Plasma processing method

Abstract

Provided is a plasma processing method for modifying an organic-inorganic hybrid film and etching another film. A plasma processing method according to the present disclosure is executed in a plasma processing device that has a chamber, said plasma processing method comprising: a preparation step for preparing, in the chamber, a substrate that has a first film and a second film containing an organic-inorganic hybrid material; a step for supplying a processing gas into the chamber; a step for generating plasma from the processing gas; and an etching step for etching the first film using the plasma, while modifying at least a part of the second film.

Description

Plasma treatment method

[0001] An exemplary embodiment of the present disclosure relates to a plasma processing method.

[0002] A technique for forming contact holes used in device manufacturing is described in Japanese Patent Application Laid-Open No. 2003-222299.

[0003] Japanese Patent Application Laid-Open No. 2004-55898

[0004] The present disclosure provides a plasma processing method for modifying an organic-inorganic hybrid film while etching other films.

[0005] In one exemplary embodiment of the present disclosure, there is provided a plasma processing method performed in a plasma processing apparatus having a chamber, the plasma processing method including: a preparation step of preparing a substrate having a first film and a second film containing an organic-inorganic hybrid material in the chamber; a step of supplying a processing gas into the chamber; a step of generating plasma from the processing gas; and a step of etching the first film with the plasma while modifying at least a portion of the second film.

[0006] According to one exemplary embodiment of the present disclosure, a plasma processing method can be provided that modifies an organic-inorganic hybrid film while etching another film.

[0007] FIG. 1 is a diagram for explaining an example of the configuration of a plasma processing system. FIG. 1 is a diagram for explaining an example of the configuration of a capacitively coupled plasma processing apparatus. FIG. 2 is a diagram showing an example of the cross-sectional structure of a substrate W. FIG. 3 is a diagram showing another example of the cross-sectional structure of a substrate W. FIG. 4 is a flowchart showing an example of the present processing method. FIG. 5 is a flowchart showing a first example of the present processing method. FIG. 6 is a diagram showing an example of the cross-sectional structure of a substrate W in the first example. FIG. 7 is a diagram showing an example of the cross-sectional structure of a substrate W in the first example. FIG. 8 is a flowchart showing a second example of the present processing method. FIG. 9 is a diagram showing an example of the cross-sectional structure of a substrate W in the second example. FIG. 10 is a diagram showing an example of the cross-sectional structure of a substrate W in the second example. FIG. 11 is a diagram showing an example of the cross-sectional structure of a substrate W in the second example. FIG. 12 is a diagram showing an example of the cross-sectional structure of a substrate W in the second example. FIG. 13 is a flowchart showing a third example of the present processing method. FIG. 14 is a diagram showing an example of the cross-sectional structure of a substrate W in the third example. FIG. 15 is a diagram showing an example of the cross-sectional structure of a substrate W in the third example. FIG. 16 is a diagram showing an example of the cross-sectional structure of a substrate W in the third example. FIG. 10 is a diagram showing an example of the cross-sectional structure of a substrate W in a third example. FIG. 11 is a diagram showing an example of the cross-sectional structure of a substrate W in a third example. FIG. 12 is a flowchart showing a fourth example of the present processing method. FIG. 13 is a diagram showing an example of the cross-sectional structure of a substrate W in a fourth example. FIG. 14 is a diagram showing an example of the cross-sectional structure of a substrate W in a fourth example. FIG. 15 is a diagram showing an example of the cross-sectional structure of a substrate W in a fourth example. FIG. 16 is a diagram showing an example of the cross-sectional structure of a substrate W in a fourth example.

[0008]

[0013] In one exemplary embodiment, a plasma processing method is provided, which is performed in a plasma processing apparatus having a chamber. The plasma processing method includes a preparation step of preparing a substrate having a first film and a second film including an organic-inorganic hybrid material in the chamber, a step of supplying a process gas into the chamber, a step of generating plasma from the process gas, and a step of etching the first film with the plasma while modifying at least a portion of the second film.

[0009] In one exemplary embodiment, in the etching step, at least a portion of the second film is modified by plasma.

[0010] In one exemplary embodiment, the method further comprises the step of irradiating the substrate with ultraviolet light, and in the etching step, at least a portion of the second film is modified by the ultraviolet light.

[0011] In one exemplary embodiment, the processing gas includes an oxidizing gas that oxidizes the inorganic material included in the organic-inorganic hybrid material, and in the etching process, the inorganic material included in the organic-inorganic hybrid material is oxidized by plasma generated from the oxidizing gas, thereby modifying at least a portion of the second film.

[0012] In one exemplary embodiment, the oxidizing gas is an oxygen-containing gas.

[0013] In one exemplary embodiment, the processing gas includes a reducing gas that reduces the inorganic material included in the organic-inorganic hybrid material, and in the etching process, the inorganic material included in the organic-inorganic hybrid material is reduced by plasma generated from the reducing gas, thereby modifying at least a portion of the second film.

[0014] In one exemplary embodiment, the reducing gas is a hydrogen-containing gas.

[0015] In one exemplary embodiment, the processing gas includes a halogen-containing gas that halogenates the inorganic material contained in the organic-inorganic hybrid material, and in the etching process, the inorganic material contained in the organic-inorganic hybrid material is halogenated by plasma generated from an oxidizing gas, thereby modifying at least a portion of the second film.

[0016] In one exemplary embodiment, the organic-inorganic hybrid material includes a metal, and the etching process modifies the second film by changing the valence of the metal's ions.

[0017] In one exemplary embodiment, the substrate has at least one first region and at least one second region other than the at least one first region, and the preparation process includes forming a first film in the at least one first region on the substrate, the first film having a pattern that defines at least one opening in the at least one second region, and forming a second film in the at least one opening.

[0018] In one exemplary embodiment, forming the first film includes forming a third film in at least one second region on the substrate, the third film having a pattern defining at least one opening in the at least one first region; forming the first film in the at least one opening; and etching the third film.

[0019] In one exemplary embodiment, the step of forming the first film includes the steps of: forming a fourth film on the substrate; forming a third film in at least one second region on the fourth film, the third film having a pattern defining at least one opening in at least one first region; forming a fifth film in the at least one opening on the fourth film; and etching the third film and the fourth film in the at least one second region, wherein the first film comprises the fifth film.

[0020] In one exemplary embodiment, the step of etching the third film and the fourth film includes the steps of etching the third film to expose the fourth film in at least one second region, and etching the fourth film in at least one second region using the fifth film as a mask, and the first film comprises the etched fourth film.

[0021] In one exemplary embodiment, the step of forming the first film includes the steps of: forming a sixth film on the substrate; forming a seventh film in at least one first region on the sixth film, the seventh film having a pattern that defines at least one opening in at least one second region; and etching the sixth film using the seventh film as a mask, wherein the first film includes the etched sixth film.

[0022] In one exemplary embodiment, the at least one first region has a circular or rectangular shape in a plan view of the substrate.

[0023] In one exemplary embodiment, the at least one first region and the at least one second region form a line and space pattern in a plan view of the substrate.

