Etching method and plasma processing apparatus

Abstract

This invention provides a technology to suppress shape abnormalities during etching. [Solution] (a) A step of preparing a substrate on a substrate support, wherein the substrate is silicon The system comprises a silicon-containing film and a mask on the silicon-containing film, wherein the mask is the silicon-containing film A process comprising a side wall defining at least one opening that exposes, (b) In the process of generating plasma from a processing gas containing hydrogen fluoride gas and bromine-containing gas The first protective film containing bromine is formed up to the lower part of the side wall, and the silicon-containing A process including forming a recess in a film, Etching methods including

Description

[Technical Field]

[0001] Exemplary embodiments of this disclosure relate to etching methods and plasma processing apparatus. [Background technology]

[0002] Patent Document 1 discloses a method for etching a film within a substrate. The film is silicon The substrate contains an aluminum film, and the substrate further has a mask provided on the film. The mask is made of an aluminum film. The method includes fascia carbon or organic polymers. Etching in this method is performed using hydrocarbon gases. Plasma generated from a processing gas containing fluorohydrocarbon gas is also used. . [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2016-39310 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] This disclosure provides a technology for suppressing shape abnormalities during etching. [Means for solving the problem]

[0005] In one exemplary embodiment of the present disclosure, (a) in the step of preparing a substrate on a substrate support: The substrate comprises a silicon-containing film and a mask on the silicon-containing film, The mask comprises a side wall that defines at least one opening that exposes the silicon-containing film. (b) The process involves generating plasma from a processing gas containing hydrogen fluoride gas and bromine-containing gas. A step of forming a first protective film containing bromine up to the lower part of the side wall, and forming a concave portion in the silicon-containing film, and a step, and an etching method is provided. including forming a concave portion in the silicon-containing film, and a step, and an etching method is provided. is provided.

Effect of the Invention

[0006] According to one exemplary embodiment of the present disclosure, a technique for suppressing shape abnormalities in etching can be provided. can be provided.

Brief Description of the Drawings

[0007] [Figure 1] It is a diagram for explaining a configuration example of a plasma processing system. [Figure 2] It is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus. [Figure 3] It is a flowchart showing an example of this etching method. [Figure 4] It is a diagram showing an example of a cross-sectional structure of a substrate W prepared in step ST1. [Figure 5] It is a diagram showing an example of a cross-sectional structure of a substrate W during the execution of step ST2.

Mode for Carrying Out the Invention

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

[0009] In one exemplary embodiment, (a) a step of preparing a substrate on a substrate support portion, wherein the substrate includes a silicon-containing film and a mask on the silicon-containing film, and the mask has side walls defining at least one opening exposing the silicon-containing film, and a step where the substrate includes a silicon-containing film and a mask on the silicon-containing film, and the mask has side walls defining at least one opening exposing the silicon-containing film, and a step defining side walls defining at least one opening exposing the silicon-containing film, and a step , (b) a step of generating plasma from a processing gas containing hydrogen fluoride gas and bromine-containing gas, forming a first protective film containing bromine up to the lower part of the side wall, and the silicon-containing forming a first protective film containing bromine up to the lower part of the side wall, and the silicon-containing An etching method is provided that includes a step of forming a recess in the film.

[0010] In one exemplary embodiment, the lower part of the sidewall includes a boundary with the silicon-containing film. including.

[0011] In one exemplary embodiment, the bromine-containing gas includes a bromine-containing unsaturated halon gas. including.

[0012] In one exemplary embodiment, the bromine-containing gas is R 1 R 2 C=CR 3 R 4 (where R 1 , R 2 , R 3 and R 4 each independently represents a hydrogen atom or a halogen atom, and at least one of R 1 , R 2 , R 3 and R 4 is a bromine atom.) and includes an unsaturated halon represented by.

[0013] [[ID=4८]]In one exemplary embodiment, the unsaturated halon includes C2BrF3.

[0014] In one exemplary embodiment, (b) further includes forming a second protective film on at least a part of the sidewall that defines the recess. including.

[0015] In one exemplary embodiment, the second protective film does not contain bromine or contains bromine at a lower concentration than the first protective film. including.

[0016] In one exemplary embodiment, the etching method further includes a step of controlling the temperature of the substrate support portion to 0 °C or lower between (c) (a) and (b ).

[0017] In one exemplary embodiment, the processing gas is a phosphorus-containing gas, a carbon-containing gas, and the above From the group consisting of halogen-containing gases and metal-containing gases that are different from bromine-containing unsaturated halon gases It further includes at least one selected gas.

[0018] In one exemplary embodiment, the phosphorus-containing gas is composed of at least PF3 and POCl3. This also includes the other side.

[0019] In one exemplary embodiment, the carbon-containing gas is a CF-based gas, a CHF-based gas, and It includes at least one selected from the group consisting of CH-based gases.

[0020] In one exemplary embodiment, the halogen-containing gas is Cl2, HCl, and HBr It includes at least one selected from the group consisting of the following.

[0021] In one exemplary embodiment, the metal-containing gas is at least WF6 and MoF6. Including one of them.

[0022] In one exemplary embodiment, the silicon-containing film is a silicon oxide film, silicon It includes at least one selected from the group consisting of nitride films and polycrystalline silicon films.

[0023] In one exemplary embodiment, the mask is made of a carbon-containing film, a metal-containing film and other silicon It includes at least one selected from the group consisting of a condensate-containing membrane.

[0024] In one exemplary embodiment, the metal-containing film includes a tungsten-containing film.

[0025] In one exemplary embodiment, the other silicon-containing film includes a BSi film.

[0026] In one exemplary embodiment, a chamber and a substrate support provided within the chamber. The system comprises a control unit and a control unit, the control unit being (a) a control for preparing the substrate on the substrate support unit. The above substrate comprises a silicon-containing film and a mask on the silicon-containing film, The control has a side wall that defines at least one opening that exposes the silicon-containing film. (b) Controls that generate plasma from a processing gas containing hydrogen fluoride gas and bromine-containing gas. The first protective film containing bromine is formed up to the lower part of the side wall, and the silicone The system is configured to perform control, which includes forming a recess in the ion-containing film. A plasma processing device is provided.

