Patent ID: 12217973

DETAILED DESCRIPTION

In the following detailed description, reference is made to the accompanying drawings, which form a part of the description. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. Furthermore, unless otherwise noted, the description of each successive drawing may reference features from one or more of the previous drawings to provide clearer context and a more substantive explanation of the current exemplary embodiment. Still, the exemplary embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein and illustrated in the drawings, may be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.

Hereinafter, various exemplary embodiments of the present disclosure will be described.

In one exemplary embodiment, there is provided a method of etching a film of a substrate. The substrate includes an underlying region, the film and a mask. The film is provided on the underlying region. The mask is provided on the film. The mask is patterned. The method comprises performing main etching on the film. The main etching is plasma etching of the film and exposes at least a part of the underlying region. The method further comprises forming a protective layer on at least a side wall surface of the mask after the performing of the main etching. A material of the protective layer is different from a material of the film. The method further comprises performing over-etching on the film after the forming of the protective layer. The over-etching is plasma etching of the film.

In the above-described method according to the exemplary embodiment, the film is etched by the main etching to expose the underlying region. An opening formed in the film by the main etching has a tapered shape. That is, the width of the opening formed in the film at the bottom thereof is smaller than at the top portion thereof. Then, in this method, the protective layer is formed at least on the side wall surface of the mask. Thereafter, in this method, the over-etching of the film is performed in a state in which the side wall surface of the mask is protected by the protective layer. That is, in this method, the over-etching of the film is performed in a state in which a decrease in the width of the mask is suppressed by the protective layer. Therefore, a decrease in the width of a pattern formed on the film can be suppressed and a verticality of a side wall surface of the film can be improved.

In the exemplary embodiment, the substrate may further include a first region and a second region. A pattern of the mask in the first region may be formed more densely than a pattern of the mask in the second region. According to this method of the exemplary embodiment, the over-etching of the film is performed in the state in which the decrease in the width of the mask is suppressed by the protective layer, and, thus, a difference in shape between the pattern formed on the film in the first region and the pattern formed on the film in the second region can be reduced.

In the exemplary embodiment, the forming of the protective layer and the performing of the over-etching may be repeated alternately.

In the exemplary embodiment, the method may further comprise performing plasma etching after the forming of the protective layer and before the performing of the over-etching. The plasma etching is performed to remove a region of the protective layer formed on a side wall surface of the film which defines the opening formed in the film.

In the exemplary embodiment, a power lever of a bias power in the performing of the plasma etching is higher than a power level of a bias power in each of the performing of the main etching and the performing of the over-etching. The bias power is supplied for attracting ions onto the substrate.

In the exemplary embodiment, the mask may be made of an organic material.

In the exemplary embodiment, the film may be a silicon-containing film.

In the exemplary embodiment, the silicon-containing film may be a silicon nitride film.

In the exemplary embodiment, the substrate may be maintained in a decompressed environment from a start of the performing of the main etching to an end of the performing of the over-etching.

In the exemplary embodiment, the performing of the main etching, the forming of the protective layer and the performing of the over-etching may be performed by using a single plasma processing apparatus.

In the exemplary embodiment, the protective layer may be conformally formed on the substrate. In one exemplary embodiment, the protective layer may be formed by atomic layer deposition.

In another exemplary embodiment, there is provided a plasma processing apparatus. The plasma processing apparatus comprises a chamber, a substrate supporting mechanism, a gas supply, a radio frequency power supply and a controller. The substrate supporting mechanism is provided within the chamber. The gas supply is configured to supply a gas into the chamber. The radio frequency power supply is configured to generate a radio frequency power to form plasma from a gas within the chamber. The controller is configured to control the gas supply and the radio frequency power supply. The controller controls the gas supply and the radio frequency power supply to perform main etching on a film of a substrate. The controller controls the gas supply and the radio frequency power supply to form a protective layer, which is made of a different material from the film, on the substrate after the main etching. The controller controls the gas supply and the radio frequency power supply to perform over-etching on the film of the substrate after the protective layer is formed.