[0024] In one exemplary embodiment, the preparation process includes forming a first film on a substrate and forming a second film on the first film, the second film having a pattern that exposes at least a portion of the first film.

[0025] In one exemplary embodiment, the first film is formed by a nanoimprint method, a self-assembly lithography method, or an inkjet method.

[0026] In one exemplary embodiment, the organic-inorganic hybrid material comprises at least one metal selected from the group consisting of Mg, Zn, Y, Ni, Ti, Fe, and Al.

[0027] In one exemplary embodiment, the method further includes the step of etching a portion of the substrate using the second film, at least a portion of which has been modified, as a mask.

[0028] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings. In each drawing, the same or similar elements are designated by the same reference numerals, and redundant explanations will be omitted. Unless otherwise specified, the positional relationships, such as up, down, left, and right, will be described based on the positional relationships shown in the drawings. The dimensional ratios in the drawings do not represent actual ratios, and the actual ratios are not limited to the ratios shown in the drawings.

[0029] <Example of Plasma Processing System> FIG. 1 is a diagram illustrating an example of the configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust port is connected to an exhaust system 40 (described later). The substrate support 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

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

[0031] <Example of CCP Plasma Processing Apparatus> FIG. 2 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

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

[0033] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also called a substrate support surface for supporting the substrate W, and the annular region 111b is also called a 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 can function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that the annular region 111b may also be provided by another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. Furthermore, at least one RF / DC electrode coupled to an RF (Radio Frequency) power supply 31 and / or a DC (Direct Current) power supply 32 (described later) may be disposed within the ceramic member 1111a. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal (described later) is supplied to the at least one RF / DC electrode, the RF / DC electrode is also called a bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as multiple lower electrodes. Furthermore, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

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

[0036] The substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow passage 1110a, or a combination thereof. A heat transfer fluid such as brine or a gas flows through the flow passage 1110a. In one embodiment, the flow passage 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a.

[0037] The showerhead 13 is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The process gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas inlet may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0038] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include one or more flow modulation devices to modulate or pulse the flow rate of the at least one process gas.

[0039] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode and / or at least one upper electrode. This generates a plasma from at least one process gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of a plasma generating unit configured to generate a plasma from one or more process gases in the plasma processing chamber 10. Furthermore, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, thereby attracting ion components in the formed plasma to the substrate W.

[0040] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0041] The second RF generator 31b is coupled to at least one lower electrode via at least one impedance matching circuit and is configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generator 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0042] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to the at least one lower electrode and configured to generate a first DC signal. The generated first bias DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to the at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0043] In various embodiments, at least one of the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof pulse waveform. In one embodiment, a waveform generator for generating the sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one period. The first and second DC generating units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0044] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 10s is regulated by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0045] <Example of Substrate W> Figure 3A is a diagram showing an example of the cross-sectional structure of a substrate W. The substrate W is an example of a substrate to which the present processing method can be applied. The substrate W has an etching film EF and an organic-inorganic hybrid film HF. The etching film EF and the organic-inorganic hybrid film HF are formed on an undercoat film UF. The organic-inorganic hybrid film HF is formed in a layer different from the etching film EF. In other words, the organic-inorganic hybrid film HF is laminated on the etching film EF. The etching film EF is an example of a first film. The organic-inorganic hybrid film HF is an example of a second film.

[0046] The base film UF may be an organic film, a dielectric film, a metal film, a semiconductor film, or the like formed on a silicon wafer. The base film UF may also be a silicon wafer. The base film UF may also be configured by laminating multiple films.

[0047] The etching film EF may be a silicon-containing film or a carbon-containing film. The silicon-containing film may be a dielectric film containing silicon (Si). The silicon-containing film may include a silicon oxide film or a silicon nitride film. The carbon-containing film may be, for example, an amorphous carbon film or a spin-on carbon (SOC) film.

[0048] The organic-inorganic hybrid film HF is a film containing an organic material and an inorganic material. The organic-inorganic hybrid film HF is an example of a second film. The inorganic material may include a metal. The metal may be at least one metal selected from the group consisting of magnesium (Mg), zinc (Zn), yttrium (Y), nickel (Ni), titanium (Ti), iron (Fe), and aluminum (Al).

[0049] The organic-inorganic hybrid film HF is patterned to define at least one opening OP on the etching film EF. That is, the organic-inorganic hybrid film HF has an opening pattern for etching the etching film EF in step ST4, which will be described later. The opening pattern may be a pattern such as a hole, a pillar, a slit, or a line-and-space pattern.

[0050] In the example shown in FIG. 3B , the substrate W further includes a carbon-containing film CF. The carbon-containing film CF is an example of a first film. The organic-inorganic hybrid film HF is an example of a second film. In the example of FIG. 3B , the organic-inorganic hybrid film HF and the carbon-containing film CF may be formed in the same layer. The two films being in the same layer includes a state in which the two films partially or entirely overlap in the thickness direction of the two films. As an example, the carbon-containing film CF may be patterned to define at least one opening on the etching film EF, and the organic-inorganic hybrid film HF may be formed by filling the opening with an organic-inorganic hybrid material.

[0051] <Example of the Present Processing Method> Figure 4 is a flowchart showing an example of the plasma processing method (also referred to as the "present processing method") of the present disclosure. The present processing method is performed on a substrate W, for example, using the plasma processing system and plasma processing apparatus 1 shown in Figures 1 and 2. An example of performing the present processing method shown in Figure 4 will be described below with reference to the respective figures. Note that in the following example, the control unit 2 shown in Figures 1 and 2 controls each part of the plasma processing apparatus 1 shown in Figure 2 to perform the present processing method.

[0052] This processing method includes a step of determining a substrate as a reference (ST1), a step of supplying a processing gas (ST2), a step of generating plasma (ST3), and a step of etching the etching film EF or the carbon-containing film CF while modifying the organic-inorganic hybrid film (ST4). Note that the order in which steps ST2 and ST3 are started is not limited to this order. Furthermore, steps ST2 to ST4 may be performed in parallel or simultaneously.

[0053] <Process ST1: Preparation of Substrate> In process ST1, a substrate W is prepared in the plasma processing space 10s of the plasma processing chamber 10. In process ST1, at least the substrate W may be placed on the substrate support 11 and held by the electrostatic chuck 1111. At least some of the processes for forming each component of the substrate W (e.g., the processes shown in FIGS. 6, 8, 11, and 14) may be performed in the plasma processing space 10s as part of process ST1. Alternatively, after all or some of the components of the substrate W are formed in an apparatus or chamber external to the plasma processing apparatus 1, the substrate W may be loaded into the plasma processing space 10s and placed on the substrate support 11.

[0054] <Step ST2: Supply of Processing Gas> In step ST2, a processing gas is supplied into the plasma processing chamber 10. The processing gas is a gas used to etch the etching film EF or the carbon-containing film CF formed on the substrate W. The processing gas may also include a gas that modifies the organic-inorganic hybrid film HF. As an example, the processing gas may include a gas that oxidizes, reduces, or halogenates the organic-inorganic hybrid film HF. As an example, the gas that reduces the inorganic material contained in the organic-inorganic hybrid film HF may be a hydrogen-containing gas. The inorganic material includes, for example, a metal.