[0027] Each embodiment of this disclosure will be described in detail below with reference to the drawings. In this context, identical or similar elements are denoted by the same symbol, and redundant explanations are omitted. Unless otherwise specified. Unless otherwise specified, the positional relationships (up, down, left, right, etc.) will be explained based on the positional relationships shown in the drawing. The ratios shown do not represent actual ratios, and actual ratios are limited to those shown in the illustrations. There isn't one.

[0028] <An example of a plasma treatment system> Figure 1 is a diagram illustrating an example configuration of a plasma processing system. In one embodiment... The plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The stem is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 comprises a plasma processing chamber 10, a substrate support section 11 and a plasma It includes a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 supplies at least one processing gas to the plasma processing space. At least one gas supply port for and a few for exhausting gas from the plasma processing space It has at least one gas outlet. The gas supply port is connected to the gas supply unit 20, which will be described later. The gas outlet is connected to the exhaust system 40, which will be described later. The substrate support section 11 is plasma It is positioned within the processing space and has a substrate support surface for supporting the substrate.

[0029] The plasma generation unit 12 receives at least one processing gas supplied into the plasma processing space. It is configured to generate plasma. Plasma is formed in the plasma processing space. Capacitively Coupled Plasma (CCP) ma), Inductively Coupled Plasma (ICP) sma), ECR (Electron Cyclotron Resonance) plastic Zuma, Helicon Wave Plasma (HWP), Or, surface wave plasma (SWP), etc. This is also acceptable. Furthermore, the AC (Alternating Current) plasma generation unit and D Various types of plasma generation, including a C (Direct Current) plasma generation unit. A composite unit may be used. In one embodiment, an AC signal used in the AC plasma generation unit AC power has frequencies within the range of 100kHz to 10GHz. Therefore, AC The signals include RF (Radio Frequency) signals and microwave signals. In this configuration, the RF signal has a frequency within the range of 100kHz to 150MHz. .

[0030] The control unit 2 causes the plasma processing apparatus 1 to perform the various processes described in this disclosure. It processes computer-executable instructions. The control unit 2 implements the various processes described here. Each element of the plasma processing apparatus 1 may be configured to be controlled in such a manner. In this configuration, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 is For example, this is implemented by computer 2a. The control unit 2 includes a processing unit 2a1, a storage unit 2a2 and The processing unit 2a1 described in this disclosure may include a communication interface 2a3. The functions that will be realized are general-purpose programmed to realize the functions described therein. Rosser, application processor, integrated circuit (integrated circuit) ,ASICs(Application Specific Integrated C IRCUITs), CPU (Central Processing Unit), conventional Conventional circuitry, and / or combinations thereof Circuits or processing circuits that include The processor may be implemented in a uitry. The processor uses transistors and other circuits. A circuit or processing circuit that includes other circuitry. This is a programmed processor that executes the program stored in memory unit 2a2. This is also acceptable. This program may be stored in memory unit 2a2 beforehand, and when needed. It may also be acquired via a medium. The acquired program is stored in the storage unit 2a2. The processing unit 2a1 reads from the storage unit 2a2 and executes the data. The medium is a computer. The storage medium may be any type of storage medium readable by the 2a, and the communication interface 2a3 It may also be a connected communication line. The memory unit 2a2 is RAM (Random Access). cess Memory), ROM (Read Only Memory), HDD (H ard Disk Drive), SSD (Solid State Drive), or This may include combinations of these. Communication interface 2a3 is LAN (Loc Communication between the plasma processing apparatus 1 and the other via a communication line such as an area network. You may believe it. In this disclosure, circuits, units, and means achieve the functions described. Hardware programmed to or configured to perform such actions. The hardware in question is any hardware described in this disclosure, or the hardware described in this disclosure. Programmed to perform or known to perform a given function. Any hardware may be used. The hardware in question is considered to be a type of circuit. In the case of a processor, the circuit, means, or unit comprises hardware and the hardware. It is a combination of software used to constitute hardware and / or a processor.

[0031] Below is an example of the configuration of a capacitively coupled plasma processing apparatus as an example of plasma processing apparatus 1. Let me explain. Figure 2 is a diagram illustrating an example of the configuration of a capacitively coupled plasma processing apparatus. be.

[0032] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, and an electric power supply unit. It includes a source system 30 and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support section 11 and a gas introduction section are included. The gas introduction section provides at least one processing gas to the plasma processing section. It is configured to be introduced into the chamber 10. The gas inlet includes the shower head 13. The substrate support section 11 is located inside the plasma processing chamber 10. The shower head 13 is It is positioned above the substrate support portion 11. In one embodiment, the shower head 13 is plastic It constitutes at least a portion of the ceiling of the Zuma processing chamber 10. The processing chamber 10 includes a shower head 13, the side wall 10a of the plasma processing chamber 10, and The plasma processing space 10s is defined by the substrate support portion 11. The 10 is grounded. The shower head 13 and the substrate support 11 are connected to the plasma processing chamber. It is electrically isolated from the 10 enclosures.

[0033] The substrate support portion 11 includes the main body portion 111 and the ring assembly 112. The main body portion 111 is , a central region 111a for supporting the substrate W, and for supporting the ring assembly 112 It has an annular region 111b. The wafer is an example of a substrate W. Annular region of the main body 111 111b surrounds the central region 111a of the main body 111 in a plan view. The substrate W is the main body The ring assembly 112 is positioned on the central region 111a of 111, and is located within the main body 111. It is positioned on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a. Therefore, the central region 111a is also called the substrate support surface for supporting the substrate W, and the annular region Region 111b is also called the ring support surface for supporting the ring assembly 112.