Hereinafter, various exemplary embodiments of the present disclosure will be explained with reference to the accompanying drawings. Further, in the drawings, similar symbols typically identify similar components, unless context dictates otherwise.

FIG.1is a flowchart illustrating a method of etching a film of a substrate according to an exemplary embodiment. A method MT illustrated inFIG.1is performed to etch a film of a substrate.FIG.2Ais a partially enlarged cross-sectional view of an example substrate to which the method illustrated inFIG.1is applicable. A substrate W illustrated inFIG.2Ahas an underlying region UR, a film EF and a mask MK.

The film EF is provided on the underlying region UR. The mask MK is provided on the film EF. The mask MK is patterned. That is, the mask MK has a pattern (e.g., line). The mask MK provides a space where the film EF is exposed around the pattern.

In the exemplary embodiment, the substrate W may have a first region R1and a second region R2. A pattern of the mask MK in the first region R1may be formed more densely than a pattern of the mask MK in the second region R2. That is, the ratio of the width of the space around the pattern to the width of the pattern of the mask MK in the first region R1is smaller than in the second region R2. For example, the width of the space around the pattern of the mask MK in the first region R1is smaller than the width of the space around the pattern of the mask MK in the second region R2.

The film EF is made of a material that is selectively etched with respect to the mask MK. The film EF may be made of a material that is also selectively etched with respect to the underlying region UR. The film EF may be a silicon-containing film or an organic film. Examples of the film EF as the silicon-containing film may include a silicon nitride film or a silicon film (e.g., polycrystalline silicon film). If the film EF is the silicon-containing film, the mask MK may be made of an organic material, amorphous carbon, metal or a metal-containing material. The metal and the metal-containing material may include, e.g., tungsten, tantalum and titanium. The metal-containing material may include a nitride, carbide or oxide of the metal. The underlying region UR may be made of, e.g., a silicon oxide.

A plasma processing apparatus is used for performing the method MT.FIG.3is a diagram schematically illustrating an example of the plasma processing apparatus which can be used to perform the method illustrated inFIG.1. A plasma processing apparatus1illustrated inFIG.3is a capacitively coupled plasma processing apparatus. The plasma processing apparatus1is equipped with a chamber10. The chamber10provides an inner space10sinside the plasma processing apparatus1.

The chamber10includes a chamber main body12. The chamber main body12has a substantially cylindrical shape. The inner space10sis provided inside the chamber main body12. The chamber main body12is made of a conductor such as aluminum. The chamber main body12is grounded. A film having corrosion resistance is formed on an inner wall surface of the chamber main body12. The film having corrosion resistance may be made of ceramic such as aluminum oxide and yttrium oxide.

A passage12pis formed at a side wall of the chamber main body12. When the substrate W is transferred between the inner space10sand the outside of the chamber10, the substrate W passes through the passage12p. This passage12pcan be opened or closed by a gate valve12g. The gate valve12gis provided along the side wall of the chamber main body12.

A support13is provided on a bottom portion of the chamber main body12. The support13is made of an insulating material. The support13has a substantially cylindrical shape. The support13extends upwards from the bottom portion of the chamber main body12within the inner space10s. The support13supports a substrate supporting mechanism14. The substrate supporting mechanism14is configured to support the substrate W within the chamber10, i.e., within the inner space10s.

The substrate supporting mechanism14includes a lower electrode18and an electrostatic chuck20. The lower electrode18and the electrostatic chuck20are provided within the chamber10. The substrate supporting mechanism14may further include an electrode plate16. The electrode plate16is made of a conductor such as aluminum and has a substantially disk shape. The lower electrode18is provided on the electrode plate16. The lower electrode18is made of a conductor such as aluminum and has a substantially disk shape. The lower electrode18is electrically connected to the electrode plate16.

