Plasma processing apparatus

Abstract

To provide an etching method and a plasma processing apparatus that are capable of forming tungsten-containing deposits with excellent etch resistance.SOLUTION: An etching method includes a step (a) of preparing a substrate including a first region containing silicon and nitrogen and a second region containing silicon and oxygen, a step (b) of forming a tungsten-containing deposit on the first region using first plasma generated from first process gas including at least one of carbon and hydrogen, fluorine, and tungsten, and a step (c) of etching the second region using second plasma generated from second process gas different from the first process gas after the step (b).SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] Exemplary embodiments of the present disclosure relate to an etching method and a plasma processing apparatus. [Background technology]

[0002] Patent Document 1 discloses a method for etching an insulating film using plasma. In this method, etching is performed while forming a conductive layer on the surface of the insulating film during etching. In the etching, plasma generated from a mixed gas of WF6 and C4F8 is used. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-50984 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides an etching method and plasma processing apparatus capable of forming tungsten-containing deposits having excellent etch resistance. [Means for solving the problem]

[0005] In one exemplary embodiment, an etching method includes: (a) providing a substrate, the substrate including a first region including silicon and nitrogen and a second region including silicon and oxygen; (b) forming a tungsten-containing deposit on the first region using a first plasma generated from a first process gas including at least one of carbon and hydrogen, fluorine, and tungsten; and (c) after (b), etching the second region using a second plasma generated from a second process gas different from the first process gas. Effect of the Invention

[0006] According to one exemplary embodiment, an etching method and plasma processing apparatus are provided that are capable of forming tungsten-containing deposits with excellent etch resistance. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram of a plasma processing apparatus according to an exemplary embodiment. [Diagram 2] FIG. 2 is a schematic diagram of a plasma processing apparatus according to an exemplary embodiment. [Diagram 3] FIG. 3 is a flow chart of an etching method according to one exemplary embodiment. [Figure 4] FIG. 4 is an enlarged cross-sectional view of a portion of an example substrate to which the method of FIG. 3 can be applied. [Diagram 5] FIG. 5 is a cross-sectional view illustrating a step of an etching method according to an example embodiment. [Figure 6] FIG. 6 is a cross-sectional view illustrating a step of an etching method according to an example embodiment. [Figure 7] FIG. 7 is a cross-sectional view illustrating a step of an etching method according to one exemplary embodiment. [Figure 8] FIG. 8 is an example of a timing chart showing the change over time of the RF power applied to the electrode in the main body and the RF power applied to the counter electrode. [Figure 9] FIG. 9 is a flow chart of an etching method according to one exemplary embodiment. [Figure 10] FIG. 10 is a cross-sectional view illustrating a step of an etching method according to one exemplary embodiment. [Figure 11] FIG. 11 is a cross-sectional view illustrating a step of an etching method according to one exemplary embodiment. [Figure 12] FIG. 12 is a cross-sectional view illustrating a step of an etching method according to one exemplary embodiment. [Figure 13] FIG. 13 is a flow chart of an etching method according to one exemplary embodiment. [Figure 14] FIG. 14 is an enlarged cross-sectional view of a portion of an example substrate to which the method of FIG. 13 can be applied. [Figure 15] FIG. 15 is a cross-sectional view illustrating a step of an etching method according to one exemplary embodiment. [Figure 16] FIG. 16 is a cross-sectional view illustrating a step of an etching method according to one exemplary embodiment. [Figure 17] FIG. 17 is a cross-sectional view illustrating a step of an etching method according to one exemplary embodiment. [Figure 18] FIG. 18 shows TEM images of cross sections of the substrate obtained by carrying out the etching methods in the first and second experiments. [Figure 19] FIG. 19 shows TEM images of cross sections of the substrate obtained by carrying out the etching methods in the third and fourth experiments. [Figure 20] FIG. 20 is a diagram showing a TEM image of a cross section of a substrate obtained by carrying out the etching method in the fifth experiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Various exemplary embodiments are described below.

[0009] In one exemplary embodiment, an etching method includes: (a) providing a substrate, the substrate including a first region including silicon and nitrogen and a second region including silicon and oxygen; (b) forming a tungsten-containing deposit on the first region using a first plasma generated from a first process gas including at least one of carbon and hydrogen, fluorine, and tungsten; and (c) after (b), etching the second region using a second plasma generated from a second process gas different from the first process gas.

[0010] According to the above etching method, a tungsten-containing deposit having excellent etching resistance can be formed when etching the second region.

[0011] The first process gas may include at least one of a carbon-containing gas and a hydrogen-containing gas, and a tungsten-containing gas.

[0012] The tungsten-containing gas may include tungsten hexafluoride gas.

[0013] The carbon-containing gas may include at least one of CH4 gas, C2H2 gas, C2H4 gas, CH3F gas, CH2F2 gas, CHF3 gas, and CO gas.

[0014] The hydrogen-containing gas may include at least one of H2 gas, SiH4 gas, and NH3 gas.

[0015] In (a), the second region is provided to cover the first region, and the etching method may further include (d) after (a) and before (b), etching the second region so as to expose the first region.

[0016] In the step (b), the temperature of the substrate support that supports the substrate may exceed 100° C. In this case, the etching resistance of the tungsten-containing deposit is further improved.

[0017] In the step (b) or after the step (b), a counter electrode containing silicon facing a substrate support supporting the substrate may be sputtered, which further improves the etching resistance of the tungsten-containing deposit.

[0018] The first region may have a recess, and the second region may be embedded in the recess. In this case, the recess can be formed by etching the second region.

[0019] The step (c) may be performed in a self-aligned contact process.

[0020] The cycle including (b) and (c) may be repeated two or more times.

[0021] In one exemplary embodiment, an etching method includes: (a) providing a substrate including a silicon nitride having an exposed top surface and a silicon oxide having an exposed top surface; (b) forming a tungsten-containing deposit on the silicon nitride using a first plasma generated from a first process gas including at least one of a carbon-containing gas and a hydrogen-containing gas and a tungsten hexafluoride gas; and (c) after (b), etching the silicon oxide using a second plasma generated from a second process gas different from the first process gas.

[0022] In one exemplary embodiment, a plasma processing apparatus includes a chamber, a substrate support for supporting a substrate in the chamber, the substrate including a first region including silicon and nitrogen and a second region including silicon and oxygen, a gas supply configured to supply a first process gas and a second process gas different from the first process gas into the chamber, the first process gas including at least one of carbon and hydrogen, fluorine, and tungsten, a plasma generator configured to generate a first plasma from the first process gas in the chamber and to generate a second plasma from the second process gas in the chamber, and a controller, wherein the controller is configured to control the gas supply and the plasma generator to form a tungsten-containing deposit on the first region using the first plasma, and the controller is configured to control the gas supply and the plasma generator to etch the second region using the second plasma.

[0023] In one exemplary embodiment, an etching method includes: (a) providing a substrate, the substrate including a first region including silicon and nitrogen and a second region including silicon and oxygen; (b) forming a carbon-containing deposit on the first region; (c) forming a tungsten-containing deposit on the carbon-containing deposit using a plasma generated from a process gas including fluorine and tungsten; and (d) after (c), etching the second region.

[0024] According to the above etching method, the total thickness of the carbon-containing deposit and the tungsten-containing deposit can be increased, thereby forming a deposit having excellent etching resistance.

[0025] The process gas may contain a tungsten-containing gas, and the flow rate ratio of the tungsten-containing gas may be the largest among all gases contained in the process gas except for an inert gas.

[0026] In the step (c), the power for generating the plasma may be applied to a counter electrode facing a substrate support that supports the substrate. In this case, the collision of ions in the plasma with the substrate can be suppressed compared to when the power for generating the plasma is applied to the substrate support. Thus, the reduction in the total thickness of the carbon-containing deposit and the tungsten-containing deposit can be suppressed.

[0027] Various exemplary embodiments will now be described in detail with reference to the drawings, in which the same or corresponding parts are designated by the same reference numerals.

[0028] 1 and 2 are diagrams that illustrate a plasma processing apparatus according to an exemplary embodiment.

[0029] In one embodiment, the plasma processing system includes a plasma processing device 1 and a control unit 2. The plasma processing device 1 includes a plasma processing chamber 10, a substrate support unit 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space, and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20, which will be described later, and the gas exhaust port is connected to an exhaust system 40, which will be described later. The substrate support unit 11 is disposed in the plasma processing space, and has a substrate support surface for supporting a substrate.

[0030] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be a capacitively coupled plasma (CCP), an inductively coupled plasma (ICP), an electron-cyclotron-resonance plasma (ECR plasma), a helicon wave plasma (HWP), or a surface wave plasma (SWP), etc. Also, various types of plasma generating units may be used, including an alternating current (AC) plasma generating unit and a direct current (DC) plasma generating unit. In one embodiment, the AC signal (AC power) used in the AC plasma generating unit has a frequency in the range of 100 kHz to 10 GHz. Thus, the AC signal includes a radio frequency (RF) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 200 kHz to 150 MHz.

[0031] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various steps described in the present disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform various steps described herein. In one embodiment, a part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include, for example, a computer 2a. The computer 2a may include, for example, a processing unit (CPU: Central Processing Unit) 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 may be configured to perform various control operations based on a program stored in the storage unit 2a2. The storage unit 2a2 may include a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0032] An example of the configuration of a plasma processing system will be described below. The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a controller 2. The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed in the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms at least a part of a ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 has at least one gas inlet for supplying at least one processing gas to the plasma processing space 10s and at least one gas outlet for exhausting gas from the plasma processing space. The sidewall 10a is grounded. The showerhead 13 and the substrate support 11 are electrically isolated from the plasma processing chamber 10 housing.