[0034] 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 functions as the lower electrode. It is possible. The electrostatic chuck 1111 is placed on the base 1110. Electrostatic chuck 111 1 is a ceramic member 1111a and an electrostatic chatter placed inside the ceramic member 1111a It includes an electrostatic chuck electrode 1111b. Note that the electrostatic chuck electrode 1111b is an adsorption electrode (clam Also called a ping electrode. In one embodiment, the electrostatic chuck electrode 11 11b is electrically connected or coupled to the chuck power supply. The chuck power supply is a DC power supply. It may also be an AC power supply. The ceramic member 1111a is located in the central region 111a It has. In one embodiment, the ceramic member 1111a also has an annular region 111b. Furthermore, other components surrounding the electrostatic chuck 1111, such as annular electrostatic chucks or annular insulating members, may be used. The member may have an annular region 111b. In this case, the ring assembly 112 is an annular static It may be placed on an electrostatic chuck or an annular insulating member, and the annular insulating member may be placed on an electrostatic chuck 1111. They may be placed on both sides of the component. Also, power to power supply 31 and / or power supply 32, which will be described later, is used. At least one bias electrode is connected or coupled to the ceramic member 1111a They may be arranged in this way. In this case, at least one bias electrode functions as the lower electrode. Furthermore, the conductive member of the base 1110 and the bias electrode in the ceramic member 1111a are multiple It may also function as a lower electrode. In one embodiment, it is configured with a voltage pulse generation unit described later. The first voltage generating unit 32a, which functions as a first voltage generating unit, provides a bias electrode within the ceramic member 1111a. The first RF generation unit 31a, which will be described later, is electrically connected or coupled to the conductive base 1110. It is electrically connected or coupled to the component. Also, the electrostatic chuck electrode 1111b is the lower electrode. It may function in this way. Therefore, the substrate support portion 11 includes at least one lower electrode.

[0035] The ring assembly 112 includes one or more annular members. In one embodiment, one or The multiple annular members include one or more edge rings and at least one covering ring. The edge ring is formed of a conductive or insulating material, and the covering is made of an insulating material. It is formed.

[0036] Furthermore, the substrate support section 11 includes the electrostatic chuck 1111, the ring assembly 112 and the substrate. This includes a temperature control module configured to adjust at least one of them to a target temperature. However, this is also acceptable. The temperature control module includes a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. It may also contain a waste product. A heat transfer fluid such as brine or gas flows through the channel 1110a. In one embodiment, a flow path 1110a is formed within the base 1110, and one or more heaters The ceramic member 1111a of the electrostatic chuck 1111 is placed inside the ceramic member 1111a. Also, the substrate support part 11 is configured to supply heat transfer gas to the gap between the back surface of the substrate W and the central region 111a. It may also include a heat transfer gas supply unit.

[0037] The shower head 13 receives at least one processing gas from the gas supply unit 20 for plasma treatment. It is configured to be introduced into the spatial space 10s. The shower head 13 has at least one A gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas inlets 13c The processed gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and undergoes multiple processes. It is introduced into the plasma processing space 10s from the gas inlet 13c. Also, shower head 1 3 includes at least one upper electrode. The gas inlet is attached to the shower head 13. Furthermore, one or more side It may include a gas injection section (SGI; Side Gas Injector).

[0038] The gas supply unit 20 includes at least one gas source 21 and at least one flow controller. 22 may be included. In one embodiment, the gas supply unit 20 has at least one processing gas The gas is supplied from the corresponding gas source 21 to the corresponding flow controller 22. It is configured to supply to the shower head 13. Each flow controller 22 is configured, for example, a mass flow controller. It may include a controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 is At least one flow modulation device modulates or pulses the flow rate of at least one processing gas. Chairs may be included.

[0039] The power supply system 30 is a power supply 3 that is electrically connected or coupled to the plasma processing chamber 10. Includes 1. In one embodiment, the power supply 31 has at least one impedance matching device It is electrically connected or coupled to the plasma processing chamber 10 via an impedance matching device. This may be a mechanically controlled matching circuit or an electronically controlled matching circuit. Power supply 31 is At least one RF signal (RF power) is transmitted to at least one lower electrode and / or less It is configured to supply to another upper electrode. This allows the plasma to be supplied to the plasma processing space 10s. Plasma is generated from at least one supplied processing gas. Therefore, the power supply 31 is It can function as at least a part of the plasma generation unit 12. Also, the bias RF signal is reduced. By supplying to at least one lower electrode, a bias potential is generated on the substrate W, and a bias potential is formed. This allows ionic components in the plasma to be drawn into the substrate W.

[0040] The power supply 31 includes a first RF generation unit 31a and a second RF generation unit 31b. The generating unit 31a supplies electricity to at least one lower electrode and / or at least one upper electrode. A saw is connected or coupled to generate plasma in the plasma processing space 10s. It is configured to generate a source RF signal (source RF power). In one embodiment, the first The RF generation unit 31a is connected to at least one impedance matching device It is electrically connected or coupled to the lower electrode and / or at least one upper electrode. In this configuration, 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 generates multiple sources having different frequencies. The system may be configured to generate RF signals. The generated one or more source RF signals are It is supplied to at least one lower electrode and / or at least one upper electrode.

[0041] The second RF generation unit 31b is electrically connected or coupled to at least one lower electrode, It is configured to generate a bias RF signal (bias RF power). In one embodiment, The second RF generation unit 31b then generates at least one impedance matching device. Both are electrically connected or coupled to one lower electrode. The first RF generation unit 31a is the lower electrode When electrically connected or coupled to the second RF generation unit 31b, the second RF generation unit 31b electrically connects to the same lower electrode. It may be connected to or coupled to, or electrically connected to or coupled to, other lower electrodes. The frequency of the source 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 that of the source RF signal. It has. In one embodiment, the bias RF signal is in the range of 100kHz to 60MHz. It has a frequency within the range. In one embodiment, the second RF generation unit 31b has different frequencies It may be configured to generate multiple bias RF signals. Several bias RF signals are supplied to at least one lower electrode. Also, various implementations In this state, at least one of the source RF signal and the bias RF signal is pulsed. That's fine.

[0042] Furthermore, the power supply system 30 is electrically connected or coupled to the plasma processing chamber 10. It may include a power supply 32. The power supply 32 includes a first voltage generation unit 32a and a second voltage generation unit 3 Includes 2b. In one embodiment, the first voltage generating unit 32a has at least one lower voltage It is electrically connected or coupled to the pole and configured to generate a first voltage signal. The first voltage signal is applied to at least one lower electrode. In one embodiment, The voltage generating unit 32b of the 2 is electrically connected or coupled to at least one upper electrode, and the second It is configured to generate a voltage signal. The generated second voltage signal has at least one It is applied to the upper electrode.

