Plasma processing method and plasma processing apparatus

Abstract

To provide a plasma processing method having an improved throughput.SOLUTION: A plasma processing method according to a present disclosure, is a plasma processing method performed in a plasma processing apparatus. The plasma processing method includes the steps of: preparing a substrate including a silicon-containing film and a carbon-containing film formed on the silicon-containing film; setting a temperature of the substrate to be a first temperature which is 0°C or less; supplying H2O to the substrate by first processing gas including a hydrogen atom and an oxygen atom; generating a plasma from the first processing gas by the high frequency and etching the carbon-containing film; setting the temperature of the substrate to be a second temperature different from the first temperature; supplying the substrate with the second processing gas including gas including hydrogen or fluorine or including both of hydrogen-containing gas and fluorine-containing gas; and generating the plasma from the second processing gas by the high frequency and etching the silicon-containing film.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] SUMMARY Exemplary embodiments of the present disclosure relate to a plasma processing method and a plasma processing apparatus. [Background technology]

[0002] Patent Document 1 describes an etching method as a technique for suppressing the occurrence of bowing during etching. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-179889 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a plasma processing method that improves throughput. [Means for solving the problem]

[0005] In one exemplary embodiment of the present disclosure, a plasma processing method is provided that is performed in a capacitively coupled plasma processing apparatus, the plasma processing method including the steps of: preparing a substrate including a silicon-containing film and a carbon-containing film formed on the silicon-containing film; setting a temperature of the substrate to a first temperature that is equal to or lower than 0° C.; and generating H 2 the step of supplying O to the substrate; generating plasma from the first process gas by radio frequency waves to etch the carbon-containing film; setting a temperature of the substrate to a second temperature different from the first temperature; supplying a second process gas to the substrate, the second process gas including a gas including hydrogen and fluorine, or including both a hydrogen-containing gas and a fluorine-containing gas; and generating plasma from the second process gas by radio frequency waves to etch the silicon-containing film. Effect of the Invention

[0006] According to one exemplary embodiment of the present disclosure, a plasma processing method that improves throughput can be provided. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a plasma processing apparatus 1 according to an exemplary embodiment. [Diagram 2] 4 is a timing chart showing an example of high frequency power HF and an electric bias. [Diagram 3] 13 is a partial enlarged view of another example of the substrate support 14 included in the plasma processing apparatus 1. FIG. [Figure 4] FIG. 1 is a schematic diagram of a substrate processing system PS according to an exemplary embodiment. [Diagram 5] 2 is a diagram showing an example of a cross-sectional structure of a substrate W. FIG. [Figure 6] 4 is a flowchart illustrating an example of the present processing method. [Figure 7] 13 is a diagram showing an example of a cross-sectional structure of the substrate W during execution of step ST3. FIG. [Figure 8] 13 is a diagram showing an example of a cross-sectional structure of the substrate W after step ST3 is completed. FIG. [Figure 9] 13 is a diagram showing an example of a cross-sectional structure of the substrate W during execution of step ST4. FIG. [Figure 10] 13 is a diagram showing an example of a cross-sectional structure of the substrate W after step ST4 is completed. FIG. [Figure 11] 1 is a graph showing the measurement results of Experiment 1. [Figure 12] 13 is a graph showing the measurement results of Experiment 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Each embodiment of the present disclosure will be described below.

[0009] In one exemplary embodiment, a plasma processing method is provided, which is a plasma processing method performed in a plasma processing apparatus, comprising the steps of: preparing a substrate including a silicon-containing film and a carbon-containing film formed on the silicon-containing film; setting a temperature of the substrate to a first temperature that is equal to or lower than 0° C.; and oxidizing the silicon-containing film by a first process gas including hydrogen atoms and oxygen atoms. 2 The method includes the steps of supplying O to the substrate, generating plasma from a first process gas by radio frequency waves to etch the carbon-containing film, setting the temperature of the substrate to a second temperature different from the first temperature, supplying a second process gas to the substrate, the second process gas including a gas including hydrogen and fluorine, or including both a hydrogen-containing gas and a fluorine-containing gas, and generating plasma from the second process gas by radio frequency waves to etch the silicon-containing film.

