Film forming apparatus and film forming method

Abstract

A film forming apparatus (1) includes a chamber (101), a stage (190) that supports a substrate, a source gas supply unit that supplies source gas into the chamber (101), a high-frequency application unit (102) that generates plasma in the chamber (101) by applying a high-frequency electromagnetic field to the source gas supplied into the chamber (101), a vacuum pump (181) for evacuating the gas including the source gas in the chamber (101), and a bias application unit (106) that applies a high-frequency bias to the substrate. An introduction port (1012a) is provided in a portion of the peripheral wall of the chamber (101) located on the -X direction side of the projection area of the substrate in the Z-axis direction, and an exhaust port (1011a) is provided in a portion of the peripheral wall located on the +X direction side of the projection area.

Description

[Technical Field]

[0001] The present invention relates to a film forming apparatus and a film forming method. [Background technology]

[0002] An integrated chip has been proposed that includes multiple metal wiring layers arranged in an interlevel dielectric (ILD) structure arranged along the front side of a substrate, a dielectric layer arranged along the back side of the substrate, conductive bond pads arranged on the dielectric layer, a backside through-substrate via (BTSV) extending from one of the multiple metal wiring layers through the substrate and the dielectric layer to the conductive bond pad, a conductive bump arranged on the conductive bond pad, and a BTSV liner arranged along the sidewall of the BTSV (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-91840 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in the manufacturing method of an integrated chip as described in Patent Document 1, there is a demand for highly accurate and selective deposition of a dielectric film that will become the BTSV liner on the inner wall of the BTSV opening so that no dielectric film is interposed between the metal wiring layer exposed at the bottom of the BTSV opening and the BTSV.

[0005] The present invention has been made in view of the above-mentioned circumstances, and has as its object to provide a film formation apparatus and a film formation method that are capable of selectively forming a film on the sidewall of a hole or a trench with high accuracy. [Means for solving the problem]

[0006] In order to achieve the above object, a film forming apparatus according to the present invention comprises: A film formation apparatus capable of selectively forming a film on a side wall of a hole or a groove with high accuracy on a film formation target having a hole or a groove formed therein, a chamber; a stage that is disposed in the chamber and supports the film-forming target from the side opposite to a film-forming target portion of the film-forming target; a raw material gas supply unit that introduces a raw material gas that serves as a base for a film to be formed on the film-forming target into the chamber; a high frequency application unit that applies a high frequency electromagnetic field to the source gas supplied into the chamber to generate plasma within the chamber; a pump for exhausting a gas containing the source gas from the chamber; a bias application unit that applies a high-frequency bias to the film-forming target supported by the stage, an inlet for introducing the raw material gas from the raw material gas supply unit into the chamber is disposed in one of the opposing portions of the peripheral wall across a projection area of ​​the film-forming target held on the stage in an arrangement direction of the stage and the film-forming target; and an exhaust port for exhausting the gas in the chamber by the pump is disposed in the other opposing portion of the peripheral wall across the projection area, In a direction perpendicular to a mounting surface of the stage on which the film-forming target is mounted, at least a part of the exhaust port is located on a side of the mounting surface facing the inside of the chamber. The source gas, which is the source of the film to be formed on the film-forming target, is flowed from one side of the film-forming target facing each other across the projection area in the arrangement direction of the stage and the film-forming target, through the upper side of the film-forming target, to the other side of the projection area, and a high-frequency electromagnetic field is applied to the source gas to generate plasma, thereby forming a film on the film-forming target. do. [Effects of the Invention]

