Film forming method and film forming apparatus

Abstract

To provide a technique capable of forming a metal film thicker than an insulator region in a semiconductor region.SOLUTION: According to an embodiment of the present disclosure, there is provided a film forming method of forming a first film containing a first metal, the method including preparing a substrate having a semiconductor region containing silicon and an insulator region on a surface thereof, and forming the first film on the surface by simultaneously supplying a raw material gas containing the first metal and an etching gas for etching the first film to the substrate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a film formation method and a film formation apparatus. [Background technology]

[0002] Patent Document 1 discloses a technique for controlling film formation conditions so as to maintain optimal emission intensities by monitoring the emission intensities of film-forming and etching species contained in plasma during film formation by plasma CVD, in which film deposition and etching reactions occur simultaneously. Patent Document 2 discloses a technique for selectively etching a TiN film at the bottom of a contact hole using a gas containing chlorine atoms, fluorine atoms, and carbon atoms. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-61415 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-179393 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that allows a metal film to be formed thicker in a semiconductor region than in an insulator region. [Means for solving the problem]

[0005] A film formation method according to one embodiment of the present disclosure is a film formation method for forming a first film containing a first metal, comprising the steps of: preparing a substrate having a semiconductor region containing silicon and an insulator region on its surface; and simultaneously supplying a source gas containing the first metal and an etching gas for etching the first film to the substrate, thereby forming the first film on the surface. [Effects of the Invention]

[0006] According to the present disclosure, a metal film can be formed in a semiconductor region to a greater thickness than in an insulator region. [Brief explanation of the drawings]

[0007] [Figure 1] 3 is a flowchart showing a film forming method according to the first embodiment. [Figure 2] 1A to 1C are cross-sectional views illustrating a film forming method according to a first embodiment. [Figure 3] 10 is a timing chart showing a first example of step S16 in FIG. [Figure 4] 10 is a timing chart showing a second example of step S16 in FIG. [Figure 5] 10 is a flowchart showing a film forming method according to a second embodiment. [Figure 6] 6 is a timing chart showing an example of step S27 in FIG. 5. [Figure 7] 1 is a diagram illustrating a processing system according to an embodiment. [Figure 8] 1 is a cross-sectional view showing a film forming apparatus according to an embodiment. [Figure 9] FIG. 10 is a diagram showing the results of measuring the thickness of a zirconium film. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. In all the accompanying drawings, the same or corresponding reference numerals are used to designate the same or corresponding members or components, and redundant descriptions will be omitted.

[0009] [Film formation method] A film formation method according to a first embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a flowchart showing the film formation method according to the first embodiment. FIG. 2 is a cross-sectional view showing the film formation method according to the first embodiment. FIG. 3 is a timing chart showing a first example of step S16 in FIG. 1. FIG. 4 is a timing chart showing a second example of step S16 in FIG. 1. The film formation method according to the first embodiment includes steps S12, S14, S16, and S18 shown in FIG. 1.

[0010] Step S12 includes preparing a substrate 100, as shown in FIG. 2(a). The substrate 100 includes a silicon substrate 110 and a silicon nitride film 120. The silicon substrate 110 is an example of a semiconductor region containing silicon (Si). The silicon nitride film 120 is provided on the silicon substrate 110. The silicon nitride film 120 is, for example, an interlayer insulating film. The silicon nitride film 120 is an example of an insulator region. A recess 130 is formed in the silicon nitride film 120. The recess 130 is, for example, a contact hole. The recess 130 has a bottom surface 131, a side surface 132, and an upper surface 133. The silicon substrate 110 forms the bottom surface 131. The silicon nitride film 120 forms the side surface 132 and the upper surface 133. A native oxide film 140 may be present on the bottom surface 131.

[0011] As shown in FIG. 2B, step S14 includes removing the native oxide film 140. Step S14 may include, for example, a COR (Chemical Oxide Removal) process and a PHT (Post Heat Treatment) process. The COR process involves supplying a halogen-containing gas and a basic gas to the substrate 100 as process gases, causing a chemical reaction between the native oxide film 140 on the surface of the recess 130 and the process gases, thereby generating a reaction product. The halogen-containing gas may be, for example, hydrogen fluoride (HF). The basic gas may be, for example, ammonia (NH). In this case, reaction products mainly containing ammonium silicofluoride [(NH)SiF] and water (HO) are generated. The PHT process involves heating the reaction products generated by the COR process to sublimate the reaction products, such as ammonium silicofluoride. Step S14 is not limited to a process including the COR process and the PHT process. For example, step S14 may not include the PHT process. If there is no native oxide film 140 on the surface of the recess 130, step S14 may be omitted.