[0033] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region (substrate support surface) 111a for supporting a substrate (wafer) W, and an annular region (ring support surface) 111b for supporting the ring assembly 112. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. In one embodiment, the main body 111 includes a base and an electrostatic chuck. The main body 111 includes a conductive member. The conductive member of the main body 111 functions as an electrode. The electrostatic chuck is disposed on the base. The upper surface of the electrostatic chuck has a substrate support surface 111a. The ring assembly 112 includes one or more annular members. At least one of the one or more annular members is an edge ring. Although not shown, the substrate support 11 may include a temperature adjustment module configured to adjust at least one of the electrostatic chuck, the ring assembly 112, and the substrate to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow path, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path. The substrate support 11 may also include a heat transfer gas supply unit configured to supply a heat transfer gas between the back surface of the substrate W and the substrate support surface 111a.

[0034] The shower head 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The shower head 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The shower head 13 also includes a conductive member. The conductive member of the shower head 13 faces the substrate support 11 and functions as an electrode (hereinafter, may be referred to as a counter electrode). The conductive member of the shower head 13 may include a silicon-containing material such as silicon. In addition to the shower head 13, the gas introduction unit may include one or more side gas injectors (SGI) attached to one or more openings formed in the side wall 10a.

[0035] The gas supply 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply 20 is configured to supply at least one process gas from a respective gas source 21 through a respective flow controller 22 to the showerhead 13. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply 20 may include one or more flow modulation devices to modulate or pulse a flow rate of the at least one process gas.

[0036] The power source 30 includes an RF power source 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power source 31 is configured to supply at least one RF signal (RF power), such as a source RF signal and a bias RF signal, to a conductive member of the substrate support 11 and / or a conductive member of the showerhead 13. This causes a plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. Thus, the RF power source 31 can function as at least a part of a plasma generating unit configured to generate a plasma from one or more processing gases in the plasma processing chamber 10. In addition, by supplying a bias RF signal to the conductive member of the substrate support 11, a bias potential is generated on the substrate W, and ion components in the formed plasma can be attracted to the substrate W.

[0037] 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 coupled to the conductive member of the substrate support 11 and / or the conductive member of the shower head 13 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 13 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate a plurality of source RF signals having different frequencies. The generated one or more source RF signals are supplied to the conductive member of the substrate support 11 and / or the conductive member of the shower head 13. The second RF generating unit 31b is coupled to the conductive member of the substrate support 11 via at least one impedance matching circuit, and is configured to generate a bias RF signal (bias RF power). In one embodiment, the bias RF signal has a lower frequency than the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 400 kHz to 13.56 MHz. In one embodiment, the second RF generator 31b may be configured to generate multiple bias RF signals having different frequencies. The generated bias RF signal or signals are provided to the conductive members of the substrate support 11. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0038] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to a conductive member of the substrate support 11 and configured to generate a first DC signal. The generated first bias DC signal is applied to the conductive member of the substrate support 11. In one embodiment, the first DC signal may be applied to another electrode, such as an electrode in an electrostatic chuck. In one embodiment, the second DC generator 32b is connected to a conductive member of the showerhead 13 and configured to generate a second DC signal. The generated second DC signal is applied to the conductive member of the showerhead 13. In various embodiments, at least one of the first and second DC signals may be pulsed. The first and second DC generating units 32a, 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided in place of the second RF generating unit 31b.

[0039] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided 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 in the plasma processing space 10s is adjusted by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0040] 3 is a flowchart of an etching method according to an example embodiment. The etching method MT shown in FIG. 3 (hereinafter, referred to as "method MT") can be performed by the plasma processing apparatus 1 of the above embodiment. The method MT can be applied to a substrate W.

[0041] 4 is a partially enlarged cross-sectional view of an example substrate to which the method of FIG. 3 can be applied. As shown in FIG. 4, in one embodiment, the substrate W includes a first region R1 and a second region R2. The first region R1 may have at least one recess R1a. The first region R1 may have a plurality of recesses R1a. Each recess R1a may be a recess for forming a contact hole. The second region R2 may be embedded in the recess R1a. The second region R2 may be provided to cover the first region R1.

[0042] The first region R1 includes silicon and nitrogen. The first region R1 is made of silicon nitride (SiN x The first region R1 may include a silicon nitride (SiN x The first portion may include a first portion including silicon carbide (SiC), and a second portion including silicon carbide (SiC). In this case, the first portion has a recess R1a.

[0043] The second region R2 includes silicon and oxygen. The second region R2 includes silicon oxide (SiO x ). The second region R2 may be a region formed by, for example, CVD or the like, or may be a region obtained by oxidizing silicon. The second region R2 may have a recess R2a. The recess R2a has a width larger than the width of the recess R1a.

[0044] The substrate W may include an underlying region UR and at least one raised region RA provided on the underlying region UR. The underlying region UR and the at least one raised region RA are covered by a first region R1. The underlying region UR may include silicon. A plurality of raised regions RA are located on the underlying region UR. Recesses R1a of the first region R1 are located between the plurality of raised regions RA. Each raised region RA may form a gate region of a transistor.

[0045] The substrate W may include a mask MK. The mask MK is provided on the second region R2. The mask MK may include metal or silicon. The mask MK may have an opening OP. The opening OP corresponds to the recess R2a of the second region R2.

[0046] Method MT will be described below with reference to Figs. 3 to 7, taking as an example a case where method MT is applied to a substrate W using the plasma processing apparatus 1 of the above embodiment. Figs. 5 to 7 are cross-sectional views showing a step of an etching method according to one exemplary embodiment. When the plasma processing apparatus 1 is used, method MT can be performed in the plasma processing apparatus 1 by controlling each part of the plasma processing apparatus 1 by a control unit 2. In method MT, as shown in Fig. 2, a substrate W on a substrate support 11 (substrate support) arranged in a plasma processing chamber 10 is processed.

[0047] 3, the method MT may include steps ST1, ST2, ST3, ST4, ST5, and ST6. Steps ST1 to ST6 may be performed in order. The method MT may not include at least one of steps ST2, ST5, and ST6. Step ST2 may be included in step ST1.

[0048] In step ST1, a substrate W shown in FIG. 4 is prepared. The substrate W may be supported by a substrate support 11 in a plasma processing chamber 10. The substrate W may have the shape shown in FIG. 4 as a result of plasma etching, or may have the shape shown in FIG. 4 from the beginning when it is provided to the plasma processing chamber 10. In step ST1, the second region R2 may be provided so as to cover the first region R1. In step ST1, the upper surface of the first region R1 and the upper surface of the second region R2 may be exposed. That is, in step ST1, the upper surface of the silicon nitride and the upper surface of the silicon oxide may be exposed.

[0049] In step ST2, as shown in FIG. 5, the second region R2 is etched so that the first region R1 is exposed. In step ST2, the first region R1 may also be etched. In particular, a shoulder portion SH in the recess R1a of the first region R1 may be etched. The etching is performed, for example, using a plasma PL generated from a processing gas. In one example, the processing gas includes a fluorine-containing gas and may include tungsten. In another example, the processing gas may include tungsten just before the first region R1 is exposed. A mask MK is used in the etching. The etching may be performed as follows. First, the gas supply unit 20 supplies a processing gas into the plasma processing chamber 10. Next, the plasma generation unit 12 generates a plasma PL from the processing gas in the plasma processing chamber 10. The control unit 2 controls the gas supply unit 20 and the plasma generation unit 12 so that the second region R2 is etched so that the first region R1 is exposed. In step ST2, bias power may or may not be applied to the electrode in the main body 111 of the substrate support 11. In particular, bias power may not be applied immediately before or after the first region R1 is exposed, which makes it easier for deposits to form and suppresses etching of the shoulder portion SH of the recess R1a.

[0050] The fluorine-containing gas may include carbon. The fluorine-containing gas may include at least one of a fluorocarbon gas and a hydrofluorocarbon gas. Fluorocarbon (C x F y ) gas may include at least one of CF4 gas, C3F6 gas, C3F8 gas, C4F8 gas, and C4F6 gas. x H y F z ) The gas may include at least one of CH2F2 gas, CHF3 gas, and CH3F gas.

[0051] In step ST2, the second region R2 including silicon oxide is etched by active species including fluorine in the plasma PL.

[0052] In step ST3, as shown in FIG. 6, a tungsten-containing deposit DP is formed on the first region R1 using a first plasma PL1 generated from a first processing gas. The tungsten-containing deposit DP may be a tungsten-containing film. When the first region R1 and the second region R2 are exposed to the first plasma PL1, the tungsten-containing deposit DP may be preferentially formed on the first region R1 compared to the second region R2. Here, "the tungsten-containing deposit DP may be preferentially formed on the first region R1 compared to the second region R2" means, for example, that the thickness of the tungsten-containing deposit DP on the first region R1 is larger than the thickness of the tungsten-containing deposit DP on the second region R2, and more specifically, that the thickness of the tungsten-containing deposit DP on the second region R2 is 50% or less of the thickness of the tungsten-containing deposit DP on the first region R1. The deposition may be performed as follows. First, the first processing gas is supplied into the plasma processing chamber 10 by the gas supply unit 20. Next, a first plasma PL1 is generated from the first processing gas by the plasma generating unit 12 in the plasma processing chamber 10. The control unit 2 controls the gas supply unit 20 and the plasma generating unit 12 so that a tungsten-containing deposit DP is formed on the first region R1.

[0053] The first process gas includes at least one of carbon and hydrogen, fluorine, and tungsten. The first process gas may include at least one of a carbon-containing gas and a hydrogen-containing gas, and a tungsten-containing gas. Fluorine may be included in the carbon-containing gas, the hydrogen-containing gas, or the tungsten-containing gas.