[0007] According to the present invention, the raw material gas introduced into the chamber from the inlet flows toward the exhaust port along the side opposite the stage side of the object to be film-formed. Therefore, if the object to be film-formed is the side wall of a hole or groove formed in the object to be film-formed, formation of a film on the bottom of the hole or groove is suppressed, and a film can be selectively formed with high accuracy on the side wall of the hole or groove, which is the object to be film-formed. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram of a film forming apparatus according to a first embodiment of the present invention. [Figure 2] 1 is a front view of a film forming apparatus according to a first embodiment. [Figure 3] FIG. 2 is a bottom view of a part of the film forming apparatus according to the first embodiment. [Figure 4A] 4 is a cross-sectional view showing a state after a multilayer structure forming step in the semiconductor manufacturing method according to the first embodiment. FIG. [Figure 4B] 4 is a cross-sectional view showing a state after a through-hole forming step in the semiconductor manufacturing method according to the first embodiment. FIG. [Figure 5A] 4 is a cross-sectional view showing a state after a sidewall film forming step in the semiconductor manufacturing method according to the first embodiment. FIG. [Figure 5B] FIG. 3 is a cross-sectional view showing a state after a sintering step in the semiconductor manufacturing method according to the first embodiment. [Figure 6] 4 is a cross-sectional view showing a state after an electrode embedding step in the semiconductor manufacturing method according to the first embodiment. FIG. [Figure 7A] 1 is an SEM photograph of a cross section of a substrate on which a film was formed by the film formation method according to Comparative Example 1. [Figure 7B] 10 is an SEM photograph of a cross section of a substrate on which a film was formed by the film formation method according to Comparative Example 2. [Figure 7C] 10 is an SEM photograph of a cross section of a substrate on which a film was formed by the film formation method according to Comparative Example 3. [Figure 8A] 1 is an SEM photograph of a cross section of a substrate on which a film is formed by the film forming method according to Example 1. [Figure 8B] 10 is an SEM photograph of a cross section of a substrate on which a film was formed by the film formation method according to Comparative Example 4. [Figure 8C] 10 is an SEM photograph of a cross section of a substrate on which a film was formed by the film formation method according to Comparative Example 5. [Figure 9A] 10 is an SEM photograph of a cross section of a substrate on which a film was formed by the film formation method according to Comparative Example 6. [Figure 9B] 10 is an SEM photograph of a cross section of a substrate on which a film was formed by the film formation method according to Comparative Example 7. [Figure 10] FIG. 10 is a schematic configuration diagram of a film forming apparatus according to a second embodiment of the present invention. [Figure 11A]10 is an SEM photograph of a cross section of a substrate on which a film is formed by the film forming method according to Example 2. [Figure 11B] 10 is an SEM photograph of a cross section of a substrate on which a film is formed by the film forming method according to Example 2. [Figure 12A] 10 is an SEM photograph of a cross section of a substrate on which a film is formed by the film forming method according to Example 3. [Figure 12B] 10 is an SEM photograph of a cross section of a substrate on which a film is formed by the film forming method according to Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Embodiment 1) An embodiment of the present invention will be described in detail below with reference to the drawings. A film formation apparatus according to the present invention includes a chamber, a stage disposed within the chamber and supporting a film formation target from the side opposite a film formation target portion of the film formation target, a source gas supply unit for introducing a source gas serving as a base for a film to be formed on the film formation target into the chamber, a high-frequency application unit for generating plasma within the chamber by applying a high-frequency electromagnetic field to the source gas or etchant gas supplied into the chamber, a pump for exhausting gas containing the source gas from the chamber, and a bias application unit for applying a high-frequency bias to the film formation target supported by the stage. The chamber has an inlet for introducing a source gas from the source gas supply unit into the chamber at one end of a peripheral wall thereof, the inlet being positioned on one side of a projection area of ​​the film formation target held on the stage in the alignment direction of the stage and the film formation target, and an exhaust port for exhausting gas within the chamber by a pump at the other end of the projection area of ​​the peripheral wall.

[0010] The film formation apparatus according to this embodiment is a so-called inductively coupled plasma CVD apparatus, and as shown in FIG. 1, this film formation apparatus 1 includes a chamber 101, a stage 190, a high-frequency application unit 102, a bias application unit 106, and raw material gas supply units 121, 122, and 123. Also, as shown in FIG. 2, the film formation apparatus 1 includes a support table 109 that supports the chamber 101. The film formation apparatus 1 forms an insulating film, such as an oxide film such as SiO2, an oxynitride insulating film such as SiON, or a nitride film such as SiN, on the upper surface of a substrate W1 placed in the chamber 101. Examples of the substrate W1 include a Si substrate, a sapphire substrate, and a glass substrate.

[0011] The chamber 101 includes a chamber body 1011 shaped like a flat rectangular box and open on one side in the thickness direction, and a lid 1012 covering the open portion of the chamber body 1011. The lid 1012 is annular and is attached to the chamber body 1011 via a sealing member (not shown), such as an O-ring, disposed over the entire end face of the chamber body 1011 in the +Z direction, thereby sealing the chamber 101. An opening 1012b is formed in the center of the lid 1012 when viewed from the thickness direction. The lid 1012 is also formed with an inlet 1012a for introducing source gases and etchant gases supplied from a supply pipe 125 (described later) into the chamber 101. The inlet 1012a opens into the inner wall of the opening 1012b of the lid 1012. In addition, on the +Z direction side of the lid body 1012, there are arranged a dielectric window 141 formed from a dielectric material such as glass and arranged to block the opening 1012b, and a window fixing member 142 that fixes the dielectric window 141 to the lid body 1012.

[0012] The support table 109 has a base member 1092 on which the chamber 101 is placed on the +Z direction side, and a support frame 1091 that supports the base member 1092. The support frame 1091 is formed by combining frames so that the outer shape is approximately rectangular parallelepiped, and an approximately rectangular parallelepiped area S1 surrounded by the frames is formed inside.

[0013] 1, the stage 190 is disposed in the chamber 101 and supports the substrate W1 on which an insulating film is to be formed. The stage 190 is made of a metal such as Al, SUS, or Cu. A heater 191 for heating the substrate W1 is embedded in the stage 190.