[0012] As shown in FIG. 2(c), step S16 includes simultaneously supplying zirconium chloride (ZrCl4), hydrogen (H2), and hydrogen chloride (HCl) to the substrate 100 to form a zirconium film 150 on the surface of the recess 130. Zirconium (Zr) is an example of a first metal, and the zirconium film is an example of a first film. Zirconium chloride is an example of a source gas, and hydrogen chloride is an example of an etching gas. When zirconium chloride and hydrogen are supplied to the substrate 100, the zirconium film 150 is formed on the bottom surface 131, side surface 132, and top surface 133 of the recess 130. At this time, since the bottom surface 131 is formed by the silicon substrate 110, a portion of the zirconium film reacts with silicon of the silicon substrate 110 that forms the bottom surface 131 on the bottom surface 131 to form zirconium silicide (ZrSi). Zirconium silicide reduces the contact resistance between the silicon substrate 110 and a ruthenium film 160 (described later). Because the side surface 132 and the top surface 133 are formed by the silicon nitride film 120, zirconium silicide is not formed on the side surface 132 and the top surface 133. Zirconium silicide is an example of a metal silicide. In this specification, the zirconium film 150 includes zirconium silicide. Hydrogen chloride etches the zirconium film 150 but hardly etches zirconium silicide. Therefore, when hydrogen chloride is supplied to the substrate 100, the zirconium film 150 formed on the bottom surface 131 is hardly etched, but the zirconium film 150 formed on the side surface 132 and the top surface 133 is etched. As a result, the zirconium film 150 can be formed thicker on the bottom surface 131 of the recess 130 than on the side surface 132 and the top surface 133. When the zirconium film 150 having a desired thickness is formed on the bottom surface 131 of the recess 130, step S16 is completed.

[0013] Step S16 may include generating plasma from zirconium chloride, hydrogen, and hydrogen chloride. In this case, reduction of zirconium chloride by hydrogen proceeds, facilitating the formation of the zirconium film 150. An RF power supply may be used to generate the plasma. Step S16 may also include supplying an inert gas such as argon. As shown in FIG. 3, step S16 may involve continuously supplying zirconium chloride, hydrogen, hydrogen chloride, and argon, and continuously supplying RF power from an RF power supply. As shown in FIG. 4, step S16 may involve continuously supplying zirconium chloride, hydrogen, hydrogen chloride, and argon, and continuously supplying RF power from an RF power supply. Step S16 may also involve adjusting the ratio of the deposition rate of the zirconium film formed on the bottom surface 131 to the deposition rate of the zirconium film formed on the side surface 132 and the top surface 133 by changing the timing of switching the RF power supply on and off.

[0014] Step S16 may include adjusting the ratio of the deposition rate of the zirconium film 150 formed on the side surface 132 and the top surface 133 to the deposition rate of the zirconium film formed on the bottom surface 131 by changing the flow rate ratio of zirconium chloride and hydrogen chloride.

[0015] Step S16 may be performed after step S14 without exposing the substrate 100 to the air atmosphere. In this case, the zirconium film 150 can be formed on the surface of the recess 130 without the native oxide film 140 being present on the surface of the recess 130.

[0016] The conditions in step S16 are, for example, as follows. ·Processing volume: 20L or more and 22L or less RF power: 100W to 1000W continuous wave Pressure: 267 Pa to 1200 Pa (2 Torr to 9 Torr) ·Substrate temperature: 350℃ or more and 500℃ or less Zirconium chloride: 1sccm to 30sccm Hydrogen: 10sccm to 4000sccm Hydrogen chloride: 5sccm to 200sccm Argon: 1200sccm or more, 2400sccm or less

[0017] Step S18 includes filling the recess 130 with a ruthenium film 160, as shown in FIG. 2(d). Ruthenium (Ru) is an example of the second metal, and the ruthenium film 160 is an example of the second film. Step S18 includes supplying a source gas containing ruthenium and carbon monoxide (CO) to the substrate 100, and filling the recess 130 with the ruthenium film 160. The source gas containing ruthenium is, for example, Ru(CO). 12 Step S18 may include maintaining the substrate 100 at a temperature of 160°C or higher and 180°C or lower.

[0018] Step S18 may be performed after step S16 without exposing the substrate 100 to the air atmosphere. In this case, oxidation of the surface of the zirconium film 150 can be prevented before the ruthenium film 160 is formed on the zirconium film 150. This prevents an increase in electrical resistance due to oxidation of the zirconium film 150. For example, the formation of the zirconium film 150 and the embedding of the ruthenium film 160 are performed in different chambers, and the substrate 100 is transported in a vacuum after the formation of the zirconium film 150 until the embedding of the ruthenium film 160. In this case, to further prevent oxidation of the surface of the zirconium film 150, the surface of the zirconium film 150 may be nitrided in the chamber in which the zirconium film 150 is formed.

