Substrate processing method and plasma processing apparatus

Abstract

The substrate processing method disclosed in this invention includes the step of preparing a substrate. The substrate includes a first region and a second region having an opening provided in the first region. The substrate processing method further includes the step of preferentially forming a top deposit on the top of the second region using a first plasma generated from a first gas. The substrate processing method further includes the step of forming a first film on the surface of the top deposit and on the sidewalls dividing the opening, the thickness of which decreases along the depth direction of the opening.

Description

Technical Field

[0001] The exemplary embodiments of the invention relate to a substrate processing method and a plasma processing apparatus. Prior Technology

[0002] In substrate processing, the shape of the mask is sometimes adjusted. Patent Document 1 below discloses a technique in which a film is formed on the mask, a reaction layer is formed on the surface of the substrate, and then the reaction layer is removed.

[0003] Patent document 2 discloses a method for etching a silicon-containing film using plasma generated from a gas containing carbon fluoride. In this method, the silicon-containing film is first etched halfway through. Then, no plasma is generated on the silicon-containing film, forming a carbon-containing film. The silicon-containing film with the carbon-containing film formed is then further etched. Previous technical documents Patent documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 2020-088355 Patent Document 2: Japanese Patent Application Publication No. 2016-21546 Summary of the Invention

[0005] [The problem the invention aims to solve]

[0006] This invention provides a technique for adjusting the shape of an area in a substrate that provides an opening. [Technical means to solve the problem]

[0007] In one exemplary embodiment, a substrate processing method is provided. The substrate processing method includes a step (a) of preparing a substrate. The substrate includes a first region and a second region disposed on the first region and having an opening provided thereon. The substrate processing method further includes a step (b) in which a top deposit is preferentially formed on the top of the second region using a first plasma generated from a first gas. The substrate processing method further includes a step (c) in which a first film is formed on the surface of the top deposit and on the sidewalls dividing the opening, the thickness of which decreases along the depth direction of the opening. [Effects of the Invention]

[0008] According to one exemplary embodiment, the shape of the region in the substrate where the opening is provided can be adjusted. Simple Explanation of the Diagram

[0009] Figure 1 is a diagram illustrating a substrate processing method according to an exemplary embodiment. Figures 2(a) to 2(d) are partial enlarged cross-sectional views of an example substrate made in a corresponding step of a substrate processing method according to an exemplary embodiment. Figures 3(a) and 3(b) are partial enlarged cross-sectional views of an example substrate made in a corresponding step of a substrate processing method according to an exemplary embodiment. Figure 4 is a diagram illustrating an example of the configuration of a plasma processing system. Figure 5 is a diagram illustrating an example of the configuration of a capacitively coupled plasma processing device. Figure 6 is a diagram illustrating a substrate processing system according to an exemplary embodiment. Figure 7 is a schematic diagram of a plasma processing apparatus according to an exemplary embodiment. Figure 8 is a flowchart of an illustrative embodiment of an etching method. Figure 9 is a cross-sectional view of a substrate to which the method in Figure 8 can be applied. Figure 10 is a cross-sectional view showing one step of an illustrative embodiment of an etching method. Figure 11 is a cross-sectional view showing one step of an illustrative embodiment of an etching method. Figure 12 is a cross-sectional view showing one step of an illustrative embodiment of an etching method. Figure 13 is a cross-sectional view showing one step of an illustrative embodiment of an etching method. Figure 14 is a cross-sectional view of an example substrate having deposits including a first deposit and a second deposit. Figure 15 shows examples of substrate cross-sections before and after deposit formation in experiments 1 through 4. Figures 16(a) to (e) are graphs showing examples of the size and depth of the recesses before and after the formation of the protective film in experiments 1 to 5. Figure 17 shows examples of substrate cross-sections after etching in experiments 1 through 5. Figures 18(a) to (e) are graphs showing examples of the recess size and depth before and after etching in experiments 1 to 5. Figure 19 is a graph showing examples of the normalized etching rates in experiments 1 through 5. Implementation

[0010] Hereinafter, various exemplary embodiments will be described in detail with reference to the accompanying drawings. Furthermore, the same or equivalent parts in each drawing will be labeled with the same symbols.

[0011] Figure 1 is a diagram illustrating a substrate processing method according to an exemplary embodiment. Figures 2(a) to 2(d), 3(a), and 3(b) are partially enlarged cross-sectional views of an example substrate produced in corresponding steps of the substrate processing method according to an exemplary embodiment. The substrate processing method shown in Figure 1 (hereinafter referred to as "method MT") includes steps STa to STc. Method MT may further include step STd. Method MT may further include step STe. Furthermore, method MT may further include step STbt.

[0012] In step STa, a substrate W is prepared. As shown in Figure 2(a), the substrate W prepared in step STa includes a first region R1 and a second region R2. The second region R2 is disposed on the first region R1. The second region R2 provides an opening OP on the first region R1. The opening OP is formed by dividing the second region R2 by the sidewall surface SW. The width of the opening OP decreases along its depth direction. That is, the sidewall surface SW has an angle of inclination relative to the vertical direction. The first region R1 is exposed at the opening OP. The substrate W may further include a base region UR, and the first region R1 may be disposed on the base region UR.

[0013] Region 2 R2 functions as a mask during the etching of Region 1 R1. Therefore, Region 2 R2 is formed of a material with a lower etching rate than that of Region 1 R1 during etching. Region 1 R1 is a silicon-containing film or an organic film. The silicon-containing film constituting Region 1 R1 is, for example, a silicon film, a silicon oxide film, a silicon nitride film, or a laminated film comprising both silicon oxide and silicon nitride films. The organic film constituting Region 1 R1 is, for example, an amorphous carbon film. Region 2 R2 is, for example, a polycrystalline silicon film, an organic film, or a resist film.

[0014] In the first example of substrate W, the first region R1 is a silicon film, and the second region R2 is a silicon oxide film. In the second example of substrate W, the first region R1 is a silicon oxide film, and the second region R2 is an organic film. In the third example of substrate W, the first region R1 is an organic film, and the second region R2 is a silicon oxide film.

[0015] Step STb is performed after step STa. In step STb, as shown in Figure 2(b), a plasma generated from the deposition process gas is used to preferentially form the top deposit TD on the top TP of region R2. The top deposit TD is formed, for example, by plasma CVD (Chemical Vapor Deposition).

[0016] The top deposit TD can be formed from a material having a lower etching rate than the material constituting the second region R2 during the etching of the first region R1 in step STe. In the case where the first region R1 is a silicon-containing film, as in the first and second examples of the substrate W described above, the top deposit TD contains carbon, boron, or a metal. In the case where the first region R1 is an organic film, as in the third example of the substrate W described above, the top deposit TD contains boron or a metal. The metal contained in the top deposit TD can include tungsten, tin, or molybdenum.

[0017] When the top deposit TD contains carbon, the deposition process gas may contain carbon but not fluorine. The deposition process gas may include, for example, carbon monoxide (CO), carbonyl sulfide (COS), or hydrocarbon gases. Hydrocarbon gases may be, for example, C₂H₂, C₂H₄, CH₄, or C₂H₆. The first process gas may also be hydrogen-free. The first process gas may further include hydrogen (H₂) as an additive gas. The first process gas may further include rare gases such as argon or helium. The first process gas may further include inert gases such as nitrogen (N₂) to supplement or replace rare gases.

[0018] When the top sediment TD contains carbon, the deposition process gas may contain a first component gas and a second component gas. The first component gas is a carbon-containing gas that does not contain fluorine, such as CO or COS. That is, the deposition process gas may contain a first component that contains carbon and does not contain fluorine. The first component may be, for example, carbon monoxide (CO) or carbonyl sulfide. The second component gas is a gas containing carbon and fluorine or hydrogen, such as hydrofluorocarbon, fluorocarbon, or hydrocarbon. That is, the deposition process gas may further contain a second component containing carbon and fluorine or hydrogen. The second component may be, for example, hydrofluorocarbon, fluorocarbon, or hydrocarbon. Hydrofluorocarbon gases may be, for example, CHF₃, CH₃F, CH₂F₂, etc. Fluorocarbon gases may be, for example, C₄F₆, etc. The second component gas containing carbon and hydrogen may be, for example, CH₄. The flow rate of the first component gas or the first component may be greater than the flow rate of the second component gas or the second component.

[0019] When the top deposit TD contains boron, the deposition process gas may contain boron trichloride gas (BCl3 gas). The deposition process gas may further contain rare gases such as argon and helium. The deposition process gas may further contain nitrogen-containing gases such as N2 gas.

[0020] When the top deposit TD contains tungsten, the deposition process gas contains tungsten. The deposition process gas may further contain at least one of carbon and hydrogen. The deposition process gas may further contain fluorine. The deposition process gas may contain at least one of a carbon-containing gas and a hydrogen-containing gas, and a tungsten-containing gas. Fluorine may be contained in the carbon-containing gas, the hydrogen-containing gas, or the tungsten-containing gas.

[0021] When the top deposit TD contains tungsten, the carbon-containing gas may include at least one of CH4, C2H2, C2H4, CH3F, CH2F2, CHF3, and CO. The hydrogen-containing gas may include at least one of H2, SiH4, and NH3. The tungsten-containing gas may include tungsten halide gas. The tungsten halide gas may include at least one of tungsten hexafluoride (WF6), tungsten hexabromide (WBr6), tungsten hexachloride (WCl6), and WF5Cl. The tungsten-containing gas may include tungsten hexacarbonyl (W(CO)6) gas. The deposition processing gas may further include rare gases such as argon, helium, xenon, or neon. The first processing gas may further include, for example, nitrogen (N2).