[0043] In various embodiments, the first and / or second voltage signals may be pulsed. In this case, the first voltage generation unit 32a and / or the second voltage generation unit 32b generate the voltage pulse. It functions as a voltage pulse generator configured to generate voltage pulses. The sequence of Russ is imprinted on at least one lower electrode and / or at least one upper electrode. It is added. In one embodiment, the sequence of voltage pulses has multiple cycles, each The cycle includes a burst of voltage pulses in the first period and a constant reference voltage in the second period. This includes, in other words, a sequence of voltage pulses in which bursts of voltage pulses are repeated. The absolute value of the voltage level of a voltage pulse is greater than the absolute value of the voltage level of the reference voltage. The pulse may be any waveform having a rectangular, trapezoidal, triangular, or a combination thereof. The arbitrary waveform may change over time. The voltage pulse may have positive polarity, or negative polarity. It may have properties. Also, the voltage pulse sequence may have one or more positive electrodes within one cycle. The first and second may include a polar voltage pulse and one or more negative voltage pulses. The voltage generating units 32a and 32b may be provided in addition to the power supply 31, and the first voltage generating unit 3 2a may be provided in place of the second RF generation unit 31b.

[0044] The exhaust system 40 includes, for example, a gas outlet located at the bottom of the plasma processing chamber 10. It may be connected to 10e. 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 is This may include turbomolecular pumps, dry pumps, or combinations thereof.

[0045] <An example of etching method> Figure 3 shows an etching method according to an exemplary embodiment (hereinafter also referred to as "this method"). This is a flowchart. This method involves a step ST1 for preparing the substrate and a step for generating plasma. This includes step ST2. Each step is one of the plasma processing systems described above (see Figures 1 and 2). The process may be carried out using any one of these plasma processing systems, or by using two or more of these plasma processing systems. It may be carried out using the plasma processing system shown in Figure 1. In the following section, the control unit 2 controls each part of the plasma processing apparatus 1 shown in Figure 2, and applies to the substrate W. Let's explain using the example of how this method is implemented.

[0046] (Step ST1: Preparation of the substrate) In step ST1, the substrate W is prepared on the substrate support portion 11. In one embodiment, the substrate W is transported into the chamber 10 by a transport arm and placed on the substrate support section 11 by a lifter. It is placed and, for example, held by suction on the substrate support portion 11 as shown in Figure 2.

[0047] Figure 4 shows an example of the cross-sectional structure of the substrate W prepared in process ST1. To that end, the substrate W has a silicon-containing film SF and a mask MK on an arbitrary underlayer film UF. The layers may be stacked in this order. The substrate W consists of a silicon-containing film SF and a silicon-containing film It comprises a mask MK placed on the SF. The mask MK exposes the silicon-containing film SF. It has at least one aperture OP. The substrate W may be used in the manufacture of semiconductor devices. Semiconductor devices include, for example, memory such as DRAM and 3D-NAND flash memory. This includes devices and logic devices.

[0048] The underlayer UF is, in one example, a silicon wafer or an organic film formed on a silicon wafer, or an induction film. These include electrochemical films, metal films, semiconductor films, etc. The underlayer film UF is composed of multiple films stacked on top of each other. stomach.

[0049] Examples of silicon-containing film SF include spin-on-glass (SOG) films and Si-containing reflective films. Silicon oxide film (SiARC), silicon oxide film, silicon nitride film, silicon oxynitride film, silicon Examples include carbide films, silicon carbonitride films, polycrystalline silicon films, and amorphous silicon films. In one embodiment, the silicon-containing film SF is a silicon oxide film, a silicon nitride film and It includes at least one selected from the group consisting of polycrystalline silicon films. For example, silico The silicon-containing film is a laminated film of silicon oxide film and silicon nitride film, or a silicon oxide film and polycrystalline silicon It is a laminated film with a silicon film. For example, silicon-containing film SF is a silicon oxide film and silicon The film may be constructed by alternately stacking nitride films. For example, the silicon-containing film SF is made of silicon The structure may consist of alternating layers of oxide film and polycrystalline silicon film. For example, silicon-containing The film SF may be a multilayer film including a silicon nitride film, a silicon oxide film, and a polycrystalline silicon film. In one embodiment, the silicon-containing film SF is selected from the group consisting of H, P, N, and B. It may contain at least one element.

[0050] The silicon-containing film SF and the undercoat film UF are, respectively, CVD (Chemical Vapor Deposit). n) method, ALD (Atomic Layer Deposition) method, MLD (Molecular Layer Deposition) method It may be formed by methods such as the PVD (Physical Vapor Deposition) method, the spin-coating method, etc. The silicon-containing film SF and the undercoat film UF may each be flat films, or they may have irregularities. It may also be a membrane having a film.

[0051] The mask MK is formed on a silicon-containing film SF and defines at least one opening OP. The mask MK is equipped with a side wall Wa. The mask MK is a carbon-containing film, a metal-containing film and other silicon-containing films. It includes at least one selected from silicon-containing films (different from silicon-containing films) This may be done. In one embodiment, the carbon-containing film is a spin-on carbon (SOC) film, an amorphous film. Fascarbon (ACL) film, photoresist film, tungsten carbide film, or boron carbide It may be a film. As an example, a carbon-containing film includes an ACL film. In one embodiment, gold The included film contains tungsten, molybdenum, ruthenium, titanium, tin, and aluminum. The film may contain at least one metal selected from the group. For example, The containing film includes a tungsten-containing film. In one embodiment, the other silicon-containing film is a tungsten-containing film. Silicon oxide film, silicon nitride film, silicon carbonitride film, polycrystalline silicon film, carbon-containing silicon It may be a film. Other silicon-containing films may be doped with elements such as phosphorus, boron, or nitrogen. It may also be included. For example, other silicon-containing films include BSi films. In one embodiment The mask MK can be a single-layer mask consisting of one layer, or a multi-layer mask consisting of two or more layers. It may also be a layered mask. In one embodiment, the mask MK is a photoresist. Good. In one embodiment, the mask MK is protected from extreme ultraviolet light. Violet; hereafter referred to as "EUV") is a photoresist exposed by EUV. Alternatively, the metal-containing resist may be exposed by EUV. In this context, the mask MK is a chemically amplified resist. d Resist; hereafter referred to as "CAR".) ) may be. For example, CAR is They may also be exposed by EUV.

