merely examples, and other gas mixtures and temperature adjustments may be performed.

[0068] As described above, it is not essential that each process in the embodiment of the present disclosure is performed in the corresponding process module 41 to 44. For example, the protective film forming process and the cap film forming process are both performed in the first process module 41, but may be performed in different process modules, in which case two first process modules 41 may be provided in the substrate processing apparatus 1 to improve throughput. In addition, the COR process and the PHT process are performed in the second process module 42 and the third process module 43, respectively, but may both be performed in the second process module 42.

[0069] 3, an example of the arrangement of the processing modules 41-44 and the vacuum transfer modules 31, 32, etc. may of course be different in number and arrangement. For example, the vacuum transfer modules 31, 32, which are part of the transfer mechanism for the wafer W, may be a transfer module in which only one can be vacuum transferred and the other can be in the air atmosphere, as long as it is possible to prevent the modules from coming into contact with the air atmosphere after removing the silicon oxide film 10a.

[0070] The present disclosure suppresses the removal of the SiN layer 13, which is one silicon-containing layer, in the process of removing the oxide film of the Si layer 10, which is another silicon-containing layer. Therefore, the upper part of the Si layer 10 and the SiN layer 13 constituting the inner wall surface of the recess 12 are not limited to a Si layer and a SiN layer, respectively, and may be another layer containing silicon. For example, a SiGe layer may be provided on the upper part of the Si layer 10 to constitute the bottom of the recess 12. In this case, the oxide film of the SiGe layer exposed at the bottom of the recess 12 contains silicon oxide and is therefore removed in the same COR and PHT processes.

[0071] The shape of the recess 12 is not limited to the shape disclosed herein, and the bottom of the recess 12 illustrated as a flat surface may include a fin shape protruding toward the opening or a recess shape. The series of processes disclosed herein can be used for the damage film 13a and silicon oxide film 10a disposed on the surface of the wafer W, and are not limited to the damage film 13a constituting the sidewall of the recess 12 and the silicon oxide film 10a constituting the bottom. For example, the damage film 13a and the silicon oxide film 10a may be provided on the horizontal surface of the wafer W. Although the damage film 13a of the SiN layer 13 is shown as an example of a protected film, the protected film is not limited to the damage film 13a formed on the SiN layer, and may be formed on a layer of another composition.

[0072] Furthermore, for example, a cleaning gas supply unit may be provided in the third processing module 43, and a cleaning process may be performed after the PHT process, and the protective film 14 may be removed, and then the wafer W may be transported to the fourth processing module 44 and a contact film forming process may be performed. Furthermore, if the protective film 14 is sufficiently thin and has little effect on the subsequent formation of the contact film 15 and the cap film 16, the protective film 14 may not be removed. In this case, the contact film 15 and the cap film 16 may be formed on the remaining protective film 14. Furthermore, in this case, if the protective film 14 is formed as thin as possible, it is possible to form a thick contact film 15 while suppressing the width of the recess 12 from narrowing, thereby suppressing an increase in the contact resistance. In addition, although the embodiment of the present disclosure illustrates the formation of the contact film 15 and the cap film 16 in the recess 12, these are not essential configurations, and a metal layer serving as a wiring material may be directly formed in the recess 12 after the silicon oxide film 10a is removed.

[0073] The protective film 14 is preferably a TiN film, but may be another metal film that does not contain silicon or silicon oxide. In this case, the other metal film is preferably made of a material that is resistant to silicon diffusion from the damaged film 13a side and oxidation, so that the damaged film 13a is not damaged when the other metal film is removed by the COR process and the PHT process. The other metal film is preferably made of a material that does not melt, sublimate, or peel at the temperatures of the COR process and the PHT process. Furthermore, the other metal film is preferably a metal film whose incubation time for the damaged film 13a, which is the film to be protected, is shorter than that for the silicon oxide film 10a. Examples of the other metal film include materials containing W (tungsten) and Ru (ruthenium).

[0074] It should be noted that the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, modified, or combined in various forms without departing from the scope and spirit of the appended claims. EXAMPLES

[0075] (Preliminary Examination) We confirmed the difference in the incubation cycle that correlates with the incubation time used in the deposition of the protective film 14 by thermal ALD in the protective film formation process. Specifically, we confirmed the incubation cycle of the TiN film for (i) a silicon oxide film and (ii) a silicon nitride film.