[0014] The source gas supply units 121, 122, and 123 introduce source gases that form the basis of the insulating film into the chamber 101. Examples of source gases include SiH4, O2, and N2. The source gas supply unit 121 includes a gas reservoir 121a that stores, for example, SiH4 gas and a supply pipe 121b through which the SiH4 gas is supplied from the gas reservoir 121a. The source gas supply unit 121 also includes a supply pipe 121e that is connected to the supply pipe 121b and supplies a dilution gas into the supply pipe 121b to dilute the source gas flowing through the supply pipe 121b. For example, H2 gas can be used as the dilution gas. The source gas supply unit 121 also includes a flow rate control valve 121c that controls the flow rate of the source gas flowing through the supply pipe 121b and a flow rate control valve 121d that controls the flow rate of the dilution gas flowing through the supply pipe 121e. The raw material gas supply unit 122 includes, for example, a gas storage unit 122a that stores O2 gas, a supply pipe 122b to which O2 gas is supplied from the gas storage unit 121a, and a flow rate control valve 122c for controlling the flow rate of the O2 gas flowing through the supply pipe 122b. The raw material gas supply unit 123 includes, for example, a gas storage unit 123a that stores N2 gas, a supply pipe 123b to which N2 gas is supplied from the gas storage unit 123a, and a flow rate control valve 123c for controlling the flow rate of the N2 gas flowing through the supply pipe 123b. The supply pipes 121b, 122b, and 123b are commonly connected to a supply pipe 125. 2, supply pipe 125 has a first section 1251 that is a long tube and to which supply pipes 121b, 122b, and 123b are commonly connected, and a second section 1252 that is also a long tube and communicates at one end with the inside of first section 1251 and extends while bending toward the +Z direction. The other end of second section 1252 of supply pipe 125 communicates via connecting section 1253 with inlet 1012a (described later) that is disposed in lid 1012.

[0015] Returning to FIG. 1 , the chamber 101 has an inlet 1012a disposed in a peripheral wall thereof, the inlet 1012a introducing source gas into the chamber 101 in a portion thereof facing the arrangement direction of the stage 190 of the substrate W1 held on the stage 109 and the substrate W1, i.e., the -X direction across a projection area A1 in the Z-axis direction. The chamber 101 also has an exhaust port 1011a disposed in a peripheral wall thereof facing the projection area A1 in the +X direction, through which the source gas in the chamber 101 is exhausted by a vacuum pump 181. The vacuum pump 181 is connected to an exhaust pipe 182 communicating with the exhaust port 1011a disposed in the peripheral wall of the chamber 101. The vacuum pump 181 may be, for example, a turbomolecular pump. When the vacuum pump 181 is operated, gas containing the source gas in the chamber 101 is exhausted through the exhaust port 1011a and the exhaust pipe 182, thereby reducing the pressure inside the chamber 101.

[0016] The high-frequency application unit 102 includes a high-frequency generation source 1021 that generates high-frequency power, a matching box 1022, and an induction coil 1023 that is arranged outside the chamber 101 and faces the dielectric window 141 of the chamber 101. As shown in Fig. 2, the high-frequency application unit 102 also includes a flat, rectangular box-shaped housing 1024a that houses the high-frequency generation source 1021 and the matching box 1022, and a flat, rectangular box-shaped housing 1024b that houses a portion of the induction coil 1023. The high-frequency application unit 102 also includes a frame 1025 that is arranged to surround the induction coil 1023 on the -Z direction side of the housing 1024b.

[0017] The induction coil 1023 is formed long and made of a conductor such as metal, and is disposed outside the chamber 101. When the chamber 101 is filled with a gas such as a source gas, the induction coil 1023 generates a high-frequency magnetic field in the chamber 101 to generate a plasma PLM in the chamber 101 by supplying high-frequency power from the high-frequency generating source 1021. The induction coil 1023 includes a sub-coil 10231 disposed in an area on the +Y direction side inside the frame 1025 and a sub-coil 10232 disposed on the −Y direction side. The area inside the housing 1024b and the area inside the frame 1025 are separated by a shielding plate 1024c shown in FIG. 3, and the induction coil 1023 is fixed to this shielding plate 1024c.

[0018] As shown in Fig. 3, subcoil 10231 has spiral portion 10231a extending spirally in a planar view and spiral portion 10231b extending spirally in a planar view and positioned adjacent to spiral portion 10231a in the X-axis direction. The outermost ends of spiral portions 10231a and 10231b are grounded to shielding plate 1024c via fixing member 10233. When viewed from the -Z direction, spiral portion 10231a extends in a clockwise spiral shape, and spiral portion 10231b extends in a counterclockwise spiral shape. Subcoil 10231 also has connecting portion 10231c connecting the outermost ends of spiral portions 10231a and 10231b positioned in the +Y direction. Furthermore, the ends of spiral portions 10231a and 10231b of subcoil 10231, which are located in the center in the X-axis direction, are electrically connected to the output end of high-frequency generation source 1021. Subcoil 10232 also has spiral portion 10232a extending spirally in plan view and spiral portion 10232b extending spirally in plan view and located adjacent to spiral portion 10232a in the X-axis direction. Here, the outermost ends of spiral portions 10231a and 10231b are grounded to shielding plate 1024c via fixing member 10233. When viewed from the -Z direction, spiral portion 10232a extends spirally counterclockwise, and spiral portion 10232b extends spirally clockwise. Subcoil 10232 also has connecting portion 10232c that connects the outermost ends of spiral portions 10232a and 10232b located on the +Y direction side. Furthermore, the ends of spiral portions 10232a and 10232b of subcoil 10232 that are located in the center in the X-axis direction are also electrically connected to the output terminal of high-frequency generation source 1021.

[0019] The shielding plate 1024c has four through-holes 1024c1 that are parallel to each other in the X-axis direction and penetrate the thickness of the shielding plate 1024c, located on the +Y-axis side of the center in the Y-axis direction. The ends of the sub-coils 10231 and 10232 are inserted into the through-holes 1024c1 from the -Z-axis side of the shielding plate 1024c and extend toward the +Z-axis side of the shielding plate 1024c. The ends of the sub-coils 10231 and 10232 are fixed to the shielding plate 1024c via insulating retainers 10235. The insulating retainers 10235 are made of, for example, ceramics.