[0052] In the example shown in Figure 4, the mask MK has a side wall Wa and a top surface Wb. The side wall Wa is small At most, one aperture OP is defined. The aperture OP is defined in a plan view of the substrate W, that is, the substrate W is shown in the diagram. When viewed from above to below, 4 may have any shape. For example, the shape may be a circle, ellipse, rectangle, line, or a combination of one or more of these. The square MK has multiple side walls, and the multiple side walls may define multiple openings OP. Each of the OPs has a linear shape and is arranged at regular intervals to form a line and space pattern. This may be done. In addition, each of the multiple openings OP has a hole shape and constitutes an array pattern. It may also be the case that the dimensions of the aperture OP are 100 nm or less, and 50 It may be less than or equal to nm, and may be less than or equal to 30 nm. In one embodiment, aperture OP These may be formed by lithography. For example, the aperture OP is a silicon-containing film SF The photoresist formed on top may be formed by exposure and development. When using EUV resist as the resist, exposure is performed using an EUV exposure apparatus. It may be so. Also, development may be dry development or wet development. .

[0053] A small number of processes for forming the substrate W underlayer UF, silicon-containing film SF, and mask MK Some of these processes may be carried out within the chamber 10 as part of process ST1. For example, mask When forming the opening OP of MK by etching, the etching in step ST1 and The processing in step ST2 may be carried out continuously within the chamber 10. In one embodiment... In this case, all or part of the substrate W is formed in an external device or chamber of the plasma processing apparatus 1. After that, the substrate W may be provided inside the chamber 10.

[0054] In one embodiment, after the substrate W is provided to the central region 111a of the substrate support portion 11, The plate support section 11 is controlled to a set temperature by the temperature control module. The set temperature is, for example, 0°C. Below, -10℃ or below, -20℃ or below, -30℃ or below, -40℃ or below, -50℃ or below, -6 A temperature of 0°C or below, or -70°C or below, is acceptable. In one example, the temperature of the substrate support part 11 is controlled to the set temperature. This involves setting the temperature of the heat transfer fluid flowing through channel 1110a and the heater temperature to the set temperature. Alternatively, this includes setting the temperature to a different temperature than the set temperature. Note that the heat transfer fluid flows through the flow path 1110a. The timing at which this begins may be before or after the substrate W is placed on the substrate support part 11, and also the same It may be at any time. Also, the temperature of the substrate support part 11 is controlled to the set temperature before process ST1. i. That is, after the temperature of the substrate support part 11 is controlled to the set temperature, the substrate support part 11 Board W may be provided.

[0055] In one embodiment, instead of controlling the substrate support portion 11 to a set temperature, the substrate W is provided The temperature may be controlled to a constant temperature. Controlling the temperature of the substrate W to a set temperature is done by the substrate support part 11. To set the temperature of the heat transfer fluid flowing through channel 1110a and / or the heater temperature to the set temperature, This includes setting the temperature to a different temperature than the set temperature.

[0056] (Process ST2: Plasma generation) In process ST2, hydrogen fluoride gas (hereinafter also referred to as "HF gas") and bromine-containing gas are used. Plasma is generated from a processing gas containing the following. In process ST2, the plasma is generated. As a result, a first protective film PM containing bromine is formed up to the bottom of the side wall Wa. Also, step ST2 In this case, the generation of plasma creates recesses RC in the silicon-containing film SF. In the application process, the formation of the first protective film PM and the formation of the recessed area RC are carried out in parallel. In the application process, the formation of the first protective film PM progresses, followed by the formation of the recessed area RC. In this embodiment, the formation of the recess RC proceeds, followed by the formation of the first protective film PM. In one embodiment, step ST2 involves supplying a processing gas to the chamber 10 and processing gas This includes generating plasma from a material.

[0057] In step ST2, a process gas is supplied into the chamber 10. The process gas is, for example, From the gas supply unit 20, through the gas inlet 13c of the central gas injection unit 13, into the chamber 10 It may be supplied. The processing gas includes HF gas and bromine-containing gas. Substrate support part 11 or base The temperature of plate W may be controlled to a set temperature, similar to process ST1.

[0058] HF gas can have the highest flow rate (partial pressure) among the processed gases, excluding inert gases. The flow rate of HF gas is the total flow rate of the process gas (if the process gas contains an inert gas, these...) (of the flow rate of all gases except gases) 50% or more by volume, 60% or more by volume, 70% by volume The above amounts may be 80% by volume or more, 90% by volume or more, or 95% by volume or more. The flow rate of HF gas is Less than 100% by volume, 99.5% or less by volume, 98% or less by volume, or It is acceptable to have a volume percentage of 96% or less. For example, the flow rate of HF gas is 7% of the total flow rate of the processed gas. It is between 0% and 96% by volume.

[0059] In one embodiment, the bromine-containing gas includes a bromine-containing unsaturated halon gas. In this context, bromine-containing unsaturated halon gas is R1 R 2 C=CR 3 R 4 (Here, R 1 , R 2 , R 3 and R 4 Each of these independently represents a hydrogen atom or a halogen atom, and R 1 , R 2 , R 3 and R 4 of It contains an unsaturated halon represented by ), which has at least one bromine atom. The unsaturated halon includes at least one of C2BrF3 and C2H2BrF. Unsaturated halons include C2BrF3. In addition to the above, bromine-containing gases further include HBr. You may stay.

[0060] In one embodiment, the processing gas is a phosphorus-containing gas, a carbon-containing gas, and a bromine-containing unsaturated halo At least one gas selected from the group consisting of halogen-containing gases and metal-containing gases that are different from halogen gases. It also contains another type of gas.