[0055] The processing gas may contain a gas capable of etching the etching film EF or the carbon-containing film CF while modifying the organic-inorganic hybrid film HF in step ST4. As an example, when the organic-inorganic hybrid film HF is a film containing Mg and the carbon-containing film CF is etched while modifying the organic-inorganic hybrid film HF, the processing gas may contain a gas containing oxygen. Furthermore, when the organic-inorganic hybrid film HF is a film containing Mg and the etching film EF is a carbon-containing film, the processing gas may contain a gas containing oxygen. Furthermore, when the organic-inorganic hybrid film HF is a film containing Mg and the etching film EF is a film containing silicon oxide, the processing gas may contain a gas containing fluorine. Furthermore, when the organic-inorganic hybrid film HF is a film containing Mg and the etching film EF is a silicon (Si) film, the processing gas may contain a gas containing chlorine.

[0056] <Step ST3: Plasma Generation> In step ST3, plasma is generated in the plasma processing chamber 10. In this embodiment, a source RF signal is supplied to the shower head 13 or the substrate support 11 in the plasma processing apparatus 1 shown in FIG. 2, and plasma is generated from the processing gas in the plasma processing space 10s. The source RF signal may be a continuous wave or a pulse wave. In addition, in step ST3, a bias signal may be supplied to the substrate support 11.

[0057] <Step ST4: Modification and Etching> In step ST4, at least a portion of the organic-inorganic hybrid film HF included in the substrate W is modified, and the etching film EF or the carbon-containing film CF is etched. The organic-inorganic hybrid film HF may be modified by active species of the plasma generated in step ST3. The modification includes oxidation, reduction, or halogenation of the organic-inorganic hybrid film HF by active species in the plasma. The oxidation or reduction of the organic-inorganic hybrid film HF includes changing the valence of metal ions included in the organic-inorganic hybrid film HF. The organic-inorganic hybrid film HF may also be modified by other methods. For example, the other methods may be irradiation with ultraviolet light. The ultraviolet light may be ultraviolet light emitted by the plasma generated in step ST3.

[0058] Furthermore, in step ST4, the etching film EF or the carbon-containing film CF is etched. The etching of the etching film EF or the carbon-containing film CF may be performed in parallel or simultaneously with the modification of the organic-inorganic hybrid film HF. As an example, the plasma generated in step ST3 may modify the organic-inorganic hybrid film HF and etch the etching film EF or the carbon-containing film CF.

[0059] Next, with reference to FIGS. 5 to 15, the details of steps ST1 to ST4 will be described with reference to four examples.

[0060] <First Example>

[0061] Fig. 5 is a flowchart showing a first example of the present processing method. Figs. 6A to 6C are views showing an example of the cross-sectional structure of the substrate W in the first example. Fig. 6A is a view showing an example of the cross-sectional structure of the substrate W after process ST1 has been performed. Fig. 6B is a view showing an example of the cross-sectional structure of the substrate W during execution of processes ST2 to ST4. Fig. 6C is a view showing an example of the cross-sectional structure of the substrate W after process ST4 has been performed. The first example of the present processing method will be described with reference to Figs. 5 and 6.

[0062] <Step ST1: Preparation of Substrate> In step ST1, a substrate W is prepared. In the first example, step ST1 includes a step of forming an etching film EF (step ST1-11) and a step of forming an organic-inorganic hybrid film HF (step ST1-12).

[0063] In step ST1-11, an etching film EF is formed. The etching film EF is formed on the base film UF, for example, as shown in FIG. 6A. In this example, the etching film EF is a silicon oxide film. The etching film EF may also be a carbon-containing film. As an example, the carbon-containing film may be an amorphous carbon film.

[0064] In step ST1-12, an organic-inorganic hybrid film HF is formed on the etching film EF. In this example, the organic-inorganic hybrid film HF is a film containing an organic magnesium (Mg) compound. As an example, the organic-inorganic hybrid film HF can be formed by applying a solution containing an organic magnesium compound onto the etching film EF.

[0065] The organic-inorganic hybrid film HF can be formed on the etching film EF by a transfer method, a nanoimprint method, a DSA (Directed Self-Assembly) method, or an inkjet method. That is, by these methods, an organic-inorganic hybrid material is attached to the region RE2 on the etching film EF to form a patterned organic-inorganic hybrid film HF on the etching film EF. As an example, when the pattern dimension of the organic-inorganic hybrid film HF is less than 1 μm, the organic-inorganic hybrid film HF can be formed by a transfer method, a nanoimprint method, or a DSA (Directed Self-Assembly) method. Furthermore, when the dimension is 1 μm or more, the organic-inorganic hybrid film HF can be formed by an inkjet method.

[0066] Also, as an example, the organic-inorganic hybrid material is a solution containing an organomagnesium compound. Region RE1 is a region where an opening OP exists on the etching film EF in a plan view of the substrate W. Region RE2 is a region where an organic-inorganic hybrid film HF is formed on the etching film EF in a plan view of the substrate W. That is, the etching film EF is exposed in region RE1 and covered by the organic-inorganic hybrid film HF in region RE2. Region RE1 is an example of a first region, and region RE2 is an example of a second region.

[0067] The substrate W obtained through steps ST1-11 and ST1-12 is placed on the substrate support 11, and the substrate W is held by the electrostatic chuck 1111.

[0068] <Step ST2: Supply of Processing Gas> In step ST2, a processing gas is supplied into the plasma processing chamber 10. In this example, the etching film EF is a silicon oxide film, and the organic-inorganic hybrid film HF is a film containing an organomagnesium compound. The processing gas may be a gas that can modify the organomagnesium compound and etch the silicon oxide film. As an example, the processing gas may include a fluorine-containing gas.

[0069] <Step ST3: Plasma Generation> In step ST3, plasma is generated in the plasma processing chamber 10. In this example, when a source RF signal is supplied to the shower head 13 or the substrate support 11 in the plasma processing apparatus 1 of Fig. 2, plasma is generated from the fluorine-containing gas contained in the processing gas supplied into the plasma processing chamber 10 in step ST2. The plasma contains activated fluorine species generated from the fluorine-containing gas.

[0070] <Step ST4: Modification and Etching> In step ST4, the active fluorine species generated in step ST3 modify at least a portion of the organomagnesium compound in the organic-inorganic hybrid film HF. As an example, the active fluorine species change the surface of the organic-inorganic hybrid film HF to magnesium fluoride (MgF). The active fluorine species also etches the silicon oxide film in the etching film EF. That is, as shown in FIG. 6B , the active fluorine species forms a layer FP containing magnesium fluoride on the surface of the organic-inorganic hybrid film HF, while etching the portion of the etching film EF exposed at the opening OP, thereby forming a recess RC in the etching film EF.

