Plasma processing method, plasma processing apparatus, and plasma processing system

Abstract

This invention provides a plasma processing method with controllable opening size. The plasma processing method of the present invention includes a preparation step and a finishing step. The preparation step is a preparation step for a substrate having: (a) an etchable film; (b) a photoresist film formed on the upper surface of the etchable film and having a side surface defining at least one opening on the upper surface of the etchable film; and (c) a first film comprising at least a first portion and a second portion; the first portion being a portion formed on the upper surface of the photoresist film, and the second portion being a portion formed on the side surface of the photoresist film, wherein the thickness of the first portion is greater than that of the second portion; the finishing step involves etching at least a portion of the side surface of the photoresist film and at least a portion of the second portion of the first film.

Description

Technical Field

[0001] The exemplary embodiments of the present invention relate to a plasma treatment method, a plasma treatment apparatus, and a plasma treatment system. Prior Technology

[0002] As a technique for improving the controllability of patterns, there is a method and apparatus for processing a substrate as described in Patent Document 1. [Previous Technical Documents] [Patent Literature]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-126999 Summary of the Invention

[0004] [The problem the invention aims to solve]

[0005] The present invention provides a plasma treatment method, a plasma treatment apparatus, and a plasma treatment system with controllable opening size. [Technical means to solve the problem]

[0006] In one exemplary embodiment of the present invention, a plasma processing method is provided. The plasma processing method includes a preparation step and a finishing step. The preparation step involves preparing a substrate having: (a) an etchable film; (b) a photoresist film formed on the upper surface of the etchable film and having a side surface defining at least one opening on the upper surface of the etchable film; and (c) a first film comprising at least a first portion and a second portion, wherein the first portion is formed on the upper surface of the photoresist film, and the second portion is formed on the side surface of the photoresist film, and the thickness of the first portion is greater than that of the second portion; the finishing step involves etching at least a portion of the side surface of the photoresist film and at least a portion of the second portion of the first film.

[0007] In one exemplary embodiment of the present invention, a plasma processing apparatus is provided. The plasma processing apparatus includes a plasma processing chamber, a gas supply unit for supplying processing gas to the plasma processing chamber, a power supply for supplying power for generating plasma within the plasma processing chamber, and a control unit. The control unit is disposed on a substrate having: (a) an etched film; (b) a photoresist film formed on the upper surface of the etched film and having a side surface defining at least one opening on the upper surface of the etched film; (c) a first film comprising at least a first portion formed on the upper surface of the photoresist film and a second portion formed on the side surface of the photoresist film, wherein the thickness of the first portion is greater than that of the second portion; and (d) a second film formed on at least the first portion of the first film. The control unit performs the following control: etching at least a portion of the side surface of the photoresist film and at least a portion of the second portion of the first film.

[0008] In one exemplary embodiment of the present invention, a plasma processing system is provided. The plasma processing system includes a first plasma processing apparatus having a first chamber and a second plasma processing apparatus having a second chamber. The first plasma processing apparatus is configured such that a substrate is disposed in the first chamber, the substrate having: (a) an etchable film; (b) a photoresist film formed on the upper surface of the etchable film and having a side surface defining at least one opening on the upper surface of the etchable film; (c) a first film and (d) a second film are formed in the first chamber, the first film comprising at least a first portion formed on the upper surface of the photoresist film and a second portion formed on the side surface of the photoresist film, wherein the thickness of the first portion is greater than that of the second portion, and the second film is formed on at least the first portion of the first film; the second plasma processing apparatus is configured to etch at least a portion of the side surface of the photoresist film and at least a portion of the second portion of the first film.

[0009] In one exemplary embodiment of the present invention, a plasma processing method is provided. The plasma processing method includes the following steps: preparing (a) an etchable film, (b) a photoresist film formed on the upper surface of the etchable film and having a side surface defining at least one opening on the upper surface of the etchable film; determining the ratio of the thickness of the photoresist film to the size of the opening; forming a first film on the photoresist film when the ratio is 1 or more but less than 2; forming a second film on the photoresist film when the ratio is less than 1; and forming a trimming step of etching at least a portion of the side surface of the photoresist film, wherein the first film (c) includes at least a first portion formed on the upper surface of the photoresist film and a second portion formed on the side surface of the photoresist film, and the thickness of the first portion is thicker than that of the second portion; and the second film (d) is formed on at least the first portion of the first film. [Effects of the Invention]

[0010] According to one exemplary embodiment of the present invention, a plasma treatment method, a plasma treatment apparatus, and a plasma treatment system with controllable opening size can be provided. Simple Explanation of the Diagram

[0011] Figure 1 is a schematic diagram of a plasma processing apparatus 1 according to an exemplary embodiment. Figure 2 is a schematic diagram of a substrate processing system PS according to an exemplary embodiment. Figure 3 is a flowchart illustrating one example of this processing method. Figure 4A shows an example of a substrate W. Figure 4B shows an example of substrate W. Figure 5A is a diagram illustrating an example of the cross-sectional structure of the substrate W following the process flow of this method. Figure 5B is a diagram illustrating an example of the cross-sectional structure of the substrate W following the process flow of this method. Figure 5C is a diagram illustrating an example of the cross-sectional structure of the substrate W following the process flow of this method. Figure 5D is a diagram illustrating an example of the cross-sectional structure of the substrate W following the process flow of this method. Figure 5E is a diagram illustrating an example of the cross-sectional structure of the substrate W following the process flow of this method. Figure 6 is a flowchart showing a variation of this processing method. Figure 7 is a flowchart showing a variation of this processing method. Figure 8 is a flowchart showing a variation of this processing method. Figure 9 is a flowchart showing a variation of this processing method. Implementation

[0012] The various embodiments of the present invention will be described below.

[0013] In one exemplary embodiment, a plasma processing method is provided. The plasma processing method includes a preparation step and a finishing step. The preparation step is a preparation step for a substrate having: (a) an etchable film; (b) a photoresist film formed on the upper surface of the etchable film and having a side surface defining at least one opening on the upper surface of the etchable film; and (c) a first film comprising at least a first portion and a second portion; wherein the first portion is a portion formed on the upper surface of the photoresist film, and the second portion is a portion formed on the side surface of the photoresist film, and the thickness of the first portion is greater than that of the second portion; the finishing step involves etching at least a portion of the side surface of the photoresist film and at least a portion of the second portion of the first film.

[0014] In one exemplary embodiment, the preparation step includes the step of forming a second film on at least a first portion of the first film.

[0015] In one exemplary embodiment, after the trimming step, an etching step is further included, in which the etched film is etched using a photoresist film, a first film, and a second film as photomasks.

[0016] In one exemplary embodiment, the photoresist film has at least one of a recessed portion and a portion extending from the side to an opening.

[0017] In one exemplary embodiment, the protruding portion extends from the side of the photoresist film across the upper surface of the etched film.

[0018] In one exemplary embodiment, the first membrane is an organic membrane and the second membrane is an inorganic membrane.

[0019] In one exemplary embodiment, the photoresist film is a Sn-containing film.

[0020] In one exemplary embodiment, the inorganic membrane is a metal-containing membrane or a Si-containing membrane.