[0019] According to the film formation method of the first embodiment, zirconium chloride and hydrogen chloride are simultaneously supplied to the substrate 100 to form the zirconium film 150 on the surface of the recess 130. In this case, the zirconium film 150 can be formed thicker on the bottom surface 131 of the recess 130 than on the side surface 132 and top surface 133. Therefore, the zirconium film 150 formed on the bottom surface 131 reduces the contact resistance between the silicon substrate 110 and the ruthenium film 160, while increasing the volume of the ruthenium film 160 embedded in the recess 130. Therefore, when the ruthenium film 160 is used as a wiring layer, the wiring resistance can be reduced.

[0020] A film forming method according to a second embodiment will be described with reference to Figures 5 and 6. Figure 5 is a flowchart showing the film forming method according to the second embodiment. Figure 6 is a timing chart showing an example of step S27 in Figure 5. The film forming method according to the second embodiment includes steps S22, S24, S26, S27, and S28 shown in Figure 5.

[0021] Steps S22, S24, S26, and S28 are the same as steps S12, S14, S16, and S18.

[0022] Step S27 is performed between steps S26 and S28. Step S27 includes supplying plasma generated from hydrogen chloride (hereinafter referred to as "hydrogen chloride plasma") to the substrate 100 without supplying zirconium chloride. In this case, the zirconium film 150 remaining on the side surface 132 and the upper surface 133 after step S26 can be etched and removed. An RF power supply may be used to generate the plasma. Step S27 may also include supplying an inert gas such as argon. As shown in FIG. 6, in step S27, hydrogen chloride and argon may be continuously supplied without supplying zirconium chloride and hydrogen, and the RF power supply may continuously supply RF power.

[0023] The conditions in step S27 are, for example, as follows. ·Processing volume: 20L or more and 22L or less RF power: 100W to 1000W continuous wave Pressure: 267 Pa to 1200 Pa (2 Torr to 9 Torr) ·Substrate temperature: 350℃ or more and 500℃ or less Zirconium chloride: 0sccm Hydrogen: 0sccm Hydrogen chloride: 5sccm to 200sccm Argon: 1200sccm or more, 2400sccm or less

[0024] According to the film formation method of the second embodiment, zirconium chloride and hydrogen chloride are simultaneously supplied to the substrate 100 to form the zirconium film 150 on the surface of the recess 130. In this case, the zirconium film 150 can be formed thicker on the bottom surface 131 of the recess 130 than on the side surface 132 and top surface 133. Therefore, the zirconium film 150 formed on the bottom surface 131 reduces the contact resistance between the silicon substrate 110 and the ruthenium film 160, while increasing the volume of the ruthenium film 160 embedded in the recess 130. As a result, when the ruthenium film 160 is used as a wiring layer, the wiring resistance can be reduced.

[0025] According to the film forming method of the second embodiment, the zirconium film 150 is formed in step S26, then hydrogen chloride plasma is supplied to the substrate 100 in step S27, and then the recess 130 is filled with the ruthenium film 160 in step S28. In this case, the recess 130 is filled with the ruthenium film 160 with no or almost no zirconium film 150 on the side surface 132 of the recess 130. This makes it possible to increase the volume of the ruthenium film 160 filled in the recess 130. As a result, the wiring resistance can be particularly reduced when the ruthenium film 160 is used as a wiring layer.

[0026] [Processing System] A processing system PS according to the embodiment will be described with reference to Fig. 7. Fig. 7 is a diagram showing the processing system according to the embodiment.

[0027] The processing system PS includes processing devices PM1 to PM8, vacuum transfer chambers VTM1 and VTM2, intermediate transfer chambers MM1 and MM2, load lock chambers LL1 to LL3, atmospheric transfer chamber LM, load ports LP1 to LP4, and a general control unit CU.

[0028] The processing devices PM1 to PM4 are connected to a vacuum transfer chamber VTM1. The interior of each of the processing devices PM1 to PM4 is depressurized to a vacuum atmosphere. Each of the processing devices PM1 to PM4 performs a desired process on a substrate. The processing devices PM1 and PM2 are devices that perform, for example, the above-mentioned steps S14 and S24. The processing devices PM3 and PM4 are devices that perform, for example, the above-mentioned steps S16, S26, and S27.