[0076] A. Preliminary Examination Conditions The first processing module 41 of the embodiment and blanket wafers in which (i) a silicon oxide film and (ii) a silicon nitride film were formed with uniform thickness over the entire surface of three bare silicon wafers of the same shape were used to confirm the difference in the growth rate of the TiN film. For this purpose, the film formation recipe, the temperature of the wafer W, the pressure setting, etc. were performed under the same conditions, and the change in film thickness due to the number of cycles was confirmed.

[0077] B. Preliminary Test Results FIG. 7 is a graph showing the results of the preliminary test. It was found that the thickness of the TiN film and the number of cycles for each of the films (i) and (ii) were linearly related to each other. According to the plot of the film thickness for each of the films (i) and (ii) in FIG. 7, it was estimated that the deposition of the TiN film started at about 30 times for the silicon oxide film (i) and started at about 0 times for the silicon nitride film (ii). From this, it was estimated that there are different incubation cycles for the deposition cycle when depositing the TiN film for each of the films (i) and (ii). It was found that selective deposition can be performed by setting the deposition cycle using the difference in the number of incubation cycles. For example, according to the results of this preliminary test, it is considered that if the number of cycles is set to 30 or less or about 30 times, the TiN film can be selectively deposited on the silicon nitride film in the case of the silicon oxide film and the silicon nitride film.

[0078] (experiment) The protective film forming process in the embodiment was performed with the number of cycles set based on the above preliminary test results, and it was confirmed whether the TiN film was selectively formed. Specifically, it was confirmed that the TiN film was selectively formed on the silicon nitride layer on the side of the recess, and was not formed on the silicon oxide film on the bottom of the recess. A. Experimental conditions The prepared wafer had a silicon nitride layer uniformly formed on a silicon layer, and a recess formed in the silicon nitride layer that slightly penetrated into the upper part of the silicon layer. This wafer was subjected to 60 deposition cycles under the same deposition conditions as the preliminary test. After deposition of the TiN film, the recess of the wafer was confirmed by SEM images. B. Experimental Results In the SEM image shown in FIG. 8, the silicon nitride layer constituting the sidewall of the recess cannot be distinguished, but the damaged film 13a described with reference to FIG. 2C and the like is formed on the surface of the silicon nitride layer. According to FIG. 8, a TiN film was formed on the silicon nitride layer on which the damaged film 13a was formed. The thickness of the TiN film was about 2 nm. On the other hand, no clear TiN film was observed on the surface of the Si layer constituting the bottom of the recess. The film formation cycle required to form a TiN film with a thickness of 1 to 2 nm under the above-mentioned experimental conditions is about 40 to 60 times. This experiment confirmed that a TiN film can be selectively formed on the side of the recess of the wafer even with a cycle number of about 40 to 60 times. [Explanation of symbols]

[0079] W wafer 13a Damaged membrane 10a Silicon oxide film 14 Protective film

Claims

1. forming a protective film of a metal or metal nitride not containing silicon so as to cover the protective film of the silicon-containing protective film and the silicon-containing oxide film exposed on the surface of the substrate; supplying a mixed gas containing hydrogen fluoride gas and ammonia gas to the substrate to react with the silicon-containing oxide film, thereby transforming the oxide film and generating a reaction product; removing the reaction product by sublimation; 13. A method for etching an oxide film, comprising:

2. 2. The method for etching an oxide film according to claim 1, wherein the protective film constitutes a side surface of a recess formed in the surface of the substrate, and the oxide film constitutes a bottom surface of the recess.

3. 3. The method for etching an oxide film according to claim 2, wherein the protective film is formed by a chemical vapor deposition method that does not use plasma.

4. In the step of forming the protective film by chemical vapor deposition, supplying a source gas containing a source of the metal to the substrate; 4. The method for etching an oxide film according to claim 3, further comprising the steps of: subsequently supplying to said substrate a reaction gas for precipitating said metal from said source material, or a reaction gas for nitriding said metal, and repeating the steps.

5. 4. The method for etching an oxide film according to claim 3, wherein the protective film is formed selectively over the film to be protected by providing a longer incubation time for the oxide film than for the film to be protected during the chemical vapor deposition process.

6. 2. The method for etching an oxide film according to claim 1, wherein the film to be protected is a silicon nitride film containing oxidized silicon.

7. 2. The method of claim 1, wherein the protective film includes a metal selected from the group consisting of titanium, tungsten, and ruthenium.

8. forming a contact metal film on the surface of the substrate after the step of sublimating and removing the reaction product; forming a cap film to cover the contact metal film; The method for etching an oxide film according to claim 1 , comprising:

9. 9. The method for etching an oxide film according to claim 8, further comprising the step of removing said protective film after the step of sublimating and removing said reaction product and before the step of forming a contact metal film.