The electrostatic chuck20is provided on the lower electrode18. The substrate W is placed on an upper surface of the electrostatic chuck20. The electrostatic chuck20includes a main body and an electrode. The main body of the electrostatic chuck20is made of a dielectric material. The electrode of the electrostatic chuck20is a film-shaped electrode and provided within the main body of the electrostatic chuck20. The electrode of the electrostatic chuck20is connected to a DC power supply20pvia a switch20s. When a voltage is applied from the DC power supply20pto the electrode of the electrostatic chuck20, an electrostatic attraction force is generated between the electrostatic chuck20and the substrate W. The substrate W is attracted to the electrostatic chuck20by the generated electrostatic attraction force and held by the electrostatic chuck20.

An edge ring FR is placed on the substrate supporting mechanism14. The edge ring FR may be made of, but not limited to, silicon, silicon carbide or quartz. When the substrate W is processed within the chamber10, the substrate W is placed on the electrostatic chuck20and within a region surrounded by the edge ring FR.

A flow path18fis provided within the lower electrode18. A heat exchange medium (e.g., coolant) is supplied into a flow path18ffrom a chiller unit22through a line22a. The chiller unit22is provided outside the chamber10. The heat exchange medium supplied into the flow path181is returned back to the chiller unit22through a line22b. In the plasma processing apparatus1, a temperature of the substrate W placed on the electrostatic chuck20is controlled by heat exchange between the heat exchange medium and the lower electrode18. Further, a heater (e.g., resistance heating element) may be provided within the substrate supporting mechanism14. The temperature of the substrate W may be controlled by the heater.

The plasma processing apparatus1may further include a gas supply line24. The gas supply line24supplies a heat transfer gas (e.g., He gas) to a gap between the upper surface of the electrostatic chuck20and a rear surface of the substrate W. The heat transfer gas is supplied from a heat transfer gas supply mechanism to the gas supply line24.

The plasma processing apparatus1may further include an upper electrode30. The upper electrode30is provided above the substrate supporting mechanism14. The upper electrode30is supported by an upper portion of the chamber main body12via a member32. The member32is made of a material having insulation properties. The upper electrode30and the member32close an upper opening of the chamber main body12.

The upper electrode30may include a ceiling plate34and a supporting body36. A lower surface of the ceiling plate34is on the side of the inner space10sand defines the inner space10s. The ceiling plate34is made of a silicon-containing material. The ceiling plate34is made of, e.g., silicon or silicon carbide. The ceiling plate34is provided with a plurality of gas discharge holes34a. The plurality of gas discharge holes34apenetrates the ceiling plate34in a thickness direction of the ceiling plate34.

The supporting body36detachably supports the ceiling plate34. The supporting body36is made of a conductive material such as aluminum. A gas diffusion space36ais formed within the supporting body36. The supporting body36is provided with a plurality of gas holes36b. The plurality of gas holes36bextends downwards from the gas diffusion space36a. The plurality of gas holes36bcommunicates with the plurality of gas discharge holes34a, respectively. The supporting body36is provided with a gas inlet port36c. The gas inlet port36cis connected to the gas diffusion space36a. A gas supply line38is connected to the gas inlet port36c.

The gas supply line38is connected to a gas source group40via a valve group41, a flow rate controller group42and a valve group43. The gas source group40, the valve group41, the flow rate controller group42and the valve group43constitute a gas supply GS. The gas source group40includes a plurality of gas sources. The plurality of gas sources of the gas source group40includes sources of a plurality of gases used in the method MT. Each of the valve group41and the valve group43includes a plurality of opening/closing valves. The flow rate controller group42includes a plurality of flow rate controllers. Each of the flow rate controllers of the flow rate controller group42may be a mass flow controller or a pressure control type flow rate controller. Each of the plurality of gas sources of the gas source group40is connected to the gas supply line38via a corresponding opening/closing valve belonging to the valve group41, a corresponding flow rate controller belonging to the flow rate controller group42and a corresponding opening/closing valve belonging to the valve group43.