[0021] In one exemplary embodiment, the metal-containing film is a Sn-containing film.

[0022] In one exemplary embodiment, the metal-containing film is a W-containing film, a Ti-containing film, or an Al-containing film.

[0023] In one exemplary embodiment, the inorganic membrane is a non-metallic inorganic membrane containing boron, phosphorus, or sulfur.

[0024] In one exemplary embodiment, a finishing step is performed using a plasma generated by a specific processing gas, wherein the etching rate of the first film relative to the generated plasma is greater than that of the second film relative to the generated plasma.

[0025] In one exemplary embodiment, the specific processing gas includes oxygen-containing gas and halogen-containing gas.

[0026] In one exemplary embodiment, the first and second films are formed by plasma CVD (Chemical Vapor Deposition).

[0027] In one exemplary embodiment, the first film system is formed using plasma generated from a gas containing carbon-containing gas, and the second film system is formed using plasma generated from a gas containing Si-containing gas.

[0028] In one exemplary embodiment, the carbon-containing gas is CxHy (x and y are integers of 1 or more), CtHuFv (t and v are integers of 1 or more, and u is an integer of 0 or more), CO, or CO2.

[0029] In one exemplary embodiment, the thickness of the first portion of the first film is greater than the thickness of the photoresist film and the thickness of the second film.

[0030] In one exemplary embodiment, the etching step involves etching the etched film and the second film.

[0031] In one exemplary embodiment, the etched film is a Si-containing film, and the second film is a Si-containing film.

[0032] In one exemplary embodiment, the trimming step and the etching step are performed in the same chamber.

[0033] In one exemplary embodiment, the trimming step further includes the following steps: measuring the size of the opening defined by the side etched in the trimming step on the etched film; forming a third film on the side etched in the trimming step based on the measured size; and etching a portion of the third film.

[0034] In one exemplary embodiment, the third membrane comprises an organic membrane.

[0035] In one exemplary embodiment, the third membrane system comprises a laminated membrane of an organic membrane and an inorganic membrane formed on the organic membrane.

[0036] In one exemplary embodiment, the trimming step includes the following steps: repeatedly measuring the size of the opening, forming the third film, and etching a portion of the third film.

[0037] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes: a plasma processing chamber; a gas supply unit that supplies processing gas to the plasma processing chamber; a power source that supplies power for generating plasma in the plasma processing chamber; and a control unit disposed on a substrate having: (a) an etched film; (b) a photoresist film formed on the upper surface of the etched film and having a side surface defining at least one opening on the upper surface of the etched film; (c) a first film comprising at least a first portion formed on the upper surface of the photoresist film and a second portion formed on the side surface of the photoresist film, wherein the thickness of the first portion is greater than that of the second portion; and (d) a second film formed on at least the first portion of the first film; the control unit performs the following control: etching at least a portion of the side surface of the photoresist film and at least a portion of the second portion of the first film.

[0038] In one exemplary embodiment, a plasma processing system is provided. The plasma processing system includes a first plasma processing apparatus having a first chamber and a second plasma processing apparatus having a second chamber. The first plasma processing apparatus is configured such that: a substrate is disposed in the first chamber, the substrate having: (a) an etched film; (b) a photoresist film formed on the upper surface of the etched film and having a side surface defining at least one opening on the upper surface of the etched film; (c) a first film and (d) a second film are formed in the first chamber, the first film comprising at least a first portion formed on the upper surface of the photoresist film and a second portion formed on the side surface of the photoresist film, and the thickness of the first portion is greater than that of the second portion, the second film being formed on at least the first portion of the first film; the second plasma processing apparatus is configured to: etch at least a portion of the side surface of the photoresist film and at least a portion of the second portion of the first film.

[0039] In one exemplary embodiment, a plasma processing method is provided. The plasma processing method includes the following steps: preparing (a) an etchable film, (b) a photoresist film formed on the upper surface of the etchable film and having a side surface defining at least one opening on the upper surface of the etchable film; determining the ratio of the thickness of the photoresist film to the size of the opening; forming a first film on the photoresist film when the ratio is greater than or equal to 1 but less than 2; forming the first film on the photoresist film when the ratio is less than 1; and forming a second film on the first film; and a finishing step of etching at least a portion of the side surface of the photoresist film; the first film (c) includes at least a first portion formed on the upper surface of the photoresist film and a second portion formed on the side surface of the photoresist film, and the thickness of the first portion is greater than that of the second portion; and the second film (d) is formed on at least the first portion of the first film.

[0040] Hereinafter, various embodiments of the present invention will be described in detail with reference to the drawings. Furthermore, identical or similar elements will be labeled with the same symbols in each drawing, and repeated descriptions will be omitted. Unless otherwise specified, positional relationships such as up, down, left, and right will be described based on the positional relationships shown in the drawings. The scale ratios in the drawings do not represent actual ratios, and actual ratios are not limited by the scales shown in the drawings.

[0041] <Composition of Plasma Processing Unit 1> Figure 1 is a schematic diagram of a plasma processing apparatus 1 according to an exemplary embodiment. A plasma processing method (hereinafter referred to as "this processing method") according to an exemplary embodiment can be performed using the plasma processing apparatus 1.

[0042] The plasma processing apparatus 1 is an inductively coupled plasma processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing chamber 10 includes a dielectric window 101. Furthermore, the plasma processing apparatus 1 includes a substrate support unit 11, a gas inlet unit, and an antenna 14. The substrate support unit 11 is disposed within the plasma processing chamber 10. The antenna 14 is disposed on or above the plasma processing chamber 10 (i.e., on or above the dielectric window 101). The plasma processing chamber 10 has a plasma processing space 10s defined by the dielectric window 101, the sidewall 102 of the plasma processing chamber 10, and the substrate support unit 11. Furthermore, the plasma processing chamber 10 has at least one gas supply port for supplying a processing gas to the plasma processing space, and at least one gas exhaust port for discharging gas from the plasma processing space. The gas supply port is connected to the gas supply unit 20 described later, and the gas exhaust port is connected to the exhaust system 40 described later. The substrate support unit 11 is disposed in the plasma processing space and has a substrate support surface for supporting the substrate.

[0043] The substrate support portion 11 includes a body portion 111 and a ring assembly 112. The body portion 111 has a central region (substrate support surface) 111a for supporting a substrate (wafer) W, and an annular region (ring support surface) 111b for supporting the ring assembly 112. The annular region 111b of the body portion 111 surrounds the central region 111a of the body portion 111 when viewed from above. The substrate W is disposed on the central region 111a of the body portion 111, and the ring assembly 112 is disposed on the annular region 111b of the body portion 111 in a manner that surrounds the substrate W on the central region 111a of the body portion 111. In one embodiment, the body portion 111 includes a base and an electrostatic chuck. The base includes a conductive member. The conductive member of the base functions as a lower electrode. The electrostatic chuck is disposed on the base. The upper surface of the electrostatic chuck has the substrate support surface 111a. The ring assembly 112 includes one or more annular members. At least one of the one or more annular members is an edge ring. Furthermore, although not shown in the figures, the substrate support 11 may also include a temperature control module configured to adjust at least one of the electrostatic chuck, 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, or a combination thereof. A heat transfer fluid such as brine or gas flows in the flow path. Additionally, the substrate support 11 may also include a heat transfer gas supply section configured to supply heat transfer gas between the back surface of the substrate W and the substrate support surface 111a.