[0029] The processing devices PM5 to PM8 are connected to the vacuum transfer chamber VTM2. The interior of each of the processing devices PM5 to PM8 is depressurized to a vacuum atmosphere. Each of the processing devices PM5 to PM8 performs a desired process on a substrate. The processing devices PM5 to PM8 are devices that perform, for example, the above-mentioned steps S18 and S28.

[0030] The interior of the vacuum transfer chamber VTM1 is depressurized to a vacuum atmosphere. A transfer mechanism TR1 is provided inside the vacuum transfer chamber VTM1. The transfer mechanism TR1 is configured to be able to transfer substrates in a depressurized state. The transfer mechanism TR1 transfers substrates between the processing devices PM1 to PM4, the intermediate transfer chambers MM1 and MM2, and the load lock chambers LL1 to LL3.

[0031] The interior of the vacuum transfer chamber VTM2 is depressurized to a vacuum atmosphere. A transfer mechanism TR2 is provided inside the vacuum transfer chamber VTM2. The transfer mechanism TR2 is configured to be able to transfer substrates in a depressurized state. The transfer mechanism TR2 transfers substrates between the processing devices PM5 to PM8 and the intermediate transfer chambers MM1 and MM2.

[0032] The intermediate transfer chambers MM1 and MM2 are provided between the vacuum transfer chambers VTM1 and VTM2. The intermediate transfer chambers MM1 and MM2 are connected to the vacuum transfer chamber VTM1 and also to the vacuum transfer chamber VTM2. The pressure inside the intermediate transfer chambers MM1 and MM2 is reduced to a vacuum atmosphere. The intermediate transfer chambers MM1 and MM2 may have a cooling mechanism for cooling the substrate.

[0033] The load lock chambers LL1 to LL3 are provided between the vacuum transfer chamber VTM1 and the atmospheric transfer chamber LM. The load lock chambers LL1 to LL3 are connected to the vacuum transfer chamber VTM1 and also to the atmospheric transfer chamber LM. The interior of the load lock chambers LL1 to LL3 can be switched between an atmospheric atmosphere and a vacuum atmosphere. The load lock chambers LL1 to LL3 may have a cooling mechanism for cooling the substrates, similar to the intermediate transfer chambers MM1 and MM2.

[0034] The atmospheric transfer chamber LM has an atmospheric atmosphere inside. For example, a downflow of clean air is formed inside the atmospheric transfer chamber LM. A transfer mechanism TR3 is provided in the atmospheric transfer chamber LM. The transfer mechanism TR3 transfers substrates between the load lock chambers LL1 to LL3 and carriers placed on the load ports LP1 to LP4.

[0035] The load ports LP1 to LP4 are provided on the long side walls of the atmospheric transfer chamber LM. A carrier is placed on each of the load ports LP1 to LP4. The carrier is, for example, a FOUP (Front Opening Unified Pod).

[0036] Gate valves GV are provided between processing devices PM1 to PM4 and vacuum transfer chamber VTM1, between processing devices PM5 to PM8 and vacuum transfer chamber VTM2, between vacuum transfer chamber VTM1 and intermediate transfer chambers MM1 and MM2, between vacuum transfer chamber VTM2 and intermediate transfer chambers MM1 and MM2, between load lock chambers LL1 to LL3 and vacuum transfer chamber VTM1, and between load lock chambers LL1 to LL3 and atmospheric transfer chamber LM.

[0037] The overall control unit CU is an electronic circuit such as a CPU (Central Processing Unit), FPGA (Field Programmable Gate Array), or ASIC (Application Specific Integrated Circuit). The overall control unit CU executes various control operations described herein by executing instruction codes stored in memory or by being a circuit designed for a specific application. For example, the overall control unit CU controls the operation of processing devices PM1-PM8, the operation of transport mechanisms TR1-TR3, switching of the atmosphere in load-lock chambers LL1-LL4, opening and closing of gate valve GV, etc.

[0038] [Operation of the Processing System] An example of the operation of the processing system PS according to the embodiment will be described with reference to Fig. 7. The following description will be given taking as an example a case where the processing system PS performs the film forming method shown in Fig. 1. The operation of the processing system PS according to the embodiment is performed under the control of the overall control unit CU. The following description will omit the opening and closing of the gate valve GV.

[0039] First, a transfer device provided outside the processing system PS loads a carrier into the load port LP1. The transfer device is, for example, an overhead hoist transport (OHT). A worker may load the carrier into the load port LP1. The carrier contains the substrate 100 described above.

[0040] Next, the transfer mechanism TR3 transfers the substrate 100 accommodated in the carrier to the load lock chamber LL1, which is in the atmospheric environment. Subsequently, the load lock chamber LL1 switches its interior from the atmospheric environment to a vacuum environment.