[0022] The flow rate ratio of tungsten-containing gases may be less than the flow rate ratio of at least one of carbon-containing gases and hydrogen-containing gases. The flow rate ratio of rare gases may be greater than the flow rate ratio of at least one of carbon-containing gases and hydrogen-containing gases. In this invention, the flow rate ratio of each gas is the ratio (volume %) of the flow rate of each gas relative to the total flow rate of the processed gases.

[0023] When the top deposit TD contains tin, the deposition process gas contains a first component gas. The deposition process gas may further contain a second component gas. The first component gas contains tin-containing substances. The second component gas may contain H₂O, H₂O₂, O₂, O₃, N₂O₄, nitrogen-containing inorganic compounds, sulfur-containing inorganic compounds, halogen compounds, carbon-containing substances, or silicon-containing substances. Alternatively, the second component gas may contain at least one of N₂ and an oxygen-containing substance. The oxygen-containing substance may be NO or CO₂.

[0024] Tin-containing substances include, for example, tin alkane compounds, oxygen-containing tin compounds, nitrogen-containing tin compounds, or tin halide compounds.

[0025] Examples of tin alkane compounds include stanane, tetramethylstanane, tributylstanane, phenyltrimethylstanane, tetravinylstanane, dimethyldichlorostanane, butyltrichlorostanane, and trichlorophenylstanane.

[0026] Oxygen-containing tin compounds include, for example, tributylmethoxytin, tributoxytin, dibutyltin diacetate, triphenyltin acetate, tributyltin oxide, triphenyltin hydroxide, dihydroxybutyltin chloride, and acetoacetone tin.

[0027] Nitrogen-containing tin compounds include, for example, dimethylaminotrimethyltin, tris(dimethylamino)tert-butyltin, azidotrimethyltin, tetra(dimethylamino)tin, N,N'-ditert-butyl-2,3-diaminobutanetin(II), etc.

[0028] Examples of tin halide compounds include tin chloride, tin bromide, tin iodide, dimethyltin dichloride, butyltin trichloride, and phenyltin trichloride. Furthermore, tin halide compounds can be tetravalent tin chloride, tin bromide, or tin iodide.

[0029] When the top sediment TD contains tin, nitrogen-containing inorganic compounds include, for example, NH₃, N₂O₄, etc. Sulfur-containing inorganic compounds include, for example, H₂S, SO₂, COS, or CS₂. Halogen compounds include, for example, CF₄, F₂, CCl₄, etc. Carbon-containing substances include hydrocarbons, fluorinated carbons, organic compounds with hydroxyl groups, carboxylic acids, carboxylic anhydrides, or carboxylic acid halides. Hydrocarbons include, for example, methane or propylene. Fluorinated carbons include, for example, CF₄ or C₄F₆. Organic compounds with hydroxyl groups include, for example, alcohols such as methanol and ethylene glycol, or phenols. Carboxylic acids include, for example, acetic acid or oxalic acid. Silicon-containing substances include, for example, silicon chloride or aminosilanes.

[0030] When the top deposit TD contains molybdenum, the deposition process gas contains molybdenum-containing substances. The deposition process gas may contain, for example, molybdenum halides. Examples of molybdenum halides include molybdenum hexafluoride (MoF6) or molybdenum hexachloride (MoCl6). The deposition process gas may further contain rare gases such as argon or helium. The deposition process gas may further contain hydrogen-containing gases such as H2.

[0031] Following step STb, step STc is performed. In step STc, the first film F1, as shown in Figure 2(c), is formed along the surface of the top deposit TD and the sidewalls SW that divide the opening OP. The first film F1 is a sub-conformal film. The thickness of the first film F1 decreases along the depth direction of the opening OP. In step STc, the first film F1 is formed in a manner that improves the perpendicularity of the sidewalls dividing the opening OP in the substrate W after its formation. The first film F1 can be a silicon oxide film, a carbon-containing film, or a metal-containing film.

[0032] In step STc, the first film F1 can be formed by unsaturated ALD (Atomic Layer Deposition) or CVD. In the unsaturated ALD method, the cycle comprising steps 1 to 4 is repeated, similar to the ALD method. In step 1, a first gas (precursor gas) is supplied to the substrate W. In step 2, the chamber containing the substrate W is rinsed. In step 3, a second gas (reactive gas) is supplied to the substrate W. In step 3, plasma can be generated from the second gas. In step 4, the chamber containing the substrate W is rinsed. When the first film F1 is a silicon oxide film, the first gas contains, for example, an aminosilane gas, SiCl4 gas, or SiF4 gas, and the second gas contains, for example, an oxygen-containing gas such as O2 gas. When the first film F1 is a carbon-containing film, the first gas contains, for example, an organic compound gas. Organic compound gases include, for example, epoxides, carboxylic acids, carboxylic acid halides, carboxylic anhydrides, isocyanates, and phenols. When the first membrane F1 is a carbon-containing membrane, the second gas includes, for example, inorganic compound gases with NH bonds, inert gases, water vapor (H₂O gas), a mixture of nitrogen and hydrogen, and a mixture of hydrogen and oxygen.

[0033] The unsaturated ALD process is performed by either method 1 or method 2. Method 1 controls the supply of the second gas such that, in the first step, the precursor contained in the first gas is adsorbed onto the entire surface of the substrate W, and in the third step, the second gas does not spread across the entire surface of the substrate W. That is, method 1 utilizes a localized reaction. Method 2 involves adsorbing the precursor onto a portion of the surface of the substrate W in the first step, and supplying the second gas to the entire surface of the substrate W in the third step. That is, method 2 utilizes localized adsorption of the precursor. The localized reaction and localized adsorption are performed by controlling one or more of the following conditions: the temperature of the substrate support portion supporting the substrate W, the pressure within the chamber, the flow rate and supply time of the first gas (precursor gas), the flow rate and supply time of the second gas (reactant gas), and the processing time. Furthermore, when plasma is used in the unsaturated ALD process, the power level of the high-frequency electricity supplied for plasma generation can be adjusted.

[0034] Step STd is performed after step STc. In step STd, as shown in Figure 2(d), a second film F2 is formed by adsorbing a precursor onto the substrate W and modifying the precursor on the substrate W. The modification of the precursor is, for example, carried out by a reaction between the precursor from the precursor gas and a reactive substance from the reactive gas. The second film F2 can be formed on the substrate W by atomic layer deposition (ALD). The second film F2 is conformally formed on the surface of the substrate W. The second film F2 can be a subconformal film. In this case, the thickness of the second film F2 decreases along the depth direction of the opening OP. The second film F2 can be formed by unsaturated ALD. The second film F2 is, for example, a tungsten-containing film, a tin-containing film, an aluminum-containing film, or a hafnium-containing film. In the ALD process, the cycle including steps 1 to 4 is repeated. In step 1, a first gas (precursor gas) is supplied to the substrate W. In step 2, the chamber containing the substrate W is rinsed. In step 3, a second gas (reactive gas) is supplied to the substrate W. In step 4, the chamber containing the substrate W is rinsed.

[0035] When the second membrane F2 is a tungsten-containing membrane, the first gas includes, for example, WF6, WCl5, and WCl6, and the second gas includes, for example, at least one of a hydrogen-containing gas and an oxygen-containing gas. The hydrogen-containing gas can be, for example, hydrogen (H2 gas). The oxygen-containing gas can be, for example, oxygen (O2 gas). The hydrogen-containing gas can include, for example, nitrogen. Examples of hydrogen-containing gases containing nitrogen include ammonia or a mixture of nitrogen and hydrogen. When the second membrane F2 is a tin-containing membrane, the first gas includes, for example, SnCl4, SnBr4, and SnI4, and the second gas includes, for example, at least one of the aforementioned hydrogen-containing gas and the aforementioned oxygen-containing gas. When the second membrane F2 is an aluminum-containing membrane, the first gas includes, for example, trimethylaluminum gas, and the second gas includes, for example, water vapor (H2O gas). When the second membrane F2 is a hafnium-containing membrane, the first gas contains, for example, HfCl4, and the second gas contains, for example, water vapor (H2O gas).

[0036] Step STbt is performed between steps STd and STe. In step STbt, as shown in Figure 3(a), the second film F2 is partially removed. That is, the second film F2 is removed from the first region R1, i.e., the bottom of the opening OP. In step STbt, the first region R1 can be etched to form a recess in the first region R1. In step STbt, the second film F2 can be partially removed by generating plasma from the removal gas. When the second film F2 is a tungsten-containing film, the removal gas includes, for example, a fluorocarbon gas. When the second film F2 is a tin-containing film, the removal gas includes, for example, a hydrogen-containing gas (hydrogen, etc.). When the second film F2 is an aluminum-containing film or a hafnium-containing film, the removal gas includes, for example, a processing gas formed by mixing an oxygen-containing gas (O2 gas, CO gas, CO2 gas, N2O gas) with a halogen-containing gas (BCl3 gas, Cl2 gas). Furthermore, in step STbt, a bias signal, such as a bias RF signal or a pulsed DC signal, can be supplied to the substrate support portion supporting the substrate W within the chamber 10. When the second film F2 is a subconformal film, since the second film F2 is not formed at the bottom of the opening OP, step STbt may not be performed.

[0037] Step STe is performed after step STd. In step STe, as shown in Figure 3(b), the first region R1 is etched. The first region R1 can be etched by generating plasma from the etching gas. When the first region R1 is a silicon film, the etching gas may contain halogen-containing gases such as HBr and Cl2. When the first region R1 is a silicon oxide film, a silicon nitride film, or a multilayer film containing silicon oxide and silicon nitride films, the etching gas may contain one or more fluorine-containing gases such as fluorocarbon gas, hydrofluorocarbon gas, nitrogen trifluoride gas, and sulfur hexafluoride gas. When the first region R1 is an organic film, the etching gas may contain oxygen-containing gases such as O2. Alternatively, when the first region R1 is an organic film, the etching gas may contain N2 gas and H2 gas. Furthermore, in step STe, a bias signal, such as a bias RF signal or a pulsed DC signal, can be supplied to the substrate support portion supporting the substrate W within the chamber 10.