[0044] The gas inlet is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. In one embodiment, the gas inlet includes a central gas injector (CGI) 13. The central gas injector 13 is disposed above the substrate support unit 11 and mounted on the central opening formed in the dielectric window 101. The central gas injector 13 has at least one gas supply port 13a, at least one gas flow path 13b, and at least one gas inlet port 13c. The processing gas supplied to the gas supply port 13a is introduced into the plasma processing space 10s through the gas flow path 13b and the gas inlet port 13c. Alternatively, the gas inlet may include, in addition to or in place of the central gas injector 13, one or more side gas injectors (SGIs) mounted on one or more openings formed on the sidewall 102.

[0045] The gas supply unit 20 may also 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 type of processing gas from its corresponding gas source 21 to the gas inlet unit 13 via its corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may also include at least one flow modulation device for modulating or pulsed the flow rate of the at least one type of processing gas.

[0046] The power supply 30 includes an RF (Radio Frequency) 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), such as a source RF signal and a bias RF signal, to the conductive members of the substrate support portion 11 and the antenna 14. Thereby, plasma is formed from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of the plasma generation portion 12. Furthermore, by supplying the bias RF signal to the conductive members of the substrate support portion 11, a bias potential can be generated on the substrate W, drawing ions from the formed plasma into the substrate W.

[0047] 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 configured to couple to the antenna 14 via at least one impedance matching circuit to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 13 MHz to 150 MHz. In one embodiment, the first RF generation unit 31a may also be configured to generate a plurality of source RF signals with different frequencies. One or more source RF signals generated are supplied to the antenna 14. The second RF generation unit 31b is configured to couple to a conductive member of the substrate support 11 via at least one impedance matching circuit to generate a bias RF signal (bias RF power). In one embodiment, the bias RF signal has a frequency lower than the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 400 kHz to 13.56 MHz. In one embodiment, the second RF generation unit 31b is configured to generate a plurality of bias RF signals with different frequencies. One or more of the generated bias RF signals are supplied to the conductive members of the substrate support unit 11. Furthermore, in various embodiments, at least one of the source RF signal and the bias RF signal may also be pulsed.

[0048] Furthermore, the power supply 30 may include a DC (Direct Current) power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a bias DC generating unit 32a. In one embodiment, the bias DC generating unit 32a is configured to be connected to a conductive member of the substrate support 11 to generate a bias DC signal. The generated bias DC signal is applied to the conductive member of the substrate support 11. In one embodiment, the bias DC signal may also be applied to other electrodes, such as electrodes within an electrostatic chuck. In various embodiments, the bias DC signal may also be pulsed. Moreover, an RF power supply 31 and a bias DC generating unit 32a may be provided simultaneously, or the bias DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0049] Antenna 14 includes one or more coils. In one embodiment, antenna 14 may also include an outer coil and an inner coil disposed coaxially. In this case, RF power supply 31 may be connected to both the outer and inner coils, or to either the outer or inner coil. In the former case, the same RF generator may be connected to both the outer and inner coils, or different RF generators may be connected to the outer and inner coils respectively.

[0050] The exhaust system 40 may be connected, for example, to a gas outlet 10e located at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 10s is adjusted by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry vacuum pump, or a combination thereof.

[0051] The control unit 50 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform the various steps described herein. The control unit 50 may be configured to control various elements of the plasma processing apparatus 1 to perform the various steps described herein. In one embodiment, part or all of the control unit 50 may also be included in the plasma processing apparatus 1. The control unit 50 may, for example, include a computer 50a. The computer 50a may, for example, include a processing unit (CPU: Central Processing Unit) 50a1, a memory unit 50a2, and a communication interface 50a3. The processing unit 50a1 may be configured to perform various control actions based on a program stored in the memory unit 50a2. The memory unit 50a2 may also include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 50a3 can communicate with the plasma processing device 1 via communication lines such as LAN (Local Area Network).

[0052] <Composition of the PS Substrate Processing System> Figure 2 is a schematic diagram of a substrate processing system PS according to an exemplary embodiment. This processing method can be performed using the substrate processing system PS.

[0053] The substrate processing system PS includes: substrate processing chambers PM1 to PM6 (hereinafter collectively referred to as "substrate processing modules PM"), a transport module TM, load clamping modules LLM1 and LLM2 (hereinafter collectively referred to as "load clamping modules LLM"), a load module LM, and load ports LP1 to LP3 (hereinafter collectively referred to as "load ports LP"). The control unit CT controls each component of the substrate processing system PS to perform specific processing on the substrate W.

[0054] The substrate processing module PM is located within the substrate W and performs processes such as etching, trimming, film formation, annealing, doping, photolithography, cleaning, and ashing on the substrate W. A portion of the substrate processing module PM can be a measurement module, and methods such as optical methods can be used to measure the film thickness and the dimensions of the patterns formed on the substrate W. The plasma processing apparatus 1 shown in Figure 1 is an example of a substrate processing module PM.

[0055] The transport module TM has a transport device for transporting substrates W, which transports substrates W between substrate processing modules PM or between substrate processing modules PM and load locking modules LLM. Substrate processing modules PM and load locking modules LLM are arranged adjacent to the transport module TM. The transport module TM, substrate processing modules PM, and load locking modules LLM are spatially isolated or connected by openable and closable gate valves.

[0056] Load-locking modules LLM1 and LLM2 are located between the transfer module TM and the load module LM. The load-locking module LLM can switch its internal pressure to atmospheric pressure or vacuum. The load-locking module LLM transfers the substrate W from the load module LM under atmospheric pressure to the transfer module TM under vacuum, and then from the transfer module TM under vacuum to the load module LM under atmospheric pressure.

[0057] The load module LM has a transport device for transporting substrates W between the load-locking module LLM and the load port LP. Inside the load port LP, for example, a FOUP (Front Opening Unified Pod) capable of holding 25 substrates W or an empty FOUP can be placed. The load module LM removes the substrates W from the FOUP in the load port LP and transports them to the load-locking module LLM. Similarly, the load module LM removes the substrates W from the load-locking module LLM and transports them to the FOUP in the load port LP.

[0058] The control unit CT controls each component of the substrate processing system PS to perform specific processing on the substrate W. The control unit CT stores process recipes that set the process steps, process conditions, transport conditions, etc., and controls each component of the substrate processing system PS to perform specific processing on the substrate W according to the process recipes. The control unit CT may also have some or all of the functions of the control unit 50 of the plasma processing apparatus 1 shown in FIG1.