[0061] For example, the phosphorus-containing gas may be, for instance, a halogenated phosphorus gas. Phosphorus gas, for example, PF3 gas and PF5 gas, contains fluorine as a halogen element. It can be phosphorus gas. Examples of halogenated phosphorus gases include PCl3 gas and PCl5 gas. It may be phosphorus chloride gas containing chlorine as a halogen element. Phosphorus halogenated gas is, for example, For example, as halogen elements in gases like PBr3, PBr5, and PI3, bromine and iodine... It may also be a gas containing. Phosphorus halogenated gas is, for example, PClF2 gas, PCl2F The gas may also contain two or more halogen elements, such as PCl2F3 gas. Phosphorus gas may be, for example, oxyphosphorus fluoride gas or oxyphosphorus chloride gas. Phosphorus chlorogenates include, for example, POF3 gas, POCl3 gas, POF2Cl2 gas, and POF It may be Cl2 gas or POF2Cl gas.

[0062] In one embodiment, the carbon-containing gas is obtained from CF-based gas, CHF-based gas, and CH-based gas. It includes at least one selected from the group. CF-based gases include, for example, CF4 gas and C2 F2 gas, C2F4 gas, C3F6 gas, C3F8 gas, C4F6 gas, C4F8 gas and C5F8 gas It may be at least one selected from the group consisting of S. CHF gases are, for example, CHF 3 gases, CH2F2 gas, CH3F gas, C2HF5 gas, and hydrofluoric acid containing three or more C atoms Selected from the group consisting of low-carbon gases (C3H2F4 gas, C3H2F6 gas, C4H2F6 gas, etc.) At least one of the selected types is sufficient.

[0063] In one embodiment, a halogen-containing gas different from a bromine-containing unsaturated halon gas is Cl 2. Contains at least one selected from the group consisting of HCl and HBr.

[0064] In one embodiment, the metal-containing gas is tungsten, titanium, lutein It comprises at least one metal selected from the group consisting of nium and molybdenum. In this state, the metal-containing gas may further contain halogens. The metal-containing gas is WF2 gas WF4 gas, WF5 gas, WF6 gas, WCl2 gas, WCl4 gas, WCl5 gas, WC Examples include l6 gas, MoF4 gas, MoF6 gas, MoCl6 gas, TiCl4 gas, etc.

[0065] In one embodiment, the processing gas may further contain an inert gas. For example, an inert gas The gas can be, for example, a noble gas such as Ar gas, He gas, or Kr gas, or N2 gas.

[0066] In one embodiment, the processing gas is replaced with a portion or all of the HF gas in the plasma. It may contain a gas capable of producing hydrogen fluoride species (HF species). HF species are hydrogen fluoride gas, It contains at least one of dical and ionic. Gases capable of producing HF species include, for example, C HF-based gases are acceptable. CHF-based gases may have 2 or more carbon atoms, 3 or more carbon atoms, or 4 or more carbon atoms. .

[0067] A gas capable of producing HF species may be, for example, a mixed gas containing a hydrogen source and a fluorine source. The source is a group consisting of, for example, H2 gas, NH3 gas, H2O gas, H2O2 gas, and CH-based gases. It may be at least one selected from the following. The fluorine source may be, for example, NF3 gas, SF6 gas, W Any fluorine-containing gas that does not contain carbon, such as F6 gas or XeF2 gas, may be used. Alternatively, fluorine-containing gases that include carbon, such as CF-based gases and CHF-based gases, may also be used.

[0068] Next, plasma is generated from the processing gas in the chamber 10. In one embodiment, A source RF signal is supplied to the lower electrode of the plate support 11 and / or the upper electrode of the shower head 13. It is supplied. When a high-frequency electric field is generated between the shower head 13 and the substrate support part 11, Plasma is generated from the processing gas in the plasma processing space 10s. At this time, the substrate support part A bias signal may be supplied to 11. The bias signal is supplied from the RF power supply 31. This may be an IAS RF signal or a bias DC signal supplied from the DC power supply 32. In this case, a bias potential is generated between the plasma and the substrate W.

[0069] Figure 5 shows an example of the cross-sectional structure of the substrate W during process ST2. In this process, bromine dissociated from the bromine-containing gas in the processing gas is deposited on the mask MK into the plasma. This results in the formation of a first protective film PM on the mask MK. The first protective film PM is Contains bromine. In one embodiment, the first protective film PM is located on the upper part of the side wall Wa of the mask MK ( From here on, this will also be referred to as "Second Region R2.") down to the lower part (hereinafter also referred to as "First Region R1.") It is formed in one embodiment, the first region R1 of the side wall Wa is formed by the mask MK and the silicone From the boundary position P1 with the saturates-containing film SF to position P2, which is half the thickness (50%) of the mask MK. It may be an inclusive region. The second region R2 is from position P2 to position P3 on the upper surface of mask MK. It may be a region including. In one embodiment, the first protective film PM is one of the first region R1 It may be formed on part of or on the whole. In one embodiment, the first protective film PM may be formed in part of the second region R1, or it may be formed in all of it. In this state, the first protective film PM is also formed on the upper surface Wb of the mask MK, as shown in Figure 5. You may do so.

[0070] Active species such as ions and radicals in the plasma are attracted to the substrate W. At this time, The scrub MK functions as a mask, and the part of the silicon-containing film SF that is exposed to the opening OP. The material is selectively etched by active species (e.g., HF species) in the plasma. As shown in Figure 5, a recess RC is formed. At this time, the first protective film PM is mask MK It functions as a protective film against the side wall Wa of the mask MK. The first protective film PM acts as a protective film against the side wall Wa of the mask MK It is formed from the upper part (second region R2) to the lower part (first region R1). The sidewall Wa is etched laterally (left-right direction in Figure 5) by active species in the plasma. This can be suppressed not only at the top but also at the bottom of the side wall Wa of the mask MK. This can help suppress the occurrence of shape abnormalities such as bowing in recessed RC sections.

[0071] When the bromine-containing gas contains bromine-containing unsaturated halon gas, the first protective film PM has side walls Wa It is formed further down, for example, up to the boundary position P1 with the silicon-containing film or in its vicinity. Obtain. In this case, the occurrence of shape abnormalities in Boeing and other aircraft can be further suppressed. One implementation form In this state, if the bromine-containing gas includes bromine-containing unsaturated halon gas and hydrogen bromide gas, The flow rate of the element-containing unsaturated halon gas may be greater than the flow rate of the hydrogen bromide gas. For example, When the bromine-containing gas includes C2BrF3 gas and hydrogen bromide gas, C2 in the chlorine-containing gas The flow rate of BrF3 gas can be higher than that of hydrogen bromide gas.