[0038] In method MT, the top deposit TD is preferentially formed on the top TP of the second region R2, increasing the thickness of the region providing the opening in the first region R1. Furthermore, the verticality of the sidewalls dividing the opening OP is improved by the first film F1 and the second film F2. Therefore, according to method MT, the shape of the region providing the opening OP in the substrate W is adjusted. Also, in method MT, the etch resistance of the mask during the etching of the first region R1 in step STe is improved by the top deposit TD and the second film F2.

[0039] The following describes various exemplary embodiments of the plasma processing apparatus and substrate processing system used in Method MT.

[0040] Figure 4 is a diagram illustrating an example of the configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. Furthermore, the plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space, and at least one gas outlet for discharging gas from the plasma processing space. The gas supply port is connected to the gas supply unit 20, and the gas outlet is connected to the exhaust system 40. The substrate support 11 is disposed within the plasma processing space and has a substrate support surface for supporting a substrate.

[0041] The plasma generation unit 12 is configured to generate plasma from at least one processing gas supplied to the plasma processing space. The plasma formed in the plasma processing space can be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR), helicon wave plasma (HWP), or surface wave plasma (SWP), etc. Furthermore, various types of plasma generation units, including AC (Alternating Current) plasma generation units and DC (Direct Current) plasma generation units, can be used. In one embodiment, the AC signal (AC power) used by the AC plasma generation unit has a frequency in the range of 100 kHz to 10 GHz. Therefore, the AC signal includes RF (Radio Frequency) signals and microwave signals. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0042] The control unit 2 processes computer-executable commands that cause the plasma processing apparatus 1 to perform the various steps described herein. The control unit 2 may be configured to control various elements of the plasma processing apparatus 1 to perform the various steps described herein. In one embodiment, the control unit 2 may be part or all of the plasma processing apparatus 1. The control unit 2 may include a processing unit 2a1, a memory unit 2a2, and a communication interface 2a3. The control unit 2 is implemented, for example, by a computer 2a. The processing unit 2a1 can perform various control actions by reading a program from the memory unit 2a2 and executing the read program. The program may be pre-stored in the memory unit 2a2 or retrieved via a medium when necessary. The retrieved program is stored in the memory unit 2a2 and read from and executed by the processing unit 2a1. The medium may be various memory media readable by the computer 2a, or a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The memory unit 2a2 may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 can communicate with the plasma processing device 1 via a communication line such as a LAN (Local Area Network).

[0043] The following describes a configuration example of a capacitively coupled plasma treatment apparatus, which is one example of a plasma treatment apparatus 1. Figure 5 is a diagram illustrating a configuration example of a capacitively coupled plasma treatment apparatus.

[0044] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. Furthermore, the plasma processing apparatus 1 includes a substrate support unit 11 and a gas inlet unit. The gas inlet unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas inlet unit includes a cluster nozzle 13. The substrate support unit 11 is disposed within the plasma processing chamber 10. The cluster nozzle 13 is disposed above the substrate support unit 11. In one embodiment, the cluster nozzle 13 constitutes at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the cluster nozzle 13, the sidewall 10a of the plasma processing chamber 10, and the substrate support unit 11. The plasma processing chamber 10 is grounded. The cluster nozzle 13 and the substrate support unit 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0045] The substrate support portion 11 includes a body portion 111 and a ring assembly 112. The body portion 111 has a central region 111a for supporting the substrate W and an annular region 111b for supporting the ring assembly 112. An example of a wafer-based substrate W. The annular region 111b of the body portion 111 surrounds the central region 111a of the body portion 111 when viewed from above. The substrate W is disposed on the central region 111a of the body portion 111, and the ring assembly 112 is disposed on the annular region 111b of the body portion 111 in a manner that surrounds the substrate W on the central region 111a of the body portion 111. Therefore, the central region 111a is also referred to as the substrate support surface for supporting the substrate W, and the annular region 111b is also referred to as the annular support surface for supporting the ring assembly 112.

[0046] In one embodiment, the body portion 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Alternatively, other members surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member, may also have an annular region 111b. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or on both the electrostatic chuck 1111 and the annular insulating member. Furthermore, at least one RF / DC electrode, which is associated with the RF power supply 31 and / or DC power supply 32, may be disposed within the ceramic component 1111a. In this case, the at least one RF / DC electrode functions as a lower electrode. When the bias RF signal and / or DC signal is supplied to the at least one RF / DC electrode, the RF / DC electrode is also referred to as a bias electrode. Moreover, the conductive component of the base 1110 and the at least one RF / DC electrode may also function as a plurality of lower electrodes. Additionally, the electrostatic electrode 1111b may also function as a lower electrode. Therefore, the substrate support portion 11 includes at least one lower electrode.

[0047] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0048] Furthermore, the substrate support portion 11 may include a temperature control module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature control module may include a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. A heat transfer fluid, such as brine or gas, flows in the flow path 1110a. In one embodiment, the flow path 1110a is formed within the base 1110, and one or more heaters are disposed within the ceramic component 1111a of the electrostatic chuck 1111. Additionally, the substrate support portion 11 may also include a heat transfer gas supply portion configured to supply heat transfer gas to the gap between the back surface of the substrate W and the central region 111a.

[0049] The cluster injector 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The cluster injector 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas inlets 13c. The processing gas supplied to the gas supply port 13a is introduced into the plasma processing space 10s through the gas diffusion chamber 13b and the plurality of gas inlets 13c. Furthermore, the cluster injector 13 includes at least one upper electrode. In addition to the cluster injector 13, the gas inlet unit also includes one or more side gas injectors (SGIs) installed at one or more openings formed in the sidewall 10a.

[0050] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from its respective gas source 21 to the cluster nozzle 13 via its respective flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may also include at least one flow modulation device for modulating or pulsed the flow rate of the at least one process gas.

[0051] The power supply 30 includes an RF power supply 31 connected to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode and / or at least one upper electrode. This allows plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of the plasma generation unit 12. Furthermore, by supplying a bias RF signal to at least one lower electrode, a bias potential can be generated on the substrate W, thereby drawing ionic components from the formed plasma into the substrate W.

[0052] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is connected to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit, and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may also be configured to generate a plurality of source RF signals with different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0053] The second RF generation unit 31b is connected to at least one lower electrode via at least one impedance matching circuit and is configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generation unit 31b may be configured to generate a plurality of bias RF signals with different frequencies. One or more bias RF signals generated are supplied to at least one lower electrode. Furthermore, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0054] Furthermore, the power supply 30 may include a DC power supply 32 integrated into the plasma processing chamber 10. The DC power supply 32 includes a first DC generating unit 32a and a second DC generating unit 32b. In one embodiment, the first DC generating unit 32a is connected to at least one lower electrode and configured to generate a first DC signal. The generated first DC signal is applied to at least one lower electrode. In one embodiment, the second DC generating unit 32b is connected to at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to at least one upper electrode.

[0055] In various embodiments, the first and second DC signals can be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses can have rectangular, trapezoidal, triangular, or combinations thereof pulse waveforms. In one embodiment, a waveform generation unit for generating a sequence of voltage pulses from the DC signal is connected between the first DC generation unit 32a and at least one lower electrode. Therefore, the first DC generation unit 32a and the waveform generation unit constitute a voltage pulse generation unit. When the second DC generation unit 32b and the waveform generation unit constitute a voltage pulse generation unit, the voltage pulse generation unit is connected to at least one upper electrode. The voltage pulses can be either positive or negative. Furthermore, the sequence of voltage pulses can include one or more positive voltage pulses and one or more negative voltage pulses within one cycle. Furthermore, the first and second DC generating units 32a and 32b can be provided outside the RF power supply 31, or the first DC generating unit 32a can be provided instead of the second RF generating unit 31b.

[0056] The exhaust system 40 can be connected to, for example, a gas outlet 10e located at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure within the plasma processing space 10s is adjusted by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry vacuum pump, or a combination thereof.

[0057] All steps of Method MT can be performed in the plasma processing apparatus 1. Each step of Method MT can be executed by controlling each part of the plasma processing apparatus 1 via the control unit 2. In step STa, the substrate W is placed on the substrate support 11. The gas used in each of steps STb to STe of Method MT is supplied to the chamber 10 from the gas supply unit 20. In each of steps STb to STe of Method MT, the pressure in the chamber 10 is adjusted to a specified pressure by the exhaust system 40. When plasma is generated in the chamber 10 in each of steps STb to STe of Method MT, the plasma is generated by the plasma generation unit 12. For example, the plasma is generated by supplying a source RF signal from the first RF generation unit 31a. Furthermore, during each of steps STb to STe of method MT, when ions from the plasma are drawn into the substrate W, a bias signal is supplied to at least one of the second RF generation unit 31b and the first DC generation unit 32a. The bias signal is at least one of the bias RF signal and the pulsed first DC signal.

[0058] Referring hereto to Figure 6, Figure 6 illustrates a substrate processing system according to an exemplary embodiment. The substrate processing system PS shown in Figure 6 can be used in method MT. The substrate processing system PS includes stages LP1-LP4, containers FP1-FP4, a loader module LM, an aligner AN, loading interlock modules LL1, LL2, process modules PM1-PM6, a transport module TM, and a control unit MC. Furthermore, the number of stages, containers, and loading interlock modules in the substrate processing system PS can be any number of one or more. Also, the number of process modules in the substrate processing system PS can be any number of two or more.

[0059] Platforms LP1 to LP4 are arranged along one edge of the loader module LM. Each of platforms LP1 to LP4 is, for example, a load port. Containers FP1 to FP4 are respectively mounted on platforms LP1 to LP4. Each of containers FP1 to FP4 is, for example, a container referred to as a FOUP (Front Opening Unified Pod). Each of containers FP1 to FP4 is configured to house a substrate W inside it.