[0054] The carbon-containing gas may include at least one of CH4 gas, C2H2 gas, C2H4 gas, CH3F gas, CH2F2 gas, CHF3 gas, and CO gas.

[0055] The hydrogen-containing gas may include at least one of H2 gas, SiH4 gas, and NH3 gas.

[0056] The tungsten-containing gas may include a tungsten halide gas. The tungsten halide gas may include at least one of tungsten hexafluoride (WF6) gas, tungsten hexabromide (WBr6) gas, tungsten hexachloride (WCl6) gas, and WF5Cl gas. The tungsten-containing gas may include tungsten hexacarbonyl (W(CO)6) gas.

[0057] The first process gas may include, for example, a noble gas such as argon gas, helium gas, xenon gas, or neon gas. The first process gas may include, for example, nitrogen (N2) gas.

[0058] The flow rate ratio of the tungsten-containing gas may be smaller than the flow rate ratio of at least one of the carbon-containing gas and the hydrogen-containing gas. The flow rate ratio of the noble gas may be larger than the flow rate ratio of at least one of the carbon-containing gas and the hydrogen-containing gas. In the present disclosure, the flow rate ratio of each gas is the ratio (volume %) of the flow rate of each gas to the total flow rate of the process gas.

[0059] The duration of step ST3 may be 1 second or more, or may be 10 seconds or more. The duration of step ST3 may be 1000 seconds or less, or may be 100 seconds or less.

[0060] In step ST3, the temperature of the substrate support 11 may be 50° C. or more, 100° C. or more, more than 100° C., 120° C. or more, 130° C. or more, more than 130° C., 140° C. or more, or 150° C. or more. The temperature of the substrate support 11 may be 250° C. or less, 220° C. or less, or 200° C. or less.

[0061] In step ST3, the pressure in the plasma processing chamber 10 may be 10 mTorr (1.3 Pa) or more. The pressure in the plasma processing chamber 10 may be 100 mTorr (13 Pa) or less, or 50 mTorr (6.7 Pa) or less.

[0062] In step ST3, RF power may be applied to the counter electrode facing the substrate support 11. The RF power may be 100 W or more and 1000 W or less, 200 W or more and 800 W or less, or 300 W or more and 500 W or less. The frequency of the RF power may be 27 MHz or more and 100 MHz or less.

[0063] In step ST3, bias power may or may not be applied to the electrodes in the main body 111 of the substrate support 11. The bias power applied to the electrodes in the main body 111 in step ST3 may be less than 100 W, which is smaller than the bias power applied to the electrodes in the main body 111 in step ST4.

[0064] At or after step ST3, a counter electrode facing the substrate support 11 may be sputtered. The counter electrode includes silicon. A negative DC voltage may be applied to the counter electrode by the second DC generating unit 32b. The absolute value of the DC voltage applied to the counter electrode may be 100 V or more, or 1000 V or less. For example, silicon is released into the first plasma PL1 by collision of noble gas ions in the first plasma PL1 with the counter electrode. The counter electrode may include an inner first electrode and an outer second electrode. The absolute value of the DC voltage applied to the first electrode may be greater than the absolute value of the DC voltage applied to the second electrode. When sputtering is performed after step ST3, sputtering may be performed using plasma generated from a process gas including a noble gas.

[0065] The tungsten-containing deposit DP may contain carbon. The tungsten-containing deposit DP may be tungsten carbide (WC x After step ST3, the maximum thickness of the tungsten-containing deposit DP may be 5 nm or more.

[0066] Without being bound by theory, the tungsten-containing deposit DP may be formed as follows: When the first process gas contains carbon, activated species containing tungsten in the first plasma PL1 react with activated species containing carbon in the first plasma PL1 to form tungsten carbide (WC) on the upper surface of the first region R1. x ) is deposited on the upper surface of the first region R1. Alternatively, when the first process gas contains hydrogen, the active species containing fluorine in the first plasma PL1 are scavenged by the active species containing hydrogen in the first plasma PL1. As a result, the tungsten-containing deposit DP derived from the active species containing tungsten remaining in the first plasma PL1 is deposited on the upper surface of the first region R1. When the first process gas contains both carbon and hydrogen, the reaction between tungsten and carbon and the scavenging of fluorine by hydrogen proceed simultaneously.

[0067] In step ST3, a carbon-containing deposit may be formed on the first region R1 before forming the tungsten-containing deposit DP. In this case, the tungsten-containing deposit DP is formed on the carbon-containing deposit. The carbon-containing deposit is formed on the first region R1 using plasma generated from a processing gas containing carbon. When the first region R1 and the second region R2 are exposed to plasma, the carbon-containing deposit may be preferentially formed on the first region R1 compared to the second region R2. The processing gas containing carbon may include a carbon-containing gas. The carbon-containing gas may include at least one of CH4 gas, C2H2 gas, C2H4 gas, CH3F gas, CH2F2 gas, CHF3 gas, and CO gas. The processing gas may include a noble gas, such as argon gas, helium gas, xenon gas, or neon gas.

[0068] 7, in step ST4, the second region R2 is etched using a second plasma PL2 generated from the second processing gas. The etching may be performed as follows. First, the gas supply unit 20 supplies the second processing gas into the plasma processing chamber 10. Next, the plasma generation unit 12 generates the second plasma PL2 from the second processing gas in the plasma processing chamber 10. The control unit 2 controls the gas supply unit 20 and the plasma generation unit 12 to etch the second region R2 using the second plasma PL2.

[0069] The second process gas is different from the first process gas. In one example, the second process gas may contain tungsten. As a result, deposits are more likely to be formed, and etching of the shoulder portion SH in the recess R1a is suppressed. In another example, the second process gas may not contain tungsten. The second process gas may contain a fluorine-containing gas. An example of the second process gas is the same as the example of the process gas in step ST2.

[0070] In step ST4, the first region R1 is covered with the tungsten-containing deposit DP and is therefore difficult to etch. The second region R2 is easier to etch than the first region R1. By etching the second region R2, a contact hole HL is formed as shown in FIG. 7. The contact hole HL corresponds to the recess R1a of the first region R1. In this manner, step ST4 may be performed in a self-aligned contact (SAC) process. After the second region R2 in the recess R1a is removed, the tungsten-containing deposit DP remains on the first region R1. Therefore, etching of the first region R1 in step ST4 is suppressed. The tungsten-containing deposit DP may be removed by cleaning after step ST4.

[0071] In step ST5, it is determined whether the tungsten-containing deposit DP remains sufficiently. The determination may be made by the control unit 2. If it is determined that the tungsten-containing deposit DP remains sufficiently, the process proceeds to step ST6. If it is determined that the tungsten-containing deposit DP does not remain sufficiently, the process returns to step ST3. The determination may be made based on the etching time. For example, the relationship between the etching time in step ST4 and the amount of reduction of the tungsten-containing deposit DP is calculated in advance. Using the relationship, the amount of reduction of the tungsten-containing deposit DP is estimated from the remaining etching time required to form the contact hole HL. If the value obtained by subtracting the estimated amount of reduction of the tungsten-containing deposit DP from the initial amount of the tungsten-containing deposit DP is equal to or greater than a threshold value, it is determined that the tungsten-containing deposit DP remains sufficiently. Alternatively, the determination may be made based on the reflected light obtained by irradiating the tungsten-containing deposit DP with light. For example, in step ST4, the reflected light obtained by irradiating the tungsten-containing deposit DP with light is measured. When the intensity of the reflected light at a wavelength corresponding to the tungsten-containing deposit DP is equal to or greater than a threshold value, it is determined that a sufficient amount of the tungsten-containing deposit DP remains.

[0072] In step ST6, it is determined whether the etching stop condition in step ST4 is satisfied. The determination can be made by the control unit 2. If it is determined that the stop condition is satisfied, the method MT is terminated. If it is determined that the stop condition is not satisfied, the process returns to step ST3.

[0073] As described above, the cycle including step ST3 and step ST4 may be repeated two or more times.

[0074] According to the method MT, a tungsten-containing deposit DP having excellent etching resistance can be formed. Without being bound by theory, the reason is believed to be as follows. In step ST3, when the first processing gas contains hydrogen, the activated species containing hydrogen in the first plasma PL1 functions as a fluorine scavenger. As a result, the fluorine concentration in the tungsten-containing deposit DP is reduced, and the etching resistance of the tungsten-containing deposit DP in step ST4 is improved. In step ST3, when the first processing gas contains carbon, carbon-tungsten bonds are formed in the tungsten-containing deposit DP. As a result, the etching resistance of the tungsten-containing deposit DP in step ST4 is improved.

[0075] Furthermore, according to the method MT, the change in thickness of the tungsten-containing deposit DP that depends on the width of the opening OP of the mask MK (loading effect) can be suppressed compared to the carbon-containing deposit, and therefore, while the etching of the first region R1 is suppressed by the tungsten-containing deposit DP, the blocking of the contact hole HL by the tungsten-containing deposit DP can be suppressed.

[0076] If the temperature of the substrate support 11 exceeds 100° C. in step ST3, the etching resistance of the tungsten-containing deposit DP is further improved. Without being bound by theory, the reason is believed to be as follows. If the temperature of the substrate support 11 is high, the temperature of the substrate W increases, and fluorine is removed from the tungsten-containing deposit DP. As a result, the fluorine concentration in the tungsten-containing deposit DP is reduced, and the etching resistance of the tungsten-containing deposit DP in step ST4 is improved.

[0077] If the counter electrode facing the substrate support 11 is sputtered in or after step ST3, the etching resistance of the tungsten-containing deposit DP is further improved. Without being bound by theory, the reason is believed to be as follows. When the counter electrode is sputtered, silicon is released from the counter electrode. Silicon functions as a scavenger for fluorine. As a result, the fluorine concentration in the tungsten-containing deposit DP is reduced, and the etching resistance of the tungsten-containing deposit DP in step ST4 is improved.