The plasma processing apparatus1includes a shield46that is detachably provided along the inner wall surface of the chamber main body12. The shield46is also provided at an outer periphery of the support13. The shield46suppresses a by-product, which has been generated during the plasma processing, from adhering to the chamber main body12. The shield46is prepared by forming a corrosion-resistant film on a surface of a member made of, e.g., aluminum. The corrosion-resistant film may be made of ceramic such as yttrium oxide.

A baffle plate48is provided between the support13and a side wall of the chamber main body12. The baffle plate48is prepared by forming a corrosion-resistant film on a surface of a member made of, e.g., aluminum. The corrosion-resistant film may be made of ceramic such as yttrium oxide. The baffle plate48is provided with a plurality of through-holes. A gas exhaust port12eis provided under the baffle plate48and at the bottom portion of the chamber main body12. The gas exhaust port12eis connected to a gas exhaust device50via a gas exhaust line52. The gas exhaust device50includes a pressure control valve and a vacuum pump such as a turbo molecular pump.

The plasma processing apparatus1further includes a first radio frequency power supply62and a second radio frequency power supply64. The first radio frequency power supply62is configured to generate first radio frequency power. In an example, the first radio frequency power has a frequency suitable for plasma formation. The first radio frequency power has a frequency in a range of, e.g., from 27 MHz to 100 MHz. For example, the frequency of the first radio frequency power may be 40 MHz. The first radio frequency power supply62is connected to the upper electrode30via a matching device66. The matching device66has a circuit configured to match an output impedance of the first radio frequency power supply62and an impedance at a load side (upper electrode30side). Further, the first radio frequency power supply62may be connected to the lower electrode18via the matching device66.

The second radio frequency power supply64is configured to generate a second radio frequency power. The second radio frequency power has a lower frequency than that of the first radio frequency power. The second radio frequency power may be used as a radio frequency bias power for ion attraction onto the substrate W. The second radio frequency power has a frequency in a range of, e.g., from 400 kHz to 40.68 MHz. For example, the frequency of the second radio frequency power may be 3.2 MHz. The second radio frequency power supply64is connected to the lower electrode18via a matching device68and the electrode plate16. The matching device68has a circuit configured to match an output impedance of the second radio frequency power supply64and an impedance at a load side (lower electrode18side).

The plasma processing apparatus1further includes a controller MC. The controller MC may be a computer including a processor, a storage such as a memory, an input device, a display device, a signal input/output interface, and the like. The controller MC controls individual components of the plasma processing apparatus1. An operator may use the input device of the controller MC to perform a command input operation and the like so as to manage the plasma processing apparatus1. Further, the display device of the controller MC may visualize and display an operation status of the plasma processing apparatus1. Also, the storage of the controller MC stores a control program and recipe data. The control program is executed by the processor of the controller MC to perform various processings in the plasma processing apparatus1. When the processor of the controller MC executes the control program and controls individual components of the plasma processing apparatus1according to the recipe data, the method MT is performed in the plasma processing apparatus1.

Referring toFIG.1again, the method MT will be described in detail. In the following description, the method MT will be explained for an example case where the method MT is performed on the substrate W by using the plasma processing apparatus1. Further, in the following description, the control of individual components of the plasma processing apparatus1by the controller MC will also be described in detail. Furthermore, in the following description, reference is made toFIG.2B,FIG.4A,FIG.4BandFIG.4Cas well asFIG.1andFIG.2A.FIG.2Bis a partially enlarged cross-sectional view illustrating a state of the example substrate after a process ST1is performed.FIG.4Ais a partially enlarged cross-sectional view illustrating a state of the example substrate after a process ST2is performed,FIG.4Bis a partially enlarged cross-sectional view illustrating a state of the example substrate after a process ST3is performed andFIG.4Cis a partially enlarged cross-sectional view illustrating a state of the example substrate after a process ST4is performed.