[0020] In addition, the portions of each of the spiral portions 10231a and 10231b of the subcoil 10231 closest to the -Y direction are fixed to the shielding plate 1024c by fixing members 10234 arranged on the -Z direction side of the shielding plate 1024c, and the ends connected to the connecting portions 10231c of each of the spiral portions 10231a and 10231b are fixed to the shielding plate 1024c by fixing members 10233 arranged on the -Z direction side of the shielding plate 1024c. The portions of each of spiral portions 10232a and 10232b of subcoil 10232 closest to the -Y direction are also fixed to shielding plate 1024c by fixing members 10234 arranged on the -Z direction side of shielding plate 1024c, and the ends of each of spiral portions 10232a and 10232b connected to connecting portions 10232c are also fixed to shielding plate 1024c by fixing members 10233 arranged on the -Z direction side of shielding plate 1024c. Fixing member 10234 has an insulating block 10234a formed with a groove inside which subcoils 10231 and 10232 are placed, and fixing piece 10234b that is rectangular in plan view and arranged on the groove 10234a2 side of insulating block 10234a for fixing subcoils 10231 and 10232 to insulating block 10234a. The insulating block 10234a is made of, for example, ceramics, and the fixing piece 10234b is made of, for example, a metal such as copper. The fixing member 10233 is made of, for example, a metal such as copper.

[0021] Returning to FIG. 1 , the high-frequency application unit 102 applies a high-frequency electromagnetic field to the source gas or etchant gas supplied into the chamber 101 by applying a high-frequency alternating current (for example, a frequency of 13.56 MHz) to the induction coil 1023. This generates a plasma PLM in the chamber 101. The bias application unit 106 applies a high-frequency bias to the substrate W1 supported by the stage 190. The bias application unit 106 applies a high-frequency voltage (for example, a high-frequency voltage with a frequency of 13.56 MHz) that oscillates between 0 V and a negative voltage of −2000 V to the stage 190. The bias application unit 106 has a high-frequency generation source 1061 and a matching box 1062.

[0022] Next, a method for manufacturing a wiring layer according to this embodiment will be described with reference to FIGS. 4 to 6. First, as shown in FIG. 4A, a composite substrate is prepared, including a substrate W1 (a Si substrate), an insulator layer L1 formed on the substrate W1, a metal layer P1 embedded in the insulator layer L1, a metal layer P2 formed on the metal layer P1, an insulator layer L3 formed to cover the metal layer P2, an insulator layer L4 formed on the insulator layer L3, a substrate W2 (a Si substrate) disposed on the insulator layer L2, and an insulator layer L2 formed on the substrate W2. Here, the insulator layers L1, L2, and L4 are formed of SiO2, and the insulator layer L3 is formed of SiN. The metal layer P1 is formed of Cu, and the metal layer P2 is formed of Ti or Ni. Furthermore, the thickness TH1 of the substrate W2 is set to, for example, 30 μm or more and 50 μm or less.

[0023] Next, as shown in FIG. 4B, a through hole TR1 is formed by etching, penetrating the insulator layer L2, the substrate W2, and the insulator layers L4 and L3 to the surface of the metal layer P2. Subsequently, as shown in FIG. 5A, using the film forming apparatus 1 according to this embodiment, a liner layer L5 is formed on the inner wall of the through hole TR1 and on the upper surface of the insulator layer L2. Here, the liner layer L5 is made of SiO2, SiN, SiON, or the like. Here, the portion of the composite substrate on which the liner layer L5 is to be formed is the side wall of the through hole TR1. Here, the film forming apparatus 1 applies a high-frequency voltage to the composite substrate supported by the stage 190 from the side opposite the insulator layer L2 side using the bias application unit 106. SiH4 gas and O2 gas are then flowed from one side of the composite substrate across a projection area (see projection area A1 in FIG. 1) in the thickness direction through the insulator layer L2 side of the composite substrate to the other side across the projection area. A high-frequency electromagnetic field is applied to the SiH4 gas and O2 gas to generate plasma, thereby depositing a liner layer L5 made of SiO2 on the side wall of the through hole TR1. The pressure in the chamber 101 is maintained at 1 Pa. The flow rate of the SiH4 gas introduced into the chamber 101 is set to be greater than 5 sccm and less than 30 sccm, and the flow rate of the O2 gas introduced into the chamber 101 is set to be greater than 10 sccm and less than 200 sccm. The composite substrate is then heated to form a metallized layer P3, as shown in FIG. 5B. Next, as shown in FIG. 6, the through holes TR1 are filled with a metal layer P4 to form a wiring layer.

[0024] Here, a film formation method according to one example of the film formation method of the present embodiment will be described in comparison with a film formation method according to a comparative example. In the film formation methods according to Example 1 and Comparative Examples 1 to 7, an SiO2 film was formed on a 4-inch diameter Si substrate on which five grooves, each 1 μm wide, 3 μm deep, and 50 mm long, were formed at 5 μm intervals. The Si substrate with these grooves was fabricated as follows: First, organic matter adhering to the Si substrate surface was removed by spin cleaning using a mixture of sulfuric acid and hydrogen peroxide (SPM), and the Si substrate was then dried by maintaining it at 90°C for 90 minutes. Next, hexamethyldisiloxane (HMDSO) was applied to the Si substrate surface using a spin coating technique, and a positive photoresist was then applied to the Si substrate surface. Next, laser light was irradiated onto the photoresist at locations corresponding to the grooves, and the photoresist was then maintained at 110°C for 90 minutes. The Si substrate was then immersed in a developer to remove the areas irradiated with the laser light, and then dry etching was performed using the photoresist as a mask to form grooves in the Si substrate.The resist was then removed to obtain a Si substrate with the grooves formed.