[0078] In step ST3, bias power may not be applied to the electrode in main body 111 of substrate support 11, or the bias power applied may be less than 100 W. In this case, when forming tungsten-containing deposit DP, etching of first region R1 by first plasma PL1 can be suppressed.

[0079] FIG. 8 is an example of a timing chart showing the time change of the bias power applied to the electrode in the main body 111 of the substrate support 11 and the RF power applied to the counter electrode. This timing chart is related to step ST4 in the method MT. In step ST4, bias power may be applied to the electrode in the main body 111. The bias power may be, for example, RF power LF. The following description is an example of the power used for a substrate W having a diameter of 300 mm. The RF power LF may be 10 W or more and 300 W or less, 30 W or more and 200 W or less, or 50 W or more and 100 W or less. The frequency of the RF power LF may be 100 kHz or more and 40.68 MHz or less. In step ST4, RF power HF may be applied to the counter electrode. The RF power HF may be 50 W or more and 1000 W or less, 80 W or more and 800 W or less, or 100 W or more and 500 W or less. The frequency of the RF power HF may be 27 MHz or more and 100 MHz or less. The RF power LF and the RF power HF may be applied periodically with a period CY. Note that the bias power may be supplied to a conductive member of the substrate support 11. Also, the RF power HF may be supplied to an antenna including one or more coils.

[0080] The cycle CY may include a first period PA, a second period PB, and a third period PC. In the first period PA, the RF power LF is maintained at a low power L1 (e.g., less than 100 W), and the RF power HF is maintained at a high power H2 (e.g., more than 100 W). In the first period PA, the deposition of the carbon-containing film on the tungsten-containing deposit DP is promoted. In the second period PB, the RF power LF is maintained at a low power L1, and the RF power HF is maintained at a low power L2 (e.g., less than 200 W). The low power L2 is smaller than the high power H2 and larger than the low power L1. In the third period PC, the RF power LF is maintained at a high power H1 (e.g., more than 50 W), and the RF power HF is maintained at a low power L2. The high power H1 is larger than the low power L1 and smaller than the high power H2. In the third period PC, the etching of the second region R2 is promoted. The second period PB is a transition period from the first period PA to the third period PC. In the step ST4, one cycle corresponding to a period CY including a first period PA, a second period PB, and a third period PC may be repeated two or more times.

[0081] The ratio of the first period PA to the cycle CY is smaller than the ratio of the third period PC to the cycle CY. The ratio of the first period PA to the cycle CY may be 10% or more, or may be less than 50%. When the ratio of the first period PA is large, the amount of tungsten-containing deposit DP etched is small. When the ratio of the first period PA is small, blocking of the contact hole HL is suppressed. The ratio of the third period PC to the cycle CY may be 50% or more. When the ratio of the third period PC is large, the etching rate of the second region R2 is large. The frequency that defines the cycle CY may be 1 kHz or more and 1 MHz or less. The time length of the cycle CY is the reciprocal of the frequency that defines the cycle CY.

[0082] Step ST4 is not necessarily limited to a step performed according to the timing chart shown in Fig. 8. In step ST4, for example, the bias power applied to the electrode in the main body 111 of the substrate support 11 and the RF power applied to the counter electrode may be constant.

[0083] 9 is a flowchart of an etching method according to an example embodiment. The etching method MT1 (hereinafter, referred to as "method MT1") shown in FIG. 9 can be performed by the plasma processing apparatus 1 of the above embodiment. The method MT1 can be applied to a substrate W.

[0084] Method MT1 will be described below with reference to Figs. 10 to 12, taking as an example a case where method MT1 is applied to a substrate W using the plasma processing apparatus 1 of the above embodiment. Figs. 10 to 12 are cross-sectional views showing a step of an etching method according to one exemplary embodiment. When the plasma processing apparatus 1 is used, method MT1 can be performed in the plasma processing apparatus 1 by controlling each part of the plasma processing apparatus 1 by a control unit 2. In method MT1, a substrate W on a substrate support 11 (substrate support) arranged in a plasma processing chamber 10 is processed, as shown in Fig. 2.

[0085] As shown in Fig. 9, method MT1 includes steps ST31 and ST32 instead of step ST3 of method MT in Fig. 3. Step ST31 may be performed after step ST2. Step ST32 may be performed after step ST31. Step ST4 may be performed after step ST32. Steps ST1 to ST2 and steps ST4 to ST6 may be performed in the same manner as in method MT.

[0086] In step ST31, as shown in FIG. 10, a carbon-containing deposit CDP is formed on the first region R1. The carbon-containing deposit CDP may be formed using a third plasma P3 generated from a third process gas. The carbon-containing deposit CDP may contain a polymer. The carbon-containing deposit CDP may contain at least one of fluorine, oxygen, and hydrogen. The carbon-containing deposit CDP may be a carbon-containing film. The carbon-containing deposit CDP may have an overhang portion OHG covering a shoulder portion SH in the recess R1a of the first region R1. The overhang portion OHG reduces the size of the recess R1a. When the first region R1 and the second region R2 are exposed to the third plasma PL3, the carbon-containing deposit CDP may be preferentially formed on the first region R1 compared to the second region R2. Here, "the carbon-containing deposit CDP may be preferentially formed on the first region R1 compared to the second region R2" means, for example, that the thickness of the carbon-containing deposit CDP on the first region R1 is larger than that of the carbon-containing deposit CDP on the second region R2, and more specifically, that the thickness of the carbon-containing deposit CDP on the second region R2 is 50% or less of the thickness of the carbon-containing deposit CDP on the first region R1. The deposition may be performed as follows. First, the gas supply unit 20 supplies a third processing gas into the plasma processing chamber 10. Next, the plasma generation unit 12 generates a third plasma PL3 from the third processing gas in the plasma processing chamber 10. The control unit 2 controls the gas supply unit 20 and the plasma generation unit 12 so that the carbon-containing deposit CDP is formed on the first region R1.

[0087] The third process gas may include a carbon-containing gas. The carbon-containing gas may include a hydrocarbon (C x H y ) gas, fluorocarbon (C x F y ) gas and carbon monoxide (CO) gas. x and y are natural numbers. The third process gas may include a noble gas.

[0088] In step ST32, as shown in FIG. 11, a tungsten-containing deposit DP is formed on the carbon-containing deposit CDP using a fourth plasma PL4 generated from a fourth process gas. Step ST32 may be performed in the same manner as step ST3, except that a fourth process gas is used instead of the first process gas. When the carbon-containing deposit CDP and the second region R2 are exposed to the fourth plasma PL4, the tungsten-containing deposit DP may be preferentially formed on the carbon-containing deposit CDP compared to the second region R2. Here, "the tungsten-containing deposit DP may be preferentially formed on the carbon-containing deposit CDP compared to the second region R2" means, for example, that the thickness of the tungsten-containing deposit DP on the carbon-containing deposit CDP is larger than the thickness of the tungsten-containing deposit DP on the second region R2, and more specifically, that the thickness of the tungsten-containing deposit DP on the second region R2 is 50% or less of the thickness of the tungsten-containing deposit DP on the carbon-containing deposit CDP. The deposition may be performed as follows. First, the gas supply unit 20 supplies a fourth process gas into the plasma processing chamber 10. Next, the plasma generation unit 12 generates a fourth plasma PL4 from the fourth process gas in the plasma processing chamber 10. The control unit 2 controls the gas supply unit 20 and the plasma generation unit 12 so that the tungsten-containing deposit DP is formed on the carbon-containing deposit CDP. The order of steps ST31 and ST32 is not limited to that shown in FIG. 9. For example, step ST31 may be performed after step ST32, and then step ST4 may be performed. The order of steps ST31 and ST32 may be changed for each cycle including steps ST31 to ST4.

[0089] The fourth process gas includes fluorine and tungsten. The fourth process gas may include a tungsten-containing gas. An example of the tungsten-containing gas includes tungsten hexafluoride.

[0090] The fourth process gas may include an inert gas such as a noble gas. The fourth process gas may include at least one of a carbon-containing gas and a hydrogen-containing gas. Examples of the carbon-containing gas and the hydrogen-containing gas are the same as those of the carbon-containing gas and the hydrogen-containing gas contained in the first process gas. The flow rate ratio of the tungsten-containing gas may be the largest among all the gases contained in the fourth process gas except for the inert gas. The fourth process gas may contain only the tungsten-containing gas, excluding the inert gas. The fourth process gas may include an oxygen gas.

[0091] The power for generating the fourth plasma PL4 can be applied to a counter electrode facing the substrate support 11.

[0092] In step ST32 or after step ST32, a counter electrode facing the substrate support 11 may be sputtered. The counter electrode contains silicon. Sputtering improves the etching resistance of the tungsten-containing deposit DP.

[0093] In step ST5 of the method MT1, it is determined whether a sufficient amount of deposit remains on the first region R1. The deposit includes a carbon-containing deposit CDP. The deposit may include a carbon-containing deposit CDP and a tungsten-containing deposit DP.

[0094] According to the method MT1, the total thickness of the carbon-containing deposit CDP and the tungsten-containing deposit DP can be increased in step ST32, thereby forming a deposit having excellent etching resistance.

[0095] Furthermore, according to the method MT1, in step ST32, the overhanging portion OHG of the carbon-containing deposit CDP can be removed while suppressing a reduction in the thickness of the carbon-containing deposit CDP on the first region R1. Therefore, a reduction in the dimension of the recess R1a caused by the overhanging portion OHG can be suppressed.

