Etching Method and Plasma Processing System

Abstract

To provide an etching method and a plasma processing system, improving uniformity of an etching rate.SOLUTION: An etching method contains a step of supplying a substrate having a first silicon-containing organic film and a second silicon-containing organic film into a chamber of a processed gas containing a HF gas and a phosphate containing gas; and a step of generating a plasma from the processed gas in the chamber by a source RF signal, and etching the first and second silicon-containing organic films by generating a bias potential to the substrate by a bias signal. In the step of etching, a step of supplying the source RF signal and the bias signal, and a step of stopping supply of at least one of the source RF signal and the bias signal or supplying at least one of the source RF signal and the bias signal in an actual value of a power lower than an actual value of the power of at least one of them in the step of supplying the signal are alternately repeated.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] Patent Document 1 describes plasma etching of a silicon-containing film using a processing gas containing a fluorocarbon gas.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to provide a technique for improving the uniformity of an etching rate.

Means for Solving the Problems

[0005] In one exemplary embodiment of the present disclosure, an etching method performed in a plasma processing apparatus having a chamber, the method comprising: (a) providing a substrate having a first silicon-containing film and a second silicon-containing film including at least a silicon-containing film of a film type different from the first silicon-containing film on a substrate support in the chamber; (b) supplying a processing gas including HF gas and a phosphorus-containing gas into the chamber; (c) generating a plasma from the processing gas in the chamber by a source RF signal and generating a bias potential on the substrate by a bias signal to etch the first silicon-containing film and the second silicon-containing film, wherein in step (c), (c1) supplying the source RF signal and the bias signal; (c2) alternately repeating a step of stopping the supply of at least one of the source RF signal and the bias signal, or supplying at least one of the source RF signal and the bias signal at an effective value of power lower than the effective value of the power of at least one of them in step (c1).

Advantages of the Invention

[0006] According to one exemplary embodiment of the present disclosure, a technique for improving the uniformity of the etching rate can be provided.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0008] Hereinafter, each embodiment of the present disclosure will be described.

[0009] In one exemplary embodiment, an etching method executed in a plasma processing apparatus having a chamber, the method including: (a) providing a substrate having a first silicon-containing film and a second silicon-containing film including at least a silicon-containing film having a film type different from that of the first silicon-containing film on a substrate support portion in the chamber; (b) supplying a processing gas including HF gas and a phosphorus-containing gas into the chamber; (c) generating plasma from the processing gas in the chamber by a source RF signal and generating a bias potential on the substrate by a bias signal to etch the first silicon-containing film and the second silicon-containing film, wherein in the step (c), (c1) supplying a source RF signal and a bias signal; (c2) alternately repeating a step of stopping the supply of at least one of the source RF signal and the bias signal, or supplying at least one of the source RF signal and the bias signal at an effective power value lower than the effective power value of at least one of the powers in the step (c1).

[0010] In one exemplary embodiment, in the step (c), the temperature of the substrate support portion is set to 0°C or lower.

[0011] In one exemplary embodiment, the step (c) further includes a step of measuring the temperature of the substrate or the substrate support portion.

[0012] In one exemplary embodiment, in at least one of the steps (c1) and (c2), based on the measured temperature, at least one of the effective power value, supply time, and duty ratio of at least one of the source RF signal and the bias signal is adjusted.

[0013] In one exemplary embodiment, the first silicon-containing film is a single-layer film composed of one type of silicon-containing film, and the second silicon-containing film is a laminated film in which two or more types of silicon-containing films are laminated.

[0014] In one exemplary embodiment, the first silicon-containing film includes a silicon oxide film.

[0015] In one exemplary embodiment, the second silicon-containing film includes a silicon oxide film and a silicon nitride film.

[0016] In one exemplary embodiment, the substrate has a carbon-containing mask on the first silicon-containing film and the second silicon-containing film.

[0017] In one exemplary embodiment, in the step of (c), the ratio of the etching rate of the second silicon-containing film to the etching rate of the first silicon-containing film is 0.95 to 1.05.

[0018] In one exemplary embodiment, the source RF signal and the bias signal are pulse waves.

[0019] In one exemplary embodiment, the source RF signal and the bias signal are continuous waves.

[0020] In one exemplary embodiment, among the processing gases supplied in the step of (b), the flow rate of HF gas is the highest except for the inert gas.

[0021] In one exemplary embodiment, the phosphorus-containing gas is a phosphorus halide gas.

[0022] In one exemplary embodiment, the processing gas further includes at least one of a fluorocarbon gas or a hydrofluorocarbon gas.

[0023] In one exemplary embodiment, the processing gas further includes a gas containing at least one of tungsten, molybdenum, and titanium.

[0024] In one exemplary embodiment, the processing gas further includes an oxygen-containing gas.

[0025] In one exemplary embodiment, the processing gas further includes a noble gas.

[0026] In one exemplary embodiment, an etching method executed in a plasma processing apparatus having a chamber, comprising: (a) providing a substrate having a first silicon-containing film and a second silicon-containing film including at least a silicon-containing film having a film type different from that of the first silicon-containing film on a substrate support in the chamber; (b) supplying a processing gas into the chamber; (c) generating a plasma containing HF species and phosphorus species from the processing gas in the chamber by a source RF signal and generating a bias potential on the substrate by a bias signal to etch the first silicon-containing film and the second silicon-containing film, wherein in step (c), (c1) supplying a source RF signal and a bias signal; (c2) stopping the supply of at least one of the source RF signal and the bias signal, or supplying at least one of the source RF signal and the bias signal at an effective power value lower than the effective power value of at least one of them in step (c1), and alternately repeating the above steps, an etching method is provided.

[0027] In one exemplary embodiment, the HF species is generated from at least one gas of HF gas or hydrofluorocarbon gas.

[0028] In one exemplary embodiment, the HF species is generated from a hydrofluorocarbon gas having 2 or more carbon atoms.

[0029] In one exemplary embodiment, the HF species is generated from a fluorine-containing gas and a hydrogen-containing gas.