[0059] <An example of this processing method> Figure 3 is a flowchart illustrating one example of this processing method. As shown in Figure 3, this processing method includes a step of preparing the substrate (preparation step: step ST1), a step of trimming the photoresist film (trimming step: step ST2), and a step of etching the film to be etched (etching step: step ST3). Furthermore, each step can be performed in any substrate processing module PM within the substrate processing system PS. Also, multiple steps can be performed consecutively within one substrate processing module PM. Furthermore, a substrate with a patterned resist can be provided in step ST1. That is, steps ST11 and ST12 can be performed in one or more substrate processing modules PM within the substrate processing system PS, and then steps ST13 and ST14 can be performed in another substrate processing module PM different from the aforementioned one or more substrate processing modules. Furthermore, steps ST11 and / or ST12 can also be performed outside the substrate processing system PS.

[0060] Figures 4A and 4B illustrate an example of substrate W. Figure 4A is a top view of substrate W. Figure 4B is a cross-sectional view of substrate W at AA'. Figures 4A and 4B illustrate substrate W in one part of the preparation steps described later. Substrate W has a structure formed by stacking a base film UF, an etched film EF, and a photoresist film PR. A specific pattern is formed on the photoresist film PR. As shown in Figure 4A, when viewing substrate W from top to bottom (as seen in Figure 4B), the photoresist film PR in this example has a pattern of a plurality of openings OP arranged repeatedly at fixed intervals.

[0061] Figure 5 is a diagram showing an example of the cross-sectional structure of the substrate W in accordance with the process flow of this method. Figures 5A, 5B, 5C, 5D, and 5E show the cross-sectional structures of the substrate W after processing in steps ST11, ST12, ST13, ST14, ST2, and ST3, respectively.

[0062] Hereinafter, with reference to the figures, an example of the processing method shown in Figure 3 will be described. The processing in each step can be performed in the substrate processing module PM of the substrate processing system PS (see Figure 2). The etching process in each step can be performed in the plasma processing apparatus 1 shown in Figure 1. The processing in one step of this processing method can be performed in one module of the substrate processing module PM, and the processing in other steps of this processing method can be performed in other modules of the substrate processing module PM. The processing in multiple steps of this processing method can be performed continuously in one module of the substrate processing module PM.

[0063] In step ST1, substrate W is prepared. Step ST1 includes the steps of forming the etched film EF (step ST11), forming the photoresist film PR (step ST12), forming the first film TD1 (step ST13), and forming the second film (step ST14).

[0064] In step ST11, an etched film EF is formed on the substrate film UF (Figure 5A). The substrate film UF is, for example, an organic film such as a spin-coated carbon film (SOC) or an amorphous carbon film formed on a silicon wafer (including both cases of formation on the surface of the silicon wafer and cases of formation on other films formed on the silicon wafer). The etched film EF is, for example, a dielectric film such as a silicon oxide film, a silicon nitride film, SiARC, or SiON. The substrate film UF and / or the etched film EF can be formed by CVD, ALD (Atomic Layer Deposition), spin coating, etc. The substrate film UF and / or the etched film EF can be a flat film or a film with irregularities.

[0065] In step ST12, a photoresist film PR is formed on the etched film EF (see Figure 5A). It has a surface TS, a side surface SS continuous from the upper surface TS, and a lower surface in contact with the etched film EF. Furthermore, the photoresist film PR has at least one opening OP. The opening OP is defined by the side surface SS of the photoresist film PR. The opening OP is the space on the etched film EF surrounded by the side surface SS. That is, in Figure 5A, the upper surface of the etched film EF has a portion covered by the photoresist film PR and a portion exposed at the bottom surface BS of the opening OP.

[0066] The photoresist film PR has a side surface SS extending from the side surface SS to the opening OP. The portion SC is, for example, a portion extending from the side surface SS of the photoresist film PR toward at least a portion of the upper surface of the etched film EF. The portion SC may, for example, be residue of the photoresist film PR present around or around the bottom surface BS of the opening OP. This residue may, for example, be resist residue that was not completely removed during the process of forming the opening OP on the photoresist film PR (e.g., a development process). Alternatively, the portion SC may be a protrusion protruding from the side surface SS toward the opening OP in the area where the side surface SS separates from the bottom surface BS. This protrusion is a portion of the side surface SS that extends further toward the opening OP than its surroundings or periphery. This protrusion may be residue of the photoresist film PR. Furthermore, the side surface SS may have depressions or cracks (including interruptions in patterns such as line patterns).

[0067] When viewed from above on substrate W (as seen from top to bottom in Figure 5A), the openings OP can have any shape. This shape can be, for example, a circle, an ellipse, a rectangle, a line, or a combination of one or more of these. The photoresist film PR can have a plurality of openings OP. As shown in Figure 4A, the plurality of openings OP can also each have a hole shape, forming an array pattern arranged at fixed intervals. Furthermore, the plurality of openings OP can also each have a line shape, arranged at fixed intervals to form a pattern of lines and gaps.

[0068] Two or more of the stacked films among the photoresist film PR, the etched film EF, and the substrate film UF can also function as a multilayer resist. For example, the substrate W may have other films under the substrate film UF, and the stacked film of the photoresist film PR, the etched film EF, and the substrate film UF can be used as a multilayer resist to etch the other films. The multilayer resist film may include, for example, organic films or other dielectric films, and inorganic films. Organic films may include, for example, spin-coated carbon films (SOC) and amorphous carbon. Dielectric films may include, for example, silicon oxide films, silicon nitride films, SiARC, and SiON. In the photoresist film PR, the metal-containing film MF may be a film containing at least one metal selected from the group consisting of tin (Sn), hafnium (Hf), indium (In), titanium (Ti), and zirconium (Zr), for example, a Sn-containing film. The photoresist film (PR) can be formed by vapor deposition methods such as CVD, MLD (Molecular Layer Deposition), or ALD, or by liquid phase deposition methods such as spin coating. The opening (OP) can be formed on the photoresist film PR by photolithography, or by etching the photoresist film PR. For example, first, a photoresist film containing metals such as tin is formed on the etched film EF. Then, light (e.g., EUV (Extreme Ultraviolet) excimer laser) is selectively irradiated onto the photoresist film using an exposure mask, exposing a pattern of a shape corresponding to the exposure mask onto the photoresist film. Pre-exposure baking (to remove solvent from the photoresist film) can be performed before exposure, or post-exposure baking (to harden the photoresist film) can be performed after exposure. Finally, the exposed photoresist film is developed. Development can be performed by dry development using thermal or plasma methods, or by wet development using a developer. For example, in the case of developing using plasma, the exposed resist film can be exposed to plasma generated from a gas containing halogen compounds such as hydrogen fluoride. This allows the formation of a photoresist film PR with an opening OP.

[0069] In step ST13, a first film TD1 is formed (see Figure 5B). The first film TD1 is formed having at least a portion formed on the upper surface TS of the photoresist film PR and a portion formed on the side surface SS of the photoresist film PR. Alternatively, the first film TD1 can also be formed on the etched film EF exposed on the bottom surface BS of the opening OP. In the first film TD1, the thickness of the portion formed on the upper surface TS is greater than the thickness of the portion formed on the side surface SS and the thickness of the portion formed on the bottom surface BS. Furthermore, the surface roughness (including the number and size of bumps and depressions) of the portion formed on the side surface SS of the first film TD1 can be less than that of the side surface SS of the photoresist film PR.