[0025] In the film formation methods according to the example and comparative examples, a Si substrate with grooves formed therein was held on the aforementioned stage 190, and then SiH4 gas, O2 gas, and N2 gas were introduced into chamber 101, and a SiO2 film was formed while a high-frequency bias was applied to the Si substrate by bias application unit 106. Here, in all of the film formation methods according to example 1 and comparative examples 1 to 7, the pressure inside chamber 101 was maintained at 1 Pa. The gas flow rates of each source gas, the high-frequency power (RF power (ICP)) output from high-frequency application unit 102, the high-frequency power (RF power (Bias)) output from bias application unit 106, and the film formation time in each of the film formation methods according to example 1 and comparative examples 1 to 7 are as shown in Table 1 below.

[0026] [Table 1]

[0027] In the film formation method according to Comparative Example 4, an SiO2 film was formed under the conditions in the upper row corresponding to "Comparative Example 4" in Table 1, and then an SiO2 film was formed under the conditions in the lower row. In the film formation method according to Comparative Example 5, an SiO2 film was formed under the conditions in the lower row corresponding to "Comparative Example 5" in Table 1, and then CF4 gas, which is an etchant gas, was supplied into the chamber 101 at a flow rate of 200 sccm, and the pressure in the chamber 101 was maintained at 1 Pa, and the process of etching the SiO2 film for 10 minutes was repeated 12 times.

[0028] Figures 7A to 7C show the results of SEM observation of the cross section of the aforementioned Si substrate after SiO2 film deposition using the film deposition methods of Comparative Examples 1 to 3. As shown in the areas PA11, PA21, and PA31 surrounded by dashed lines in Figures 7A to 7C, the upper ends of the grooves were blocked with SiO2 films in all film deposition methods. Furthermore, as shown in the areas PA12, PA22, and PA32 surrounded by dashed lines, deposition of an SiO2 film with a height of approximately 300 nm to 400 nm was confirmed at the bottom of the grooves in all film deposition methods.

[0029] FIGS. 8A to 8C show the results of SEM observation of the cross section of the aforementioned Si substrate after SiO2 film deposition using the film deposition methods of Example 1 and Comparative Examples 4 and 5. As shown in FIG. 8A, in the film deposition method of Example 1, the upper end of the groove was not blocked with an SiO2 film, and no SiO2 film deposition was observed at the bottom of the groove. That is, it was confirmed that the SiO2 film was selectively formed only on the sidewall of the groove. On the other hand, as shown in the areas PA41 and PA42 surrounded by dashed lines in FIGS. 8B and 8C, in the film deposition methods of Comparative Examples 4 and 5, a portion of the groove was blocked with an SiO2 film. Note that no SiO2 film deposition was observed at the bottom of the groove in either of the film deposition methods of Comparative Examples 4 and 5.

[0030] 9A and 9B show the results of SEM observation of the cross section of the Si substrate after the SiO2 film was formed by the film formation methods of Comparative Examples 6 and 7. As shown in Fig. 9A and 9B, in the film formation methods of Comparative Examples 6 and 7, it was confirmed that the SiO2 film was deposited from the sidewalls to the bottom of the trench.

[0031] From these results, it was found that when a SiO2 film is selectively formed on the sidewalls of the trench, it is preferable that the flow rate of SiH4 gas introduced into the chamber 101 during film formation be greater than 5 sccm and less than 30 sccm, and that the flow rate of O2 gas introduced into the chamber 101 be greater than 10 sccm and less than 30 sccm. In particular, from the results corresponding to the film formation method of Example 1, it was found that it is more preferable that the flow rate of SiH4 gas introduced into the chamber 101 be 10 sccm and that the flow rate of O2 gas introduced into the chamber 101 be 20 sccm while applying a high frequency power of 1000 W to the Si substrate by the bias application unit 106 during film formation.

[0032] As described above, according to the film forming apparatus 1 of this embodiment, the source gas introduced into the chamber 101 from the inlet 1012a of the chamber 101 flows along the surface of the composite substrate toward the exhaust outlet 1011a of the chamber 101. Therefore, for example, as shown in Fig. 4B, when a through hole TR1 is formed in the composite substrate, film formation on the exposed portion of the metal layer P2 at the bottom of the through hole TR1 is suppressed, and the liner layer L5 can be selectively formed on the side wall of the through hole TR1 with high accuracy.

[0033] Furthermore, induction coil 1023 according to this embodiment has sub-coils 10231 and 10232, with the winding direction of spiral portion 10231a of sub-coil 10231 being opposite to the winding direction of spiral portion 10231b. Similarly, the winding direction of spiral portion 10232a of sub-coil 10232 is also opposite to the winding direction of spiral portion 10232b. This allows the distribution of the magnetic fields generated by sub-coils 10231 and 10232 to be uniform, thereby enabling a relatively uniform plasma PLM to be generated within chamber 101.