[0071] The surface of the organic-inorganic hybrid film HF may be isotropically modified as shown in FIG. 6C . That is, the thickness of the layer FP on the top surface TS of the organic-inorganic hybrid film HF may be approximately equal to the thickness of the layer FP on the sidewalls SS of the organic-inorganic hybrid film HF. The surface of the organic-inorganic hybrid film HF may also be anisotropically modified. As an example, the thickness of the layer FP on the top surface TS of the organic-inorganic hybrid film HF may be thicker than the thickness of the layer FP on the sidewalls SS of the organic-inorganic hybrid film HF. The layer FP may also be formed only on the top surface TS of the organic-inorganic hybrid film HF.

[0072] Furthermore, at least a portion of the organic-inorganic hybrid film HF may be modified by ultraviolet light. In this case, ozone generated by the ultraviolet light may convert at least a portion of the organic-inorganic hybrid film HF into magnesium oxide (MgO). As an example, the plasma processing apparatus 1 shown in FIG. 2 may include an apparatus for generating ultraviolet light, and the apparatus may irradiate the substrate W with ultraviolet light. Furthermore, the plasma generated in step ST3 may generate ultraviolet light, and at least a portion of the organic-inorganic hybrid film HF may be modified by the ultraviolet light. Furthermore, the organic-inorganic hybrid film HF may be modified by both the ultraviolet light and the active species generated in step ST3. That is, in this example, the organic-inorganic hybrid film HF may be modified so that at least a portion of the organic-inorganic hybrid film HF contains both magnesium fluoride and magnesium oxide.

[0073] As shown in FIG. 6C , steps ST2 to ST4 form a recess RC in the etching film EF. The recess RC is a space continuing from the opening OP defined by the sidewall of the organic-inorganic hybrid film HF. The recess RC is also a space defined by the sidewall and bottom of the etching film EF. The recess RC may expose the base film UF at its bottom.

[0074] The present processing method of this example may include a step of removing the organic-inorganic hybrid film HF after step ST4. The present processing method of this example may also include a step of etching the base film UF using the etching film EF as a mask after step ST4. In this step, the base film UF may be etched and the organic-inorganic hybrid film HF may be removed.

[0075] <Second Example> Fig. 7 is a flowchart showing a second example of the present processing method. Figs. 8A to 8F are views showing an example of the cross-sectional structure of the substrate W in the second example. Figs. 8A to 8D are views showing an example of the cross-sectional structure of the substrate W corresponding to step ST1. Fig. 8E is a view showing an example of the cross-sectional structure of the substrate W during execution of steps ST2 to ST4. Fig. 8F is a view showing an example of the cross-sectional structure of the substrate W after execution of step ST4. The second example of the present processing method will be described with reference to Figs. 7 and 8.

[0076] <Process ST1: Preparation of Substrate> First, in process ST1, a substrate W is prepared. In the second example, process ST1 includes a step of forming an etching film EF (process ST1-21), a step of forming a photoresist film PR (process ST1-22), a step of forming a carbon-containing film CF (process ST1-23), a step of removing the photoresist film PR (process ST1-24), and a step of forming an organic-inorganic hybrid film HF (process ST1-25).

[0077] In step ST1-21, an etching film EF is formed. The etching film EF is formed on the base film UF, for example, as shown in FIG. 8A. In this example, the etching film EF is a silicon oxide film. The etching film EF may also be a carbon-containing film. As an example, the carbon-containing film may be an amorphous carbon film.

[0078] In step ST1-22, a photoresist film PR is formed on the etching film EF. As shown in FIG. 8A, the photoresist film PR has an opening pattern including at least one opening OP. The photoresist film PR is formed in a region RE2 on the etching film EF. The region RE2 is a region where an organic-inorganic hybrid film HF will be formed in step ST1-25, which will be described later.

[0079] The photoresist film PR may be formed by applying a resist liquid onto the etching film EF, exposing the applied resist liquid to light, and developing the light. For example, the resist liquid may be a positive resist liquid for immersion exposure.

[0080] In step ST1-23, a carbon-containing film CF is formed on the etching film EF. The carbon-containing film CF may be formed in at least one opening OP, as shown in FIG. 8B . That is, the carbon-containing film CF is formed in a region RE1 on the etching film EF. The carbon-containing film CF may also be formed in the same layer as the photoresist film PR. As an example, the carbon-containing film CF is formed by filling at least one opening OP with carbon paste. The carbon paste may be applied to the substrate W by a spin coating method, and the opening OP may be filled with the carbon paste.

[0081] In step ST1-24, the photoresist film PR is etched. As an example, the photoresist film PR can be etched by plasma etching. The plasma etching may use plasma generated from a gas containing a nitrogen-containing gas and a hydrogen-containing gas. The nitrogen-containing gas may be, for example, nitrogen (N ２ ) gas. The hydrogen-containing gas is, for example, hydrogen (H ２ ) The photoresist film PR may be entirely etched. For example, when the opening OP has a hole shape, the photoresist film PR is etched to form pillars of the carbon-containing film CF on the etching film EF, as shown in FIG. 8C .

[0082] In step ST1-25, an organic-inorganic hybrid film HF is formed on the etching film EF. As shown in FIG. 8C, the organic-inorganic hybrid film HF can be formed in a region RE2 on the etching film EF. The organic-inorganic hybrid film HF can also be formed in the same layer as the carbon-containing film CF. As an example, the organic-inorganic hybrid film HF is formed by applying an organic-inorganic hybrid material onto the substrate W by a spin coating method. In this example, the organic-inorganic hybrid material is a solution containing an organomagnesium compound.

[0083] The substrate W obtained through steps ST1-21 to ST1-25 is placed on the substrate support part 11, and the substrate W is held by the electrostatic chuck 1111.

[0084] <Step ST2: Supply of Processing Gas> In step ST2, a processing gas is supplied into the plasma processing chamber 10. In this example, in step ST4 described later, the organic-inorganic hybrid film HF is modified and the carbon-containing film CF is etched. Therefore, the processing gas may be a gas that can modify the organomagnesium compound contained in the organic-inorganic hybrid film HF and etch the carbon-containing film CF. As an example, the processing gas may contain an oxygen-containing gas. The oxygen-containing gas may be, for example, oxygen (O ２ ) may be.

[0085] <Step ST3: Plasma Generation> In step ST3, plasma is generated in the plasma processing chamber 10. In this example, when a source RF signal is supplied to the shower head 13 or the substrate support 11 in the plasma processing apparatus 1 of Fig. 2, plasma is generated from the oxygen-containing gas contained in the processing gas supplied into the plasma processing chamber 10 in step ST2. The plasma contains activated oxygen species generated from the oxygen-containing gas.

[0086] <Step ST4: Modification and Etching> In step ST4, at least a portion of the organic-inorganic hybrid film HF is modified. In this example, the active oxygen species generated in step ST3 modify at least a portion of the organomagnesium compounds in the organic-inorganic hybrid film HF. As an example, the active oxygen species convert the surface of the organic-inorganic hybrid film HF into magnesium oxide (MgO). The active oxygen species also etch the carbon-containing film CF. That is, as shown in FIG. 8E , the active oxygen species form a layer FP containing magnesium oxide on the surface of the organic-inorganic hybrid film HF while etching the portion of the etching film EF exposed at the opening OP, thereby forming a recess RC in the etching film EF.