As illustrated inFIG.1, the method MT includes the process ST1, the process ST2and the process ST4. In an exemplary embodiment, the method MT may further include the process ST3. The process ST3is performed after the process ST2is performed and before the process ST4is performed. In the exemplary embodiment, the substrate W is maintained in a decompressed environment from the start of the process ST1to the end of the process ST4. That is, the substrate W is not exposed to the atmosphere from the start of the process ST1to the end of the process ST4. In the exemplary embodiment, the method MT is performed using the single plasma processing apparatus1. The substrate W is placed within the decompressed inner space10sof the plasma processing apparatus1from the start of the process ST1to the end of the process ST4.

In the method MT, the substrate W is placed on the substrate supporting mechanism14. The substrate W is held by the electrostatic chuck20. In the method MT, the process ST1is performed first. In the process ST1, main etching is performed on the film EF. The main etching is plasma etching of the film EF and exposes at least a part of the underlying region UR, as illustrated inFIG.2B.

In the process ST1, plasma is formed from a processing gas within the chamber10to etch the film EF. The film EF is etched by chemical species in the formed plasma. If the film EF is a silicon nitride film, the processing gas used in the process ST1includes a hydrofluorocarbon gas (e.g., CH3F). If the film EF is a silicon film, the processing gas used in the process ST1includes a halogen-containing gas. The halogen-containing gas is, for example, a HBr gas and/or a Cl2gas. If the film EF is an organic film, the processing gas used in the process ST1is, for example, an oxygen-containing gas. The oxygen-containing gas is an oxygen gas (O2gas), a carbon monoxide gas, a carbon dioxide gas or a mixed gas of two or more of these gases. If the film EF is the organic film, the processing gas used in the process ST1may be a mixed gas of a nitrogen gas (N2gas) and a hydrogen gas (H2gas).

To perform the process ST1, the controller MC controls the gas supply GS to supply the processing gas into the chamber10. To perform the process ST1, the controller MC controls the gas exhaust device50to control the pressure inside the chamber10to a predetermined level. To perform the process ST1, the controller MC controls the first radio frequency power supply62to supply the first radio frequency power. Further, to perform the process ST1, the controller MC controls the second radio frequency power supply64to supply the second radio frequency power.

As illustrated inFIG.2B, an opening formed in the film EF by the main etching in the process ST1has a tapered shape. That is, the width of the opening formed in the film EF by the main etching in the process ST1in the bottom portion thereof is smaller than that in the top portion thereof.

Then, in the method MT, the process ST2is performed. The process ST2is performed after the process ST1. In the process ST2, a protective layer PL is formed on at least a side wall surface of the mask MK. In the process ST2according to the exemplary embodiment, the protective layer PL may be conformally formed on the substrate W, as illustrated inFIG.4A. A material of the protective layer PL may be different from the material of the film EF. The material of the protective layer PL is, for example, silicon oxide. To form the protective layer PL in the process ST2, the controller MC controls the gas supply GS and at least one of the first radio frequency power supply62and the second radio frequency power supply64.

A method of forming the protective layer PL is not limited, but may be, for example, atomic layer deposition. The atomic layer deposition may be performed to uniformly form the protective layer PL on both the first region R1and the second region R2.FIG.5is a flowchart illustrating an example of the process ST2in the method illustrated inFIG.1. In the example illustrated inFIG.5, the process ST2includes a process ST21and a process ST23. The process ST2may further include a process ST22and a process ST24.

In the process ST21, a first gas is supplied to the substrate W. The first gas contains a precursor gas. The first gas may further contain a carrier gas such as an inert gas. The precursor gas may be an aminosilane-based gas. As the aminosilane-based gas, a gas having a molecular structure with a relatively small number of amino groups may be used. For example, monoaminosilane (H3—Si—R (R is an amino group, which may contain an organic group and may be substituted) may be used as the aminosilane-based gas. The aminosilane-based gas may include aminosilane, which may have one to three silicon atoms, or may include aminosilane having one to three amino groups. The aminosilane having one to three silicon atoms may be monosilane (monoaminosilane) having one to three amino groups, disilane having one to three amino groups or trisilane having one to three amino groups. Further, the aminosilane may have an amino group which may be substituted. Furthermore, the amino group may be substituted by any one of a methyl group, an ethyl group, a propyl group and a butyl group. Moreover, the methyl group, the ethyl group, the propyl group or the butyl group may be substituted by halogen.