[0070] Furthermore, when viewed from above the substrate W, the portion of the first film TD1 formed on the upper surface TS of the photoresist film PR can be formed to extend from the upper surface TS to the opening OP. This portion, for example, is formed to partially or completely overlap with a portion of the SC when viewed from above the substrate W. Furthermore, the surface of this portion can be curved or planar.

[0071] The first film TD1 is, for example, an organic film. The first film TD1 is formed, for example, by PECVD (Plasma Enhanced Chemical Vapor Deposition) using plasma, where the plasma is generated from a processing gas containing hydrocarbon (CxHy) series gases (x and y are positive numbers). This processing gas can also be a gas containing CtH uF v series gases (t and v are positive numbers, u is a number greater than 0). As an example, the processing gas can be a gas containing CH3F or C4F6. Furthermore, the processing gas can also contain inert gases such as N2. By adjusting the film formation conditions, the first film TD1 is formed such that the thickness of the upper surface TS is greater than the thickness of the side surface SS and the bottom surface BS. Furthermore, the first film TD1 can also be, for example, an inorganic film containing Si.

[0072] In step ST14, a second membrane TD2 is formed (see Figure 5C). The second membrane TD2 is formed at least on the portion of the first membrane TD1 formed on the upper surface TS. The second membrane TD2 may selectively be formed on the portion of the first membrane TD1 formed on the upper surface TS. Furthermore, the second membrane TD2 may also be formed on the portions of the first membrane TD1 formed on the side surface SS and the bottom surface BS. The surface of this portion may be curved or planar.

[0073] The second film TD2 is, for example, an inorganic film containing Si. The second film TD2 is formed by PECVD using a plasma generated from a Si-containing gas. By adjusting the film formation conditions, the second film TD2 is selectively formed on the portion of the first film TD1 formed on the upper surface TS. Furthermore, as an example, the second film TD2 can also be a non-metallic inorganic film containing boron, phosphorus, or sulfur, or a metallic film containing tin, tungsten, titanium, or aluminum.

[0074] In step ST2, a portion of the SC of the photoresist film PR is trimmed (see Figure 5D). The trimming of the SC portion can be performed by anisotropic etching of a portion of the first film TD1, a portion of the second film TD2, and the portion of the SC of the photoresist film PR using a plasma generated from one or more processing gases. Alternatively, anisotropic etching can be performed on a portion of the first film TD1 and a portion of the second film TD2, and isotropic etching can also be performed. The one or more processing gases are, for example, gases that cause the etch rate of the photoresist film PR and / or the first film TD1 relative to the plasma to be greater than the etch rate of the second film TD2 relative to the plasma. For example, when the first film TD1 is an organic film and the second film TD2 is a Si-containing film, the aforementioned one or more gases may include oxygen-containing gases and halogen-containing gases.

[0075] Furthermore, in step ST2, after trimming the photoresist film PR, a specific film can be formed at least on the sidewall SS of the photoresist film PR. Moreover, the photoresist film PR with the aforementioned specific film formed on the sidewall SS can be further trimmed. This allows for appropriate trimming of the photoresist film PR even if the thickness of the first film TD1 and / or the second film TD2 is insufficient. In one example, after trimming the photoresist film PR in step ST2, the size (diameter) of the opening OP formed on the photoresist film PR can be measured. Based on the measured size, a specific film can be formed at least on the sidewall SS of the photoresist film PR. This specific film can also be formed on the sidewall of the first film TD1 and / or the sidewall of the second film TD2 that defines the opening OP. Furthermore, this specific film can also be formed on the upper surface of the second film TD2. This specific film can be formed from the same material as the first film TD1 or the same material as the second film TD2. Furthermore, the specific film can be a laminated film consisting of a film formed from the same material as the first film TD1 and a film formed from the same material as the second film TD2. The thickness of the specific film can be set based on the size (diameter) of the opening OP formed on the photoresist film PR.

[0076] Furthermore, the size of the opening OP can be measured using an optical measuring device. This measuring device can be one of the substrate processing modules PM shown in Figure 2. As an example, when this processing method processes a plurality of substrates W (e.g., 25 pieces) as a unit (hereinafter also referred to as a "batch"), the size of the opening OP can be measured for each substrate included in the batch. Also, the size of the opening OP can be measured for a specific substrate included in a batch, and the measured value can be used as the size of the opening of the specific substrate and the other substrates included in the batch. Among the plurality of substrates included in a batch, the substrate that is the object of measurement can be any one of the following in the batch: (a) the substrate that was first subjected to this processing method, (b) the substrate that was last subjected to this processing method, or (c) any substrate that was subjected to this processing method other than the first and last ones.

[0077] In step ST3, the etched film EF is etched (see Figure 5E). Using the photoresist film PR, the first film TD1, and the second film TD2 as photomasks, the etched film EF is anisotropically etched. That is, starting from the portion exposed on the bottom surface BS of the opening OP, the etched film EF is anisotropically etched along the depth direction of the opening OP.

[0078] For the etched film EF, etching can be performed by selectively etching the etched film EF relative to the first film TD1 and the photoresist film PR. When the etched film EF is a silicon oxide film, silicon nitride film, SiON or other Si-containing film, the processing gas used for etching the etched film EF can be a fluorocarbon gas and / or a hydrofluorocarbon gas.

[0079] Next, embodiments and reference examples of this processing method will be described. This invention is not limited to the following embodiments.

[0080] <Example> In this embodiment, the substrate W has a structure formed by sequentially depositing an organic film (first film TD1) and a Si-containing film (second film TD2) on a multilayer structure of a SOC film (base film UF), a SiON film (etched film EF), and a photoresist film (photoresist film PR) (see FIG5C). The opening pattern of the photoresist film is the same as that shown in FIG4A in the reference example.

[0081] In this embodiment, an organic film (first film TD1) is formed by PECVD using a mixed gas of CH4 and Ar. A Si-containing film (second film TD2) is then formed by PECVD using a mixed gas of SiCl4, H2, and Ar. After forming the organic and Si-containing films, portions of the organic film, the Si-containing film, and the photoresist film are etched using plasma etching with a mixed gas of O2, HBr, and Ar. Subsequently, the SiON film is etched using the organic film, the Si-containing film, and the photoresist film as photomasks. Furthermore, the SiON film is etched using plasma generated from a mixed gas of CHF-based gases, NF3, N2, and Ar.

[0082] <Reference Example> The substrate W in the reference example has the same structure as the embodiment, consisting of a sequentially stacked SOC film (base film UF), a SiON film (etched film EF), and a photoresist film (photoresist film PR) (see Figure 5A). The aperture pattern of the photoresist film is the hole pattern shown in Figure 4A. In the reference example, after forming the aperture pattern on the photoresist film, the SiON film is etched using the photoresist film as a photomask. Furthermore, the SiON film is etched using a plasma generated from a mixed gas of CHF-based gas, NF3, N2, and Ar.