[0087] The surface of the organic-inorganic hybrid film HF may be isotropically modified as shown in FIG. 8F . That is, the thickness of the layer FP on the top surface TS of the organic-inorganic hybrid film HF may be approximately equal to the thickness of the layer FP on the sidewalls SS of the organic-inorganic hybrid film HF. The surface of the organic-inorganic hybrid film HF may also be anisotropically modified. As an example, the thickness of the layer FP on the top surface TS of the organic-inorganic hybrid film HF may be thicker than the thickness of the layer FP on the sidewalls SS of the organic-inorganic hybrid film HF. The layer FP may also be formed only on the top surface TS of the organic-inorganic hybrid film HF.

[0088] At least a portion of the organic-inorganic hybrid film HF may be modified by ultraviolet light. In this case, ozone generated by the ultraviolet light may convert at least a portion of the organic-inorganic hybrid film HF into magnesium oxide (MgO). As an example, the plasma processing apparatus 1 shown in FIG. 2 may include a device for generating ultraviolet light, and the device may irradiate the substrate W with ultraviolet light. Alternatively, the plasma generated in step ST3 may generate ultraviolet light, and at least a portion of the organic-inorganic hybrid film HF may be modified by the ultraviolet light. Alternatively, the organic-inorganic hybrid film HF may be modified by both the ultraviolet light and the active species generated in step ST3.

[0089] As shown in FIG. 8F , steps ST2 to ST4 form a recess RC in the etching film EF. The recess RC is a space continuing from the opening OP defined by the sidewall of the organic-inorganic hybrid film HF. The recess RC is also a space defined by the sidewall and bottom of the etching film EF. The recess RC may expose the base film UF at its bottom.

[0090] The processing method of this example may include, after step ST4, a step of etching the etching film EF using the organic-inorganic hybrid film HF as a mask. In this step, the etching film EF may be etched and a part of the organic-inorganic hybrid film HF may be etched.

[0091] <Third Example>

[0092] Fig. 9 is a flowchart showing a third example of the present processing method. Figs. 10A to 10G are views showing an example of the cross-sectional structure of the substrate W in the third example. Figs. 10A to 10D are views showing an example of the cross-sectional structure of the substrate W corresponding to step ST1. Figs. 10E and 10F are views showing an example of the cross-sectional structure of the substrate W during execution of steps ST2 to ST4. Fig. 10G is a view showing an example of the cross-sectional structure of the substrate W after execution of step ST4. The third example of the present processing method will be described with reference to Figs. 9 and 10.

[0093] <Process ST1: Preparation of Substrate> First, in process ST1, a substrate W is prepared. In the third example, process ST1 includes a step of forming an etching film EF (process ST1-31), a step of forming a carbon-containing film CF (process ST1-32), a step of forming an anti-reflection film BF (process ST1-33), a step of forming a photoresist film PR (process ST1-34), a step of etching the anti-reflection film BF (process ST1-35), a step of etching the carbon-containing film CF (process ST1-36), and a step of forming an organic-inorganic hybrid film HF (process ST1-37).

[0094] In step ST1-31, an etching film EF is formed. The etching film EF is formed on the base film UF, for example, as shown in FIG. 10A. In this example, the etching film EF is a silicon oxide film. The etching film EF may also be a carbon-containing film. As an example, the carbon-containing film may be an amorphous carbon film.

[0095] In step ST1-32, a carbon-containing film CF is formed on the etching film EF. The carbon-containing film CF can be formed on the entire surface of the etching film EF, as shown in FIG. 10A. In this example, the carbon-containing film CF is a spin-on carbon (SOC) film.

[0096] In step ST1-33, an antireflective film BF is formed on the carbon-containing film CF. As shown in FIG. 10A, the antireflective film BF can be formed on the entire surface of the carbon-containing film CF. The antireflective film BF may be a silicon-containing film. As an example, the silicon-containing film may be a SiON film. The antireflective film BF and / or the carbon-containing film CF is an example of a sixth film.

[0097] In process ST1-34, a photoresist film PR is formed on the anti-reflection film BF. As shown in FIG. 10A, the photoresist film PR has an opening pattern including at least one opening OP. The photoresist film PR is formed in a region RE1 on the anti-reflection film BF. That is, in region RE2, the space present above the anti-reflection film BF becomes the opening OP. Region RE2 is a region where an organic-inorganic hybrid film HF will be formed in process ST1-37, which will be described later. The photoresist film PR is an example of a seventh film.

[0098] The photoresist film PR may be formed by applying a resist liquid onto the carbon-containing film CF, exposing the applied resist liquid, and developing the resist liquid. As an example, the resist liquid may be a positive resist liquid for immersion exposure.

[0099] In step ST1-35, the antireflective film BF is etched. As shown in FIG. 10B, the antireflective film BF is etched using the photoresist film PR as a mask. As an example, the antireflective film BF can be etched by plasma etching. The plasma etching may use plasma generated from a gas containing a fluorine-containing gas. Note that, together with the antireflective film BF, a portion of the photoresist film PR and / or the carbon-containing film CF may also be etched.

[0100] In step ST1-36, the carbon-containing film CF is etched. As shown in FIGS. 10B and 10C, the carbon-containing film CF is etched using the photoresist film PR and / or the anti-reflective film BF as a mask. Furthermore, during etching of the carbon-containing film CF, the photoresist film PR may be entirely etched. As an example, the carbon-containing film CF may be etched by plasma etching. The plasma etching may use plasma generated from a gas containing an oxygen-containing gas. The oxygen-containing gas may be, for example, oxygen (O ２ 10C , pillars of the antireflective film BF and the carbon-containing film CF are formed on the etched film EF. The etched antireflective film BF and / or the carbon-containing film CF included in the pillars are an example of a first film.

[0101] In step ST1-37, an organic-inorganic hybrid film HF is formed. The organic-inorganic hybrid film HF can be formed in region RE2 on the etching film EF, as shown in FIG. 10D. The organic-inorganic hybrid film HF can also be formed in the same layer as the anti-reflective film BF and the carbon-containing film CF. In FIG. 10D, the organic-inorganic hybrid film HF and the carbon-containing film CF are an example of films formed in the same layer. The organic-inorganic hybrid film HF and the anti-reflective film BF are also an example of films formed in the same layer. The organic-inorganic hybrid film HF and the stacked film of the anti-reflective film BF and the carbon-containing film CF are also an example of films formed in the same layer.

[0102] As an example, the organic-inorganic hybrid film HF is formed by applying an organic-inorganic hybrid material by spin coating onto the substrate W. In this example, the organic-inorganic hybrid material is a solution containing an organomagnesium compound.

[0103] The substrate W obtained through steps ST1-31 to ST1-37 is placed on the substrate support 11, and the substrate W is held by the electrostatic chuck 1111.