[0096] In step ST32, if the fourth process gas does not contain either carbon or hydrogen, an overhang portion is unlikely to be formed in the tungsten-containing deposit DP. Therefore, it is possible to suppress a reduction in the size of the recess R1a caused by the overhang portion of the tungsten-containing deposit DP. The formation of the overhang portion of the tungsten-containing deposit DP can be promoted by at least one of the carbon-containing gas and the hydrogen-containing gas.

[0097] In step ST32, when power for generating the fourth plasma PL4 is applied to the counter electrode, collision of ions in the fourth plasma PL4 with the substrate W can be suppressed compared to when the power is applied to the substrate support part 11. Thus, a reduction in the total thickness of the carbon-containing deposit CDP and the tungsten-containing deposit DP can be suppressed.

[0098] The above-mentioned methods MT and MT1 may be applied to a substrate W including a second region R2 and a first region R1 having an opening on the second region R2. In this case, the second region R2 is etched using the first region R1 as a mask to form a contact hole. The dimension of the contact hole may be 20 nm or more and 100 nm or less. The contact hole may be a HARC (High Aspect Ratio Contact). The aspect ratio of the contact hole may be 2 or more.

[0099] The tungsten-containing deposit DP may be deposited for the purpose of declocking (suppression of blocking of the opening). For example, if clocking (blocking) of the opening occurs during etching, the tungsten-containing deposit DP may be deposited for the purpose of declocking, regardless of the presence or absence of a deposit on the first region R1.

[0100] Fig. 13 is a flowchart of an etching method according to one example embodiment. The etching method MT2 (hereinafter, referred to as "method MT2") shown in Fig. 13 can be performed by the plasma processing apparatus 1 of the above embodiment. The method MT2 can be applied to the substrate W of Fig. 14.

[0101] Fig. 14 is a partially enlarged cross-sectional view of an example substrate to which the method of Fig. 13 can be applied. As shown in Fig. 14, in one embodiment, the substrate W includes a first region R1 and a second region R2. The first region R1 may have at least one opening OP1. The first region R1 may have multiple openings OP1. The second region R2 may be below the first region R1. The substrate W may further include a base region UR. The base region UR may be below the second region R2.

[0102] The first region R1 may not contain silicon or nitrogen. The first region R1 may be a resist. The resist may be an EUV resist.

[0103] The second region R2 includes silicon and oxygen. The second region R2 includes silicon oxide (SiO x The second region R2 may be a SOG (Spin on Glass) film.

[0104] The underlayer region UR may include a first underlayer region UR1, a second underlayer region UR2, and a third underlayer region UR3. The first underlayer region UR1, the second underlayer region UR2, and the third underlayer region UR3 are arranged in order. The third underlayer region UR3 is provided between the second region R2 and the second underlayer region UR2. The first underlayer region UR1, the second underlayer region UR2, and the third underlayer region UR3 may be a laminated film.

[0105] The first underlayer region UR1 may contain silicon and nitrogen. The first underlayer region UR1 may be made of silicon nitride (SiN x The second underlayer region UR2 may include silicon and oxygen. The second underlayer region UR2 may include silicon oxide (SiO x The third underlayer region UR3 may be a SOC (Spin on Carbon) film or a carbon-containing film.

[0106] Method MT2 will be described below with reference to Figs. 13 to 17, taking as an example a case where method MT2 is applied to a substrate W using the plasma processing apparatus 1 of the above embodiment. Figs. 15 to 17 are cross-sectional views showing a step of an etching method according to one exemplary embodiment. When the plasma processing apparatus 1 is used, method MT2 can be performed in the plasma processing apparatus 1 by controlling each part of the plasma processing apparatus 1 by a control unit 2. In method MT2, a substrate W on a substrate support 11 (substrate support) arranged in a plasma processing chamber 10 is processed, as shown in Fig. 2.

[0107] As shown in Fig. 13, method MT2 includes step ST1, step ST3, and step ST4. Method MT2 may further include step ST33 after step ST3 and before step ST4. In method MT2, each step in method MT and method MT1 may be performed. Step ST1 in method MT2 may be performed in the same manner as method MT. Steps ST3 and ST4 in method MT2 may be performed in the same manner as steps ST3 and ST4 in method MT, except for the following points.

[0108] 15, in step ST3, a tungsten-containing deposit DP is formed on the first region R1 using a first plasma PL11 generated from the first process gas. When the first region R1 and the second region R2 are exposed to the first plasma PL11, the tungsten-containing deposit DP may be preferentially formed on the first region R1 compared to the second region R2.

[0109] The first process gas may not contain carbon and hydrogen. The first process gas may contain a noble gas, fluorine, and tungsten. The first process gas may contain a noble gas and a tungsten-containing gas. Fluorine may be contained in the tungsten-containing gas. The first process gas may further contain a hydrogen-containing gas. The hydrogen-containing gas may contain at least one of H2 gas, SiH4 gas, and CH4 gas. The first process gas may not contain a noble gas. The first process gas may contain a hydrogen-containing gas, fluorine, and tungsten. Examples of the gases contained in the first process gas are the same as the examples of the gases contained in the first process gas in step ST3 of the method MT. Other process conditions (such as the flow rate ratio of each gas, the process time, the temperature, the pressure, and the applied power) in step ST3 of the method MT2 may be the same as the process conditions in step ST3 of the method MT. However, in step ST3 of the method MT2, the temperature of the substrate support 11 may be 0° C. or higher, or 20° C. or higher.

[0110] In step ST33, as shown in FIG. 16, the tungsten-containing deposit DP may be exposed to a plasma HPL generated from a process gas containing a hydrogen-containing gas (hydrogen plasma process). This allows the tungsten-containing deposit DP to be modified into a tungsten-containing deposit HDP. The tungsten-containing deposit HDP may include metallic tungsten generated by reducing tungsten oxide with hydrogen plasma. The process gas containing hydrogen-containing gas may be different from the first process gas in step ST3.

[0111] In step ST4, as shown in Fig. 17, the second region R2 is etched through the opening OP1 using a second plasma PL12 generated from the second processing gas. This forms a recess RS in the second region R2. The recess RS corresponds to the opening OP1 in the first region R1. The second processing gas may be different from the processing gas in step ST33. The process conditions in step ST4 of the method MT2 (such as the type of the second processing gas, the flow rate ratio of each gas, processing time, temperature, pressure, and applied power) may be the same as the process conditions in step ST4 of the method MT.

[0112] According to the method MT2, a tungsten-containing deposit DP having excellent etching resistance can be formed. As a result, the remaining thickness of the first region R1 is increased after step ST4, and therefore the etching selectivity of the second region R2 to the first region R1 is increased. Furthermore, the verticality of the sidewall of the recess RS formed in the second region R2 is improved.

[0113] When step ST33 is performed, the remaining thickness of the first region R1 after step ST4 becomes even larger. This is presumably because the hydrogen plasma treatment reduces tungsten oxide to generate metallic tungsten, thereby further improving the etching resistance of the first region R1.

[0114] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and modifications may be made. In addition, elements in different embodiments can be combined to form other embodiments.

[0115] For example, a molybdenum-containing gas may be used instead of or in addition to the tungsten-containing gas. The molybdenum-containing gas may include a molybdenum halide gas. The molybdenum halide gas may include at least one of molybdenum hexafluoride (MoF6) gas and molybdenum hexachloride (MoCl6) gas.

[0116] Various experiments performed to evaluate Method MT will be described below, but the experiments described below are not intended to limit the present disclosure.

[0117] (First experiment) In the first experiment, silicon nitride (SiN x A first region R1 including a silicon oxide (SiO x A substrate W including a first region R1 and a second region R2 including a first region R1 and a second region R2 was prepared. The upper surface of the first region R1 and the upper surface of the second region R2 were exposed. Thereafter, the substrate W was subjected to steps ST3 and ST4 using a plasma processing apparatus 1.

[0118] In step ST3, a first plasma PL1 was generated from a first processing gas, and the first region R1 and the second region R2 were exposed to the first plasma PL1. The first processing gas was a mixed gas of tungsten hexafluoride (WF6) gas, methane (CH4) gas, and argon (Ar) gas. The flow rate ratio of the tungsten hexafluoride gas was smaller than the flow rate ratio of the methane gas. The flow rate ratio of the argon gas was larger than the flow rate ratio of the methane gas.

[0119] In step ST3, the temperature of the substrate support 11 is 150° C. No negative DC voltage is applied to the counter electrode facing the substrate support 11.

[0120] In step ST4, a second plasma PL2 was generated from a second process gas to etch the second region R2. The second process gas was a mixed gas of C4F6 gas, argon gas, and oxygen (O2) gas.

[0121] (Second experiment) In the second experiment, the same method as the first experiment was performed except that the counter electrode facing the substrate support 11 was sputtered in step ST3. The counter electrode included an inner first electrode and an outer second electrode. The absolute value of the DC voltage applied to the first electrode was 800V. The absolute value of the DC voltage applied to the second electrode was 400V.

[0122] (Third experiment) In the third experiment, the same method as the first experiment was carried out, except that in step ST3, a mixed gas of methane (CH4) gas, carbon monoxide (CO) gas, and argon (Ar) gas was used as the first processing gas.

[0123] (4th experiment) In the fourth experiment, the same method as the first experiment was carried out, except that in step ST3, a mixed gas of tungsten hexafluoride (WF6) gas and argon (Ar) gas was used as the first processing gas.