[0083] Table 1 shows the measurement results of the Critical Dimension (CD) and Local Critical Dimension Uniformity (CD 3σ) of the openings OP in the examples and reference examples. Furthermore, in Table 1, "photoresist film" refers to the measurement results of the openings formed on the photoresist film. Also, "SiON film" refers to the measurement results of the openings formed on the SiON film. And, CD is the average value. [Table 1] Photoresist film Reference Example Example SiON membrane SiON membrane CD(nm) 23.00 19.60 22.90 LCDU(nm) 3.94 2.53 1.28 LCDU / CD 0.171 0.129 0.056

[0084] As shown in Table 1, the measurement results in the embodiments are better than those in the reference examples. Specifically, firstly, the LCDU of the openings in the SiON film in the embodiments is significantly improved compared to the LCDU of the openings in the SiON film in the reference examples. That is, a significant improvement in the uniformity of the CD of the openings in the SiON film is achieved in the embodiments. Furthermore, in the embodiments, the CD of the SiON film is close to that of the photoresist film. Moreover, although the CD of the SiON film in the reference examples is much smaller than the CD of the photoresist film, a significant improvement is also observed in the LCDU of the SiON film multiplied by an appropriate value compared to the reference examples.

[0085] In this processing method, a first film TD1 is formed on the photoresist film PR, and a second film TD2 is then formed on the first film TD1. Therefore, portions of SC present on the side surface SS defining the opening of the photoresist film PR can be selectively removed or reduced. Furthermore, even if there are depressions or cracks (including interruptions in patterns such as line patterns) on the side surface SS defining the opening of the photoresist film PR, these depressions can be filled or reduced by forming the first film TD1 on the photoresist film PR. This reduces the surface roughness of the side surface SS defining the opening OP of the photoresist film PR, thus allowing appropriate control over the size or shape of the opening OP. Moreover, in this processing method, the photoresist film PR (and / or the first film TD1 and / or the second film TD2) is used as a photomask to etch the etched film EF, thus allowing appropriate control over the size or shape of the opening formed on the etched film EF.

[0086] Furthermore, in this processing method, a first film TD1 and a second film TD2 are selectively formed on the photoresist film PR. That is, in this processing method, the first film TD1 and the second film TD2 are formed such that the thickness of the portion formed on the upper surface TS of the photoresist film PR is greater than the thickness of the portion formed on the side surface SS. Therefore, even when the thickness of the photoresist film PR is relatively thin, the etchable film EF can be etched under a sufficiently large selectivity between the etchable film EF and the etching mask (photoresist film PR and the first film TD1 and the second film TD2).

[0087] <Example 1 of the variation of this processing method> Figure 6 is a flowchart illustrating a variation of this processing method. The difference between this example and the example shown in Figure 3 is that the preparation step ST1 further includes a step ST121 for determining the thickness of the photoresist film PR. That is, in this example, based on the thickness of the photoresist film PR formed in step ST12, the remaining steps in the preparation step ST1 will differ.

[0088] After forming the photoresist film PR in step ST12, the dimensions (e.g., the diameter of the opening OP) formed on the photoresist film PR and the thickness of the photoresist film PR are measured in step ST121. Furthermore, the ratio of the film thickness of the photoresist film PR to the size of the opening OP (hereinafter also referred to as the "aspect ratio") is calculated. If the aspect ratio is 2 or greater, steps ST13 and ST14 are skipped, and preparation step ST1 is completed. Then, in step ST2, a portion SC of the photoresist film PR is trimmed. This trimming is performed, for example, by anisotropic etching of the photoresist film PR. The first thickness can be arbitrarily defined based on the thickness or material of the etched film EF, the type of processing gas used for etching the etched film EF, etc.

[0089] When the aspect ratio is 1 or higher but less than 2, similarly to Figure 3, a first film TD1 is formed on the photoresist film PR in step ST13. Then, step 14 is skipped, and preparation step ST1 is completed. Then, in step ST2, a portion SC of the photoresist film PR is trimmed. The second thickness can be arbitrarily specified based on the thickness or material of the first film TD1, the thickness or material of the etched film EF, the type of processing gas used for etching the etched film EF, etc.

[0090] If the aspect ratio is less than 1, proceed with steps ST13 and ST14 as shown in Figure 3 to complete preparation step ST1. Then, as shown in Figure 3, trim part SC of the photoresist film PR in step ST2.

[0091] Furthermore, in step ST121, the size of the opening OP and the thickness of the photoresist film PR can be measured using an optical measuring device. This measuring device can be one of the substrate processing modules PM shown in Figure 2. For example, when this processing method processes multiple substrates W (e.g., 25 pieces) as a unit (hereinafter also referred to as a "batch"), the size of the opening OP and / or the thickness of the photoresist film PR can be measured for each substrate included in the batch. Also, in step ST121, the size of the opening OP and / or the thickness of the photoresist film PR can be measured for a specific substrate included in a batch, and the aspect ratio calculated based on the measured value can be used as the aspect ratio of the specific substrate and the other substrates included in the batch. Among the multiple substrates included in a batch, the substrate subject to measurement can be any one of the following: (a) the substrate for which this processing method was initially performed, (b) the substrate for which this processing method was last performed, or (c) any substrate for which this processing method was performed, excluding the initial and final ones.

[0092] Based on this example, the preparatory steps for trimming the photoresist film can be appropriately selected based on the film thickness.

[0093] <Example 2 of the variation of this processing method> Figures 7-9 are flowcharts illustrating variations of this processing method. These examples differ from the example shown in Figure 3 in that, in addition to step ST2, at least one of the steps between ST12 and ST13, and between ST13 and ST14, includes a step of trimming at least a portion of the side surface of the photoresist film PR (ST1-a, ST1-b). More specifically, in the example shown in Figure 7, the step between ST12 and ST13 includes a step of trimming a portion SC of the photoresist film PR using a plasma generated from one or more processing gases (ST1-a). In the example shown in Figure 8, the step between ST13 and ST14 includes a step of trimming a portion of the first film TD1 (e.g., at least a portion of the second portion of the first film TD) and a portion SC of the photoresist film PR using a plasma generated from one or more processing gases (ST1-b). In the example shown in Figure 9, between steps ST12 and ST13, there is a step (ST1-a) in which a portion SC of the photoresist film PR is trimmed using a plasma generated from one or more processing gases; and between steps ST13 and ST14, there is a step (ST1-b) in which a portion of the first film TD1 (e.g., at least a portion of the second portion of the first film TD) is trimmed using a plasma generated from one or more processing gases. Furthermore, in the example of Figure 9, in step ST1-a, a portion SC of the photoresist film PR may be trimmed, and in step ST1-b, a portion of the first film TD and the remaining portion of the photoresist film PR may be trimmed.

[0094] According to this example, the portion of SC present on the side SS defining the opening of the photoresist film PR can be removed or reduced with greater precision.

[0095] The above embodiments are described for illustrative purposes and various changes can be made without departing from the scope and spirit of the present invention. For example, in addition to the plasma processing apparatus 1 for inductively coupled plasma, this processing method can also be performed using a plasma processing apparatus that uses any plasma source such as capacitively coupled plasma or microwave plasma.

[0096] Furthermore, the present invention includes the following embodiments.