[0034] (Embodiment 2) The film formation method of this embodiment differs from embodiment 1 in that it includes an Ar plasma exposure step in which, prior to the film formation step in which an insulator layer is formed on the substrate on the film formation target portion of the film formation target, Ar gas is introduced into the chamber, and a high-frequency electromagnetic field is applied to the Ar gas supplied into the chamber to generate Ar plasma in the chamber, thereby exposing the film formation target portion of the film formation target to Ar plasma containing Ar ions.

[0035] As shown in FIG. 10, a film forming apparatus 2001 according to this embodiment includes a chamber 101, a stage 190, a high-frequency application unit 102, a bias application unit 106, source gas supply units 121, 122, and 123, and an Ar gas supply unit 2124. Note that in FIG. 10, components similar to those in the first embodiment are denoted by the same reference numerals as in FIG. 1. The Ar gas supply unit 2124 introduces Ar gas into the chamber 101. The Ar gas supply unit 2124 includes, for example, a gas storage unit 124a for storing Ar gas and a supply pipe 124b through which Ar gas is supplied from the gas storage unit 124a. The Ar gas supply unit 2124 also includes a supply pipe 124e connected to the supply pipe 124b for supplying a dilution gas into the supply pipe 124b to dilute the Ar gas flowing through the supply pipe 124b. For example, H2 gas can be used as the dilution gas. Furthermore, the Ar gas supply unit 2124 has a flow rate control valve 124c for adjusting the flow rate of Ar gas flowing through the supply pipe 124b and a flow rate control valve 124d for adjusting the flow rate of dilution gas flowing through the supply pipe 124e. The supply pipe 124b is connected to the inside of the chamber 101 through an inlet (not shown) provided in the lid 1012.

[0036] The method for manufacturing a wiring layer according to this embodiment is substantially the same as that according to the first embodiment, except for the step of forming a liner layer L5 on the inner wall of the through hole TR1 and the upper surface of the insulator layer L2, as shown in FIG. 5A. In this embodiment, first, in a film-forming apparatus 2001, Ar gas is introduced into a chamber 101. A high-frequency electromagnetic field is applied to the Ar gas supplied into the chamber 101 to generate plasma within the chamber 101. Then, an Ar plasma exposure step is performed within the chamber 101, in which the side of the composite substrate where the through hole TR1 opens is exposed to plasma containing Ar ions for a period of 2 minutes to 10 minutes. The flow rate of the Ar gas introduced into the chamber 101 is set to 300 sccm to 500 sccm. The pressure within the chamber 101 is maintained at 2 Pa. During the Ar plasma exposure step, the sidewall of the through hole TR1 is irradiated with Ar contained in the plasma, thereby etching the opening end of the through hole TR1. Next, the film forming apparatus 2001 discharges Ar gas from the chamber 101, and then applies a high-frequency voltage from the bias application unit 106 to the composite substrate supported by the stage 190 from the side opposite the insulator layer L2, while introducing SiH4 gas and O2 gas into the chamber 101. A high-frequency electromagnetic field is applied to the SiH4 gas and O2 gas to generate plasma, thereby performing a film forming process in which a liner layer L5 made of SiO2 is formed on the side wall of the through hole TR1. At this time, the pressure inside the chamber 101 is maintained at 1 Pa.

[0037] Here, the film formation methods of Examples 2 and 3 according to the present embodiment will be described. In the film formation methods of each Example, as in Example 1, a SiO film was formed on a 4-inch diameter Si substrate on which five grooves, each 1 μm wide, 3 μm deep, and 50 mm long, were formed at 5 μm intervals. The method for fabricating the Si substrate with these grooves was the same as in Example 1. In the film formation methods of Examples 2 and 3, the Si substrate with the grooves was held on the stage 190 and subjected to the Ar plasma exposure step. After that, SiH gas, O gas, and N gas were introduced into the chamber 101, and a film formation step was performed in which a SiO film was formed while a high-frequency bias was applied to the Si substrate by the bias application unit 106. In both the film formation methods of Examples 2 and 3, the pressure in the chamber 101 during the Ar plasma exposure step was maintained at 2 Pa, and the flow rate of Ar gas was set to 400 sccm. Furthermore, the exposure time to the plasma containing Ar ions on the grooved surface of the Si substrate in the Ar plasma exposure step was set to 10 min in Example 2 and 5 min in Example 3. Furthermore, the gas flow rates of SiH4 gas, O2 gas, and N2 gas in the film formation steps according to Examples 2 and 3 were set to 10 sccm, 100 sccm, and 100 sccm, respectively, and the pressure inside the chamber 101 was maintained at 1 Pa. Furthermore, the high-frequency power (RF power (ICP)) output from the high-frequency application unit 102 and the high-frequency power (RF power (Bias)) output from the bias application unit 106 were both set to 100 W and 500 W. Furthermore, the film formation time in the film formation step according to Example 2 was set to 60 min, and the film formation time in the film formation step according to Example 3 was set to 100 min.