[0030] In one exemplary embodiment, a plasma processing system includes a chamber, a substrate support provided in the chamber, a power supply, and a control unit. The control unit performs controls including: (a) providing a substrate having a first silicon-containing film and a second silicon-containing film including at least a silicon-containing film of a film type different from that of the first silicon-containing film on the substrate support; (b) supplying a processing gas including HF gas and a phosphorus-containing gas into the chamber; and (c) generating plasma from the processing gas in the chamber by a source RF signal and generating a bias potential on the substrate by a bias signal to etch the first silicon-containing film and the second silicon-containing film. In the control of (c), the control unit performs controls including: (c1) supplying the source RF signal and the bias signal from the power supply; and (c2) alternately repeating a control of stopping the supply of at least one of the source RF signal and the bias signal from the power supply, or supplying at least one of the source RF signal and the bias signal with an effective value of power lower than the effective value of at least one of the powers in the step of (c1).

[0031] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or similar elements are denoted by the same reference numerals, and redundant descriptions are omitted. Unless otherwise specified, the positional relationships such as up, down, left, and right are described based on the positional relationships shown in the drawings. The dimensional ratios in the drawings do not represent actual ratios, and the actual ratios are not limited to the illustrated ratios.

[0032] <Configuration Example of Plasma Processing System> A configuration example of a plasma processing system will be described below. FIG. 1 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

[0033] The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a control unit 2. The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. Further, the plasma processing apparatus 1 includes a substrate support unit 11 and a gas introduction unit. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes a shower head 13. The substrate support unit 11 is disposed in the plasma processing chamber 10. The shower head 13 is disposed above the substrate support unit 11. In one embodiment, the shower head 13 constitutes at least a part of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the shower head 13, the side wall 10a of the plasma processing chamber 10, and the substrate support unit 11. The plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space 10s and at least one gas discharge port for discharging gas from the plasma processing space. The plasma processing chamber 10 is grounded. The shower head 13 and the substrate support unit 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0034] The substrate support unit 11 includes a main body portion 111 and a ring assembly 112. The main body portion 111 has a central region 111a for supporting the substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of the substrate W. The annular region 111b of the main body portion 111 surrounds the central region 111a of the main body portion 111 in a plan view. The substrate W is disposed on the central region 111a of the main body portion 111, and the ring assembly 112 is disposed on the annular region 111b of the main body portion 111 so as to surround the substrate W on the central region 111a of the main body portion 111. Accordingly, the central region 111a is also referred to as a substrate support surface for supporting the substrate W, and the annular region 111b is also referred to as a ring support surface for supporting the ring assembly 112.

[0035] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that other members surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member, may have the annular region 111b. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. Also, at least one RF / DC electrode coupled to an RF (Radio Frequency) power supply 31 and / or a DC (Direct Current) power supply 32 described later may be disposed within the ceramic member 1111a. In this case, at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal described later are supplied to the at least one RF / DC electrode, the RF / DC electrode is also referred to as a bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as a plurality of lower electrodes. Also, the electrostatic electrode 1111b may function as a lower electrode. Accordingly, the substrate support portion 11 includes at least one lower electrode.

[0036] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge ring is formed of a conductive material or an insulating material, and the cover ring is formed of an insulating material.

[0037] Further, the substrate support portion 11 may include a temperature control module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature control module may include a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path 1110a. In one embodiment, the flow path 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. Further, the substrate support portion 11 may include a heat transfer gas supply portion configured to supply a heat transfer gas between the back surface of the substrate W and the central region 111a.

[0038] The shower head 13 is configured to introduce at least one process 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 a plurality of gas introduction ports 13c. The process 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 plurality of gas introduction ports 13c. Further, the shower head 13 includes at least one upper electrode. The gas introduction portion may include, in addition to the shower head 13, one or more side gas injectors (SGI) attached to one or more openings formed in the side wall 10a.

[0039] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from the corresponding gas source 21 to the shower head 13 via the corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Further, the gas supply unit 20 may include one or more flow modulation devices for modulating or pulsing the flow rate of at least one process gas.

[0040] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode and / or at least one upper electrode. Thereby, plasma is formed from at least one processing gas supplied to the plasma processing space 10s. Accordingly, the RF power supply 31 can function as at least a part of a plasma generation unit configured to generate plasma from one or more processing gases in the plasma processing chamber 10. Also, by supplying a bias RF signal to at least one lower electrode, a bias potential is generated on the substrate W, and the ion component in the formed plasma can be drawn into the substrate W.

[0041] In one embodiment, the RF power supply 31 includes a first RF generation unit 31a and a second RF generation unit 31b. The first RF generation unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit, and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generation 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 at least one lower electrode and / or at least one upper electrode.

[0042] The second RF generation unit 31b is coupled to at least one lower electrode via at least one impedance matching circuit and is configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generation unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0043] Also, the power supply 30 may include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generation unit 32a and a second DC generation unit 32b. In one embodiment, the first DC generation unit 32a is connected to at least one lower electrode and is configured to generate a first DC signal. The generated first bias DC signal is applied to at least one lower electrode. In one embodiment, the second DC generation unit 32b is connected to at least one upper electrode and is configured to generate a second DC signal. The generated second DC signal is applied to at least one upper electrode.

[0044] In various embodiments, at least one of the first and second DC signals may be pulsed. In this case, a sequence of DC-based voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a pulse waveform that is rectangular, trapezoidal, triangular, or a combination thereof. In one embodiment, a waveform generation unit for generating a sequence of voltage pulses from a DC signal is connected between the first DC generation unit 32a and at least one lower electrode. Accordingly, the first DC generation unit 32a and the waveform generation unit constitute a voltage pulse generation unit. When the second DC generation unit 32b and the waveform generation unit constitute a voltage pulse generation unit, the voltage pulse generation unit is connected to at least one upper electrode. The voltage pulses may have a positive polarity or a negative polarity. Also, the sequence of voltage pulses may include one or more positive-polarity voltage pulses and one or more negative-polarity voltage pulses within one cycle. Note that the first and second DC generation units 32a, 32b may be provided in addition to the RF power supply 31, or the first DC generation unit 32a may be provided in place of the second RF generation unit 31b.