[0060] The loader module LM has a chamber. The pressure inside the chamber of the loader module LM is set to atmospheric pressure. The loader module LM has a conveying device TU1. The conveying device TU1 is, for example, a conveying robot, controlled by the control unit MC. The conveying device TU1 is configured to convey substrate W through the chamber of the loader module LM. The conveying device TU1 can convey substrate W between each of the containers FP1~FP4 and the aligner AN, between the aligner AN and each of the loading interlock modules LL1, LL2, and between each of the loading interlock modules LL1, LL2 and each of the containers FP1~FP4. The aligner AN is connected to the loader module LM. The aligner AN is configured to adjust the position and / or orientation of the substrate W (position correction).

[0061] Loading interlock modules LL1 and LL2 are each located between the loader module LM and the transport module TM. Each of the loading interlock modules LL1 and LL2 provides a pre-decompression chamber.

[0062] The transfer module TM is connected to each of the load interlock modules LL1 and LL2 via gate valves. The transfer module TM has a transfer chamber TC whose internal space is configured to be depressurized. The transfer module TM has a transfer device TU2. The transfer device TU2 is, for example, a transfer robot, controlled by a control unit MC. The transfer device TU2 is configured to transfer substrate W via the transfer chamber TC. The transfer device TU2 can transfer substrate W between each of the load interlock modules LL1 and LL2 and each of the process modules PM1 to PM6, and between any two process modules PM1 to PM6.

[0063] Each of the process modules PM1 to PM6 is configured as an apparatus for performing specialized substrate processing. Each of the process modules PM1 to PM6 can be a plasma processing apparatus such as plasma processing apparatus 1. The plasma generated by the plasma generation section of each of the process modules PM1 to PM6 can be capacitively coupled plasma, inductively coupled plasma, ECR plasma, spiral wave excited plasma, or surface wave plasma, etc.

[0064] The control unit (MC) controls all components of the substrate processing system (PS). The control unit (MC) can be a computer equipped with a processor, memory, input device, and display device. The control unit (MC) executes control programs stored in the memory and controls all components of the substrate processing system (PS) based on process recipe data stored in the memory. Each step of the method (MT) can be executed by the control unit (MC) controlling the various components of the substrate processing system (PS).

[0065] In step STa, the substrate W can be transported to one of the process modules PM1 to PM6 used in step STb by means of the transport device TU1 and the transport device TU2.

[0066] In one embodiment, steps STb, STc, and STd can be performed by one of the process modules PM1 to PM6. In this case, steps STbt and STe can be performed by another process module among PM1 to PM6, or by two other process modules respectively.

[0067] In another embodiment, step STb can be performed by one of the process modules PM1 to PM6, and steps STc and STd can be performed by the other process module among PM1 to PM6. In this case, steps STbt and STe can be performed by the other process module among PM1 to PM6, or by two other process modules respectively.

[0068] In another embodiment, steps STb, STc, and STd can be performed separately by three process modules PM1 to PM6. In this case, steps STbt and STe can be performed by another process module among process modules PM1 to PM6, or by two other process modules respectively.

[0069] Figure 7 is a schematic diagram illustrating an exemplary embodiment of a plasma processing apparatus. As shown in Figure 7, the plasma processing apparatus 1 of Figure 5 may further include an optical observation device OC. The optical observation device OC may include a chamber that can communicate with the plasma processing chamber 10. The substrate W can be moved between the plasma processing chamber 10 and the chamber of the optical observation device OC by a transfer robot. The substrate W is housed in the chamber of the optical observation device OC by the transfer robot, and alignment of the substrate W can be performed within the chamber of the optical observation device OC. Then, the optical observation device OC can measure the dimension (CD: Critical Dimension) of the recess RS (see Figure 10) of the substrate W. The optical observation device OC can measure the thickness of the protective film PR (see Figure 12) of the substrate W. The measurement results can be sent from the optical observation device OC to the control unit 2.

[0070] Figure 8 is a flowchart illustrating an etching method according to an exemplary embodiment. The etching method MT1 shown in Figure 8 (hereinafter referred to as "method MT1") can be performed by the plasma processing apparatus 1 of the above embodiment. Method MT1 can be applied to a substrate W. Method MT1 is an example of a substrate processing method.

[0071] Figure 9 is a cross-sectional view of a substrate to which the method of Figure 8 can be applied. As shown in Figure 9, in one embodiment, the substrate W has an etch target film RE and a mask MK on the etch target film RE. The etch target film RE may be disposed on a base film UR1. The mask MK may have at least one opening OP1.

[0072] The etchable film RE may include at least one of silicon-containing films and organic films. The silicon-containing film may include at least one of silicon films, silicon-germanium films, silicon oxide films, and silicon nitride films. The silicon-containing film may be a laminated film formed by alternating layers of silicon oxide and silicon nitride films. The organic film may be an amorphous carbon film. The etchable film RE may, for example, be a film used in memory devices such as DRAM or 3D-NAND.

[0073] The mask MK may contain at least one of a silicon-containing material, an organic material, and a metal. The silicon-containing material may contain polycrystalline silicon. The organic material may contain at least one of a photoresist and a spin-on carbon (SOC). When the etchable film RE contains a silicon-containing film, the mask MK may contain at least one of a second silicon-containing material different from the first silicon-containing material constituting the silicon-containing film, an organic material, and a metal. When the etchable film RE contains an organic film, the mask MK may contain at least one of a silicon-containing material, a second organic material different from the first organic material constituting the organic film, and a metal.

[0074] The substrate film UR1 may contain a material different from the etched target film RE. The substrate film UR1 may contain at least one of silicon-containing films, organic films, and metal-containing films.

[0075] Hereinafter, method MT1 will be described using the plasma processing apparatus 1 of the above-described embodiment applied to substrate W as an example, with reference to Figures 8 to 13. Figures 10 to 13 are cross-sectional views showing one step of an illustrative embodiment of the etching method. When using the plasma processing apparatus 1, method MT1 can be executed in the plasma processing apparatus 1 by controlling each part of the plasma processing apparatus 1 through the control unit 2. In method MT1, as shown in Figure 7, the substrate W disposed on the substrate support 11 (substrate support) within the plasma processing chamber 10 is processed.

[0076] As shown in Figure 8, method MT1 may include steps ST1 to ST7. Steps ST1 to ST7 may be executed sequentially. Method MT1 may also exclude at least one of steps ST2, ST3, ST6, and ST7. Step ST5 may also be performed after step ST3 and before step ST4.

[0077] In step ST1, the substrate W shown in FIG9 is provided. The substrate W may be provided into the plasma processing chamber 10. The substrate W may be supported by the substrate support 11 within the plasma processing chamber 10.

[0078] In step ST2, as shown in Figure 10, the target film RE is etched using the first plasma PL1 generated from the first processing gas to form a recess RS. The recess RS may correspond to the opening OP1 of the mask MK. The size of the recess RS at its upper end may be less than 100 nm. The size of the recess RS may gradually decrease from its upper end towards its bottom. The aspect ratio of the recess RS may be 5 or more. The bottom of the recess RS may reach the substrate film UR1 or not. The recess RS may be an opening.

[0079] When the etchable film RE contains a silicon-containing film, the first processing gas may contain a halogen-containing gas. The halogen-containing gas may contain at least one of a fluorine-containing gas and a chlorine-containing gas. When the first processing gas contains a fluorine-containing gas, the etchable film RE may contain a silicon oxide film or a silicon nitride film. When the first processing gas contains a chlorine-containing gas, the etchable film RE may contain a silicon film or a silicon-germanium film. Examples of fluorine-containing gases include fluorocarbon (CxFy) gas, hydrofluorocarbon (CxHyFz) gas, and nitrogen trifluoride (NF3 gas). x, y, and z are natural numbers. The first processing gas may contain an oxygen-containing gas.

[0080] When the etched film RE contains an organic film, the first processing gas may contain an oxygen-containing gas. Examples of oxygen-containing gases include oxygen, carbon monoxide, carbonyl sulfide (COS), and sulfur oxides (SO₂).

[0081] Step ST2 can be performed as follows. First, the first processing gas is supplied to the plasma processing chamber 10 by the gas supply unit 20. Second, the first plasma PL1 is generated from the first processing gas in the plasma processing chamber 10 by the plasma generation unit 12. The control unit 2 controls the gas supply unit 20 and the plasma generation unit 12 so that the first plasma PL1 etches the etchable film RE to form a recess RS.

[0082] Step ST2 can be performed simultaneously with step ST1. The base film UR1 constitutes the first region. The etched target film RE and the mask MK constitute the second region. The opening OP1 (first opening) of the mask MK and the recess RS (second opening) of the etched target film RE constitute the opening OP.

[0083] In step ST3, the deposits adhering to the mask MK in step ST2 are removed by the fourth plasma generated from the fourth processing gas. When the etchable film RE contains a silicon-containing film, the deposits may contain fluorine and carbon. The fourth processing gas may contain an oxygen-containing gas. Examples of oxygen-containing gases include oxygen. When the etchable film RE contains an organic film, sometimes no deposits adhere to the mask MK in step ST2. In this case, step ST3 can be omitted.

[0084] Step ST3 can be performed as follows. First, the fourth processing gas is supplied to the plasma processing chamber 10 by the gas supply unit 20. Second, the fourth plasma is generated from the fourth processing gas in the plasma processing chamber 10 by the plasma generation unit 12. The control unit 2 controls the gas supply unit 20 and the plasma generation unit 12 so that the adhering material attached to the mask MK is removed by the fourth plasma.

[0085] In step ST4, as shown in Figure 11, a deposit DP is formed on the upper surface MKt of the shield MK by the second plasma PL2 generated from the second processing gas. The deposit DP may not form on the sidewall of the opening OP1 of the shield MK. The deposit DP is preferentially formed on the top of the shield MK.