[0041] Next, the transfer mechanism TR1 receives the substrate 100 from the load lock chamber LL1 and transfers it to the processing apparatus PM1. Subsequently, the processing apparatus PM1 performs step S14. That is, the processing apparatus PM1 removes the native oxide film 140.

[0042] Next, the transfer mechanism TR1 receives the substrate 100 from the processing device PM1 and transfers it to the processing device PM3. Subsequently, the processing device PM3 performs step S16. That is, the processing device PM3 simultaneously supplies zirconium chloride, hydrogen, and hydrogen chloride to the substrate 100 to form a zirconium film 150 on the surface of the recess 130. In this case, the supply of zirconium chloride as a source gas and the supply of hydrogen chloride as an etching gas can be performed simultaneously in the same processing device PM3, thereby shortening the processing time.

[0043] Next, the transfer mechanism TR1 receives the substrate 100 from the processing device PM3 and transfers it to the intermediate transfer chamber MM1, where the substrate 100 is then cooled by the cooling mechanism.

[0044] Next, the transfer mechanism TR2 receives the substrate 100 from the intermediate transfer chamber MM1 and transfers it to the processing apparatus PM5. The processing apparatus PM5 then performs step S18. That is, the processing apparatus PM5 fills the recess 130 with a ruthenium film 160. The temperature at which the processing apparatus PM5 performs step S18 is lower than the temperature at which the processing apparatus PM3 performs step S16. The substrate 100 cooled in the intermediate transfer chamber MM1 is transferred to the processing apparatus PM5. In this case, it is possible to reduce temperature fluctuations caused by carrying the substrate 100 into the processing apparatus PM5. Therefore, the ruthenium film 160 can be stably formed in the processing apparatus PM5.

[0045] Next, the transfer mechanism TR2 receives the substrate 100 from the processing device PM5 and transfers it to the intermediate transfer chamber MM2, where the substrate 100 is then cooled by the cooling mechanism.

[0046] Next, the transfer mechanism TR1 receives the substrate 100 from the intermediate transfer chamber MM2 and transfers it to the load lock chamber LL2. Subsequently, the load lock chamber LL2 switches its interior from a vacuum atmosphere to an atmospheric atmosphere.

[0047] Next, the transfer mechanism TR3 receives the substrate 100 from the load lock chamber LL2, transfers it to the carrier placed on the load port LP2, and stores the substrate 100 in the carrier. This completes the processing of one substrate 100.

[0048] The transport path of the substrate 100 in the operation of the processing system PS described above is an example, and the transport path of the substrate 100 is not limited to this.

[0049] [Film forming equipment] A film forming apparatus 1, which is an example of a processing apparatus PM3 included in the processing system PS, will be described with reference to Fig. 8. Fig. 8 is a cross-sectional view showing the film forming apparatus 1 according to an embodiment. The processing apparatus PM4 may have the same configuration as the processing apparatus PM3. The processing apparatuses PM1, PM2, PM4 to PM8 may have the same configuration as the processing apparatus PM3, except for the type of gas.

[0050] The film forming apparatus 1 includes a processing vessel 2. The processing vessel 2 accommodates a substrate W. The substrate W may be the substrate 100 described above. The processing vessel 2 has a substantially cylindrical shape. The processing vessel 2 is a vacuum vessel whose interior can be depressurized. An exhaust chamber 21 is provided in the center of the bottom wall of the processing vessel 2.

[0051] The exhaust chamber 21 has a generally cylindrical shape that protrudes downward. An exhaust flow path 22 is connected to the side of the exhaust chamber 21. An exhaust unit 24 is connected to the exhaust flow path 22 via a pressure adjustment unit 23. The pressure adjustment unit 23 includes a pressure adjustment valve such as a butterfly valve. The pressure adjustment unit 23 adjusts the pressure inside the processing vessel 2. The exhaust unit 24 includes a vacuum pump. The exhaust unit 24 reduces the pressure inside the processing vessel 2 via the exhaust flow path 22. A transfer port 25 is provided on the side of the processing vessel 2. The transfer port 25 is an opening through which the substrate W passes when being loaded into the processing vessel 2 and when being unloaded from the processing vessel 2. The transfer port 25 is opened and closed by a gate valve 26.