10. A substrate processing apparatus for processing a substrate, a first processing module including a processing vessel including a mounting stage on which the substrate is placed, and a film formation gas supply unit for supplying a film formation gas to the processing vessel; a second processing module including a processing vessel including a mounting table on which the substrate is placed, and a mixed gas supply unit configured to supply a mixed gas containing hydrogen fluoride gas and ammonia gas to the processing vessel; a third processing module including a processing vessel including a mounting stage on which the substrate is placed, and a sublimation processing section for performing at least one of heating the substrate and evacuating the processing vessel; A control unit, the control unit is configured to output a control signal for executing a processing step of: supplying the film forming gas into the processing vessel of the first processing module while the substrate, having a silicon-containing protected film and a silicon-containing oxide film exposed on its surface, is placed on the placement stage of the first processing module, to form a protective film of a metal or metal nitride not containing silicon so as to cover the protected film; then, while the substrate is placed on the placement stage of the second processing module, supplying the mixed gas into the processing vessel of the second processing module to react with the silicon-containing oxide film and transform the oxide film to generate a reaction product; and, while the substrate is placed on the placement stage of the third processing module, sublimating the reaction product onto the substrate on which the reaction product has been generated by the sublimation processing unit, thereby removing the reaction product.

11. The substrate processing apparatus according to claim 10 , wherein the protective film constitutes a side surface of a recess formed in the surface of the substrate, and the oxide film constitutes a bottom surface of the recess.

12. The substrate processing apparatus according to claim 11 , wherein the film forming gas forms the protective film by a chemical vapor deposition method that does not use plasma.

13. the deposition gas supply unit includes a source gas supply unit for supplying a source gas containing a source of the metal, and a reaction gas supply unit for supplying a reaction gas for extruding the metal from the source onto the substrate or for nitriding the metal; The substrate processing apparatus according to claim 12 , wherein the control unit is configured to output a control signal for repeatedly supplying the source gas and the reactive gas to the substrate in the supply of the film forming gas.

14. the film-forming gas has a characteristic that an incubation time for the oxide film is longer than that for the protective film when the film-forming gas is formed by the chemical vapor deposition method; The substrate processing apparatus of claim 12, wherein the control unit is configured to output a control signal to stop the supply of the film forming gas after the protective film is formed on the protected film and before the protective film is formed on the oxide film, in order to selectively form the protective film on the protected film.

15. The substrate processing apparatus according to claim 10 , wherein the film to be protected is a silicon nitride film containing oxidized silicon.

16. The substrate processing apparatus of claim 10 , wherein the protective film includes a metal selected from titanium, tungsten, and ruthenium.

17. a fourth processing module including a processing vessel including a mounting table on which the substrate is mounted, and a contact deposition gas supply unit that supplies a contact deposition gas for forming a contact metal film in the processing vessel to the processing vessel; a fifth processing module including a processing vessel including a mounting table on which the substrate is placed, and a cap film forming gas supply unit configured to supply a cap film forming gas to the processing vessel for forming a cap film in the processing vessel, 11. The substrate processing apparatus of claim 10, wherein the control unit is configured to output a control signal for executing, after the process step of sublimating and removing the reaction products, a process step of placing the substrate on a mounting table of the fourth processing module and supplying the contact film formation gas to the processing vessel to form a contact metal film on a surface of the substrate, and then a process step of placing the substrate on the mounting table of the fifth processing module and supplying the cap film formation gas to the processing vessel to form a cap film to cover the contact metal film.

18. the third processing module or the fourth processing module has a cleaning gas supply unit that supplies a cleaning gas for removing the protective film to the processing vessel, 18. The substrate processing apparatus of claim 17, wherein the control unit is configured to output a control signal for executing a processing step of supplying the cleaning gas to the processing vessel to remove the protective film after the processing step of sublimating and removing the reaction product and before performing the processing step of forming the contact metal film.

19. 18 . The substrate processing apparatus according to claim 17 , wherein the film forming gas and the cap film forming gas are a common gas, and the first process module and the fifth process module are provided as a common process module.

20. a vacuum transfer chamber to which the processing containers of the first to fifth processing modules are connected; a substrate transfer mechanism disposed within the vacuum transfer chamber; Equipped with The substrate processing apparatus of claim 17, wherein the control unit is configured to output a control signal for executing a transfer step of transferring the substrate by the substrate transfer mechanism via the vacuum transfer chamber to any one of the processing containers of the first to fifth processing modules in which the processing step is performed.

Images