[0086] Deposits (DP) may contain at least one of silicon, carbon, boron, and metals. Examples of metals include titanium, tungsten, and tin.

[0087] The second processing gas may contain at least one of silicon-containing gases, carbon-containing gases, boron-containing gases, and metal-containing gases. Examples of silicon-containing gases include SiCl₄, SiF₄, and Si₂Cl₆. Examples of carbon-containing gases include hydrocarbon gases such as CH₄, C₂H₂, or C₃H₆. Examples of boron-containing gases include BCl₃. The metal-containing gas may contain at least one of tungsten-containing gases and tin-containing gases. Examples of tungsten-containing gases include tungsten hexafluoride (WF₆). Examples of tin-containing gases include TDMASn (tetramethylaminotin(IV)) gas, SnCl₄, SnBr₄, and SnI₄. The second processing gas may contain hydrogen. The second processing gas may contain rare gases.

[0088] Step ST4 can be performed as follows. First, the second processing gas is supplied to the plasma processing chamber 10 by the gas supply unit 20. Second, the second plasma PL2 is generated from the second processing gas in the plasma processing chamber 10 by the plasma generation unit 12. The control unit 2 controls the gas supply unit 20 and the plasma generation unit 12 so that the second plasma PL2 forms a deposit DP on the upper surface MKt of the shield MK.

[0089] In step ST5, as shown in Figure 12, a protective film PR is formed on the sidewall RSa of the recess RS. The protective film PR can also be formed on the sidewall of the opening OP1. The protective film PR can also be formed on the upper surface DPt of the deposit DP. The protective film PR can also be formed on the side of the deposit DP. The protective film PR can have a first thickness on the upper surface DPt of the deposit DP. The protective film PR can have a second thickness on the sidewall RSa of the recess RS. The second thickness is less than the first thickness. The thickness of the protective film PR can gradually decrease from the upper surface DPt of the deposit DP towards the bottom of the recess RS. In this case, the protective film PR is a non-conformal film (a sub-conformal film). The protective film PR may also not be formed on the bottom of the recess RS. If step ST5 is performed before step ST4, the protective film PR can be formed on the upper surface MKt of the mask MK. In step ST3, the deposit DP can be formed on the protective film PR on the upper surface MKt of the mask MK.

[0090] The protective film (PR) may contain the same material as the deposit (DP) or a different material. The protective film (PR) may contain at least one of silicon-containing films, organic films, and metal-containing films. Silicon-containing films may contain at least one of silicon oxide films and silicon nitride films.

[0091] The protective film PR can be formed using a fifth processing gas. The fifth processing gas may contain at least one of silicon-containing gas, carbon-containing gas, and metal-containing gas.

[0092] The protective film PR can be formed by ALD or CVD methods. Examples of ALD methods include thermal ALD and PE (Plasma Enhanced)-ALD. In the case of forming the protective film PR by ALD, step ST5 includes: an adsorption step of supplying the precursor (fifth processing gas) to the sidewall RSa of the recess RS, and an activation step of activating the adsorbed precursor. Activation can be performed using plasma generated from the processing gas. The adsorption and activation steps can be repeated alternately. A rinsing step can be performed between the adsorption and activation steps. The thickness of the protective film PR can be adjusted by controlling that the precursor does not adsorb onto a portion of the surface of the substrate W (e.g., the bottom of the recess) during the adsorption step. For example, the adsorption position can be controlled by forming a factor that hinders precursor adsorption on a portion of the surface of the substrate W. Alternatively, the thickness of the protective film PR can be adjusted by controlling that the plasma does not reach a portion of the surface of the substrate W (e.g., the bottom of the recess) during the activation step.

[0093] When the protective film PR includes a silicon-containing film, a silicon-containing gas is used as a precursor in the adsorption step. When the protective film PR includes a silicon oxide film, examples of silicon-containing gases include aminosilane gas, SiCl₄ gas, and SiF₄ gas. In the activation step, an oxygen-containing gas is used as the treatment gas. Examples of oxygen-containing gases include oxygen. When the protective film PR includes a silicon nitride film, examples of silicon-containing gases include aminosilane gas, SiCl₄ gas, dichlorosilane gas, and hexachlorosilane gas. In the activation step, a nitrogen-containing gas is used as the treatment gas. Examples of nitrogen-containing gases include nitrogen and ammonia.

[0094] When the protective membrane PR contains an organic membrane, an organic gas is used as a precursor in the adsorption step. Examples of organic gases include epoxides, carboxylic acids, carboxylic acid halides, carboxylic anhydrides, isocyanates, and phenols. In the activation step, a variety of gases are used as treatment gases. Examples of various gases include inorganic compound gases with NH bonds, inert gases, water vapor (H₂O gas), a mixture of nitrogen and hydrogen, and a mixture of hydrogen and oxygen.

[0095] When the protective film PR contains a metal film, a metal-containing gas is used as a precursor in the adsorption step. The metal-containing gas may contain at least one of oxygen-containing metal compounds, nitrogen-containing metal compounds, sulfur-containing metal compounds, and metal halides. Examples of metal halides include TiCl₄, WF₆, WCl₅, WCl₆, SnCl₄, SnBr₄, and SnI₄. In the activation step, at least one of a hydrogen-containing gas and an oxygen-containing gas is used as the treatment gas. When a hydrogen-containing gas is used, the protective film PR becomes a metal-containing film. When an oxygen-containing gas is used, the protective film PR becomes a metal oxide film. The hydrogen-containing gas may contain nitrogen. In this case, the protective film PR becomes a metal nitride film. Examples of hydrogen-containing gases containing nitrogen include ammonia and mixtures of nitrogen and hydrogen.

[0096] Step ST5 can be performed as follows. First, the fifth processing gas is supplied to the plasma processing chamber 10 by the gas supply unit 20. Second, plasma is generated from the processing gas in the plasma processing chamber 10 by the plasma generation unit 12. The control unit 2 controls the gas supply unit 20 and the plasma generation unit 12 so that a protective film PR is formed on the sidewall RSa of the recess RS by plasma.

[0097] In step ST6, as shown in Figure 13, the recess RS is etched using the third plasma PL3 generated from the third processing gas. In step ST6, the protective film PR, deposit DP, and mask MK are also etched. When the bottom of the recess RS reaches the base film UR1 in step ST2, the sidewalls RSa of the recess RS are primarily etched in step ST6. In this case, the size of the recess RS increases due to the lateral etching progress. When the bottom of the recess RS does not reach the base film UR1 in step ST2, the bottom of the recess RS is primarily etched in step ST6. In this case, the depth of the recess RS increases due to the longitudinal etching progress. The size of the recess RS (opening OP) can be measured using an optical observation device OC or calculated from SEM images.

[0098] The third processing gas may contain the same gas as the first processing gas. When the etchable film RE contains a silicon-containing film, the third processing gas may contain a halogen-containing gas. When the etchable film RE contains an organic film, the third processing gas may contain an oxygen-containing gas.

[0099] Step ST6 can be performed as follows. First, the third processing gas is supplied to the plasma processing chamber 10 by the gas supply unit 20. Second, the third plasma PL3 is generated from the third processing gas in the plasma processing chamber 10 by the plasma generation unit 12. The control unit 2 controls the gas supply unit 20 and the plasma generation unit 12 so that the recess RS is etched by the third plasma PL3.

[0100] In step ST7, steps ST3 to ST6 are repeated.

[0101] According to the plasma processing apparatus 1 and method MT1 described above, when etching the recess RS in step ST6, the mask MK is protected by the deposit DP formed on the surface MKt above the mask MK. Therefore, when etching the recess RS in step ST6, a higher etch selectivity for the mask MK can be obtained.

[0102] Furthermore, since the sidewall RSa of the recess RS is protected by the protective film PR, etching of the sidewall RSa of the recess RS in step ST6 can be suppressed. Thus, abnormal shape (bending) of the recess RS can be suppressed.

[0103] When a protective film PR is formed on the surface DPt above the deposit DP, the deposit DP and the mask MK are protected by the protective film PR. Therefore, a higher etch selectivity for the mask MK can be obtained when etching the recess RS. The protective film PR can have a first thickness on the surface DPt above the deposit DP and a second thickness on the sidewall RSa of the recess RS, and the second thickness can be less than the first thickness. In this case, the deposit DP and the mask MK can be protected by the protective film PR while the clogging of the recess RS can be suppressed.

[0104] When method MT1 includes step ST3, deposit DP can be formed on the surface MKt above the mask MK after the adhering material has been removed.

[0105] When method MT1 includes step ST7, the etching amount of the recess RS can be increased.

[0106] Figure 14 is a cross-sectional view of a substrate having an example of a deposit including a first deposit and a second deposit. As shown in Figure 14, the deposit DP may include a first deposit DP1 formed on the surface MKt above the mask MK, and a second deposit DP2 formed on the first deposit DP1. The second deposit DP2 may contain a material different from the first deposit DP1. Examples of the materials of the first deposit DP1 and the second deposit DP2 are the same as examples of the materials of the deposit DP. The first deposit DP1 may contain carbon, and the second deposit DP2 may contain tungsten.

[0107] When a deposit DP includes a first deposit DP1 and a second deposit DP2, the materials of the etching target film RE and the mask MK can be considered, and an appropriate combination of the materials of the first deposit DP1 and the second deposit DP2 can be selected.

[0108] The above descriptions illustrate various exemplary embodiments, but the embodiments are not limited to these exemplary embodiments. Various additions, omissions, substitutions, and modifications can be made. Furthermore, elements from different embodiments can be combined to form other embodiments.

[0109] The following describes various experiments conducted to evaluate method MT1. The experiments described below do not limit the scope of this invention.