[0045] The exhaust system 40 may be connected to, for example, a gas outlet 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 turbo molecular pump, a dry pump, or a combination thereof.

[0046] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to execute various processes described in the present disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to execute the various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 is realized, for example, by a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and perform various control operations by executing the read program. This program may be stored in the storage unit 2a2 in advance, or may be acquired via a medium when necessary. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 and executed. The medium may be various storage media readable by the computer 2a, or may be a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a LAN (Local Area Network).

[0047] <An example of an etching method> FIG. 2 is a flowchart showing an etching method (hereinafter also referred to as "the present processing method") according to one exemplary embodiment. As shown in FIG. 2, the present processing method includes a step ST1 of providing a substrate, a step ST2 of setting the temperature of the substrate support, a step ST3 of supplying a processing gas, and a step ST4 of performing etching. The processing in each step may be executed by the plasma processing system shown in FIG. 1. Hereinafter, a case where the control unit 2 controls each part of the plasma processing apparatus 1 to execute the present processing method on the substrate W will be described as an example.

[0048] (Process ST1: Provision of Substrate) In process ST1, substrate W is provided within the plasma processing space 10s of plasma processing apparatus 1. Substrate W is disposed on the upper surface of substrate support portion 11 so as to face the upper electrode, and is held by substrate support portion 11 by electrostatic chuck 1111.

[0049] FIG. 3 is a top view showing an example of substrate W provided in process ST1. FIG. 4 is a view showing a part of the AA' cross-section of substrate W shown in FIG. 3. Substrate W may be used in the manufacture of semiconductor devices including semiconductor memory devices such as DRAM and 3D-NAND flash memory.

[0050] Substrate W has a first region RE1 and a second region RE2. In a plan view of substrate W (the top view of FIG. 3), the first region RE1 and the second region RE2 are regions each having a predetermined range on substrate W. The first region RE1 and the second region RE2 may be two adjacent regions, or may be two separated regions. The first region RE1 may be, for example, a contact region or a peripheral circuit region in a semiconductor memory device. The contact region is, in one example, a region provided with one or more contact holes for electrically connecting one or more memory cells and a peripheral circuit. Also, the second region RE2 may be, for example, a memory cell region in a semiconductor memory device.

[0051] Substrate W has an underlayer film UF provided across the first region RE1 to the second region RE2. The underlayer film UF may be, for example, a silicon wafer, an organic film, a dielectric film, a metal film, a semiconductor film, etc. formed on a silicon wafer. The underlayer film UF may be a single-layer film or a laminated film in which a plurality of films are laminated. In one example, the underlayer film UF is a polysilicon film.

[0052] The substrate W has a first silicon-containing film SF1 provided on the underlayer film UF in the first region RE1. In one example, the first silicon-containing film SF1 may include at least one of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a polysilicon film. The first silicon-containing film SF1 may be a single-layer film or a laminated film in which two or more types of silicon-containing films are laminated. In one example, the first silicon-containing film SF1 is a single-layer film of a silicon oxide film.

[0053] The substrate W has a second silicon-containing film SF2 provided on the underlayer film UF in the second region RE2. The second silicon-containing film SF2 includes at least a silicon-containing film having a film type different from that of the first silicon-containing film SF1. The first silicon-containing film SF1 and the second silicon-containing film SF2 may have the same thickness as each other or may have different thicknesses. In one example, the second silicon-containing film SF2 may include at least one of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a polysilicon film. The second silicon-containing film SF2 may be a single-layer film or a laminated film in which two or more types of silicon-containing films are laminated. In one example, the second silicon-containing film SF2 is a laminated film in which a silicon nitride film SF2a and a silicon oxide film SF2b are alternately and repeatedly laminated.

[0054] The substrate W further has a mask MK. The mask MK is provided on the first silicon-containing film SF1 and the second silicon-containing film SF2. That is, the mask MK is provided across the first region RE1 to the second region RE2. The mask MK has a predetermined pattern. In the first region RE1, one or more openings OP1 are provided in the mask MK (note that a circular opening provided in the first region RE1 is also called an opening OP1a, and a rectangular slit (opening) is also called an opening OP1b). In one example, each of the one or more openings OP1 is an opening defined by sidewalls formed in the mask MK. Also, in the second region RE2, one or more openings OP2 are provided in the mask MK (note that a circular opening provided in the second region RE2 is also called an opening OP2a, and a rectangular slit (opening) is also called an opening OP2b). In one example, the one or more openings OP2 are openings defined by sidewalls formed in the mask MK).

[0055] In one example, the openings OP1 and OP2 are openings for forming holes, contact holes, line and space, slits, trenches, etc. in which memory cells are formed in the first silicon-containing film SF1 and / or the second silicon-containing film SF2. In one example, in plan view, the openings OP1 and OP2 have shapes such as circular, elliptical, linear, rectangular, etc. The openings OP1 and OP2 may have the same shape in plan view, or may have different shapes. The opening OP1 may have the same width as the opening OP2 (for example, the diameter of a circular opening, the minor axis of an elliptical opening, the line width of a linear opening, and the length of the short side or long side of a rectangular opening) or a different width. Also, the openings OP1 and OP2 may be integrally formed openings. As an example, the openings OP1 and OP2 may be part of one slit formed across the first region RE1 to the second region RE2).

[0056] In one example, as shown in FIG. 3, a plurality of openings OP1a having a circular shape in plan view may be provided in the first region RE1 of the mask MK. Further, a plurality of openings OP2a having a circular shape in plan view may be provided in the second region RE2 of the mask MK. The width (diameter) of the opening OP1a provided in the first region RE1 may be wider, narrower, or the same as the width (diameter) of the opening OP2a provided in the second region RE2.