To perform the process ST21, the controller MC controls the gas supply GS to supply the first gas into the chamber10. To perform the process ST21, the controller MC controls the gas exhaust device50to control the pressure inside the chamber10to a predetermined level. In the process ST21according to the exemplary embodiment, the plasma may not be formed. Therefore, in the process ST21according to an exemplary embodiment, the first radio frequency power and the second radio frequency power may not be supplied.

In the process ST21, molecules contained in the first gas adhere as a reaction precursor onto the surface of the substrate W. The molecules contained in the first gas adhere onto the surface of the substrate W by chemical adsorption based on chemical bonding.

The process ST22is performed between the process ST21and the process ST23. In the process ST22, the inner space10sis purged. That is, the first gas inside the chamber10is exhausted. In the process ST22, an inert gas may be supplied into the chamber10. To perform the process ST22, the controller MC operates the gas exhaust device50. To perform the process ST22, the controller MC may control the gas supply GS to supply the inert gas into the chamber10. In the process ST22, molecules excessively adhering onto the substrate W are removed.

In the subsequent process ST23, plasma is formed from a second gas within the chamber10. The second gas contains an oxygen-containing gas. The oxygen-containing gas is, for example, an oxygen gas (O2gas), a carbon monoxide gas, a carbon dioxide gas or a mixed gas of two or more of these gases. In the process ST2, a monolayer of silicon oxide is formed by a reaction between chemical species in the plasma and the reaction precursor.

To perform the process ST23, the controller MC controls the gas supply GS to supply the second gas into the chamber10. To perform the process ST23, the controller MC controls the gas exhaust device50to control the pressure inside the chamber10to a predetermined level. To perform the process ST23, the controller MC controls the first radio frequency power supply62to supply the first radio frequency power. Otherwise or in addition, to perform the process ST23, the controller MC controls the second radio frequency power supply64to supply the second radio frequency power.

The process ST24is performed after the process ST23. The process ST24is the same as the process ST22.

A sequence including the process ST21and the process ST23or the processes ST21to ST24is performed one or more times based on a required thickness of the protective layer PL. If the sequence is performed a plurality of times, i.e., if the sequence is repeated, the process ST2further includes a process ST25. In the process ST25, it is determined whether a stop condition is satisfied. The stop condition is satisfied when a repetition number of the sequence reaches a predetermined number of times. If it is determined in the process ST25that the stop condition is not satisfied, the sequence is performed again. Meanwhile, if it is determined in the process ST25that the stop condition is satisfied, the process ST2is ended.

As described above, the process ST3is performed after the process ST2is performed and before the process ST4is performed. Further, after the process ST2, the process ST3may not be performed, but the process ST4may be performed.

In the process ST3, plasma etching is performed. The plasma etching in the process ST3is performed to remove a region of the protective layer PL formed on a side wall surface SWS. The side wall surface SWS refers to a side wall surface of the film EF and defines the opening formed by the main etching in the process ST1. In the process ST3, plasma is formed from a processing gas within the chamber10. The processing gas includes, for example, a fluorocarbon gas (e.g., CF4gas). The processing gas may further include an inert gas. The inert gas may be a rare gas such as an argon gas.

In the process ST3, the protective layer PL is partially removed by active species in the formed plasma. The plasma etching in the process ST3is anisotropic etching in which a region of the protective layer PL extending from a vertical surface (e.g., side wall surface of the mask MK) remains and the other region of the protective layer PL is etched. Specifically, as illustrated inFIG.4B, a region of the protective layer PL formed on an upper surface of the mask MK and extending along the side wall surface SWS of the film EF is removed by the plasma etching in the process ST3.

To perform the process ST3, the controller MC controls the gas supply GS to supply the processing gas into the chamber10. To perform the process ST3, the controller MC controls the gas exhaust device50to control the pressure inside the chamber10to a predetermined level. To perform the process ST3, the controller MC controls the first radio frequency power supply62to supply the first radio frequency power. To perform the process ST3, the controller MC controls the second radio frequency power supply64to supply the second radio frequency power.