[0124] (Experimental Results) TEM images of the cross section of the substrate W on which the method was performed in the first to fourth experiments were observed. FIG. 18 is a diagram showing TEM images of the cross section of the substrate obtained by performing the etching method in the first and second experiments. FIG. 18(a) shows the cross section of the substrate W after step ST3 and before step ST4 in the first experiment. FIG. 18(b) shows the cross section of the substrate W after step ST4 in the first experiment. In FIG. 18(a) and (b), a film (black part in the figure) formed on the first region R1 was confirmed. From the result of TEM-EDX, it was confirmed that the part corresponding to the film in FIG. 18(a) contains tungsten. That is, it was confirmed that the film in FIG. 18(a) is a tungsten-containing deposit DP. The thickness of the tungsten-containing deposit DP was measured in each of FIG. 18(a) and (b), and the reduction amount of the tungsten-containing deposit DP by step ST4 was calculated. The reduction amount of the tungsten-containing deposit DP in the first experiment was 4.0 nm. In addition, the thickness of the entire deposit (the sum of the tungsten-containing deposit DP and the deposit on the tungsten-containing deposit DP) in Figure 18(b) was measured, and the thickness of the tungsten-containing deposit DP in Figure 18(a) was subtracted from the measured thickness to calculate the reduction in the entire deposit. The reduction in the entire deposit in the first experiment was 0.4 nm.

[0125] FIG. 18(c) shows a cross section of the substrate W after step ST3 and before step ST4 in the second experiment. FIG. 18(d) shows a cross section of the substrate W after step ST4 in the second experiment. In FIG. 18(c) and (d), a tungsten-containing deposit DP formed on the first region R1 was confirmed as in the first experiment. In the second experiment, the reduction in the tungsten-containing deposit DP due to step ST4 was calculated as in the first experiment. In the second experiment, the reduction in the tungsten-containing deposit DP due to step ST4 was calculated as in the first experiment. In the second experiment, the reduction in the tungsten-containing deposit DP was 1.4 nm. In addition, the thickness of the entire deposit in FIG. 18(d) was measured, and the thickness of the tungsten-containing deposit DP in FIG. 18(c) was subtracted from the measured thickness to calculate the reduction in the entire deposit. In the second experiment, the reduction in the entire deposit was −2.6 nm, that is, the thickness of the entire deposit increased by 2.6 nm.

[0126] FIG. 19 shows TEM images of the cross section of the substrate obtained by carrying out the etching method in the third and fourth experiments. FIG. 19(a) shows the cross section of the substrate W after the deposition step and before the etching step in the third experiment. FIG. 19(b) shows the cross section of the substrate W after the deposition step in the third experiment. In FIG. 19(a) and (b), the carbon-containing film DP1 formed on the first region R1 was confirmed. In the third experiment, as in the first experiment, the thickness of the entire deposit in FIG. 19(b) was measured, and the thickness of the carbon-containing film DP1 in FIG. 19(a) was subtracted from the measured thickness to calculate the reduction in the entire deposit. The reduction in the entire deposit in the third experiment was 1.9 nm.

[0127] FIG. 19(c) shows a cross section of the substrate W after the deposition step and before the etching step in the fourth experiment. FIG. 19(d) shows a cross section of the substrate W after the etching step in the fourth experiment. In FIG. 19(c), a tungsten-containing film DP2 formed on the first region R1 was confirmed. On the other hand, in FIG. 19(d), the tungsten-containing film DP2 was not confirmed. It can be seen that the tungsten-containing film DP2 disappeared due to the etching step in the fourth experiment.

[0128] The results of the first to fourth experiments show that when the first process gas contains at least one of carbon and hydrogen, fluorine, and tungsten, a tungsten-containing deposit DP having excellent etching resistance can be formed. Also, the results of the first and second experiments show that the etching resistance of the tungsten-containing deposit DP in step ST4 is further improved by sputtering the counter electrode facing the substrate support 11.

[0129] (Fifth experiment) In the fifth experiment, silicon nitride (SiN x A first region R1 including a silicon oxide (SiO x A substrate W including a first region R1 and a second region R2 including a first region R1 and a second region R2 was prepared. The upper surface of the first region R1 and the upper surface of the second region R2 were exposed. Thereafter, the substrate W was subjected to steps ST3 and ST4 using a plasma processing apparatus 1.

[0130] In step ST3, first, plasma was generated from a process gas that was a mixed gas of carbon monoxide (CO) gas and argon (Ar) gas, and a carbon-containing deposit was formed on the first region R1 using the plasma. Next, a first plasma PL1 was generated from the first process gas, and a tungsten-containing deposit DP was formed on the carbon-containing deposit using the first plasma PL1. The first process gas was a mixed gas of tungsten hexafluoride (WF6) gas, hydrogen (H2) gas, and argon (Ar) gas. The flow rate ratio of the tungsten hexafluoride gas was smaller than the flow rate ratio of the hydrogen gas. The flow rate ratio of the argon gas was larger than the flow rate ratio of the hydrogen gas.

[0131] In step ST3, the temperature of the substrate support 11 is 150° C. The counter electrodes include an inner first electrode and an outer second electrode. The absolute value of the DC voltage applied to the first electrode is 800 V. The absolute value of the DC voltage applied to the second electrode is 400 V.

[0132] In step ST4, a second plasma PL2 was generated from a second process gas to etch the second region R2. The second process gas was a mixed gas of C4F6 gas, argon gas, and oxygen (O2) gas.

[0133] (Experimental Results) A TEM image of a cross section of the substrate W on which the method was performed in the fifth experiment was observed. FIG. 20 is a diagram showing a TEM image of a cross section of a substrate obtained by performing the etching method in the fifth experiment. FIG. 20(a) shows a cross section of the substrate W after step ST3 and before step ST4 in the fifth experiment. FIG. 20(b) shows a cross section of the substrate W after step ST4 in the fifth experiment. In FIG. 20(a) and (b), a tungsten-containing deposit DP formed on the first region R1 was confirmed as in the first experiment. In the fifth experiment, the reduction amount of the tungsten-containing deposit DP due to step ST4 was calculated as in the first experiment. The reduction amount of the tungsten-containing deposit DP in the fifth experiment was 1.2 nm. The thickness of the entire deposit in FIG. 20(b) was measured, and the thickness of the tungsten-containing deposit DP in FIG. 20(a) was subtracted from the thickness to calculate the reduction amount of the entire deposit. The reduction amount of the entire deposit in the fifth experiment was 0.9 nm.

[0134] The results of the fifth experiment show that when the first process gas contains a hydrogen-containing gas, a tungsten-containing deposit DP having excellent etching resistance can be formed.

[0135] (Experiment 6) In the sixth experiment, the same method as the first experiment was carried out, except that carbon monoxide (CO) gas was added to the first processing gas in step ST3. The flow rate ratio of the carbon monoxide gas was greater than the flow rate ratio of the methane gas.

[0136] (Experiment 7) In the seventh experiment, the same method as the first experiment was carried out, except that hydrogen (H2) gas was added to the first process gas in step ST3. The flow rate ratio of the hydrogen gas was greater than the flow rate ratio of the methane gas.

[0137] (Experiment 8) In the eighth experiment, the same method as the second experiment was carried out except that carbon monoxide (CO) gas was added to the first processing gas in step ST3. The flow rate ratio of the carbon monoxide gas was greater than the flow rate ratio of the methane gas.

[0138] (Experiment No. 9) In the ninth experiment, the same method as the second experiment was carried out, except that hydrogen (H2) gas was added to the first processing gas in step ST3. The flow rate ratio of hydrogen gas was greater than the flow rate ratio of methane gas.

[0139] (Experimental Results) In the sixth to ninth experiments, a TEM image of a cross section of the substrate W on which the method was performed was observed. In the sixth to ninth experiments, the reduction in the tungsten-containing deposit DP due to step ST4 was calculated in the same manner as in the first experiment. The reduction in the tungsten-containing deposit DP in the sixth experiment was 3.8 nm. The reduction in the tungsten-containing deposit DP in the seventh experiment was 2.3 nm. The reduction in the tungsten-containing deposit DP in the eighth experiment was 3.7 nm. The reduction in the tungsten-containing deposit DP in the ninth experiment was 1.7 nm. Also, in the sixth to ninth experiments, the reduction in the total deposit was calculated in the same manner as in the first experiment. The reduction in the total deposit was 1.2 nm. The reduction in the total deposit was -0.7 nm in the seventh experiment, that is, the thickness of the total deposit increased by 0.7 nm. The reduction in the total deposit was 0.7 nm in the eighth experiment. The reduction in the total deposit was -1.4 nm in the ninth experiment, that is, the thickness of the total deposit increased by 1.4 nm.

[0140] The results of the sixth to ninth experiments show that a tungsten-containing deposit DP having excellent etching resistance can be formed even if the gas species of the first process gas is different. Furthermore, it is found that the deposition rate of the tungsten-containing deposit DP can be controlled by changing the gas species of the first process gas. Furthermore, the results of the sixth to ninth experiments show that the etching resistance of the tungsten-containing deposit DP in step ST4 is further improved by applying a negative DC voltage to the counter electrode facing the substrate support 11.

[0141] (Experiment 10) In the tenth experiment, the same method as in the fourth experiment was carried out, except that the temperature of the substrate support 11 was 100° C. in the deposition step corresponding to step ST3.

[0142] (Experimental Results) A TEM image of a cross section of the substrate W on which the methods were performed in the fourth and tenth experiments was observed. In the tenth experiment, a tungsten-containing film DP2 thicker than the tungsten-containing film DP2 shown in (c) of Figure 19 was confirmed. However, in the tenth experiment, it was confirmed that the tungsten-containing film DP2 was lost and the top surface of the first region R1 was etched by the etching process.

[0143] From the results of the fourth and tenth experiments, it can be seen that when the temperature of the substrate support 11 exceeds 100° C., the etching resistance of the tungsten-containing film DP2 in the etching step is improved.

[0144] Various experiments performed to evaluate Method MT1 are described below, but the experiments described below are not intended to limit the present disclosure.