[0110] (Experiment 1) In the first experiment, a substrate W having an etchable film RE and a mask MK was prepared. The etchable film RE has a SiO2 film and a SiN film on the SiO2 film. The mask MK is disposed on the SiN film. The mask MK contains polycrystalline silicon. Next, the substrate W is provided into the plasma processing chamber 10 of the plasma processing apparatus 1 (step ST1).

[0111] Next, the SiN film and SiO2 film are etched by the first plasma PL1 generated from the first processing gas containing fluorocarbon gas to form the recess RS (step ST2).

[0112] Next, the deposits attached to the shield MK are removed by a fourth plasma generated from a fourth treatment gas containing oxygen (step ST3). The deposits contain carbon and fluorine.

[0113] Next, a deposit DP is formed on the surface MKt above the shield MK using a second plasma PL2 generated from a second processing gas containing SiCl4 gas, hydrogen, and argon (step ST4). The deposit DP contains silicon.

[0114] Next, silicon-containing gas is adsorbed onto the sidewall RSa of the recess RS. A protective film PR is formed on the sidewall RSa of the recess RS using plasma generated from the treatment gas containing oxygen-containing gas (step ST5). The protective film PR is also formed on the upper surface of the deposit DP. The protective film PR is a silicon-containing film. The protective film PR is formed by the ALD method. The protective film PR may have a first thickness on the upper surface DPt of the deposit DP and a second thickness on the sidewall RSa of the recess RS. The second thickness may be less than the first thickness.

[0115] Next, the recess RS is etched using the third plasma PL3 generated from the third processing gas containing fluorocarbon gas (step ST6).

[0116] Next, repeat steps ST3 to ST6 (step ST7).

[0117] (Experiment 2) In Experiment 2, step ST4 was performed in the same manner as in Experiment 1, except that CH4 gas was used instead of SiCl4 gas. The sediment DP contained carbon.

[0118] (Experiment 3) In Experiment 3, step ST4 was performed in the same manner as in Experiment 1, except that BCl3 gas was used instead of SiCl4 gas and hydrogen gas. The deposit DP contained boron.

[0119] (Experiment 4) In Experiment 4, step ST4 was performed in the same manner as in Experiment 1, except that WF6 and CH4 gases were used instead of SiCl4 and hydrogen. The deposit DP contained tungsten.

[0120] (Experiment 5) In Experiment 5, the same method as in Experiment 1 was performed, except that step ST4 was omitted. As a result, no deposit DP was formed.

[0121] (Thickness of sediment) Figure 15 shows examples of cross-sectional views of the substrate before and after deposition in experiments 1 through 4. BF shows an example of a cross-sectional view of the substrate before deposition in experiments 1 through 4. EX1 through EX4 show examples of cross-sectional views of the substrate after deposition in experiments 1 through 4. In experiment 1, the thickness of the DP deposition was 41 nm. In experiment 2, the thickness of the DP deposition was 40 nm. In experiment 3, the thickness of the DP deposition was 44 nm. In experiment 4, the thickness of the DP deposition was 48 nm. In experiment 1, compared to experiments 2 and 3, the clogging of the opening OP1 of the mask MK caused by the DP deposition was suppressed. In experiments 2 and 3, compared to experiment 4, the clogging of the opening OP1 of the mask MK caused by the DP deposition was suppressed.

[0122] In experiments 1, 3, and 4, the thickness of the deposit DP remained unchanged even after the protective film PR was formed in step ST5. In experiment 2, the thickness of the deposit DP was 22 nm after the protective film PR was formed in step ST5. It is speculated that this is because the deposit DP was etched by plasma generated from oxygen during the activation step of forming the protective film PR using the ALD method.

[0123] (Thickness of the protective film) Figure 16 is a graph showing the dimensions and depths of the recesses before and after the formation of the protective film in experiments 1 through 5. Figure 16(a) shows the graph for experiment 5. Figure 16(b) shows the graph for experiment 1. Figure 16(c) shows the graph for experiment 2. Figure 16(d) shows the graph for experiment 3. Figure 16(e) shows the graph for experiment 4. In each graph, the vertical axis represents the depth of the recess RS. The depth range of 0–0.3 μm corresponds to the mask MK. The depth range of 0.3–0.5 μm corresponds to the SiN film. The depth range of 0.5–2.0 μm corresponds to the SiO2 film. The horizontal axis represents the dimension (CD: Critical Dimension) of the recess RS. The depth and dimension of the recess RS can be calculated from the SEM image. In each graph, a chain line RF1 represents the dimension of the recess RS before the formation of the protective film PR. The solid lines E1 to E5 represent the dimensions of the recesses RS after the protective film PR is formed in experiments 1 to 5, respectively. As can be seen from the graphs, the dimensions of the recesses RS decrease due to the protective film PR.

[0124] As shown in Figures 16(a) to (c), the thickness of the protective film PR in experiments 1 and 2 was approximately the same as in experiment 5. However, as shown in Figure 16(d), the thickness of the protective film PR in experiment 3 was smaller compared to experiment 5. As shown in Figure 16(e), the thickness of the protective film PR in experiment 4 was smaller compared to experiment 3. It is speculated that the deposit DP narrowed the opening OP1 of the shield MK, making it difficult for the protective film PR to form within the recess RS, thus reducing the thickness of the protective film PR. However, in experiment 2, the thickness of the protective film PR did not decrease. It is speculated that this is because the thickness of the deposit DP was relatively small, making it difficult for the opening OP1 of the shield MK to narrow.

[0125] (Remaining thickness of the mask) Figure 17 shows examples of cross-sectional views of the substrate after etching in experiments 1 through 5. EX1 through EX5 show examples of cross-sectional views of the substrate after etching in experiments 1 through 5, respectively. In experiment 5, the remaining thickness of the mask MK was 208 nm. In experiment 1, the remaining thickness of the mask MK was 218 nm. In experiment 2, the remaining thickness of the mask MK was 231 nm. In experiment 3, the remaining thickness of the mask MK was 230 nm. In experiment 4, the remaining thickness of the mask MK was 263 nm. In experiment 1, the remaining thickness of the mask MK increased compared to experiment 5. In experiments 2 and 3, the remaining thickness of the mask MK increased compared to experiment 1. In experiment 4, the remaining thickness of the mask MK increased compared to experiments 2 and 3. The greater the remaining thickness of the mask MK, the higher the etching selectivity for the mask MK.

[0126] (Dimensions and depth of the recess) Figure 18 is a graph showing the dimensions and depths of the recesses before and after etching in experiments 1 through 5. Figure 18(a) shows the graph for experiment 5. Figure 18(b) shows the graph for experiment 1. Figure 18(c) shows the graph for experiment 2. Figure 18(d) shows the graph for experiment 3. Figure 18(e) shows the graph for experiment 4. In each graph, the vertical axis represents the depth of the recess RS. The depth range of 0–0.3 μm corresponds to the mask MK. The depth range of 0.3–0.5 μm corresponds to the SiN film. The depth range of 0.5–2.0 μm corresponds to the SiO2 film. The horizontal axis represents the dimensions of the recess RS. In each graph, the chain line RF2 represents the dimensions of the recess RS before etching. The solid lines E11–E15 represent the dimensions of the recess RS after etching in experiments 1 through 5, respectively. As can be seen from the graphs, the size of the recess RS is increased by etching.

[0127] As shown in Figure 18(a), in Experiment 5, after etching, the difference BB between the size of the recess RS at the deeper maximum point P1 and the size of the recess RS at the shallower maximum point P2 is 13 nm. The larger the difference BB, the greater the degree of bending. The difference BB was calculated similarly for Experiments 1 through 4. In Experiments 1 through 4, after etching, the differences BB were 9.3 nm, 9.9 nm, 9.6 nm, and 10.0 nm, respectively. Therefore, it can be seen that in Experiments 1 through 4, after etching, the degree of bending is smaller compared to Experiment 5.

[0128] (Etching rate) Figure 19 is a graph showing the normalized etching rates in experiments 1 through 5. In the graph, the vertical axis represents the normalized etching rate with the etching rate of the mask MK in experiment 5 set to 1. The etching rates in experiments 1 through 4 were calculated by dividing the total etching amount of the deposit DP and the mask MK by the etching time. The graphs show that the etching resistance of the deposit DP in experiment 4 is higher than that in experiment 2. The etching resistance of the deposit DP in experiment 2 is higher than that in experiment 3. The etching resistance of the deposit DP in experiment 3 is higher than that in experiment 1.

[0129] The above descriptions illustrate various exemplary embodiments, but the embodiments are not limited to these exemplary embodiments. Various additions, omissions, substitutions, and modifications are also possible. Furthermore, elements from different embodiments can be combined to form other embodiments.

[0130] Various exemplary embodiments of the present invention are described below in [E1] to [E49].

[0131] [E1] A substrate processing method, comprising: (a) A step of preparing a substrate, wherein the substrate includes a first region and a second region disposed on the first region and having an opening thereon; (b) The step of preferentially forming a top deposit on the top of the second region using a self-generated gas plasma; (c) The step of forming a first film on the surface of the top deposit and the sidewalls dividing the opening, the thickness of which decreases along the depth direction of the opening; and (d) Following (c) above, a second film is formed on the substrate by adsorbing a precursor onto the substrate and modifying the precursor on the substrate; and The first region is a silicon-containing film, and the top deposit contains carbon, boron, or metal; or the first region is an organic film, and the top deposit contains boron or metal.

[0132] [E2] The substrate processing method of [E1] further includes (e) after (d) the step of etching the first region.

[0133] [E3] In the substrate processing method of [E2], the top deposit is formed by a material having a lower etching rate than the material constituting the second region during the etching of the first region in (e).

[0134] [E4] The substrate processing method of any one of [E1] to [E3], wherein in (c) above, the first film system is formed in a manner that improves the verticality of the sidewall surface in the substrate after its formation, which divides the opening to be formed.