[0104] <Step ST2: Supply of Processing Gas> In step ST2, a processing gas is supplied into the plasma processing chamber 10. In this example, in step ST4 described later, the organic-inorganic hybrid film HF is modified, and the anti-reflective film BF and the carbon-containing film CF are etched. Therefore, the processing gas may be a gas that can modify the organomagnesium compound contained in the organic-inorganic hybrid film HF and etch the anti-reflective film BF and the carbon-containing film CF. As an example, the processing gas may contain a fluorine-containing gas and / or an oxygen-containing gas. The fluorine-containing gas may be, for example, a fluorocarbon gas (C ｘ F ｙ (x and y are positive integers). The oxygen-containing gas may be, for example, oxygen (O ２ ) may be.

[0105] The type of process gas supplied in step ST2 may be changed depending on the progress of etching in step ST4 (described later). That is, in step ST4, a first process gas may be supplied during the period in which the anti-reflective film BF is etched, and a second process gas different from the first process gas may be supplied during the period in which the carbon-containing film CF is etched. As an example, the first process gas may contain a fluorine-containing gas. The second process gas may contain an oxygen-containing gas.

[0106] <Step ST3: Plasma Generation> In step ST3, plasma is generated in the plasma processing chamber 10. In this example, when a source RF signal is supplied to the shower head 13 or the substrate support 11 in the plasma processing apparatus 1 of FIG. 2, plasma is generated from the processing gas supplied into the plasma processing chamber 10 in step ST2. The plasma contains activated species generated from the processing gas. The activated species may be activated species of fluorine and / or activated species of oxygen.

[0107] <Step ST4: Modification and Etching> In step ST4, at least a portion of the organic-inorganic hybrid film HF is modified, and the anti-reflective film BF and the carbon-containing film CF are etched. In this example, after the anti-reflective film BF is etched while modifying a portion of the surface of the organic-inorganic hybrid film HF, the carbon-containing film CF is etched while modifying another portion of the surface of the organic-inorganic hybrid film HF.

[0108] First, the active fluorine species generated in step ST3 modify at least a portion of the organomagnesium compound in the organic-inorganic hybrid film HF. As an example, the active fluorine species convert the surface of the organic-inorganic hybrid film HF into magnesium fluoride (MgF). The active fluorine species also etch the anti-reflective film BF. That is, as shown in FIG. 10E, the active fluorine species etches the anti-reflective film BF while forming a layer FP-1 containing magnesium fluoride on the surface of the organic-inorganic hybrid film HF exposed by the etching. This forms a recess RC defined by the sidewall of the organic-inorganic hybrid film HF and the carbon-containing film CF.

[0109] Furthermore, in this example, after the anti-reflective film BF is etched, the process gas is switched from a gas containing a fluorine-containing gas to a gas containing an oxygen-containing gas. Then, the activated oxygen species generated in step ST3 modify at least a portion of the organomagnesium compound in the organic-inorganic hybrid film HF. As an example, the activated oxygen species change the surface of the organic-inorganic hybrid film HF to magnesium oxide (MgO). The activated oxygen species also etches the carbon-containing film CF. That is, as shown in FIG. 10F , the activated oxygen species etches the carbon-containing film CF while forming a layer FP-2 containing magnesium oxide on the surface of the organic-inorganic hybrid film HF. This forms a recess RC defined by the sidewall of the organic-inorganic hybrid film HF and the etching film EF.

[0110] The surface of the organic-inorganic hybrid film HF may be isotropically modified, as shown in FIG. 10G. That is, the thickness of the layer FP on the top surface TS of the organic-inorganic hybrid film HF may be approximately equal to the thickness of the layer FP on the sidewall SS of the organic-inorganic hybrid film HF. The surface of the organic-inorganic hybrid film HF may also be anisotropically modified. As an example, the thickness of the layer FP on the top surface TS of the organic-inorganic hybrid film HF may be thicker than the thickness of the layer FP on the sidewall SS of the organic-inorganic hybrid film HF. The layer FP may also be formed only on the top surface TS of the organic-inorganic hybrid film HF. The layer FP-1 and the layer FP-2 may have the same thickness or different thicknesses.

[0111] At least a portion of the organic-inorganic hybrid film HF may be modified by ultraviolet light. In this case, ozone generated by the ultraviolet light may convert at least a portion of the organic-inorganic hybrid film HF into magnesium oxide (MgO). As an example, the plasma processing apparatus 1 shown in FIG. 2 may include a device for generating ultraviolet light, and the device may irradiate the substrate W with ultraviolet light. Alternatively, the plasma generated in step ST3 may generate ultraviolet light, and at least a portion of the organic-inorganic hybrid film HF may be modified by the ultraviolet light. Alternatively, the organic-inorganic hybrid film HF may be modified by both the ultraviolet light and the active species generated in step ST3.

[0112] 10G, a recess RC is formed in the space where the anti-reflection film BF and the carbon-containing film CF have been removed, as shown in FIG. 10G. The recess RC is a space defined by the sidewalls of the organic-inorganic hybrid film HF. The bottom of the recess RC may be exposed to the etching film EF.

[0113] The processing method of this example may include, after step ST4, a step of etching the etching film EF using the organic-inorganic hybrid film HF as a mask. In this step, the etching film EF may be etched and a part of the organic-inorganic hybrid film HF may be etched.

[0114] <Fourth Example> Fig. 11 is a flowchart showing a fourth example of the present processing method. Figs. 12A to 12G are views showing an example of the cross-sectional structure of the substrate W in the fourth example. Figs. 12A to 12D are views showing an example of the cross-sectional structure of the substrate W corresponding to step ST1. Figs. 12E and 12F are views showing an example of the cross-sectional structure of the substrate W during execution of steps ST2 to ST4. Fig. 12G is a view showing an example of the cross-sectional structure of the substrate W after execution of step ST4. The fourth example of the present processing method will be described with reference to Figs. 11 and 12 .

[0115] <Process ST1: Preparation of Substrate> First, in process ST1, a substrate W is prepared. In the fourth example, process ST1 includes a step of forming an etching film EF (process ST1-41), a step of forming a carbon-containing film CF (process ST1-42), a step of forming a photoresist film PR (process ST1-43), a step of forming a silselquioxane film SQ (process ST1-44), a step of etching the photoresist film PR (process ST1-45), a step of etching the carbon-containing film CF (process ST1-46), and a step of forming an organic-inorganic hybrid film HF (process ST1-47).

[0116] In step ST1-41, an etching film EF is formed. The etching film EF is formed on the base film UF, for example, as shown in FIG. 12A. In this example, the etching film EF is a silicon oxide film. The etching film EF may also be a carbon-containing film. As an example, the carbon-containing film may be an amorphous carbon film.

[0117] In step ST1-42, a carbon-containing film CF is formed on the etching film EF. The carbon-containing film CF can be formed on the entire surface of the etching film EF, as shown in FIG. 12A. In this example, the carbon-containing film CF is a spin-on carbon (SOC) film. The carbon-containing film CF is an example of the fourth film.