[0145] (Experiment 11) In the 11th experiment, silicon nitride (SiN x A first region R1 including a silicon oxide (SiO x A substrate W including a first region R1 and a second region R2 including a first region R1 and a second region R2 was prepared. The upper surface of the first region R1 and the upper surface of the second region R2 were exposed. Thereafter, the substrate W was subjected to steps ST31, ST32, and ST4 using a plasma processing apparatus 1.

[0146] In step ST31, a third plasma PL3 was generated from a third process gas, and the first region R1 and the second region R2 were exposed to the third plasma PL3. The third process gas was a mixed gas of C4F6 gas, argon (Ar) gas, and oxygen (O2) gas. By step ST31, a carbon-containing deposit CDP was formed on the first region R1.

[0147] In step ST32, a fourth plasma PL4 was generated from a fourth process gas, and the carbon-containing deposit CDP and the second region R2 were exposed to the fourth plasma PL4. The fourth process gas was a mixed gas of tungsten hexafluoride (WF6) gas and argon (Ar) gas. By step ST32, a tungsten-containing deposit DP was formed on the carbon-containing deposit CDP.

[0148] In step ST4, a second plasma PL2 was generated from a second process gas to etch the second region R2. The second process gas was a mixed gas of C4F6 gas, argon gas, and oxygen (O2) gas.

[0149] (Experiment 12) In the twelfth experiment, the same method as the eleventh experiment was carried out, except that in step ST31, a mixed gas of carbon monoxide (CO) gas and argon (Ar) gas was used as the third process gas.

[0150] (Experiment 13) In the thirteenth experiment, the same method as the eleventh experiment was carried out, except that in step ST31, a mixed gas of methane (CH4) gas and argon (Ar) gas was used as the third process gas.

[0151] (Experiment 14) In the 14th experiment, the same method as in the 11th experiment was carried out, except that step ST31 was not carried out.

[0152] (Experimental Results) In the 11th to 14th experiments, TEM images of the cross sections of the substrate W after step ST31 and after step ST32 were observed.

[0153] In the eleventh experiment, after step ST31, the thickness of the carbon-containing deposit CDP on the upper surface of the first region R1 was 6.7 nm. After step ST32, the sum of the thicknesses of the carbon-containing deposit CDP and the tungsten-containing deposit DP on the upper surface of the first region R1 was 20.4 nm. Also, after step ST32, the carbon-containing deposit CDP did not have an overhanging portion.

[0154] In the twelfth experiment, after step ST31, the thickness of the carbon-containing deposit CDP on the upper surface of the first region R1 was 4.5 nm. After step ST32, the thickness of the carbon-containing deposit CDP on the upper surface of the first region R1 was 3.8 nm, and the thickness of the tungsten-containing deposit DP was 10.7 nm. Also, after step ST32, the carbon-containing deposit CDP did not have an overhanging portion.

[0155] In the thirteenth experiment, after step ST31, the thickness of the carbon-containing deposit CDP on the upper surface of the first region R1 was 7.8 nm. After step ST32, the thickness of the carbon-containing deposit CDP on the upper surface of the first region R1 was 7.8 nm, and the thickness of the tungsten-containing deposit DP was 5.9 nm. Also, after step ST32, the carbon-containing deposit CDP did not have an overhanging portion.

[0156] In the fourteenth experiment, after step ST32, the thickness of the tungsten-containing deposit DP was 4.4 nm. No carbon-containing deposit was formed on the upper surface of the first region R1.

[0157] From the results of the 11th to 14th experiments, it is found that the method MT1 can increase the total thickness of the carbon-containing deposit CDP and the tungsten-containing deposit DP. It is also found that the method MT1 can remove the overhanging portion of the carbon-containing deposit CDP.

[0158] (Experiment 15) In the 15th experiment, the same method as the 12th experiment was performed, except that a different type of fourth process gas was used in step ST32 to sputter the counter electrode facing the substrate support 11. The fourth process gas was a mixed gas of tungsten hexafluoride (WF6) gas, argon (Ar) gas, methane (CH4) gas, and carbon monoxide (CO) gas. The flow rate ratio of the tungsten hexafluoride gas was smaller than the flow rate ratio of the methane (CH4) gas and smaller than the flow rate ratio of the carbon monoxide (CO) gas.

[0159] (Experiment 16) In the 16th experiment, the same method as the 12th experiment was performed, except that a different type of fourth process gas was used in step ST32 to sputter the counter electrode facing the substrate support 11. The fourth process gas was a mixed gas of tungsten hexafluoride (WF6) gas, methane (CH4) gas, and hydrogen (H2) gas. The flow rate ratio of the tungsten hexafluoride gas was smaller than the flow rate ratio of the methane (CH4) gas and smaller than the flow rate ratio of the hydrogen (H2) gas.

[0160] (Experiment 17) In the 17th experiment, the same method as the 12th experiment was performed, except that a different type of fourth process gas was used in step ST32 to sputter the counter electrode facing the substrate support 11. The fourth process gas was a mixed gas of tungsten hexafluoride (WF6) gas, argon (Ar) gas, and hydrogen (H2) gas. The flow rate ratio of the tungsten hexafluoride gas was smaller than the flow rate ratio of the hydrogen (H2) gas.

[0161] (Experimental Results) In the twelfth experiment and the fifteenth to seventeenth experiments, a TEM image of the cross section of the substrate W after step ST32 was observed.

[0162] In the twelfth experiment, the total thickness of the carbon-containing deposit CDP and the tungsten-containing deposit DP was 14.5 nm after step ST32. The tungsten-containing deposit DP did not have an overhanging portion.

[0163] In the fifteenth experiment, the total thickness of the carbon-containing deposit CDP and the tungsten-containing deposit DP was 11.0 nm after step ST32. The carbon-containing deposit CDP did not have an overhanging portion. On the other hand, the tungsten-containing deposit DP had an overhanging portion.

[0164] In the 16th experiment, the total thickness of the carbon-containing deposit CDP and the tungsten-containing deposit DP was 10.0 nm after step ST32. The carbon-containing deposit CDP did not have an overhanging portion. On the other hand, the tungsten-containing deposit DP had an overhanging portion.

[0165] In the seventeenth experiment, the total thickness of the carbon-containing deposit CDP and the tungsten-containing deposit DP was 10.0 nm after step ST32. The carbon-containing deposit CDP did not have an overhanging portion. On the other hand, the tungsten-containing deposit DP had an overhanging portion.

[0166] The results of the twelfth and fifteenth to seventeenth experiments show that if the fourth process gas does not contain either carbon or hydrogen in step ST32, an overhang portion is unlikely to be formed in the tungsten-containing deposit DP.

[0167] (Experiment 18) In the 18th experiment, the same method as in the 13th experiment was carried out.

[0168] (Experiment 19) In the 19th experiment, the same method as the 18th experiment was carried out, except that a counter electrode facing the substrate support 11 was formed by sputtering between step ST32 and step ST4.

[0169] (Experimental Results) In the eighteenth and nineteenth experiments, TEM images of the cross section of the substrate W before and after step ST4 were observed.

[0170] In the eighteenth experiment, the total thickness of the carbon-containing deposit CDP and the tungsten-containing deposit DP was 12.3 nm before step ST4, and the thickness of the carbon-containing deposit CDP was 5.6 nm after step ST4.

[0171] In the nineteenth experiment, the total thickness of the carbon-containing deposit CDP and the tungsten-containing deposit DP was 12.0 nm before step ST4, and the total thickness of the carbon-containing deposit CDP and the tungsten-containing deposit DP was 11.6 nm after step ST4.

[0172] The results of the 18th and 19th experiments show that by sputtering the counter electrode facing the substrate support 11, the etching resistance of the tungsten-containing deposit DP is improved.

[0173] Various experiments performed to evaluate method MT2 are described below, but the experiments described below are not intended to limit the present disclosure.

[0174] (Experiment No. 20) In the 20th experiment, a substrate W having the structure shown in Fig. 14 was prepared. The first region R1 was a resist. The second region R2 was a silicon oxide film. Then, the process ST3 and the process ST4 were performed on the substrate W using the plasma processing apparatus 1 (see Fig. 13).

[0175] In step ST3, a first plasma PL11 was generated from the first processing gas, and the first region R1 and the second region R2 were exposed to the first plasma PL11 (see FIG. 15). The first processing gas was a mixed gas of tungsten hexafluoride (WF6) gas and argon (Ar) gas. The flow rate ratio of the tungsten hexafluoride gas was smaller than the flow rate ratio of the argon gas.

[0176] In step ST3, the temperature of the substrate support 11 is 20° C. The RF power applied to the counter electrode facing the substrate support 11 is 100 W. No bias power is applied to the electrode in the main body 111 of the substrate support 11.

[0177] In step ST4, a second plasma PL12 was generated from the second process gas to etch the second region R2 (see FIG. 17). The second process gas was a mixed gas of CF4 gas and nitrogen (N2) gas.

[0178] (Experiment No. 21) In the 21st experiment, the same method as in the 20th experiment was carried out, except that step ST33 was carried out between step ST3 and step ST4.

[0179] In step ST33, the tungsten-containing deposit DP was exposed to plasma HPL generated from hydrogen (H2) gas (see FIG. 16).

[0180] In step ST33, the RF power applied to the counter electrode facing the substrate support 11 is 100 W. No bias power is applied to the electrode in the main body 111 of the substrate support 11.

[0181] (Experiment No. 22) In the 22nd experiment, the same method as in the 20th experiment was carried out, except that step ST3 was not carried out.