[0052] A mounting table 3 is provided within the processing chamber 2. The mounting table 3 holds the substrate W in a substantially horizontal position. The mounting table 3 has a substantially circular shape in a plan view. The mounting table 3 is supported by a support member 31. A recess 32 is provided on the surface of the mounting table 3. The recess 32 has a substantially circular shape in a plan view. The substrate W is mounted in the recess 32. The recess 32 has an inner diameter slightly larger than the diameter of the substrate W. The recess 32 has a depth substantially equal to the thickness of the substrate W. The mounting table 3 is made of a ceramic material such as aluminum nitride (AlN). The mounting table 3 may also be made of a metal material such as nickel (Ni). Instead of the recess 32, an annular guide member for guiding the peripheral edge of the substrate W may be provided on the surface of the mounting table 3.

[0053] A lower electrode 33 is provided inside the mounting table 3. An RF power supply 34 is connected to the lower electrode 33. The RF power supply 34 supplies a first RF (Radio Frequency) power to the lower electrode 33. The first RF power is bias RF power for attracting ions into the substrate W. The first RF power has a frequency in the range of 100 kHz to 60 MHz, for example. A matching box 35 is provided between the lower electrode 33 and the RF power supply 34. A DC (Direct Current) power supply may be connected to the lower electrode 33. The DC power supply supplies bias DC power or pulsed DC power to the lower electrode 33. The lower electrode 33 may be grounded. When the entire mounting table 3 is made of metal, the entire mounting table 3 functions as the lower electrode. Therefore, the lower electrode 33 does not need to be provided inside the mounting table 3.

[0054] A temperature adjustment mechanism 36 is provided inside the mounting table 3. The temperature adjustment mechanism 36 is located below the lower electrode 33. The temperature adjustment mechanism 36 adjusts the temperature of the substrate W placed in the recess 32 to a set temperature based on a control signal from the control unit 9. The temperature adjustment mechanism 36 includes, for example, a heater. The temperature adjustment mechanism 36 may also include a fluid flow path through which a temperature adjustment fluid flows.

[0055] The mounting table 3 is provided with a plurality of (e.g., three) lifting pins 41. The plurality of lifting pins 41 hold and lift up and down the substrate W placed in the recess 32. Each lifting pin 41 is made of ceramics such as alumina (Al2O3). Each lifting pin 41 may also be made of quartz. The lower ends of the lifting pins 41 are attached to a support plate 42. The support plate 42 is connected via a lifting shaft 43 to a lifting mechanism 44 provided outside the processing chamber 2.

[0056] The lifting mechanism 44 is provided below the exhaust chamber 21. A bellows 45 is provided between the lifting mechanism 44 and an opening 21a for the lifting shaft 43 formed in the lower surface of the exhaust chamber 21. The support plate 42 has a shape that allows it to rise and fall without coming into contact with the support member 31 of the mounting table 3. The lifting mechanism 44 raises and lowers the upper ends of the lifting pins 41 between a position above the bottom surface of the recess 32 and a position below the bottom surface of the recess 32. This causes the substrate W to rise and lower between a position where it is placed on the bottom surface of the recess 32 (the position shown in FIG. 6) and a position away from the bottom surface of the recess 32 (not shown).

[0057] The lower end of the support member 31 passes through the opening 21b of the exhaust chamber 21. The lower end of the support member 31 is supported by a lifting mechanism 46 via a lifting plate 47 provided below the processing vessel 2. A bellows 48 is provided between the bottom of the exhaust chamber 21 and the lifting plate 47. This maintains the airtightness inside the processing vessel 2 even when the lifting plate 47 moves up and down.

[0058] The lifting mechanism 46 lifts and lowers the lifting plate 47, thereby lifting and lowering the mounting table 3. In this way, the gap between the mounting table 3 and the gas supply unit 5 can be adjusted.

[0059] A gas supply unit 5 is provided on a ceiling wall 27 of the processing vessel 2 via an insulating member 28. The gas supply unit 5 functions as an upper electrode. The gas supply unit 5 faces the lower electrode 33. An RF power supply 51 is connected to the gas supply unit 5. The RF power supply 51 supplies a second RF power to the gas supply unit 5. The second RF power is RF power for generating plasma required for film formation on the substrate W. The second RF power has a frequency in the range of, for example, 100 kHz to 150 MHz. A matching box 52 is provided between the gas supply unit 5 and the RF power supply 51. When RF power is supplied from the RF power supply 51 to the gas supply unit 5, an RF electric field is generated between the gas supply unit 5 (upper electrode) and the lower electrode 33.

[0060] The gas supply unit 5 has a gas diffusion chamber 53. The gas diffusion chamber 53 has a hollow shape. A number of holes 54 are arranged, for example, evenly, on the bottom surface of the gas diffusion chamber 53 to distribute and supply the processing gas into the processing vessel 2. A heating mechanism 55 is embedded above the gas diffusion chamber 53 in the gas supply unit 5. The heating mechanism 55 includes, for example, a heater. The heating mechanism 55 heats the gas supply unit 5 to a set temperature based on a control signal from the control unit 9.