[0135] [E5] The substrate processing method of any one of [E1] to [E4], wherein in (b) above, the top deposit is formed by plasma CVD.

[0136] [E6] The substrate processing method of any one of [E1] to [E5], wherein in (c) above, the first film is formed by unsaturated ALD method.

[0137] [E7] The substrate processing method of any one of [E1] to [E6], wherein the first film is a silicon oxide film or a carbon-containing film.

[0138] [E8] The substrate processing method of any one of [E1] to [E7], wherein the second film is a tungsten-containing film, a tin-containing film, an aluminum-containing film, or a hafnium-containing film.

[0139] [E9] The substrate processing method of any one of [E1] to [E8], wherein the second region is a polycrystalline silicon film, an organic film, or a resist film.

[0140] [E10] The substrate processing method of any one of [E1] to [E9], wherein the first region is a silicon film, a silicon oxide film, a silicon nitride film, a laminated film including a silicon oxide film and a silicon nitride film, or an amorphous carbon film.

[0141] [E11] A plasma treatment apparatus comprising: chamber; A substrate support portion is disposed within the aforementioned cavity; The gas supply unit is configured to supply gas into the aforementioned chamber; The plasma generation unit is configured to generate plasma from gas within the aforementioned chamber; and The control unit is configured to control the gas supply unit and the plasma generation unit; and The control unit described above is configured to perform operations by controlling the gas supply unit and the plasma generation unit. (a) A step of preparing a substrate, wherein the substrate includes a first region and a second region disposed on the first region and having an opening thereon; (b) The step of preferentially forming a top deposit on the top of the second region using a first plasma generated from the first gas; (c) The step of forming a first film on the surface of the top deposit and the sidewalls dividing the opening, the thickness of which decreases along the depth direction of the opening; and (d) Following (c) above, a second film is formed on the substrate by adsorbing a precursor onto the substrate and modifying the precursor on the substrate; and The first region mentioned above is a silicon-containing film, and the top deposit mentioned above contains carbon, boron, or metal; or the first region mentioned above is a carbon-containing film, and the top deposit mentioned above contains boron or metal.

[0142] [E12] The plasma processing apparatus, such as [E11], wherein the control unit is configured to perform the following by controlling the gas supply unit and the plasma generation unit: (e) Following (d) above, the step of etching the first region described above.

[0143] [E13] A substrate processing system comprising: Multiple process modules; The transfer module includes a chamber that can be connected to each of the plurality of process modules and is pressure-reducing, and a transfer device disposed in the chamber and configured to transfer a substrate; The control unit is configured to control the plurality of process modules and the conveying module. The control unit described above is configured to perform the following actions by controlling the plurality of process modules and the conveying module: (a) A step of preparing a substrate, wherein the substrate includes a first region and a second region disposed on the first region and having an opening thereon; (b) The step of preferentially forming a top deposit on the top of the second region using a first plasma generated from the first gas; (c) The step of forming a first film on the surface of the top deposit and the sidewalls dividing the opening, the thickness of which decreases along the depth direction of the opening; and (d) Following (c) above, a second film is formed on the substrate by adsorbing a precursor onto the substrate and modifying the precursor on the substrate; and The first region mentioned above is a silicon-containing film, and the top deposit mentioned above contains carbon, boron, or metal; or the first region mentioned above is a carbon-containing film, and the top deposit mentioned above contains boron or metal.

[0144] [E14] The substrate processing system, such as [E13], wherein the control unit is configured to perform the following by controlling at least one of the plurality of process modules and the transport module: (e) Following (d) above, the step of etching the first region described above.

[0145] [E15] An etching method comprising: (a) A step of providing a substrate having an etchable film and a mask on the etchable film; (b) Following (a) above, the step of etching the etched object film to form a recess by using a first plasma generated from the first processing gas; (c) Following (b) above, the step of forming a deposit on the upper surface of the shield using a second plasma generated from the second processing gas; (d) The step of forming a protective film on the sidewall of the recess after (b) above; and (e) Following (c) and (d) above, the step of etching the above-mentioned recess by means of a third plasma generated from the third processing gas.

[0146] According to the etching method described above [E15], the mask is protected by a deposit formed on the upper surface of the mask during etching of the recess. Therefore, a higher etch selectivity for the mask can be obtained during etching of the recess.

[0147] [E16] The etching method, such as [E15], further includes (f) after (b) above, the step of removing the deposits attached to the mask in (b) above by means of a fourth plasma generated from the fourth processing gas.

[0148] In this case, deposits can be formed on the surface above the shield after the adhering material has been removed.

[0149] [E17] Etching methods such as [E15] or [E16], wherein the deposits contain at least one of silicon, carbon, boron and metal.

[0150] [E18] Etching methods according to any of [E15] to [E17], wherein the etched film comprises a silicon-containing film. The aforementioned shielding includes at least one of a second silicon-containing material, an organic material, and a metal, which is different from the first silicon-containing material constituting the aforementioned silicon-containing film.

[0151] [E19] Etching methods as described in any of [E15] to [E17], wherein the etched film comprises an organic film. The aforementioned shield includes at least one of a silicon-containing substance, a second organic substance different from the first organic substance constituting the aforementioned organic film, and a metal.

[0152] [E19] The etching method of any one of [E15] to [E18] further includes (g) repeating the steps (c) to (e) above after (e) above.

[0153] In this case, the amount of etching in the recess can be increased.

[0154] [E20] The etching method of any one of [E15] to [E19], wherein the deposit comprises a first deposit formed on the upper surface of the shield and a second deposit formed on the first deposit, the second deposit comprising a material different from the first deposit.

[0155] In this case, the materials of the etched film and the mask can be considered, and an appropriate combination of the materials of the first deposit and the second deposit can be selected.

[0156] [E21] Etching methods according to any of [E15] to [E20], wherein the etched film comprises a silicon-containing film. The first processed gas mentioned above includes halogen-containing gases.

[0157] [E22] The etching method of any one of [E15] to [E20], wherein the etched film comprises an organic film, The first processed gas mentioned above contains oxygen-containing gas.

[0158] [E23] The etching method of any one of [E15] to [E22], wherein the second processing gas comprises at least one of silicon-containing gas, carbon-containing gas, boron-containing gas and metal-containing gas.

[0159] [E24] The etching method of any one of [E15] to [E23], wherein the protective film is formed on the surface above the deposit.

[0160] In this case, the deposits and mask are protected by a protective film. Therefore, a higher etch selectivity for the mask can be obtained when etching the recess.

[0161] [E25] The etching method of [E24] is such that the protective film has a first thickness on the surface above the deposit, a second thickness on the sidewall of the recess, and the second thickness is less than the first thickness.

[0162] In this situation, the protective film can both protect and shield the deposits while preventing blockage of the recesses.

[0163] [E26] Etching methods such as [E15] to [E25], wherein the aforementioned protective film is formed by ALD or CVD.

[0164] [E27] The etching method of any one of [E15] to [E26], wherein the protective film comprises at least one of a silicon-containing film, an organic film, and a metal-containing film.

[0165] [E28] Etching methods such as [E15] to [E27], wherein the protective film comprises the same material as the deposit.

[0166] [E29] Etching methods such as [E15] to [E27], wherein the protective film comprises a material different from the deposit.

[0167] [E30] Etching methods such as [E15] to [E29], wherein the aforementioned protective film is formed using a fifth processing gas. The fifth processing gas mentioned above includes at least one of silicon-containing gas, carbon-containing gas, and metal-containing gas.

[0168] [E31] Etching methods according to any of [E15] to [E30], wherein the etched film comprises a silicon-containing film. The third processing gas mentioned above includes halogen-containing gases.

[0169] [E32] Etching methods as described in any of [E15] to [E30], wherein the etched film comprises an organic film. The third processing gas mentioned above contains oxygen-containing gas.

[0170] [E33] A plasma treatment apparatus comprising: chamber; A substrate support for supporting a substrate within the cavity, wherein the substrate has an etch target film and a mask on the etch target film; The gas supply unit is configured to supply the first processing gas, the second processing gas, and the third processing gas into the aforementioned chamber; The plasma generation unit is configured to generate a first plasma, a second plasma, and a third plasma from the first processing gas, the second processing gas, and the third processing gas, respectively, within the aforementioned chamber; and Control Department; and The control unit described above is configured to control the gas supply unit and the plasma generation unit, such that... The first plasma is used to etch the etched film to form a recess. After the aforementioned recess is formed, a deposit is formed on the upper surface of the aforementioned shield using the aforementioned second plasma. After the above-mentioned recess is formed, a protective film is formed on the sidewall of the recess. After the above-mentioned deposits and the above-mentioned protective film are formed, the above-mentioned recesses are etched by the above-mentioned third plasma.

[0171] According to the plasma processing apparatus [E33] described above, the mask is protected by the deposit formed on the upper surface of the mask during etching of the recess. Therefore, a higher etch selectivity for the mask can be obtained during etching of the recess.

[0172] [E34] The plasma processing apparatus, such as [E33], further includes an optical observation device for measuring the dimensions of the aforementioned recess.

[0173] [E35] A substrate processing method, comprising: (a) A step of preparing a substrate, wherein the substrate includes a first region and a second region disposed on the first region and having an opening thereon; (b) The step of preferentially forming a top deposit on the top of the second region using a self-generated gas plasma; and (c) The step of forming a first membrane on the surface of the top deposit and the sidewalls dividing the opening, the thickness of which decreases along the depth direction of the opening.

[0174] [E36] The substrate processing method of [E35] further includes (d) after (c) above, a step of forming a second film on the substrate by adsorbing a precursor onto the substrate and modifying the precursor on the substrate; and The first region is a silicon-containing film, and the top deposit contains carbon, boron, or metal; or the first region is an organic film, and the top deposit contains boron or metal.