[0057] In one example, as shown in FIG. 3, an opening having a slit shape in plan view may be provided across the first region RE1 to the second region RE2 of the mask MK. The opening has an opening OP1b which is a portion provided in the first region RE1 of the mask MK and an opening OP2b which is a portion provided in the second region RE2. The widths of the opening OP1b and the opening OP2b may be wider, narrower, or the same as the width (diameter) of the opening OP1a and / or the opening OP2a. Also, the width of the opening OP1b may be wider, narrower, or the same as the width of the opening OP2b. Further, the opening having a slit shape in FIG. 3 may be provided in only one of the first region RE1 and the second region RE2. That is, the opening may be a slit having only one of the opening OP1b and the opening OP2b.

[0058] The mask MK is formed of a material having an etching rate lower than the etching rates of the first silicon-containing film SF1 and the second silicon-containing film SF2 in step ST4. The mask MK may be formed of a carbon-containing material. The mask MK may be, for example, an amorphous carbon film, a photoresist film, or a SOC film (spin-on carbon film). The mask MK may also be a metal-containing film containing a metal such as tungsten, for example.

[0059] At least a part of the process of forming each component of the substrate W may be performed in the plasma processing chamber 10. In one example, the step of etching the mask MK to form the openings OP1 and OP2 may be executed in the plasma processing chamber 10. That is, the etching of the openings OP1, OP2 and the first silicon-containing film SF1 and the second silicon-containing film SF2 described later may be continuously executed in the same chamber. Also, after all or part of each component of the substrate W is formed by a device or chamber outside the plasma processing apparatus 1, the substrate W may be carried into the plasma processing space 10s of the plasma processing apparatus 1 and disposed on the upper surface of the substrate support portion 11.

[0060] (Substrate ST2: Temperature setting of the substrate support portion) In step ST2, the temperature of the substrate support portion 11 is adjusted to a set temperature of 0 °C or lower by the temperature control module. The set temperature may be -10 °C or lower, -20 °C or lower, -30 °C or lower, -40 °C or lower, -50 °C or lower, -60 °C or lower, or -70 °C or lower. In one example, adjusting or maintaining the temperature of the substrate support portion 11 includes adjusting or maintaining the temperature of the heat transfer fluid flowing through the flow path 1110a to the set temperature or a temperature different from the set temperature. In one example, adjusting or maintaining the temperature of the substrate support portion 11 includes controlling the pressure of the heat transfer gas (e.g., He) between the electrostatic chuck 1111 and the back surface of the substrate W. Note that the timing at which the heat transfer fluid starts to flow through the flow path 1110a may be before, after, or at the same time as the substrate W is placed on the substrate support portion 11. Also, in this processing method, step ST2 may be performed before step ST1. That is, after adjusting the temperature of the substrate support portion 11 to the set temperature, the substrate W may be provided to the substrate support portion 11. Note that in this processing method, the temperature of the substrate support portion 11 is also maintained at the set temperature in steps ST3 and ST4.

[0061] (Step ST3: Supply of the processing gas) In step ST3, the processing gas is supplied from the gas supply unit 20 into the plasma processing space 10s. The processing gas includes HF gas (hydrogen fluoride gas) and a phosphorus-containing gas. During step ST3, the temperature of the substrate support portion 11 is maintained at the set temperature (e.g., -70 °C).

[0062] Among the processing gases, excluding the inert gas, the flow rate of HF gas may be the highest. In one example, the HF gas may be 50% by volume or more, 60% by volume or more, 70% by volume or more, or even 80% by volume or more with respect to the total flow rate of the processing gas excluding the inert gas. As the HF gas, a high-purity one, for example, one with a purity of 99.999% or more can be used.

[0063] The processing gas may contain, instead of or in addition to the HF gas, a gas capable of generating HF species in the plasma. Note that the HF species include at least any one of hydrogen fluoride gas, radicals, and ions.

[0064] In one example, as the gas capable of generating HF species, a hydrofluorocarbon gas may be used. The hydrofluorocarbon gas may have 2 or more, 3 or more, or 4 or more carbon atoms. The hydrofluorocarbon gas, in one example, may be used as at least one selected from the group consisting of CH2F2 gas, C3H2F4 gas, C3H2F6 gas, C3H3F5 gas, C4H2F6 gas, C4H5F5 gas, C4H2F8 gas, C5H2F6 gas, C5H2F 10 gas and C5H3F7 gas. The hydrofluorocarbon gas, in one example, is used as at least one selected from the group consisting of CH2F2 gas, C3H2F4 gas, C3H2F6 gas, and C4H2F6 gas.

[0065] In one example, as the gas capable of generating HF species, a fluorine-containing gas and a hydrogen-containing gas may be used. The fluorine-containing gas, in one example, may use a fluorocarbon gas. The fluorocarbon gas may include at least one selected from the group consisting of C2F2 gas, C2F4 gas, C3F6 gas, C3F8 gas, C4F6 gas, C4F8 gas, and C5F8 gas. The fluorine-containing gas, in one example, may also use NF3 gas or SF6 gas. The hydrogen-containing gas, in one example, may use H2 gas, CH4 gas, or NH3 gas.

[0066] The phosphorus-containing gas is a gas containing a phosphorus-containing molecule. The phosphorus-containing molecule is phosphorus pentoxide (P4O10 ) oxides such as phosphorus octoxide (P4O8) and phosphorus hexoxide (P4O6) may also be used. Phosphorus decoxide is sometimes called phosphorus pentoxide (P2O5). The phosphorus-containing molecule may be a halide (phosphorus halide) such as phosphorus trifluoride (PF3), phosphorus pentafluoride (PF5), phosphorus trichloride (PCl3), phosphorus pentachloride (PCl5), phosphorus tribromide (PBr3), phosphorus pentabromide (PBr5), or phosphorus iodide (PI3). That is, the phosphorus-containing molecule may contain fluorine as a halogen element, such as phosphorus fluoride. Alternatively, the phosphorus-containing molecule may contain a halogen element other than fluorine as a halogen element. The phosphorus-containing molecule may be a phosphoryl halide such as phosphoryl fluoride (POF3), phosphoryl chloride (POCl3), or phosphoryl bromide (POBr3). The phosphorus-containing molecule may be phosphine (PH3), calcium phosphide (such as Ca3P2), phosphoric acid (H3PO4), sodium phosphate (Na3PO4), hexafluorophosphoric acid (HPF6), etc. The phosphorus-containing molecule may be fluorophosphines (H g PF h ). Here, the sum of g and h is 3 or 5. Examples of fluorophosphines include HPF2 and H2PF3. The treatment gas may contain, as at least one phosphorus-containing molecule, one or more of the above phosphorus-containing molecules. For example, the treatment gas may contain, as at least one phosphorus-containing molecule, at least one of PF3, PCl3, PF5, PCl5, POCl3, PH3, PBr3, or PBr5. When each phosphorus-containing molecule contained in the treatment gas is a liquid or a solid, each phosphorus-containing molecule may be vaporized by heating or the like and supplied into the plasma treatment space 10s.