[0118] In step ST1-43, a photoresist film PR is formed on the carbon-containing film CF. As shown in FIG. 12A, the photoresist film PR has an opening pattern including at least one opening OP. The photoresist film PR is formed in a region RE2 on the carbon-containing film CF. That is, in region RE1, a space existing above the carbon-containing film CF becomes the opening OP. Region RE2 is a region where an organic-inorganic hybrid film HF will be formed in step ST1-37, which will be described later. The photoresist film PR is an example of a third film.

[0119] The photoresist film PR may be formed by applying a resist liquid onto the carbon-containing film CF, exposing the applied resist liquid, and developing the resist liquid. As an example, the resist liquid may be a positive resist liquid for immersion exposure.

[0120] In step ST1-44, a silsesquioxane film (also referred to as an "SQ film") SQ is formed. As shown in FIG. 12B, the SQ film SQ may be formed in at least one opening OP. That is, the SQ film SQ is formed in a region RE1 on the carbon-containing film CF. The SQ film SQ may also be formed in the same layer as the photoresist film PR. As an example, the SQ film SQ is formed by filling at least one opening OP with a solution containing silsesquioxane (also referred to as an "SQ solution"). For example, the SQ solution may be applied to the substrate W by a spin coating method to fill the opening OP with the SQ solution. Alternatively, the SQ film SQ formed by filling the opening OP with the SQ solution may be irradiated with ultraviolet light. The SQ film SQ is an example of a fifth film.

[0121] In step ST1-45, the photoresist film PR is etched. As an example, the photoresist film PR can be etched by plasma etching. The plasma etching may use plasma generated from a gas containing an oxygen-containing gas. The oxygen-containing gas may be, for example, oxygen (O ２ ) gas. The photoresist film PR may be entirely etched.

[0122] In step ST1-46, the carbon-containing film CF is etched. As shown in FIGS. 12B and 12C, the carbon-containing film CF is etched using the SQ film SQ as a mask. As an example, the carbon-containing film CF can be etched by plasma etching. The plasma etching may use plasma generated from a gas containing an oxygen-containing gas. The oxygen-containing gas may be, for example, oxygen (O ２ ) By etching the carbon-containing film CF, pillars of the SQ film SQ and the carbon-containing film CF are formed on the etched film EF, as shown in FIG. 12C. The etched carbon-containing film CF included in the pillars is an example of a first film. Also, the stacked film of the SQ film SQ and the etched carbon-containing film CF is an example of a first film.

[0123] Note that the process ST1-45 and the process ST1-46 may be performed consecutively, that is, the photoresist film PR and the carbon-containing film CF may be etched consecutively using the same process gas.

[0124] In step ST1-47, an organic-inorganic hybrid film HF is formed. The organic-inorganic hybrid film HF can be formed in region RE2 on the etching film EF, as shown in FIG. 12D. The organic-inorganic hybrid film HF can also be formed in the same layer as the SQ film SQ and the carbon-containing film CF. In FIG. 12D, the organic-inorganic hybrid film HF and the carbon-containing film CF are an example of films formed in the same layer. The organic-inorganic hybrid film HF and the SQ film SQ are also an example of films formed in the same layer. The stacked film of the organic-inorganic hybrid film HF, the SQ film SQ, and the carbon-containing film CF is also an example of films formed in the same layer.

[0125] As an example, the organic-inorganic hybrid film HF is formed by applying an organic-inorganic hybrid material by spin coating onto the substrate W. In this example, the organic-inorganic hybrid material is a solution containing an organomagnesium compound.

[0126] The substrate W obtained through steps ST1-41 to ST1-47 is placed on the substrate support 11, and the substrate W is held by the electrostatic chuck 1111.

[0127] <Step ST2: Supply of Processing Gas> In step ST2, a processing gas is supplied into the plasma processing chamber 10. In this example, in step ST4 described later, the organic-inorganic hybrid film HF is modified, and the SQ film SQ and the carbon-containing film CF are etched. Therefore, the processing gas may be a gas that can modify the organomagnesium compound contained in the organic-inorganic hybrid film HF and etch the SQ film SQ and the carbon-containing film CF. As an example, the processing gas may contain a fluorine-containing gas and / or an oxygen-containing gas. The fluorine-containing gas may be, for example, a fluorocarbon gas (C ｘ F ｙ (x and y are positive integers). The oxygen-containing gas may be, for example, oxygen (O ２ ) may be.

[0128] The type of process gas supplied in step ST2 may be changed depending on the progress of etching in step ST4 (described later). That is, in step ST4, a first process gas may be supplied during the etching period for the SQ film SQ, and a second process gas different from the first process gas may be supplied during the etching period for the carbon-containing film CF. As an example, the first process gas may contain a fluorine-containing gas. The second process gas may contain an oxygen-containing gas.

[0129] <Step ST3: Plasma Generation> In step ST3, plasma is generated in the plasma processing chamber 10. In this example, when a source RF signal is supplied to the shower head 13 or the substrate support 11 in the plasma processing apparatus 1 of FIG. 2, plasma is generated from the processing gas supplied into the plasma processing chamber 10 in step ST2. The plasma contains activated species generated from the processing gas. The activated species may be activated species of fluorine and / or activated species of oxygen.

[0130] <Step ST4: Modification and Etching> In step ST4, at least a portion of the organic-inorganic hybrid film HF is modified, and the SQ film SQ and the carbon-containing film CF are etched. In this example, after the SQ film SQ is etched while modifying a portion of the surface of the organic-inorganic hybrid film HF, the carbon-containing film CF is etched while modifying another portion of the surface of the organic-inorganic hybrid film HF.

[0131] First, the active fluorine species generated in step ST3 modify at least a portion of the organomagnesium compound in the organic-inorganic hybrid film HF. As an example, the active fluorine species convert the surface of the organic-inorganic hybrid film HF into magnesium fluoride (MgF). The active fluorine species also etch the anti-reflective film BF. That is, as shown in FIG. 10E, the active fluorine species etches the anti-reflective film BF while forming a layer FP-1 containing magnesium fluoride on the surface of the organic-inorganic hybrid film HF exposed by the etching. This forms a recess RC defined by the sidewall of the organic-inorganic hybrid film HF and the carbon-containing film CF.

[0132] Furthermore, in this example, after the anti-reflective film BF is etched, the process gas is switched from a gas containing a fluorine-containing gas to a gas containing an oxygen-containing gas. Then, the activated oxygen species generated in step ST3 modify at least a portion of the organomagnesium compound in the organic-inorganic hybrid film HF. As an example, the activated oxygen species change the surface of the organic-inorganic hybrid film HF to magnesium oxide (MgO). The activated oxygen species also etches the carbon-containing film CF. That is, as shown in FIG. 10F , the activated oxygen species etches the carbon-containing film CF while forming a layer FP-2 containing magnesium oxide on the surface of the organic-inorganic hybrid film HF. This forms a recess RC defined by the sidewall of the organic-inorganic hybrid film HF and the etching film EF.