[0072] In one embodiment, step ST2 is performed on at least a portion of the side wall Wc defining the recess RC This may further include forming a second protective film, which is not shown. In one embodiment, the second The protective film may contain reaction products generated by etching. For example, silicon-containing If the film contains a silicon nitride film, the second protective film is ammonium silicofluoride (NH4 ) may contain 2SiF6(AFS). In one embodiment, the second protective film does not contain bromine. It may contain squid or bromine at a lower concentration than that of the first protective film PM.

[0073] In one embodiment, during the formation process of the recessed RC, the bottom of the recess reaches the underlying film UF. By doing so, at least a portion of the undercoat UF can be exposed to the opening OP. (Step ST) 2 is after at least a portion of the undercoat UF is exposed, or at least a portion of the undercoat UF The process may be terminated before (for example, immediately before) exposure. Also, process ST2 may be terminated under the given stop conditions. The process may be terminated when the following condition is met. The termination condition is, for example, the etching time. It may be the depth of the recessed RC. The operation at the end of etching is source R The F signal, bias RF signal, bias DC signal, and the cessation of the supply of the first processing gas may be used. stomach.

[0074] <Examples> Next, we will describe an example of evaluating pattern shapes based on this method. This disclosure is as follows: This is not limited in any way by the embodiments described herein.

[0075] (Reference example 1) A device having a configuration similar to the plasma processing apparatus 1 shown in Figure 2 was prepared. The substrate of this device A substrate was placed on the support portion 11. This substrate had the same configuration as the substrate W shown in Figure 4. As the silicon-containing film SF, a laminated film of silicon oxide and silicon nitride was used. There was. For the mask MK, an amorphous carbon film was used. Multiple openings OP were formed that exposed the smotherapeutic film SF. That is, multiple openings OP were They were formed to constitute a pattern of contact holes.

[0076] Etching is performed using the above plasma processing apparatus to form a contact hole pattern. In etching, a processing gas containing HF gas, HBr gas, and PF3 gas was used. there was.

[0077] As a result of the etching described above, the recesses formed in the silicon-containing film contain Boeing (hereinafter referred to as A shape like this is also called the "Boeing shape." It was confirmed that this was occurring. Also, In addition to the top surface of the mask, bromine-containing gas is present at the upper part of the side wall that defines the opening OP of the mask. A protective film originating from (HBr gas) was observed to form.

[0078] (Reference example 2) Except for changing the amount of HBr gas to 2.5 times the amount in the etching conditions of Reference Example 1, The contact hole pattern was formed in the same manner as in Reference Example 1.

[0079] As a result of the above etching, the bowing shape of the recess formed in the silicon-containing film is shown as an example. It was about the same as 1. That is, the maximum value of the opening dimension of the Boeing in Reference Example 2 (hereinafter Also called "BCD".) was 95.2% of the BCD in Reference Example 1. In this case, as in Reference Example 1, in addition to the top surface of the mask, the side walls that define the opening OP of the mask. A protective film originating from bromine-containing gas (HBr gas) was observed in the upper part of the sample.

[0080] (Example 1) In the etching conditions of Reference Example 1, C2BrF3 gas was also used as the processing gas. Except for the above, the contact hole pattern was formed in the same manner as in Reference Example 1.

[0081] As a result of the etching described above, the bowing shape of the recesses formed in the silicon-containing film was improved. This was observed. Specifically, the BCD of Example 1 was 92.6% of the BCD of Reference Example 1. In Example 1, in addition to the top surface of the mask, the upper to lower part of the side wall of the mask (mask The entire area, up to the boundary with the silicon-containing film, is affected by bromine-containing gas (C2BrF3 gas). A protective film was observed. Thus, a protective film originating from bromine-containing gas formed at the opening of the mask. When the P-force was formed down to the lower part of the sidewall, there was a tendency for the boeing to be suppressed. Furthermore, when using unsaturated halons such as C2BrF3 as the bromine-containing gas, A protective film originating from the material tended to form down to the lower part of the side wall.

[0082] Embodiments of this disclosure further include the following embodiments:

[0083] (Note 1) (a) A step of preparing a substrate on a substrate support, wherein the substrate comprises a silicon-containing film and The system comprises a mask on the silicon-containing film, the mask exposing the silicon-containing film. A process comprising a side wall defining at least one opening, (b) A process in which plasma is generated from a processing gas containing hydrogen fluoride and bromine-containing gas. The first protective film containing bromine is formed up to the lower part of the side wall, and the silicon-containing film A process including forming a recess therein, Etching methods, including

[0084] (Note 2) The lower part of the side wall includes the boundary with the silicon-containing film, as described in Appendix 1. Method.

[0085] (Note 3) The bromine-containing gas includes bromine-containing unsaturated halon gas, as described in Appendix 1 or 2. Method of ing.

[0086] (Note 4) The aforementioned bromine-containing gas is R 1 R 2 C=CR 3 R4 (Here, R 1 , R 2 , R 3 and R 4 Each is independent Standing up, it represents a hydrogen atom or a halogen atom, R 1 , R 2 , R 3 and R 4 At least one of them smells It is an elementary atom.) Includes unsaturated halons represented by any of the notes 1 to 3. Method of ing.

[0087] (Note 5) The etching method described in Appendix 4, wherein the unsaturated halon includes C2BrF3.

[0088] (Note 6) (b) above, a second protective film is formed on at least a portion of the side wall defining the recess. The etching method described in any of the appendices 1 to 5, further including the above.

[0089] (Note 7) The second protective film is bromine-free, or contains a lower concentration of bromine than the first protective film. Including the etching method described in Appendix 6.

[0090] (Note 8) (c) Between (a) and (b), the temperature of the substrate support portion is controlled to 0°C or below. An etching method described in any of Appendix 1 to 8, further including the process of controlling.

[0091] (Note 9) The aforementioned processing gas is different from phosphorus-containing gas, carbon-containing gas, and bromine-containing unsaturated halon gas. At least one gas selected from the group consisting of halogen-containing gases and metal-containing gases. The etching method described in any of the appendices 1 to 9, further including the above.

[0092] (Note 10) The phosphorus-containing gas includes at least one of PF3 and POCl3, as described in Appendix 9. Checking method.