[0067] The processing gas may further contain a carbon-containing gas. The carbon-containing gas may be at least one or both of a fluorocarbon gas and a hydrofluorocarbon gas. The fluorocarbon gas may contain at least one selected from the group consisting of C2F2 gas, C2F4 gas, C3F6 gas, C3F8 gas, C4F6 gas, C4F8 gas and C5F8 gas. The hydrofluorocarbon gas may contain at least one selected from the group consisting of CHF3 gas, CH2F2 gas, CH3F gas, C2HF5 gas, C2H2F4 gas, C2H3F3 gas, C2H4F2 gas, C3HF7 gas, C3H2F2 gas, C3H2F4 gas, C3H2F6 gas, C3H3F5 gas, C4H2F6 gas, C4H5F5 gas, C4H2F8 gas, C5H2F 10 gas and C5H3F7 gas. Further, the carbon-containing gas may be a linear one having an unsaturated bond. The linear carbon-containing gas having an unsaturated bond may be, for example, at least one selected from the group consisting of C3F6 (hexafluoropropene) gas, C4F8 (octafluoro-1-butene, octafluoro-2-butene) gas, C3H2F4 (1,3,3,3-tetrafluoropropene) gas, C4H2F6 (trans-1,1,1,4,4,4-hexafluoro-2-butene) gas, C4F8O (pentafluoroethyl trifluorovinyl ether) gas, CF3COF gas (1,2,2,2-tetrafluoroethan-1-one), CHF2COF (difluoroacetic acid fluoride) gas and COF2 (carbonyl fluoride) gas.

[0068] The processing gas may further contain a tungsten-containing gas. The tungsten-containing gas may be a gas containing tungsten and a halogen. In one example, WF a Cl bIt is a gas (a and b are each an integer of 0 or more and 6 or less, and the sum of a and b is 2 or more and 6 or less). Specifically, examples of the tungsten-containing gas include gases containing tungsten and fluorine such as tungsten difluoride (WF2) gas, tungsten tetrafluoride (WF4) gas, tungsten pentafluoride (WF5) gas, and tungsten hexafluoride (WF6) gas, and gases containing tungsten and chlorine such as tungsten dichloride (WCl2) gas, tungsten tetrachloride (WCl4) gas, tungsten pentachloride (WCl5) gas, and tungsten hexachloride (WCl6) gas. Among these, it may be at least one of WF6 gas and WCl6 gas. The flow rate of the tungsten-containing gas may be 5% by volume or less, 1% by volume or less, 0.5% by volume or less, or 0.2% by volume or less with respect to the total flow rate of the processing gas excluding the inert gas.

[0069] Instead of or in addition to the tungsten-containing gas, the processing gas may contain at least one of a molybdenum-containing gas and a titanium-containing gas.

[0070] The processing gas may further contain an oxygen-containing gas. The oxygen-containing gas may be, for example, at least one gas selected from the group consisting of O2, CO, CO2, H2O, and H2O2. In one example, the processing gas may contain at least one gas selected from the group consisting of oxygen-containing gases other than H2O, that is, O2, CO, CO2, and H2O2. The flow rate of the oxygen-containing gas may be adjusted according to the flow rate of a carbon-containing gas such as a fluorocarbon gas or a hydrofluorocarbon gas.

[0071] The processing gas may further contain a noble gas such as Ar gas, He gas, or Kr gas or an inert gas such as nitrogen gas.

[0072] (Step ST4: Etching) FIG. 5 is a diagram showing an example of the cross-sectional structure of the substrate W during the process of Step ST4. In Step ST4, the first silicon-containing film SF1 and the second silicon-containing film SF2 are etched simultaneously. During Step ST4, the temperature of the substrate support portion 11 is maintained at a set temperature (for example, -70°C).

[0073] In process ST4, the supply and stop of at least one of the source RF signal and the bias signal may be alternately repeated. For example, while the source RF signal is continuously supplied, the supply and stop of the bias signal may be alternately repeated. Also, for example, while the supply and stop of the source RF signal are alternately repeated, the bias signal may be continuously supplied. Also, for example, the supply and stop of both the source RF signal and the bias signal may be alternately repeated. Here, the source RF signal is a signal for generating plasma from the process gas and is supplied from the first RF generation unit 31a to the lower electrode and / or the upper electrode. The source RF signal has a frequency in the range of 10 MHz to 150 MHz in one example.

[0074] Also, the bias signal is a signal for generating a bias potential on the substrate W and is supplied from the second RF generation unit 31b as a bias RF signal or from the DC generation unit 32a as a bias DC signal to the lower electrode. The bias signal has a frequency in the range of 1 to 200 kHz in one example. The bias signal may have a frequency in the range of 5 to 100 kHz.