[0061] A gas supply path 6 communicates with the gas diffusion chamber 53. A gas source 61 is connected to the upstream side of the gas supply path 6 via a first gas line 62 and a second gas line 63. The gas source 61 includes supply sources of various process gases, mass flow controllers, and valves.

[0062] The first gas line 62 connects the gas source 61 and the gas supply path 6. A first temperature adjustment unit 64 is provided in the first gas line 62. The first temperature adjustment unit 64 adjusts the temperature of the processing gas flowing through the first gas line 62. The first temperature adjustment unit 64 includes, for example, a heater.

[0063] The second gas line 63 connects the gas source 61 and the gas supply path 6. A second temperature adjustment unit 65 is provided in the middle of the second gas line 63. The second temperature adjustment unit 65 adjusts the temperature of the processing gas flowing through the second gas line 63. The second temperature adjustment unit 65 includes, for example, a heater.

[0064] By providing the first gas line 62, the second gas line 63, the first temperature adjustment unit 64, and the second temperature adjustment unit 65, the processing gas can be introduced into the gas diffusion chamber 53 at an appropriate temperature depending on the type of processing gas.

[0065] The various process gases include the process gases used in the film formation methods according to the first and second embodiments. The various process gases include, for example, zirconium chloride, hydrogen, hydrogen chloride, and argon. Zirconium chloride, hydrogen, and argon are introduced into the gas diffusion chamber 53 from, for example, a gas source 61 via a first gas line 62. Zirconium chloride has a low vapor pressure. Therefore, the first temperature adjustment unit 64 adjusts the temperature of the zirconium chloride flowing through the first gas line 62 to a first temperature at which the zirconium chloride vaporizes. The first temperature is, for example, 190°C or higher. Hydrogen chloride is introduced into the gas diffusion chamber 53 from the gas source 61 via a second gas line 63. If the hydrogen chloride becomes too hot, it may corrode components constituting the second gas line 63. Therefore, the second temperature adjustment unit 65 adjusts the temperature of the hydrogen chloride flowing through the second gas line 63 to a second temperature lower than the first temperature. The second temperature is, for example, 100°C or lower.

[0066] The film forming apparatus 1 includes a control unit 9. The control unit 9 is an electronic circuit such as a CPU (Central Processing Unit), FPGA (Field Programmable Gate Array), or ASIC (Application Specific Integrated Circuit). The control unit 9 executes various control operations described in this specification by executing instruction codes stored in a memory or by being a circuit designed for a specific application.

[0067] [Experimental results] First, a silicon substrate and a silicon nitride substrate were prepared. Then, a zirconium film was formed on each of the prepared silicon substrate and silicon nitride substrate under the following conditions A and B in the film formation apparatus 1. Then, the thickness of the zirconium film formed on each substrate was measured.

[0068] (Condition A) RF Power: 300W continuous wave Pressure: 800 Pa (6 Torr) ·Substrate temperature: 450℃ Zirconium chloride: 1 sccm Hydrogen: 4000sccm Hydrogen chloride: 0sccm Argon: 2400sccm Duration: 180 seconds

[0069] (Condition B) RF Power: 300W continuous wave Pressure: 800 Pa (6 Torr) ·Substrate temperature: 450℃ Zirconium chloride: 1 sccm Hydrogen: 4000sccm Hydrogen chloride: 50sccm Argon: 2400sccm Duration: 180 seconds

[0070] Fig. 9 shows the results of measuring the thickness of zirconium films. In Fig. 9, the upper row shows the thickness of zirconium films formed on silicon substrates, and the lower row shows the thickness of zirconium films formed on silicon nitride substrates. In Fig. 9, the left column shows the thickness of zirconium films formed under condition A, and the right column shows the thickness of zirconium films formed under condition B.

[0071] As shown in Figure 9, under condition A, the thickness of the zirconium film formed on the silicon substrate was 4.5 nm, and the thickness of the zirconium film formed on the silicon nitride substrate was 6.6 nm. Under condition B, the thickness of the zirconium film formed on the silicon substrate was 3.1 nm, and the thickness of the zirconium film formed on the silicon nitride substrate was 0.7 nm. These results demonstrate that by simultaneously supplying zirconium chloride and hydrogen chloride, it is possible to form a thicker zirconium film on the silicon substrate than on the silicon nitride film.