In the exemplary embodiment, the bias power, i.e., the second radio frequency power, supplied in the process ST3may have a higher power level than the second radio frequency power supplied in the process ST1and the process ST4. According to this exemplary embodiment, it is possible to efficiently remove the region of the protective layer PL extending along the side wall surface SWS of the film EF by improving the anisotropy of the plasma etching in the process ST3.

The process ST4is performed after the process ST2or the process ST3. In the process ST4, over-etching of the film EF is performed. The over-etching is plasma etching of the film EF. The over-etching corrects the shape of the side wall surface SWS of the film EF to improve the verticality thereof, as illustrated inFIG.4C.

In the process ST4, to perform the over-etching on the film EF, plasma is formed from a processing gas within the chamber10. The film EF is etched by chemical species in the formed plasma. In the process ST4, the same processing gas as used in the process ST1may be used. If the film EF is the silicon nitride film, the processing gas used in the process ST4includes a hydrofluorocarbon gas (e.g., CH3F). If the film EF is the silicon film, the processing gas used in the process ST4includes a halogen-containing gas. The halogen-containing gas is, for example, a HBr gas and/or a Cl2gas. If the film EF is the organic film, the processing gas used in the process ST4is, for example, an oxygen-containing gas. The oxygen-containing gas is an oxygen gas (O2gas), a carbon monoxide gas, a carbon dioxide gas or a mixed gas of two or more of these gases. If the film EF is the organic film, the processing gas used in the process ST4may be a mixed gas of a nitrogen gas (N2gas) and a hydrogen gas (H2gas).

To perform the process ST4, the controller MC controls the gas supply GS to supply the processing gas into the chamber10. To perform the process ST4, the controller MC controls the gas exhaust device50to control the pressure inside the chamber10to a predetermined level. To perform the process ST4, the controller MC controls the first radio frequency power supply62to supply the first radio frequency power. Further, to perform the process ST4, the controller MC controls the second radio frequency power supply64to supply the second radio frequency power.

In the exemplary embodiment, a sequence including the processes ST2to ST4may be performed one or more times. That is, the process ST2and the process ST4may be repeated alternately. If the sequence is performed a plurality of times, i.e., if the sequence is repeated, the method MT includes a process ST5. In the process ST5, it is determined whether a stop condition is satisfied. The stop conditions is satisfied when a repetition number of the sequence reaches a predetermined number of times. If it is determined in the process ST5that the stop condition is not satisfied, the sequence is performed again. Meanwhile, if it is determined in the process ST5that the stop condition is satisfied, the method MT is ended.

In the method MT, after the main etching of the film EF is performed in the process ST1, the protective layer PL is formed on at least the side wall surface of the mask MK. Then, in the method MT, the over-etching of the film EF is performed in a state in which the side wall surface of the mask MK is protected by the protective layer PL. That is, in the method MT, the over-etching of the film EF is performed in a state in which a decrease in the width of the mask MK is suppressed by the protective layer PL. Therefore, a decrease in the width of the pattern formed on the film EF can be suppressed and the verticality of the side wall surface of the film EF can be improved.

In the exemplary embodiment, the substrate W has the above-described first region R1and second region R2. In the method MT, the over-etching of the film EF is performed in a state in which the decrease in the width of the mask MK is suppressed by the protective layer PL. Therefore, according to the method MT, a difference in shape between the pattern formed on the film EF in the first region R1and the pattern formed on the film EF in the second region R2can be reduced.

Hereinafter, reference is made toFIG.6.FIG.6is a diagram schematically illustrating an example of a processing system which can be used in the method illustrated inFIG.1. At least one of the processes ST1to ST4of the method MT may be performed using an apparatus different from apparatuses used in the other processes. Otherwise, each of the processes ST1to ST4may be performed using a different apparatus. In this case, a processing system PS illustrated inFIG.6may be used to perform the method MT.