[0175] [E37] The substrate processing method of [E36] further includes (e) after (d) the step of etching the first region.

[0176] [E38] In the substrate processing method of [E37], the top deposit is formed by a material having a lower etching rate than the material constituting the second region during the etching of the first region in (e).

[0177] [E39] The substrate processing method of any one of [E36] to [E38], wherein the second film is a tungsten-containing film, a tin-containing film, an aluminum-containing film, or a hafnium-containing film.

[0178] [E40] The substrate processing method of any one of [E35] to [E39], wherein in (c) above, the first film system is formed in a manner that improves the verticality of the sidewall surface in the substrate after its formation, which divides the opening.

[0179] [E41] The substrate processing method of any one of [E35] to [E40], wherein in (a) above, the first region is a base film, the second region includes an etch target film on the base film and a mask on the etch target film, and the opening includes a first opening of the mask and a second opening of the etch target film; The above (a) includes the following steps: forming the second opening by etching the etchable film through the first opening.

[0180] [E42] The substrate processing method of [E41] further includes (d) after (c) above, a step of etching the sidewall surface that forms the second opening.

[0181] [E43] The substrate processing method of any one of [E35] to [E42], wherein in (b) above, the top deposit is formed by plasma CVD.

[0182] [E44] The substrate processing method of any one of [E35] to [E43], wherein in (c) above, the first film is formed by unsaturated ALD or CVD.

[0183] [E45] The substrate processing method of any one of [E35] to [E44], wherein the first film is a silicon oxide film, a carbon-containing film, or a metal-containing film.

[0184] [E46] The substrate processing method of any one of [E35] to [E45], wherein the second region is a polycrystalline silicon film, an organic film, or a resist film.

[0185] [E47] The substrate processing method of any one of [E35] to [E46], wherein the first region is a silicon film, a silicon oxide film, a silicon nitride film, a laminated film comprising a silicon oxide film and a silicon nitride film, or an amorphous carbon film.

[0186] [E48] The substrate processing method of any one of [E35] to [E47], wherein the top deposit comprises at least one of silicon, carbon, boron and metal.

[0187] [E49] A plasma treatment apparatus comprising: chamber; A substrate support portion is disposed within the aforementioned cavity; The gas supply unit is configured to supply gas into the aforementioned chamber; The plasma generation unit is configured to generate plasma from gas within the aforementioned chamber; and The control unit is configured to control the gas supply unit and the plasma generation unit; and The control unit described above is configured to perform operations by controlling the gas supply unit and the plasma generation unit. (a) A step of preparing a substrate, wherein the substrate includes a first region and a second region disposed on the first region and having an opening thereon; (b) The step of preferentially forming a top deposit on the top of the second region using a first plasma generated from the first gas; (c) The step of forming a first membrane on the surface of the top deposit and the sidewalls dividing the opening, the thickness of which decreases along the depth direction of the opening.

[0188] Based on the above description, it should be understood that the various embodiments of the present invention are described in this specification for illustrative purposes only, and various modifications can be made without departing from the scope and spirit of the present invention. Therefore, the various embodiments disclosed in this specification are not intended to be limiting, and the true scope and spirit are indicated by the appended claims.

[0189] 1: Plasma treatment device 2: Control Department 2a: Computer 2a1: Processing Department 2a2: Memory Department 2a3: Communication Interface 10: Chamber 10a: Sidewall 10e: Gas exhaust outlet 10s: Plasma processing space 11:Substrate support department 12: Plasma Generation Section 13: Cluster Head 13a: Gas supply port 13b: Gas diffusion chamber 13c: Gas inlet 20: Gas Supply Department 21: Gas Source 22: Flow controller 30: Power supply 31: RF power supply 31a: First RF Generation Unit 31b: Second RF Generation Unit 32: DC power supply 32a: First DC Generation Unit 32b: Second DC Generation Unit 40: Exhaust System 111: Ontology Department 111a: Central Region 111b: Annular region 112: Ring Assembly 1110:Abutment 1110a flow path 1111: Electrostatic Chuck 1111a: Ceramic components 1111b: Electrostatic electrode AN: Aligner BF: Example of a cross-section of a substrate DP: Sediments DP1: First sediment DP2: Second sediment DPt: Upper surface EX1~EX5: Examples of cross-sections of the substrate F1: First membrane F2: Second membrane FP1~FP4: Container LL1, LL2: Loading interlock modules LM: Loader Module LP1~LP4: Taiwan MC: Control Department MK: Mask MKt: Upper surface MT: Method MT1: Etching Method OC: Optical observation device OP: Open OP1: Opening PL1: Plasma 1 PL2: Plasma 2 PL3: Plasma 3 PM1~PM6: Process Module PR: Protective film PS: Substrate processing system R1: Region 1 R2: Region 2 RE: Etching the film of the target object RS: concave part RSa: Sidewall ST1~ST7: Steps STa: Steps STb: Steps STbt: Steps STc: Steps STd: Steps STe: Steps SW: Sidewall TC: transport chamber TD: Top Sediment TM: Transport Module TP: Top TU1: Transport device TU2: Transport device UR: Basement region UR1: Basement membrane W: substrate

Claims

1. A substrate processing method, comprising: (a) a step of preparing a substrate, wherein the substrate includes a first region and a second region disposed on the first region and having an opening thereon; (b) a step of preferentially forming a top deposit on the top of the second region using a gas-generated plasma; (c) a step of forming a first film on the surface of the top deposit and the sidewalls dividing the opening thereon, the thickness of which decreases along the depth direction of the opening; and (d) a step of forming a second film on the substrate after (c) by adsorbing a precursor onto the substrate and modifying the precursor on the substrate; wherein the first region is a silicon-containing film and the top deposit contains carbon, boron, or a metal, or the first region is an organic film and the top deposit contains boron or a metal.

2. The substrate processing method of claim 1 further includes (e) after (d) above, the step of etching the first region.

3. The substrate processing method of claim 2, wherein the top deposit is formed by a material having a lower etching rate than the material constituting the second region during the etching of the first region in (e).

4. The substrate processing method according to any one of claims 1 to 3, wherein the second film is a tungsten-containing film, a tin-containing film, an aluminum-containing film, or a hafnium-containing film.

5. The substrate processing method according to any one of claims 1 to 3, wherein in (c) above, the first film system is formed in a manner that improves the verticality of the sidewall surface dividing the opening in the substrate after its formation.

6. The substrate processing method of any one of claims 1 to 3, wherein in (b) above, the top deposit is formed by plasma CVD.

7. The substrate processing method of any one of claims 1 to 3, wherein in (c) above, the first film is formed by unsaturated ALD or CVD.

8. The substrate processing method according to any one of claims 1 to 3, wherein the first film is a silicon oxide film, a carbon-containing film, or a metal-containing film.

9. The substrate processing method of any one of claims 1 to 3, wherein the second region is a polycrystalline silicon film, an organic film, or a resist film.

10. The substrate processing method according to any one of claims 1 to 3, wherein the first region is a silicon film, a silicon oxide film, a silicon nitride film, a laminated film comprising a silicon oxide film and a silicon nitride film, or an amorphous carbon film.

11. The substrate processing method of any one of claims 1 to 3, wherein the top deposit comprises at least one of silicon, carbon, boron and metal.

12. A substrate processing method, comprising: (a) a step of preparing a substrate, wherein the substrate includes a first region and a second region disposed on the first region and having an opening thereon; (b) a step of preferentially forming a top deposit on the top of the second region using a gas-generated plasma; and (c) a step of forming a first film on the surface of the top deposit and the sidewalls dividing the opening thereon, the thickness of which decreases along the depth direction of the opening; In (a) above, the first region is a base film, the second region includes an etch target film on the base film and a mask on the etch target film, and the opening includes a first opening of the mask and a second opening of the etch target film; (a) above includes the step of forming the second opening by etching the etch target film through the first opening.

13. The substrate processing method of claim 12 further includes (d) after (c) above, a step of etching the sidewall surface that forms the second opening.

14. A plasma processing apparatus comprising: a chamber; a substrate support disposed within the chamber; a gas supply unit configured to supply gas into the chamber; a plasma generation unit configured to generate plasma from gas within the chamber; and a control unit configured to control the gas supply unit and the plasma generation unit; wherein the control unit is configured to perform, by controlling the gas supply unit and the plasma generation unit: (a) a step of preparing a substrate, wherein the substrate includes a first region and a second region disposed on the first region and having an opening thereon; and (b) a step of preferentially forming a top deposit on the top of the second region using a first plasma generated from a first gas. (c) the step of forming a first film on the surface of the top deposit and the sidewalls dividing the opening, the thickness of which decreases along the depth direction of the opening; and (d) the step of forming a second film on the substrate after (c) by adsorbing a precursor onto the substrate and modifying the precursor on the substrate; wherein the first region is a silicon-containing film and the top deposit contains carbon, boron, or metal, or the first region is an organic film and the top deposit contains boron or metal.

15. A plasma processing apparatus comprising: a chamber; a substrate support disposed within the chamber; a gas supply unit configured to supply gas into the chamber; a plasma generation unit configured to generate plasma from gas within the chamber; and a control unit configured to control the gas supply unit and the plasma generation unit; wherein the control unit is configured to perform, by controlling the gas supply unit and the plasma generation unit: (a) a step of preparing a substrate, wherein the substrate includes a first region and a second region disposed on the first region and having an opening thereon; (b) a step of preferentially forming a top deposit on the top of the second region using a first plasma generated from a first gas; and (c) a step of forming a first film on the surface of the top deposit and on the sidewalls dividing the opening thereon, the thickness of which decreases along the depth direction of the opening; In (a) above, the first region is a base film, the second region includes an etch target film on the base film and a mask on the etch target film, and the opening includes a first opening of the mask and a second opening of the etch target film; (a) includes the step of forming the second opening by etching the etch target film through the first opening.

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