[0075] Both the source RF signal and the bias signal may be continuous waves or pulse waves, or one may be a continuous wave and the other may be a pulse wave. When both the source RF signal and the bias signal are pulse waves, the periods of both pulse waves may be synchronized. Also, the duty ratio of the pulse wave may be set as appropriate, for example, it may be 1 to 80%, or 5 to 50%. Note that the duty ratio is the ratio of the period of the pulse wave during which the power or voltage level is high. Also, when using a bias DC signal, the pulse wave may have a waveform of a rectangle, trapezoid, triangle, or a combination thereof. The polarity of the bias DC signal may be negative or positive as long as the potential of the substrate W is set so as to give a potential difference between the plasma and the substrate and draw in ions.

[0076] As described above, in step ST4, the supply and stop of at least one of the source RF signal and the bias signal may be repeated a plurality of times. While the source RF signal and / or the bias signal is being supplied, there is heat input due to these signals, so the surface temperature of the substrate W becomes higher than the set temperature of the substrate support portion 11 (for example, -70°C). While the supply of the source RF signal and / or the bias signal is stopped, there is no heat input due to these signals, so the surface temperature of the substrate W approaches the set temperature of the substrate support portion 11 (for example, -70°C). That is, by repeating the supply and stop of at least one of the source RF signal and the bias signal, the surface temperature of the substrate W is controlled. The surface temperature of the substrate W is maintained at a lower temperature compared to the case where the supply of the source RF signal and the bias signal is continuous.

[0077] In step ST4, the supply and stop of the source RF signal and / or the bias signal may be periodically repeated. That is, a period T1 during which the source RF signal and / or the bias signal is supplied and a period T2 during which it is stopped are defined as one cycle, and the cycle may be repeated a plurality of times. In one example, the period T1 and the period T2 may each be in the range of 0.1 to 30 seconds, may be in the range of 0.5 to 20 seconds, or may be in the range of 1 to 10 seconds. The ratio of the period T1 to the period T2 (on / off ratio) may be appropriately set based on the target surface temperature of the substrate W. If the period of the period T2 becomes longer with respect to the period T1, the surface temperature of the substrate W becomes lower, and if the period of the period T2 becomes shorter with respect to the period T1, the surface temperature of the substrate W becomes higher.

[0078] By supplying a source RF signal and a bias RF signal, plasma is generated from a processing gas, a bias potential is generated on the substrate W, and chemical species in the plasma are attracted to the surface of the substrate W. As a result, as shown in FIG. 5, the portion of the first silicon-containing film SF1 exposed at the opening OP1 is etched in the depth direction (the direction from top to bottom in FIG. 5). Based on the shape of the opening OP1 of the mask MK, a recess RC1 is formed in the first silicon-containing film SF1. Further, the portion of the second silicon-containing film SF2 exposed at the opening OP2 is etched in the depth direction. Then, based on the shape of the opening OP2 of the mask MK, a recess RC2 is formed in the second silicon-containing film SF2. That is, the etching of the first silicon-containing film SF1 and the second silicon-containing film SF2 proceeds simultaneously.

[0079] In step ST4, etching may be performed by repeating the supply and stop of the source RF signal and / or the bias signal. As a result, compared with the case where the source RF signal and the bias signal are continuously supplied, the surface temperature of the substrate W decreases, and the adsorption of HF species in the recesses RC1 and RC2 can be promoted. Therefore, the etching rates of the first silicon-containing film SF1 and the second silicon-containing film SF2 increase. Further, the amount of increase in the etching rate due to the decrease in the surface temperature of the substrate W is different between the first silicon-containing film SF1 and the second silicon-containing film SF2. Therefore, by adjusting the amount of decrease in the surface temperature of the substrate W, the difference in the etching rates of the first silicon-containing film SF1 and the second silicon-containing film SF2 can be reduced. That is, the selectivity of the second silicon-containing film with respect to the first silicon-containing film can be made close to 1. For example, the selectivity can be suppressed in the range of 0.95 to 1.05.

[0080] FIG. 6 is a diagram showing an example of the cross-sectional structure of the substrate W after the treatment in step ST4. In the treated substrate W, the first silicon-containing film SF1 and the second silicon-containing film SF2 are etched in the depth direction, and the bottoms of the recess RC1 and the recess RC2 have reached the underlying film UF almost simultaneously. The aspect ratio of the recess RC1 and / or the recess RC2 in this state may be, for example, 20 or more, 30 or more, 40 or more, 50 or more, or 100 or more.

[0081] According to this treatment method, while increasing the etching rates of the first silicon-containing film SF1 and the second silicon-containing film SF2, the uniformity of the etching rates of both can be improved. Therefore, this treatment method can preferably etch the first silicon-containing film SF1 and the second silicon-containing film SF2 even in a case where, for example, it is difficult to obtain a selectivity with respect to the underlying film UF and stop etching with the underlying film UF.

[0082] <Example> Next, an example of this treatment method will be described. The present disclosure is not limited in any way by the following examples.

[0083] (Example 1) In Example 1, this treatment method was applied using the plasma processing apparatus 1, and a substrate having the same structure as the substrate W shown in FIG. 4 was etched. As the mask MK, a polysilicon film was used. As the first silicon-containing film SF1, a single-layer film of a silicon oxide film (also referred to as an "Ox film") was used. As the second silicon-containing film SF2, a laminated film (also referred to as an "ON film") in which a silicon nitride film SF2a and a silicon oxide film SF2b were alternately and repeatedly laminated was used. The processing gas contained HF gas, a phosphorus-containing gas, and argon gas. During the etching, the temperature of the substrate support portion 11 was set to -70°C, and the supply (5 seconds) and stop (10 seconds) of the source RF signal and the bias signal were repeated.

[0084] (Reference Example 1) Using the plasma processing apparatus 1, a substrate having the same configuration as in Example 1 was etched. Etching was performed under the same conditions as in Example 1, except that the supply of the source RF signal and the bias signal was continued during etching.

[0085] In Example 1, the etching rate of the Ox film was 1169 nm / min, and the etching rate of the ON film was 1196 nm / min. In Example 1, the selectivity of the ON film with respect to the Ox film was 0.98. Also, the surface temperature of the substrate W was -31°C. On the other hand, in Comparative Example 1, the etching rate of the Ox film was 722 nm / min, and the etching rate of the ON film was 558 nm / min. In Comparative Example 1, the selectivity of the ON film with respect to the Ox film was 0.77. Also, the surface temperature of the substrate W was 27°C.