[0182] (Experimental Results) In the 20th experiment, a TEM image of the cross section of the substrate W after step ST3 was observed. It was found that a tungsten-containing deposit DP having a thickness of about 7 nm was formed on the first region R1. In addition, the result of TEM-EDX confirmed that the tungsten-containing deposit DP contained tungsten. On the other hand, no tungsten-containing deposit was confirmed on the second region R2 at the opening OP1.

[0183] TEM images of the cross section of the substrate W on which the method was performed in the 20th to 22nd experiments were observed. In the 20th experiment, the remaining thickness of the first region R1 after etching was 17.2 nm. In the 21st experiment, the remaining thickness of the first region R1 after etching was 20.8 nm. In the 22nd experiment, the remaining thickness of the first region R1 after etching was 9.3 nm. Furthermore, in the 20th and 21st experiments, the verticality of the sidewalls of the recesses RS formed in the second region R2 was improved compared to the 22nd experiment. In the 20th to 22nd experiments, the local dimensional uniformity (LCDU) of the recesses RS was comparable in each of the recesses RS having relatively large dimensions and the recesses RS having relatively small dimensions.

[0184] (Appendix 1) (a) providing a substrate, the substrate including a first region including silicon and nitrogen and a second region including silicon and oxygen; (b) forming a tungsten-containing deposit on the first region using a first plasma generated from a first process gas comprising at least one of carbon and hydrogen, fluorine, and tungsten; (c) after (b), etching the second region using a second plasma generated from a second process gas different from the first process gas; An etching method comprising: (Appendix 2) 2. The etching method of claim 1, wherein the first process gas contains at least one of a carbon-containing gas and a hydrogen-containing gas, and a tungsten-containing gas. (Appendix 3) 3. The etching method of claim 2, wherein the tungsten-containing gas comprises tungsten hexafluoride gas. (Appendix 4) The etching method according to claim 2 or 3, wherein the carbon-containing gas includes at least one of CH4 gas, C2H2 gas, C2H4 gas, CH3F gas, CH2F2 gas, CHF3 gas, and CO gas. (Appendix 5) 5. The etching method according to claim 2, wherein the hydrogen-containing gas contains at least one of H2 gas, SiH4 gas, and NH3 gas. (Appendix 6) In the (a) above, the second region is provided to cover the first region, The etching method includes: (d) after (a) and before (b), etching the second region so as to expose the first region; The etching method according to any one of claims 1 to 5, further comprising: (Appendix 7) 7. The etching method according to claim 1, wherein in (b), a temperature of a substrate support that supports the substrate is higher than 100°C. (Appendix 8) The etching method according to any one of claims 1 to 7, wherein in (b) or after (b), a counter electrode containing silicon facing a substrate support that supports the substrate is sputtered. (Appendix 9) 9. The etching method according to any one of claims 1 to 8, wherein the first region has a recess, and the second region is embedded in the recess. (Appendix 10) 10. The etching method according to claim 9, wherein the step (c) is performed in a self-aligned contact step. (Appendix 11) 11. The etching method according to any one of claims 1 to 10, wherein the cycle including (b) and (c) is repeated two or more times. (Appendix 12) (a) providing a substrate comprising a silicon nitride having an exposed top surface and a silicon oxide having an exposed top surface; (b) forming a tungsten-containing deposit on the silicon nitride using a first plasma generated from a first process gas comprising tungsten hexafluoride gas and at least one of a carbon-containing gas and a hydrogen-containing gas; (c) after (b), etching the silicon oxide using a second plasma generated from a second process gas different from the first process gas; An etching method comprising: (Appendix 13) A chamber; a substrate support for supporting a substrate within the chamber, the substrate including a first region including silicon and nitrogen and a second region including silicon and oxygen; a gas supply configured to supply a first process gas and a second process gas into the chamber, the second process gas being different from the first process gas, the first process gas comprising at least one of carbon and hydrogen, fluorine, and tungsten; a plasma generating unit configured to generate a first plasma from the first process gas in the chamber and to generate a second plasma from the second process gas in the chamber; A control unit; Equipped with the control unit is configured to control the gas supply unit and the plasma generation unit to form a tungsten-containing deposit on the first region using the first plasma; The control unit is configured to control the gas supply unit and the plasma generation unit so as to etch the second region using the second plasma. (Appendix 14) (a) providing a substrate, the substrate including a first region including silicon and nitrogen and a second region including silicon and oxygen; (b) forming a carbon-containing deposit on the first region; (c) forming a tungsten-containing deposit on the carbon-containing deposit using a plasma generated from a process gas comprising fluorine and tungsten; (d) after (c), etching the second region; An etching method comprising: (Appendix 15) 15. The etching method according to claim 14, wherein in (c), the power for generating the plasma is applied to a counter electrode that faces a substrate support that supports the substrate. (Appendix 16) (a) providing a substrate, the substrate including a first region having an opening and a second region underlying the first region, the second region including silicon and oxygen; (b) forming a tungsten-containing deposit on the first region using a first plasma generated from a first process gas comprising a noble gas, fluorine, and tungsten; (c) after (b), etching the second region through the opening using a second plasma generated from a second process gas different from the first process gas; An etching method comprising: (Appendix 17) 17. The etching method of claim 16, further comprising: (d) after (b) and before (c), exposing the tungsten-containing deposit to a third plasma generated from a third process gas comprising a hydrogen-containing gas.

[0185] From the foregoing, it will be understood that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the appended claims. [Explanation of symbols]

[0186] 1...plasma processing apparatus, 2...control section, 10...plasma processing chamber, 11...substrate support section, 12...plasma generation section, 20...gas supply section, DP...tungsten-containing deposit, R1...first region, R2...second region, W...substrate.

Claims

1. A chamber; a substrate support for supporting a substrate within the chamber, the substrate including a first region including silicon and nitrogen and a second region including silicon and oxygen; a gas supply configured to supply a first process gas and a second process gas into the chamber, the second process gas being different from the first process gas, the first process gas comprising at least one of carbon and hydrogen, fluorine, and tungsten and / or molybdenum; a plasma generating unit configured to generate a first plasma from the first process gas in the chamber and to generate a second plasma from the second process gas in the chamber; A control unit; Equipped with the control unit is configured to control the gas supply unit and the plasma generation unit to form a deposit including tungsten and / or molybdenum on the first region using the first plasma; The control unit is configured to control the gas supply unit and the plasma generation unit so as to etch the second region using the second plasma.

2. A chamber, a substrate support for supporting a substrate within the chamber; a gas supply configured to supply a first process gas and a second process gas into the chamber, the second process gas being different from the first process gas, the first process gas comprising at least one of carbon and hydrogen, fluorine, and tungsten and / or molybdenum; a plasma generating unit configured to generate a first plasma from the first process gas in the chamber and to generate a second plasma from the second process gas in the chamber; A control unit; Equipped with The control unit controls the gas supply unit and the plasma generation unit, (a) providing a substrate on the substrate support, the substrate having a first region and a second region below the first region, the first region having at least one opening exposing the second region; (b) forming a deposit comprising tungsten and / or molybdenum on the first region using the first plasma; and (c) etching the second region using the second plasma; and 16. A plasma processing apparatus configured to perform a process including:

3. A plasma processing apparatus as described in claim 1 or 2, wherein the gas supply unit includes at least one flow rate controller.

4. The plasma processing apparatus of claim 3, wherein the gas supply unit supplies the first processing gas and the second processing gas supplied from a gas source into the chamber via the at least one flow rate controller.

5. The plasma processing apparatus of claim 3, wherein the gas supply section includes one or more flow rate modulation devices that modulate or pulse a flow rate of at least one of the first processing gas and the second processing gas.

6. A plasma processing apparatus as described in claim 1 or 2, further comprising a temperature control module for adjusting the temperature of the substrate.

7. The plasma processing apparatus of claim 6, wherein the temperature control module includes a heater, a heat transfer medium, a flow path, or a combination thereof.

8. A plasma processing apparatus as described in claim 6, wherein the control unit controls the temperature control module to adjust the temperature of the substrate support to above 100°C during deposition formation.

9. A plasma processing apparatus as described in claim 1 or 2, wherein the first processing gas includes at least one of a carbon-containing gas and a hydrogen-containing gas, and a tungsten-containing gas and / or a molybdenum-containing gas.

10. The plasma processing apparatus of claim 9, wherein the tungsten-containing gas includes a tungsten halide.

11. The plasma processing apparatus according to claim 9, wherein the tungsten-containing gas includes at least one of tungsten hexafluoride (WF 6 ) gas, tungsten hexabromide (WBr 6 ) gas, tungsten hexachloride (WCl 6 ) gas, WF 5 Cl gas, and tungsten hexacarbonyl (W(CO) 6 ) gas.

12. The plasma processing apparatus of claim 9, wherein the molybdenum-containing gas includes a molybdenum halide.

13. The plasma processing apparatus of claim 9, wherein the molybdenum-containing gas includes at least one of molybdenum hexafluoride (MoF 6 ) gas and molybdenum hexachloride (MoCl 6 ) gas.

14. The plasma processing apparatus of claim 9, wherein the carbon-containing gas includes at least one of CH 4 gas, C 2 H 2 gas, C 2 H 4 gas, CH 3 F gas, CH 2 F 2 gas, CHF 3 gas, and CO gas.

15. The plasma processing apparatus of claim 9, wherein the hydrogen-containing gas includes at least one of H 2 gas, SiH 4 gas, and NH 3 gas.

16. A plasma processing apparatus as described in claim 1 or 2, wherein the deposits include tungsten-containing deposits and / or molybdenum-containing deposits.

17. A plasma processing apparatus as described in claim 1 or 2, wherein the deposit includes a carbon-containing deposit and a tungsten-containing deposit and / or a molybdenum-containing deposit on the carbon-containing deposit.

18. A plasma processing apparatus as described in claim 2, wherein the first region is an EUV resist.

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