[0097] (Postscript 1) A plasma processing method includes a preparation step and a finishing step. The preparation step is a preparation step for a substrate, the substrate having: (a) an etchable film; (b) a photoresist film formed on the upper surface of the etchable film and having a side surface defining at least one opening on the upper surface of the etchable film; and (c) a first film comprising at least a first portion and a second portion; the first portion being a portion formed on the upper surface of the photoresist film, the second portion being a portion formed on the side surface of the photoresist film, and the thickness of the first portion being greater than that of the second portion. The above-mentioned trimming steps involve etching at least a portion of the above-mentioned side surface of the above-mentioned photoresist film and at least a portion of the above-mentioned second part of the above-mentioned first film.

[0098] (Postscript 2) As described in Appendix 1, the plasma treatment method includes the step of forming a second film on at least the first portion of the first film.

[0099] (Note 3) As described in Appendix 1 or 2, the plasma treatment method, in which The above preparation steps include the following steps: Prepare a film with the above-mentioned etched film, and The substrate of the aforementioned photoresist film; At least a portion of the aforementioned side surface of the aforementioned photoresist film is trimmed; and The first film is formed on the modified photoresist film.

[0100] (Postscript 4) As described in Appendix 2 or 3, the plasma processing method further includes, after the above-mentioned trimming step, an etching step in which the above-mentioned photoresist film, the above-mentioned first film and the above-mentioned second film are used as photomasks to etch the above-mentioned film to be etched.

[0101] (Note 5) As described in any of Appendix 1 to 4, the photoresist film has at least one of a recessed portion and a portion extending from the side to the opening.

[0102] (Note 6) As described in Appendix 5, the plasma processing method wherein the protruding portion extends from the side surface of the photoresist film to the upper surface of the etched film.

[0103] (Note 7) As described in Appendix 2, the plasma treatment method wherein the first membrane is an organic membrane and the second membrane is an inorganic membrane.

[0104] (Postscript 8) The plasma processing method described in any of the appendices 1 to 7, wherein the photoresist film is a Sn-containing film.

[0105] (Note 9) As described in Appendix 7, the plasma treatment method wherein the inorganic membrane is a metal-containing membrane or a Si-containing membrane.

[0106] (Postscript 10) As described in Appendix 9, the plasma treatment method wherein the aforementioned metal-containing film is a Sn-containing film.

[0107] (Postscript 11) As described in Appendix 9, the plasma treatment method wherein the metal-containing film is a W-containing film, a Ti-containing film, or an Al-containing film.

[0108] (Postscript 12) As described in Appendix 7, the plasma treatment method wherein the inorganic membrane is a non-metallic inorganic membrane containing boron, phosphorus or sulfur.

[0109] (Postscript 13) As described in any of the plasma treatment methods in Appendices 1 to 7, the above-mentioned trimming steps are performed using plasma generated from a specific treatment gas. The etching rate of the first film relative to the plasma generated is greater than that of the second film relative to the plasma generated.

[0110] (Postscript 14) As described in Appendix 13, the plasma treatment method includes oxygen-containing gases and halogen-containing gases.

[0111] (Postscript 15) The plasma treatment method described in any of Appendices 2, 4 and 7, wherein the first membrane and the second membrane are formed by plasma CVD.

[0112] (Postscript 16) As described in Appendix 15, the plasma treatment method includes... The first membrane system described above is formed using plasma generated from a gas containing carbon-containing gas. The second film system described above is formed using a plasma generated from a gas containing Si gas.

[0113] (Postscript 17) As described in Appendix 16, the aforementioned carbon-containing gas is CxHy (x and y are integers of 1 or more), CtHuFv (t and v are integers of 1 or more, and u is an integer of 0 or more), CO, or CO2.

[0114] (Postscript 18) The plasma processing method described in any of Appendices 2, 4 and 7 to 12, wherein the thickness of the first portion of the first film is greater than the thickness of the photoresist film and the thickness of the second film.

[0115] (Postscript 19) As described in Appendix 4, the plasma processing method wherein the etching step is performed on the etched film and the second film.

[0116] (Postscript 20) As described in Appendix 19, the plasma processing method wherein the etched film is a Si-containing film and the second film is a Si-containing film.

[0117] (Postscript 21) As described in Appendix 4, 19 or 20, the plasma treatment method wherein the above-mentioned trimming step and the above-mentioned etching step are performed in the same chamber.

[0118] (Postscript 22) The plasma treatment method described in any of the appendices 1 to 21, among which The above-mentioned repair steps further include the following steps: Measure the size of the opening defined on the etched film by the side surface etched in the above-described finishing steps; Based on the dimensions measured above, a third film is formed on the side surface etched in the above-mentioned finishing step; and Etching is performed on one portion of the third film described above.

[0119] (Postscript 23) As described in Appendix 22, the plasma treatment method wherein the third membrane mentioned above comprises an organic membrane.

[0120] (Postscript 24) As described in Appendix 23, the plasma processing method wherein the third membrane system comprises a laminated membrane consisting of the organic membrane and an inorganic membrane formed on the organic membrane.

[0121] (Postscript 25) The plasma treatment method described in any of Appendices 22 to 24 includes the following steps: repeatedly measuring the size of the opening, forming the third film, and etching a portion of the third film.

[0122] (Postscript 26) A plasma processing apparatus includes: a plasma processing chamber; a gas supply unit for supplying processing gas to the plasma processing chamber; a power source for supplying electricity for generating plasma in the plasma processing chamber; and a control unit. The aforementioned control unit is equipped with a substrate, which has: (a) an etched film; (b) a photoresist film formed on the upper surface of the etched film and having a side surface defining at least one opening on the upper surface of the etched film; (c) a first film comprising at least a first portion formed on the upper surface of the photoresist film and a second portion formed on the side surface of the photoresist film, wherein the thickness of the first portion is greater than that of the second portion; and (d) a second film formed on at least the first portion of the first film; The aforementioned control unit performs the following control: etching at least a portion of the aforementioned side surface of the aforementioned photoresist film and at least a portion of the aforementioned second portion of the aforementioned first film.

[0123] (Postscript 27) A plasma processing system comprising a first plasma processing device having a first chamber and a second plasma processing device having a second chamber. The first plasma processing apparatus described above is configured such that: a substrate is disposed in the first chamber, the substrate having: (a) an etched film; (b) a photoresist film formed on the upper surface of the etched film, and having a side surface defining at least one opening on the upper surface of the etched film; and (c) a first film and (d) a second film are formed in the first chamber, wherein the first film includes at least a first portion formed on the upper surface of the photoresist film and a second portion formed on the side surface of the photoresist film, and the thickness of the first portion is greater than that of the second portion, and the second film is formed on at least the first portion of the first film. The second plasma processing apparatus is configured to etch at least a portion of the aforementioned side surface of the photoresist film and at least a portion of the aforementioned second portion of the first film.