[0086] In Example 1, compared with Comparative Example 1, the etching rates of both the first silicon-containing film SF1 (Ox film) and the second silicon oxide film SF2 (ON film) were improved. This is presumably because the decrease in the temperature of the substrate W promoted the adsorption of HF species on the surfaces of the Ox film and the ON film. Also, in Example 1, compared with Comparative Example 1, the selectivity of the ON film with respect to the Ox film, that is, the uniformity of the etching rates of the Ox film and the ON film was also improved. This is presumably because the Ox film has a greater promoting effect on the adsorption of HF species (that is, the increase amount of the etching rate) due to the temperature decrease than the ON film.

[0087] <Modification> Embodiments of the present disclosure can be variously modified without departing from the scope and spirit of the present disclosure.

[0088] For example, in step ST4, instead of or in addition to repeating the supply and stop of the source RF signal and / or the bias signal, the following process may be performed. That is, in step ST4, (A1) a step of supplying the source RF signal and the bias signal, and (A2) a step of supplying at least one of the source RF signal and the bias signal with an effective value of power lower than that of the corresponding signal in the step of (A1) may be alternately repeated. Even in this case, the surface temperature of the substrate W can be reduced compared to the case where the source RF signal and the bias signal are continuously supplied. Thus, the same effect as repeating the supply and stop of the source RF signal and / or the bias signal can be obtained.

[0089] For example, in step ST4, the temperature of the substrate W or the substrate support 11 may be measured. Then, based on the measured temperature, the output of at least one of the source RF signal and the bias signal used in step ST4 may be adjusted. Here, the "output of the signal" may be, for example, one or more of the effective value of the power of the signal, the supply time of the signal, and the duty ratio of the signal. By adjusting the output of the signal, the temperature of the substrate W can be adjusted. For example, when the measured temperature of the substrate W or the substrate support 11 is higher than the set value, the output of the above signal may be lowered (lowering the effective value of the power, shortening the supply time, reducing the duty ratio, etc.) to lower the surface temperature of the substrate W.

[0090] For example, in step ST4, instead of or in addition to repeating the supply and stop of the source RF signal and / or the bias signal, the following process may be performed. That is, a step of supplying the source RF signal and the bias signal to etch the first silicon-containing film and the second silicon-containing film, and this step may include (B1) a step of measuring the temperature of the substrate W and / or the substrate support 11, and (B2) a step of controlling the temperature of the substrate W and / or the substrate support 11 to be below a given temperature based on the measured temperature.

[0091] The temperature control of the substrate W and / or the substrate support portion 11 in the step of (B2) may be performed, for example, by adjusting the effective value of the power of the source RF signal, the supply time, or the duty ratio. Further, the temperature control may be performed by adjusting the effective value of the power of the bias RF signal, the supply time, or the duty ratio. Further, the temperature control may be performed by adjusting the temperature or the flow rate of the electrothermal fluid flowing through the flow path 1110a. Further, the temperature control may be performed by adjusting the temperature or the flow rate of the heat transfer gas supplied between the back surface of the substrate W and the central region 111a. Further, the temperature control may be performed by adjusting the adsorption force between the electrostatic chuck 1111 and the substrate W. Note that the temperature control may be performed by adjusting any one or more of the above.

[0092] For example, this processing method may be executed using a plasma processing apparatus using an arbitrary plasma source such as an inductively coupled plasma or a microwave plasma, in addition to the capacitively coupled plasma processing apparatus 1.

[0093] The embodiments of the present disclosure further include the following aspects.

[0094] (Appendix 1) A device manufacturing method executed in a plasma processing apparatus having a chamber, (a) A step of providing a substrate having a first silicon-containing film and a second silicon-containing film including at least a silicon-containing film having a film type different from that of the first silicon-containing film on a substrate support portion in the chamber; (b) A step of supplying a processing gas including HF gas and a phosphorus-containing gas into the chamber; (c) A step of generating plasma from the processing gas in the chamber by a source RF signal and generating a bias potential on the substrate by a bias signal while setting the temperature of the substrate support portion to 0°C or lower, thereby simultaneously etching the first silicon-containing film and the second silicon-containing film. In the step (c), steps (c1) of supplying the source RF signal and the bias signal, and (c2) of stopping the supply of the source RF signal and the bias signal are alternately repeated. Device manufacturing method.

[0095] (Appendix 2) To a computer of a plasma processing system including a chamber, a substrate support provided in the chamber, and a power supply, (a) Control to provide a substrate having a first silicon-containing film and a second silicon-containing film including at least a silicon-containing film of a film type different from the first silicon-containing film on the substrate support; (b) Control to supply a processing gas including HF gas and phosphorus-containing gas into the chamber; (c) While setting the temperature of the substrate support to 0°C or lower, generating plasma from the processing gas in the chamber by a source RF signal and generating a bias potential on the substrate by a bias signal to simultaneously etch the first silicon-containing film and the second silicon-containing film. In the control of (c), a program that executes control to alternately repeat (c1) control to supply the source RF signal and the bias signal from the power supply and (c2) control to stop the supply of the source RF signal and the bias signal from the power supply.

[0096] (Appendix 3) A storage medium storing the program according to Appendix 2.

[0097] (Appendix 4) An etching method executed in a plasma processing apparatus having a chamber, the method comprising: (a) A step of providing a substrate having a first silicon-containing film and a second silicon-containing film including at least a silicon-containing film of a film type different from the first silicon-containing film on a substrate support in the chamber; (b) A step of supplying a processing gas including HF gas and phosphorus-containing gas into the chamber; (c) Generating plasma from the processing gas in the chamber by the source RF signal and generating a bias potential on the substrate by the bias signal to etch the first silicon-containing film and the second silicon-containing film, The step (c) includes: (c1) measuring the temperature of the substrate or the substrate support; and (c2) controlling the temperature of the substrate or the substrate support to be equal to or lower than a given temperature based on the measured temperature. Etching method.