[0038] FIGS. 11A and 11B show the results of SEM observation of the cross section of the Si substrate after forming an SiO film using the film formation method of Example 2. The photograph in FIG. 11B is an enlarged view of a portion AP201 surrounded by a dashed line in the photograph in FIG. 11A. As shown in FIGS. 11A and 11B, with the film formation method of Example 2, the upper end of the groove was not blocked with an SiO film, and no SiO film was found deposited at the bottom of the groove. That is, it was confirmed that the SiO film was selectively formed only on the sidewalls of the groove. FIGS. 12A and 12B show the results of SEM observation of the cross section of the Si substrate after forming an SiO film using the film formation method of Example 3. The photograph in FIG. 12B is an enlarged view of a portion AP202 surrounded by a dashed line in the photograph in FIG. 12A. As shown in Figures 12A and 12B, even in the film formation method of Example 2, the upper end of the groove was not blocked with an SiO2 film, and no SiO2 film was found deposited at the bottom of the groove. That is, it was confirmed that the SiO2 film was selectively formed only on the sidewalls of the groove. Furthermore, from the comparison of the photograph of Figure 8A with the photographs of Figures 11A to 12B, it can be confirmed that in the film formation methods of Examples 2 and 3, an SiO2 film was selectively formed on the sidewalls of the groove, compared to the film formation method of Example 1.

[0039] These results indicate that when selectively depositing an SiO2 film on the side walls of a groove, it is preferable to expose the surface of the Si substrate on which the groove is formed to a plasma containing Ar ions before the film deposition process.

[0040] As described above, the film formation method according to this embodiment includes an Ar plasma exposure step, prior to the film formation step of forming an SiO2 film, in which, with Ar gas introduced into chamber 101, a high-frequency electromagnetic field is applied to the Ar gas supplied into chamber 101 to generate plasma in chamber 101 and expose the composite substrate to the plasma. As a result, for example, as shown in Figure 4B, when a through hole TR1 is formed in the composite substrate, film formation on the exposed portion of metal layer P2 at the bottom of through hole TR1 is suppressed, and the liner layer L5 can be selectively formed on the side wall of through hole TR1 with high accuracy.

[0041] Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations of the above-described embodiments. For example, other types of films, such as SiN films and AlN films, may be formed on the substrate W.

[0042] The present invention allows various embodiments and modifications without departing from the broad spirit and scope of the present invention. Furthermore, the above-described embodiments are intended to explain the present invention and do not limit the scope of the present invention. That is, the scope of the present invention is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and within the scope of the meaning of the invention equivalent thereto are considered to be within the scope of the present invention.

[0043] This application is based on Japanese Patent Application No. 2022-167462, filed on October 19, 2022. The entire specification, claims and drawings of Japanese Patent Application No. 2022-167462 are incorporated herein by reference. [Industrial Applicability]

[0044] The present invention is suitable for manufacturing electronic devices such as MEMS (Micro Electron Mechanical Systems) and MOS-FETs (Metal-Oxide-Semiconductor Field-Effect-Transistors). [Explanation of symbols]

[0045] 1, 2001: film forming apparatus, 101: chamber, 102: high frequency application unit, 106: bias application unit, 109: support stand, 121, 122, 123: raw material gas supply unit, 181: vacuum pump, 182: exhaust pipe, 190: stage, 121a, 122a, 123a, 124a: gas storage unit, 121b, 121e, 122b, 123b, 124b, 124e, 12 5: supply pipe, 121c, 121d, 122c, 123c, 124c, 124d: flow rate control valve, 141: dielectric window, 142: window fixing member, 190: stage, 191: heater, 1011: chamber body, 1011a: exhaust port, 1012: lid, 1012a: inlet, 1012b: opening, 1021, 1061: high frequency generation source, 1022, 1062: Matching box, 1023: induction coil, 1024a, 1024b: housing, 1024c: shielding plate, 1024c1: through hole, 1025: frame, 1091: support frame, 1092: base member, 1251: first portion, 1252: second portion, 1253: coupling portion, 2124: Ar gas supply portion, 10231, 10232: sub-coil, 10231a, 10231b, 1 0232a, 10232b: spiral portion, 10231c, 10232c: connecting portion, 10233, 10234: fixing member, 10234a: insulating block, 10234b: fixing piece, 10235: insulating retaining portion, L1, L2, L3: insulating layer, L5: liner layer, P1, P2: metal layer, P3: metallized layer, PLM: plasma, TR1: through hole, W1, W2: substrate

Claims

1. A film formation apparatus capable of selectively forming a film on the sidewall of a hole or groove with high accuracy on a film formation target having a hole or groove formed therein, a chamber; a stage that is disposed in the chamber and supports the film-forming target from the side opposite to a film-forming target portion of the film-forming target; a raw material gas supply unit that introduces a raw material gas that serves as a base for a film to be formed on the film-forming target into the chamber; a high frequency application unit that applies a high frequency electromagnetic field to the source gas supplied into the chamber to generate plasma within the chamber; a pump for exhausting a gas containing the source gas from the chamber; a bias application unit that applies a high-frequency bias to the film-forming target supported by the stage, an inlet for introducing the raw material gas from the raw material gas supply unit into the chamber is disposed in one of the opposing portions of the peripheral wall across a projection area of ​​the film-forming target held on the stage in an arrangement direction of the stage and the film-forming target; and an exhaust port for exhausting the gas in the chamber by the pump is disposed in the other opposing portion of the peripheral wall across the projection area, In a direction perpendicular to a mounting surface of the stage on which the film-forming target is placed, at least a part of the exhaust port is located on a side of the chamber in a direction in which the mounting surface faces the inside of the chamber, and the source gas that is the source of the film to be formed on the film-forming target is caused to flow from one side opposing the projection area of ​​the film-forming target in the arrangement direction of the stage and the film-forming target, passing above the film-forming target, to the other side corresponding to the projection area, and a high-frequency electromagnetic field is applied to the source gas to generate plasma, thereby forming a film on the film-forming target. Film deposition equipment.