[0072] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0073] In the above embodiment, a recess including a bottom surface and a side surface is formed on the surface of a substrate, and a silicon-containing semiconductor film forms the bottom surface and an insulating film forms the side surface. However, the present disclosure is not limited to this. The substrate may have a silicon-containing semiconductor film and an insulating film on its surface, and the recess may not be formed on the surface of the substrate.

[0074] In the above embodiment, the semiconductor region is a silicon substrate, but the present disclosure is not limited to this. The semiconductor region may be a germanium substrate or a silicon germanium substrate. The semiconductor region may be a substrate having a silicon-containing film, such as a silicon film, a germanium film, or a silicon germanium film, formed on its surface.

[0075] In the above embodiment, the insulator region is a silicon nitride film, but the present disclosure is not limited to this. The insulator region may be a silicon oxide film.

[0076] In the above embodiment, the source gas is zirconium chloride, but the present disclosure is not limited to this. The source gas may be any metal chloride. The source gas may be titanium chloride (TiCl4), tungsten chloride (WCl5), molybdenum chloride (MoCl5), or hafnium chloride (HfCl4).

[0077] In the above embodiment, the etching gas is hydrogen chloride, but the present disclosure is not limited to this. The etching gas may be any gas containing chlorine. The etching gas may be chlorine (Cl2).

[0078] In the above embodiment, the film forming apparatus is an apparatus that uses capacitively coupled plasma (CCP), but is not limited to this. For example, the film forming apparatus may be an apparatus that uses inductively coupled plasma (ICP) or microwave discharge plasma.

[0079] In the above embodiment, the film forming apparatus is a single-wafer type apparatus that processes substrates one by one, but the present disclosure is not limited to this. For example, the film forming apparatus may be a batch type apparatus that processes multiple substrates at once. [Explanation of symbols]

[0080] 100 boards 110 Silicon substrate 120 Silicon nitride film 130 recess 140 Native oxide film 150 Zirconium film 160 Ruthenium film

Claims

1. 1. A film forming method for forming a first film including a first metal, comprising: A step of preparing a substrate having a semiconductor region containing silicon and an insulator region on a surface thereof; a step of simultaneously supplying a source gas containing the first metal and an etching gas for etching the first film to the substrate, thereby forming the first film on the surface; The film forming method includes the steps of:

2. the step of forming the first film includes generating plasma from the source gas and the etching gas; The film forming method according to claim 1 .

3. the step of forming the first film includes forming a metal silicide from the silicon contained in the semiconductor region and the first metal contained in the source gas; The film forming method according to claim 1 .

4. forming the first film includes forming the first film to a greater thickness on the semiconductor region than on the insulator region; The film forming method according to claim 1 .

5. the step of forming the first film includes adjusting a ratio of a deposition rate of the first film formed on the semiconductor region to a deposition rate of the first film formed on the insulator region by changing a flow rate ratio of the source gas and the etching gas. The film forming method according to claim 1 .

6. the step of forming the first film includes adjusting a ratio of a deposition rate of the first film formed on the semiconductor region to a deposition rate of the first film formed on the insulator region by changing a timing of switching on and off an RF power supply used to generate the plasma. The film forming method according to claim 2 .

7. a step of supplying plasma generated from the etching gas without supplying the source gas to the substrate after the step of forming the first film, The film forming method according to claim 1 .

8. a recess having a bottom surface and a side surface is formed on the surface of the substrate, the semiconductor region forms the bottom surface; the insulator region forms the side surface; The film forming method according to claim 1 .

9. a step of filling the recess with a second film containing a second metal after the step of forming the first film; The film forming method according to claim 8 .

10. the step of filling the recessed portion is performed after the step of forming the first film without exposing the substrate to an atmospheric atmosphere. The film forming method according to claim 9 .

11. a step of removing a native oxide film on the surface of the substrate before the step of forming the first film; The film forming method according to claim 1 .

12. the step of forming the first film is performed after the step of removing the native oxide film without exposing the substrate to an air atmosphere. The film forming method according to claim 11.

13. the source gas is a metal chloride, The etching gas is a gas containing chlorine. The film forming method according to claim 1 .

14. the metal chloride is zirconium chloride; The chlorine-containing gas is hydrogen chloride. The film forming method according to claim 13.

15. the insulator region is a silicon nitride film or a silicon oxide film; The film forming method according to claim 1 .

16. A film forming apparatus for forming a first film including a first metal, A processing vessel; a gas supply unit that supplies a gas into the processing chamber; A control unit; Equipped with The control unit A step of preparing a substrate having a semiconductor region containing silicon and an insulator region on a surface thereof; a step of simultaneously supplying a source gas containing the first metal and an etching gas for etching the first film to the substrate, thereby forming the first film on the surface; configured to perform Film deposition equipment.

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