[0124] (Postscript 28) A plasma treatment method, It includes the following steps: Prepare (a) an etchable film and (b) a photoresist film formed on the upper surface of the etchable film and having a side surface defining at least one opening on the upper surface of the etchable film; Calculate the ratio of the thickness of the photoresist film to the size of the opening. When the ratio is 1 or more but less than 2, a first film is formed on the photoresist film; When the ratio mentioned above is less than 1, a first film is formed on the photoresist film, and a second film is formed on the first film; and At least a portion of the aforementioned side surface of the photoresist film is etched as a finishing step; The first film (c) comprises at least a first portion formed on the upper surface of the photoresist film and a second portion formed on the side surface of the photoresist film, wherein the thickness of the first portion is greater than that of the second portion. The second membrane (d) is formed on at least the first portion of the first membrane.

[0125] 1: Plasma treatment device 10: Plasma treatment chamber 10e: Gas exhaust outlet 11:Substrate support department 12: Plasma Generation Section 13: Central Gas Injection Unit 13: Gas Inlet Section 13a: Gas supply port 13b: Gas flow path 13c: Gas inlet 14: Antenna 20: Gas Supply Department 21: Gas Source 22: Flow controller 30: Power supply 31: RF power supply 31a: First RF Generation Unit 31b: 2nd RF Generation Unit 32: DC power supply 32a: Bias DC Generator 40: Exhaust System 50: Control Department 50a: Computer 50a1: Processing Department 50a2: Memory Department 50a3: Communication Interface 101: Dielectric window 102: Sidewall 111: Ontology Department 111a: Central region (substrate support surface) 111b: Annular region (annular support surface) 112: Ring Component BS: Bottom CT: Control Unit EF: Etched film LLM1: Load-locking module LLM2: Load-locking module LM: Load cell module LP1: Load Port LP2: Load port LP3: Load Port PM1: Substrate Processing Room PM2: Substrate Processing Room PM3: Substrate Processing Room PM4: Substrate Processing Room PM5: Substrate Processing Room PM6: Substrate Processing Room SC: Part OP: Open PR: Photoresist film SS: Side view TD1: First membrane TD2: Second membrane TS: Upper surface UF: Basement membrane W: substrate

Claims

1. A plasma processing method comprising: a preparation step, which is a preparation step for preparing a substrate, the substrate having: (a) an etchable film; (b) a photoresist film formed on the upper surface of the etchable film and having a side surface defining at least one opening on the upper surface of the etchable film; and (c) a first film comprising at least a first portion and a second portion; the first portion being a portion formed on the upper surface of the photoresist film, the second portion being a portion formed on the side surface of the photoresist film, the first portion having a thickness greater than the second portion; a formation step, which forms the first film before the etchable film is etched; and a finishing step, which etches at least a portion of the side surface of the photoresist film and at least a portion of the second portion of the first film, wherein at least a portion of the side surface of the photoresist film and at least a portion of the second portion of the first film are etched but the first portion remains.

2. The plasma treatment method of claim 1, wherein the preparation step includes the step of forming a second film on at least the first portion of the first film.

3. The plasma processing method of claim 1, wherein the preparation step includes the following steps: preparing a substrate having the etched film and the photoresist film; trimming at least a portion of the side surface of the photoresist film; and forming a first film on the trimmed photoresist film.

4. The plasma processing method of claim 2, after the above-mentioned trimming step, further includes an etching step in which the above-mentioned photoresist film, the above-mentioned first film and the above-mentioned second film are used as photomasks to etch the above-mentioned film to be etched.

5. The plasma processing method of claim 1, wherein the photoresist film has at least one of a recessed portion and a portion extending from the side to the opening.

6. The plasma processing method of claim 5, wherein the protruding portion extends from the side surface of the photoresist film to the upper surface of the etched film.

7. The plasma treatment method of claim 2, wherein the first membrane is an organic membrane and the second membrane is an inorganic membrane.

8. The plasma processing method of any one of claims 1 to 7, wherein the photoresist film is a Sn-containing film.

9. The plasma treatment method of claim 7, wherein the inorganic film is a metal-containing film or a Si-containing film.

10. In the plasma treatment method of claim 9, the metal-containing film is a Sn-containing film.

11. The plasma treatment method of claim 9, wherein the metal-containing film is a W-containing film, a Ti-containing film, or an Al-containing film.

12. The plasma treatment method of claim 7, wherein the inorganic membrane is a non-metallic inorganic membrane containing boron, phosphorus or sulfur.

13. The plasma processing method of any one of claims 1 to 7, wherein the above-mentioned trimming step is performed using a plasma generated by a specific processing gas, wherein the etching rate of the first film relative to the generated plasma is greater than the etching rate of the second film relative to the generated plasma.

14. The plasma treatment method of claim 13, wherein the specific treatment gas includes oxygen-containing gas and halogen-containing gas.

15. The plasma processing method of any one of claims 2, 4 and 7, wherein the first membrane and the second membrane are formed by plasma CVD.

16. The plasma processing method of claim 15, wherein the first film system is formed using plasma generated from a gas containing carbon-containing gas, and the second film system is formed using plasma generated from a gas containing Si-containing gas.

17. The plasma treatment method of claim 16, wherein the carbon-containing gas is CxHy (x and y are integers of 1 or more), CtHuFv (t and v are integers of 1 or more, and u is an integer of 0 or more), CO, or CO2.

18. The plasma processing method of any one of claims 2, 4, 7 and 9 to 12, wherein the thickness of the first portion of the first film is greater than the thickness of the photoresist film and the thickness of the second film.

19. The plasma processing method of claim 4, wherein the etching step is to etch the etched film and the second film.

20. The plasma processing method of claim 19, wherein the etched film is a Si-containing film and the second film is a Si-containing film.

21. The plasma treatment method as described in claims 4, 19 or 20, wherein the above-mentioned trimming step and the above-mentioned etching step are performed in the same chamber.

22. The plasma processing method of any one of claims 1 to 7, 9 to 12, 19, and 20, wherein the trimming step further comprises the following steps: measuring the size of the opening defined on the etched film by the side surface etched in the trimming step; forming a third film on the side surface etched in the trimming step based on the measured size; and etching a portion of the third film.

23. The plasma treatment method of claim 22, wherein the third membrane comprises an organic membrane.

24. The plasma processing method of claim 23, wherein the third membrane system comprises a laminated membrane consisting of the organic membrane and an inorganic membrane formed on the organic membrane.

25. The plasma processing method of claim 22, wherein the above-mentioned trimming step includes the following steps, which are to repeatedly perform the steps of measuring the size of the above-mentioned opening, forming the above-mentioned third film, and etching a portion of the above-mentioned third film.

26. A plasma processing method comprising the steps of: preparing (a) an etchable film, (b) a photoresist film formed on the upper surface of the etchable film and having a side surface defining at least one opening on the upper surface of the etchable film; determining the ratio of the thickness of the photoresist film to the size of the opening; forming a first film on the photoresist film when the ratio is 1 or more but less than 2; forming the first film on the photoresist film when the ratio is less than 1, and forming a second film on the first film, wherein the first film is formed before the etchable film is etched; and a finishing step of etching at least a portion of the side surface of the photoresist film; the first film (c) comprising at least a first portion formed on the upper surface of the photoresist film and a second portion formed on the side surface of the photoresist film, wherein the thickness of the first portion is greater than that of the second portion, and the second film (d) formed on at least the first portion of the first film.

Images