2. The source gas supply unit supplies SiH ４ Gas and O ２ Supply gas, The pressure in the chamber is maintained at 1 Pa; The SiH introduced into the chamber ４ The flow rate of the gas is greater than 5 sccm and less than 30 sccm, and the O ２ The flow rate of the gas is greater than 10 sccm and less than 200 sccm. The film forming apparatus according to claim 1 .

3. the bias application unit applies high-frequency power of 1000 W to the film-forming target, The SiH introduced into the chamber ４ The gas flow rate is 10 sccm. The O introduced into the chamber ２ The gas flow rate is 20 sccm. The film forming apparatus according to claim 2 .

4. an Ar gas supply unit that introduces Ar gas into the chamber to etch the film-forming target; an Ar plasma exposure step is performed in which, before the raw material gas supply unit supplies the raw material gas, Ar gas is introduced into the chamber from the Ar gas supply unit, and the high frequency application unit applies a high frequency electromagnetic field to the Ar gas supplied into the chamber to generate Ar plasma in the chamber, and the film-forming target is exposed to the Ar plasma for a period of 2 minutes or more and 10 minutes or less; the flow rate of the Ar gas introduced into the chamber is 300 sccm or more and 500 sccm or less; The film forming apparatus according to claim 1 .

5. In the Ar plasma exposure step, the pressure in the chamber is maintained at 2 Pa; The flow rate of the Ar gas introduced into the chamber is 300 sccm. The film forming apparatus according to claim 4 .

6. The high frequency application unit a high frequency generating source that generates high frequency power; an induction coil disposed outside the chamber, the induction coil generating a high-frequency magnetic field within the chamber to generate plasma within the chamber when the high-frequency power generated by the high-frequency generating source is supplied to the chamber while the chamber is filled with the source gas; The induction coil is a first spiral portion extending in a spiral shape in a plan view, one end of which is on the central side electrically connected to the output end of the high frequency generating source and the other end of which is on the outer side grounded; a second spiral portion that extends spirally in a plan view, is disposed adjacent to the first spiral portion, has one end on a central side electrically connected to the output end of the high frequency generating source, and has the other outer end grounded; The winding direction of the second spiral portion is opposite to the winding direction of the first spiral portion. The film forming apparatus according to claim 1 .

7. A film formation method capable of selectively forming a film with high accuracy on a side wall of a hole or a groove of a film formation target supported by a stage and having a hole or a groove formed therein, comprising: a film formation process in which, while applying a high-frequency voltage to the film formation target, a source gas that is a source of a film to be formed on the film formation target is made to flow from one side of the film formation target across a projection area of ​​the film formation target in an arrangement direction of the stage and the film formation target to the other side of the projection area, passing above the film formation target, and a high-frequency electromagnetic field is applied to the source gas to generate plasma, thereby forming a film on the film formation target; In the film forming step, the stage is disposed within a chamber; the source gas is introduced into the chamber from an inlet for introducing the source gas into the inside of the chamber, the inlet being disposed in one of the opposing portions of the peripheral wall of the chamber across a projection area of ​​the film-forming target in an arrangement direction of the stage and the film-forming target, and the gas in the chamber is discharged from an exhaust port for exhausting a gas containing the source gas in the chamber, the exhaust port being disposed in the other opposing portion of the peripheral wall across the projection area; at least a part of the exhaust port is located on a side of the stage in a direction perpendicular to a mounting surface on which the film-forming target is mounted, the mounting surface facing the inside of the chamber; Film formation method.

8. the film-forming target is a substrate having a hole or a groove formed therein, and the film-forming target portion is a side wall of the hole or the groove; In the film forming step, The source gas contains at least SiH ４ Gas and O ２ Contains gas, The pressure during film formation was maintained at 1 Pa. The SiH ４ Set the gas flow rate to greater than 5 sccm and less than 30 sccm; The above O ２ Set the gas flow rate to greater than 10 sccm and less than 200 sccm. The film forming method according to claim 7 .

9. In the film forming step, The SiH ４ The gas flow rate was set to 10 sccm. The above O ２ The gas flow rate was set to 20 sccm. Applying 1000 W of high-frequency power to the film-forming target; The film forming method according to claim 8 .

10. and an Ar plasma exposure step of, before the film formation step, generating Ar plasma in the chamber by applying a high-frequency electromagnetic field to the Ar gas supplied into the chamber while introducing Ar gas into the chamber with the stage disposed inside, and exposing the film formation target to the Ar plasma for 2 minutes or more and 10 minutes or less, the flow rate of the Ar gas introduced into the chamber is 300 sccm or more and 500 sccm or less; The film forming method according to any one of claims 7 to 9.

11. In the Ar plasma exposure step, The pressure in the chamber is maintained at 2 Pa; The flow rate of the Ar gas introduced into the chamber is 300 sccm. The film forming method according to claim 10.

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