[0133] The surface of the organic-inorganic hybrid film HF may be isotropically modified, as shown in FIG. 12G. That is, the thickness of the layer FP on the top surface TS of the organic-inorganic hybrid film HF may be approximately equal to the thickness of the layer FP on the sidewall SS of the organic-inorganic hybrid film HF. The surface of the organic-inorganic hybrid film HF may also be anisotropically modified. As an example, the thickness of the layer FP on the top surface TS of the organic-inorganic hybrid film HF may be thicker than the thickness of the layer FP on the sidewall SS of the organic-inorganic hybrid film HF. The layer FP may also be formed only on the top surface TS of the organic-inorganic hybrid film HF. The layer FP-1 and the layer FP-2 may have the same thickness or different thicknesses.

[0134] At least a portion of the organic-inorganic hybrid film HF may be modified by ultraviolet light. In this case, ozone generated by the ultraviolet light may convert at least a portion of the organic-inorganic hybrid film HF into magnesium oxide (MgO). As an example, the plasma processing apparatus 1 shown in FIG. 2 may include a device for generating ultraviolet light, and the device may irradiate the substrate W with ultraviolet light. Alternatively, the plasma generated in step ST3 may generate ultraviolet light, and at least a portion of the organic-inorganic hybrid film HF may be modified by the ultraviolet light. Alternatively, the organic-inorganic hybrid film HF may be modified by both the ultraviolet light and the active species generated in step ST3.

[0135] 10G, a recess RC is formed in the space where the anti-reflection film BF and the carbon-containing film CF have been removed, as shown in FIG. 10G. The recess RC is a space defined by the sidewalls of the organic-inorganic hybrid film HF. The bottom of the recess RC may be exposed to the etching film EF.

[0136] The processing method of this example may include, after step ST4, a step of etching the etching film EF using the organic-inorganic hybrid film HF as a mask. In this step, the etching film EF may be etched and a part of the organic-inorganic hybrid film HF may be etched.

[0137] According to this treatment method, it is possible to modify at least a portion of the organic-inorganic hybrid film while etching the remaining films, and it is also possible to reduce the change in the dimensions of the organic-inorganic hybrid film HF before and after modification.

[0138] The above embodiments have been described for illustrative purposes and various modifications may be made without departing from the scope and spirit of the present disclosure.

[0139] 1... plasma processing apparatus, 2... control unit, 10... plasma processing chamber, 10s... plasma processing space, 11... substrate support unit, 12... plasma generation unit, 13... shower head, 20... gas supply unit, 30... power supply, 31... RF power supply, 32... DC power supply, CF... carbon-containing film, EF... etching film, HF... organic-inorganic hybrid film

Claims

1. A plasma processing method performed in a plasma processing apparatus having a chamber, comprising: a preparation step of preparing a substrate having a first film and a second film containing an organic-inorganic hybrid material in the chamber; a step of supplying a processing gas into the chamber; a step of generating plasma from the processing gas; and an etching step of etching the first film with the plasma while modifying at least a portion of the second film.

2. The plasma processing method according to claim 1, wherein in the etching step, at least a portion of the second film is modified by the plasma.

3. The plasma processing method according to claim 1, further comprising the step of irradiating the substrate with ultraviolet light, wherein in the etching step, at least a portion of the second film is modified by the ultraviolet light.

4. The plasma processing method according to claim 2, wherein the processing gas contains an oxidizing gas that oxidizes the inorganic material contained in the organic-inorganic hybrid material, and in the etching step, the inorganic material contained in the organic-inorganic hybrid material is oxidized by plasma generated from the oxidizing gas, thereby modifying at least a portion of the second film.

5. The plasma processing method according to claim 4, wherein the oxidizing gas is an oxygen-containing gas.

6. The plasma processing method according to claim 2, wherein the processing gas contains a reducing gas that reduces the inorganic material contained in the organic-inorganic hybrid material, and in the etching step, the inorganic material contained in the organic-inorganic hybrid material is reduced by plasma generated from the reducing gas, thereby modifying at least a portion of the second film.

7. The plasma processing method according to claim 6, wherein the reducing gas is a hydrogen-containing gas.

8. The plasma processing method according to claim 2, wherein the processing gas contains a halogen-containing gas that halogenates the inorganic material contained in the organic-inorganic hybrid material, and in the etching step, the inorganic material contained in the organic-inorganic hybrid material is halogenated by plasma generated from the oxidizing gas, thereby modifying at least a portion of the second film.

9. The plasma processing method according to claim 2, wherein the organic-inorganic hybrid material contains a metal, and the second film is modified in the etching step by changing the valence of the metal ions.

10. The plasma processing method according to any one of claims 1 to 9, wherein the substrate has at least one first region and at least one second region other than the at least one first region, and the preparation step includes: forming the first film in the at least one first region on the substrate, the first film having a pattern that defines at least one opening in the at least one second region; and forming the second film in the at least one opening.

11. The plasma processing method of claim 10, wherein the step of forming the first film comprises the steps of: forming a third film in the at least one second region on the substrate, the third film having a pattern that defines at least one opening in the at least one first region; forming the first film in the at least one opening; and etching the third film.

12. The plasma processing method according to claim 11, wherein the step of forming the first film includes the steps of: forming a fourth film on the substrate; forming the third film on the fourth film in the at least one second region, the third film having a pattern that defines at least one opening in the at least one first region; forming a fifth film in the at least one opening on the fourth film; and etching the third film and the fourth film in the at least one second region, and the first film is composed of the fifth film.

13. The plasma processing method according to claim 12, wherein the step of etching the third film and the fourth film includes the steps of: etching the third film to expose the fourth film in the at least one second region; and etching the fourth film in the at least one second region using the fifth film as a mask; and wherein the first film is configured to include the etched fourth film.

14. The plasma processing method according to claim 10, wherein the step of forming the first film includes the steps of: forming a sixth film on the substrate; forming a seventh film on the sixth film in the at least one first region, the seventh film having a pattern that defines at least one opening in the at least one second region; and etching the sixth film using the seventh film as a mask; and wherein the first film is composed of the etched sixth film.

15. The plasma processing method according to any one of claims 10 to 14, wherein the at least one first region has a circular or rectangular shape in a plan view of the substrate.

16. The plasma processing method according to any one of claims 10 to 14, wherein the at least one first region and the at least one second region form a line and space pattern in a plan view of the substrate.

17. The plasma processing method according to any one of claims 1 to 9, wherein the preparation step includes the steps of: forming the first film on the substrate; and forming the second film on the first film, the second film having a pattern that exposes at least a portion of the first film.

18. The plasma processing method according to claim 14, wherein the first film is formed by a nanoimprint method, a self-assembly lithography method, or an inkjet method.

19. The plasma processing method according to any one of claims 1 to 15, wherein the organic-inorganic hybrid material contains at least one metal selected from the group consisting of Mg, Zn, Y, Ni, Ti, Fe, and Al.

20. The plasma processing method according to any one of claims 1 to 19, further comprising the step of etching a portion of the substrate using the second film, at least a portion of which has been modified, as a mask.

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