The processing system PS illustrated inFIG.6includes tables2ato2d, containers4ato4d, a loader module LM, an aligner AN, load lock modules LL1and LL2, process modules PM1to PM6, a transfer module TF and the controller MC. Further, in the processing system PS, the number of tables, the number of containers and the number of load lock modules may be any number equal to or more than two. Also, the number of process modules may be any number equal to or more than two.

The tables2ato2dare arranged along an edge of the loader module LM. The containers4ato4dare mounted on the tables2ato2d, respectively. Each of the containers4ato4dis, for example, a container called a Front Opening Unified Pod (FOUP). Each of the containers4ato4dis configured to accommodate substrates W therein.

The loader module LM has a chamber therein. The pressure inside the chamber of the loader module LM is set to an atmospheric pressure. A transfer device TU1is provided within the chamber of the loader module LM. The transfer device TU1is, for example, a multi-joint robot and controlled by the controller MC. The transfer device TU1is configured to transfer the substrates W between each of the containers4ato4dand the aligner AN, between the aligner AN and each of the load lock modules LL1and LL2and between each of the load lock modules LL1and LL2and each of the containers4ato4d. The aligner AN is connected to the loader module LM. The aligner AN is configured to perform position adjustment (position correction) of the substrate W.

The load lock module LL1and the load lock module LL2are provided between the loader module LM and the transfer module TF. Each of the load lock module LL1and the load lock module LL2provides a preliminary decompression room.

The transfer module TF is connected to the load lock module LL1and the load lock module LL2via respective gate valves. The transfer module TF has a transfer chamber TC that can be decompressed. A transfer device TU2is provided within the transfer chamber TC. The transfer device TU2is, for example, a multi-joint robot and controlled by the controller MC. The transfer device TU2is configured to transfer substrates W between each of the load lock modules LL1and LL2and each of the process modules PM1to PM6and between any two of the process modules PM1to PM6.

Each of the process modules PM1to PM6is a processing apparatus configured to perform a preset substrate processing. One or more of the process modules PM1to PM6may be plasma processing apparatuses like the plasma processing apparatus1. The process ST1, the process ST3and the process ST4may be performed using one or more process modules that function as the plasma processing apparatuses. The others of the process modules PM1to PM6may be film forming apparatuses used in the process ST2.

In the processing system PS, the controller MC is configured to control individual components of the processing system PS. The processing system PS can transfer the substrates W between the process modules without exposing the substrates W to the atmosphere. Therefore, in the processing system PS, the method MT can be performed from the start of the process ST1to the end of the process ST4without exposing the substrate W to the atmosphere.

While various exemplary embodiments have been described above, various omissions, substitutions, and changes may be made without being limited to the above-described exemplary embodiments. Further, other exemplary embodiments can be implemented by combining elements in different exemplary embodiments.

By way of example, the method MT may be performed by using a plasma processing apparatus other than the capacitively coupled plasma processing apparatus. For example, a plasma processing apparatus used for performing the method MT may be an inductively coupled plasma processing apparatus or a plasma processing apparatus configured to form plasma by a surface wave such as microwave.

According to the exemplary embodiments, when the film of the substrate is etched, it is possible to suppress the decrease in the width of the pattern formed on the film and improve the verticality of a side wall surface of the film.

From the foregoing, it will be appreciated that various exemplary embodiments of the present disclosure have been described herein for purposes of illustration and various changes can be made without departing from the scope and spirit of the present disclosure. Accordingly, various exemplary embodiments described herein are not intended to be limiting, and the true scope and spirit are indicated by the following claims.

The claims of the present application are different and possibly, at least in some aspects, broader in scope than the claims pursued in the parent application. To the extent any prior amendments or characterizations of the scope of any claim or cited document made during prosecution of the parent could be construed as a disclaimer of any subject matter supported by the present disclosure, Applicants hereby rescind and retract such disclaimer. Accordingly, the references previously presented in the parent applications may need to be revisited.