Description of reference numerals

[0098] 1... Plasma processing apparatus, 2... Control unit, 10... Plasma processing chamber, 10s... Plasma processing space, 11... Substrate support, 13... Shower head, 20... Gas supply unit, 31a... First RF generation unit, 31b... Second RF generation unit, 32a... First DC generation unit, SF1... First silicon-containing film, SF2... Second silicon-containing film, MK... Mask, OP1, OP2... Openings, RC1, RC2... Recesses, UF... Underlying film, W... Substrate

Claims

1. An etching method performed in a plasma processing apparatus having a chamber, comprising: (a) providing a substrate having a first silicon-containing film and a second silicon-containing film including at least a silicon-containing film having a film type different from that of the first silicon-containing film on a substrate support in the chamber; (b) supplying a processing gas containing HF gas and a phosphorus-containing gas into the chamber; (c) generating plasma from the processing gas in the chamber by a source RF signal and generating a bias potential on the substrate by a bias signal to etch the first silicon-containing film and the second silicon-containing film, wherein in step (c), steps (c1) of supplying the source RF signal and the bias signal and (c2) of stopping the supply of at least one of the source RF signal and the bias signal, or supplying at least one of the source RF signal and the bias signal at an effective power value lower than the effective power value of the at least one in step (c1) are alternately repeated, wherein the period of step (c1) and the period of step (c2) are each in the range of 1 second to 10 seconds. Etching method.

2. The etching method according to claim 1, wherein in step (c), the temperature of the substrate support is set to 0° C. or lower.

3. The etching method according to claim 1 or 2, wherein step (c) further includes a step of measuring the temperature of the substrate or the substrate support.

4. The etching method according to claim 3, wherein in at least one of steps (c1) and (c2), based on the measured temperature, at least one of the effective power value, supply time, and duty ratio of at least one of the source RF signal and the bias signal is adjusted.

5. The etching method according to claim 1, wherein the first silicon-containing film is a single-layer film composed of one type of silicon-containing film, and the second silicon-containing film is a laminated film in which two or more types of silicon-containing films are laminated.

6. The etching method according to claim 1, wherein the first silicon-containing film includes a silicon oxide film.

7. The etching method according to claim 1, wherein the second silicon-containing film includes a silicon oxide film and a silicon nitride film.

8. The etching method according to claim 1, wherein the substrate has a carbon-containing mask film on the first silicon-containing film and the second silicon-containing film.

9. The etching method according to claim 1, wherein in the step (c), the ratio of the etching rate of the second silicon-containing film to the etching rate of the first silicon-containing film is 0.95 to 1.

05.

10. The etching method according to claim 1, wherein the source RF signal and the bias signal are pulse waves.

11. The etching method according to claim 1, wherein the source RF signal and the bias signal are continuous waves.

12. The etching method according to claim 1, wherein among the processing gases supplied in the step (b), the flow rate of the HF gas is the highest excluding the inert gas.

13. The etching method according to claim 1, wherein the phosphorus-containing gas is a phosphorus halide gas.

14. The etching method according to claim 1, wherein the processing gas further includes at least one of a fluorocarbon gas or a hydrofluorocarbon gas.

15. The etching method according to claim 1, wherein the processing gas further includes a gas containing at least one of tungsten, molybdenum, and titanium.

16. The etching method according to claim 1, wherein the processing gas further includes an oxygen-containing gas.

17. The etching method according to claim 1, wherein the processing gas further includes a noble gas.

18. An etching method performed in a plasma processing apparatus having a chamber, comprising: (a) providing a substrate having a first silicon-containing film and a second silicon-containing film including at least a silicon-containing film of a film type different from the first silicon-containing film on a substrate support portion in the chamber; (b) supplying a processing gas into the chamber; (c) generating a plasma containing HF species and phosphorus chemical species from the processing gas in the chamber by a source RF signal, and generating a bias potential on the substrate by a bias signal to etch the first silicon-containing film and the second silicon-containing film. In the step (c), (c1) a step of supplying the source RF signal and the bias signal; and (c2) stopping the supply of at least one of the source RF signal and the bias signal, or supplying at least one of the source RF signal and the bias signal with an effective power value lower than the effective power value of the at least one in the step (c1) are alternately repeated. The period of the step (c1) and the period of the step (c2) are each in the range of 1 second to 10 seconds. Etching method.

19. The etching method according to claim 18, wherein the HF species is generated from at least one gas of HF gas or hydrofluorocarbon gas.

20. The etching method according to claim 18, wherein the HF species is generated from a hydrofluorocarbon gas having 2 or more carbon atoms.

21. The etching method according to claim 18, wherein the HF species is generated from a fluorine-containing gas and a hydrogen-containing gas.

22. A chamber, a substrate support provided in the chamber, a power source, and a control unit, The control unit (a) Control to provide a substrate having a first silicon-containing film and a second silicon-containing film including at least a silicon-containing film of a film type different from the first silicon-containing film on the substrate support; (b) Control to supply a processing gas including HF gas and a phosphorus-containing gas into the chamber; (c) Control to generate plasma from the processing gas in the chamber by a source RF signal and generate a bias potential on the substrate by a bias signal, thereby etching the first silicon-containing film and the second silicon-containing film. In the control of (c), (c1) control to supply the source RF signal and the bias signal from the power source; and (c2) stopping the supply of at least one of the source RF signal and the bias signal from the power source, or supplying at least one of the source RF signal and the bias signal with an effective power value lower than the effective power value of the at least one in the step (c1) are alternately repeated. In the control of (c), (c1) control to supply the source RF signal and the bias signal from the power source; and (c2) stopping the supply of at least one of the source RF signal and the bias signal from the power source, or supplying at least one of the source RF signal and the bias signal with an effective power value lower than the effective power value of the at least one in the step (c1) are alternately repeated. The period of the step (c1) and the period of the step (c2) are each in the range of 1 second to 10 seconds. Plasma processing system.

Images