[0093] (Note 11) The carbon-containing gas is selected from the group consisting of CF-based gases, CHF-based gases, and CH-based gases. The etching method described in Appendix 9 or 10, comprising at least one of the following.

[0094] (Note 12) The halogen-containing gas is selected from the group consisting of Cl2, HCl, and HBr, and is less than one of the following: An etching method described in any of the appendices 9 to 11, including one of the types.

[0095] (Note 13) The aforementioned metal-containing gas includes at least one of WF6 and MoF6, as specified in appendices 9 to 12. Etching method as described below.

[0096] (Note 14) The silicon-containing film is made from a silicon oxide film, a silicon nitride film, and a polycrystalline silicon film. Etching as described in any of the appendices 1 to 13, including at least one selected from the group. Method.

[0097] (Note 15) The mask is selected from the group consisting of carbon-containing films, metal-containing films, and other silicon-containing films. An etching method according to any one of Appendix 1 to 14, comprising at least one of the following.

[0098] (Note 16) The etching method described in Appendix 15 includes an amorphous carbon film as the carbon-containing film. .

[0099] (Note 17) The metal-containing film includes a tungsten-containing film, as described in Appendix 15 or 16. method.

[0100] (Note 18) The aforementioned other silicon-containing film includes a BSi film, as described in any of appendices 15 to 17. How to chat.

[0101] (Note 19) Chamber and, A substrate support portion provided within the chamber, Control unit and Equipped with, The control unit, (a) A control for preparing a substrate on a substrate support, wherein the substrate has a silicon-containing film and The device comprises a mask on the silicon-containing film, the mask exposing the silicon-containing film. A control and a side wall comprising at least one opening, (b) A control system that generates plasma from a processing gas containing hydrogen fluoride and bromine-containing gas. This involves forming a first protective film containing bromine up to the lower part of the side wall, and the silicon-containing Control, including forming a recess in the film, A plasma processing apparatus configured to perform control including the following.

[0102] Each of the embodiments described above is for illustrative purposes only and is not intended to limit the scope of this disclosure. This is not a diagram. Each embodiment can be described in various ways without departing from the scope and spirit of this disclosure. It can be modified. For example, some components in one embodiment can be added to another embodiment. It is possible to modify some components in one embodiment to correspond to those in another embodiment. It can be replaced with the component that does not. [Explanation of Symbols]

[0103] 1...Plasma processing apparatus, 2...Control unit, 10...Plasma processing chamber, 11...Substrate Support part, W... Substrate, SF... Silicon-containing film, MK... Mask, OP... Aperture, Wa... ...side wall, RC...recess, R1...first region, R2...second region, PM...first protective film

Claims

1. (a) A step of preparing a substrate on a substrate support, wherein the substrate comprises a silicon-containing film and The system comprises a mask on the silicon-containing film, the mask exposing the silicon-containing film. A process comprising a side wall defining at least one opening, (b) In the process of generating plasma from a processing gas containing hydrogen fluoride gas and bromine-containing gas The first protective film containing bromine is formed up to the lower part of the side wall, and the silicon-containing A process including forming a recess in a film, Etching methods, including

2. The lower part of the side wall includes the boundary with the silicon-containing film, as described in claim 1. Method of ing.

3. The etching according to claim 1, wherein the bromine-containing gas includes a bromine-containing unsaturated halon gas. method.

4. The aforementioned bromine-containing gas is R 1 R 2 C=CR 3 R 4 (Here, R 1 , R 2 , R 3 and R 4 Each is independent represents a hydrogen atom or a halogen atom, and R 1 , R 2 , R 3 and R 4 at least one of which is bromine The etching method according to claim 1, comprising an unsaturated halon represented by (which is an elementary atom).

5. The aforementioned unsaturated halon is C 2 BrF 3 The etching method according to claim 4, including the method described in claim 4.

6. (b) above, a second protective film is formed on at least a portion of the side wall defining the recess. The etching method according to claim 1, further comprising the following:

7. The second protective film is bromine-free, or contains a lower concentration of bromine than the first protective film. The etching method according to claim 6, including.

8. (c) Between (a) and (b), the temperature of the substrate support portion is controlled to 0°C or below. The etching method according to claim 1, further comprising the step of controlling.

9. The aforementioned processing gas is different from phosphorus-containing gas, carbon-containing gas, and bromine-containing unsaturated halon gas. At least one gas selected from the group consisting of halogen-containing gases and metal-containing gases. The etching method according to claim 1, further comprising:

10. The phosphorus-containing gas is PF 3 and POCl 3 The claim 9 includes at least one of the following Etching method.

11. The carbon-containing gas is selected from the group consisting of CF-based gases, CHF-based gases, and CH-based gases. The etching method according to claim 9, comprising at least one of the following.

12. The halogen-containing gas is Cl 2 Selected from the group consisting of HCl and HBr, The etching method according to claim 9, which includes one type.

13. The aforementioned metal-containing gas is WF 6 and MoF 6 The E according to claim 9, which includes at least one of the Checking method.

14. The silicon-containing film is made from a silicon oxide film, a silicon nitride film, and a polycrystalline silicon film. The etching method according to claim 1, comprising at least one selected from the group.

15. The mask is selected from the group consisting of carbon-containing films, metal-containing films, and other silicon-containing films. The etching method according to claim 1, comprising at least one of the following.

16. The etching method according to claim 15, wherein the carbon-containing film includes an amorphous carbon film. Law.

17. The etching method according to claim 15, wherein the metal-containing film includes a tungsten-containing film.

18. The etching method according to claim 15, wherein the other silicon-containing film includes a BSi film.

19. Chamber and, A substrate support portion provided within the chamber, Control unit and Equipped with, The control unit, (a) A control for preparing a substrate on a substrate support, wherein the substrate has a silicon-containing film and The device comprises a mask on the silicon-containing film, the mask exposing the silicon-containing film. A control and a side wall that defines at least one opening, (b) Control for generating plasma from a processing gas containing hydrogen fluoride gas and bromine-containing gas. The first protective film containing bromine is formed up to the lower part of the side wall, and the silicon Control, including forming recesses in the containing film, A plasma processing apparatus configured to perform control including the following.

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