[0010] In one exemplary embodiment, the plasma processing apparatus includes a plasma processing chamber, a substrate support disposed within the plasma processing chamber for supporting a substrate, and an upper electrode disposed in the plasma processing chamber facing the substrate support, the step of preparing the substrate includes a step of placing the substrate on the substrate support, the step of etching the carbon-containing film includes a step of supplying a high frequency wave to the substrate support or the upper electrode to generate a plasma from a first processing gas in the plasma processing chamber and to etch the carbon-containing film, and the step of etching the silicon-containing film includes a step of supplying a high frequency wave to the substrate support or the upper electrode to generate a plasma from a second processing gas in the plasma processing chamber and to etch the silicon-containing film.

[0011] In one exemplary embodiment, the plasma processing apparatus includes a first plasma processing chamber and a second plasma processing chamber, a first substrate support disposed in the first plasma processing chamber and configured to support a substrate, a first upper electrode disposed in the first plasma processing chamber and facing the first substrate support, a second substrate support disposed in the second plasma processing chamber and configured to support a substrate, and a second upper electrode disposed in the second plasma processing chamber and facing the second substrate support, and the step of preparing the substrate includes a step of disposing the substrate on the first substrate support, and the step of etching the carbon-containing film includes a step of disposing the substrate on the first substrate support. the step of etching the silicon-containing film includes a step of supplying a high frequency wave to the second substrate support or the second upper electrode to generate a plasma from a first processing gas in the first plasma processing chamber and etching the carbon-containing film, the plasma processing method further includes a step of transferring the substrate from the first substrate support to a second substrate support, the step of setting the temperature of the substrate to a second temperature different from the first temperature includes a step of setting the temperature of the substrate to the second temperature in the second substrate support, and the step of etching the silicon-containing film includes a step of supplying a high frequency wave to the second substrate support or the second upper electrode to generate a plasma from the second processing gas in the second plasma processing chamber and etching the silicon-containing film.

[0012] In one exemplary embodiment, the plasma processing apparatus includes a transfer chamber connected to a first plasma processing chamber and a second plasma processing chamber, and the internal pressure of the transfer chamber is lower than atmospheric pressure. In a process of transferring a substrate, the substrate is transferred from the first substrate support to the second substrate support via the transfer chamber.

[0013] In one exemplary embodiment, the second temperature is lower than the first temperature.

[0014] In one exemplary embodiment, the second temperature is higher than the first temperature.

[0015] In one exemplary embodiment, the carbon-containing film is an amorphous carbon film.

[0016] In one exemplary embodiment, a plasma processing method is provided that is carried out in a plasma processing apparatus having a plasma processing chamber, the plasma processing method includes the steps of: supplying a carbon-containing gas into the plasma processing chamber; generating plasma from the carbon-containing gas by radio frequency waves to form a protective film on at least a portion of the inner wall of the plasma processing chamber; providing a substrate including a silicon-containing film and a carbon-containing film formed on the silicon-containing film in the plasma processing chamber; supplying a first process gas including hydrogen atoms and oxygen atoms into the plasma processing chamber to form a protective film on at least a portion of the inner wall of the plasma processing chamber; 2 The method includes the steps of supplying O to the substrate, generating plasma from a first process gas by radio frequency waves and etching the carbon-containing film, supplying a second process gas containing a gas containing hydrogen and fluorine or a second process gas containing a hydrogen-containing gas and a fluorine-containing gas to the substrate prepared in a plasma processing chamber, and supplying radio frequency waves to generate plasma from the second process gas and etch the silicon-containing film.

[0017] In one exemplary embodiment, the method further includes setting a temperature of the substrate to a first temperature and setting a temperature of the substrate to a second temperature different from the first temperature, wherein in the step of etching the carbon-containing film, the carbon-containing film is etched after the substrate is set to the first temperature, and in the step of etching the silicon-containing film, the SiO film is etched after the substrate is set to the second temperature.

[0018] In one exemplary embodiment, the protective film is a carbon-containing film.

[0019] In one exemplary embodiment, a plasma processing apparatus is provided, the plasma processing apparatus includes at least one plasma processing chamber, a temperature adjustment unit for setting a temperature of a substrate in the at least one plasma processing chamber, a gas supply unit configured to supply a gas into the at least one plasma processing chamber, a plasma generation unit configured to generate plasma from the gas in the at least one plasma processing chamber, and a controller configured to control the temperature adjustment unit, the gas supply unit, and the plasma generation unit, the controller setting a temperature of a substrate including a silicon-containing film and a carbon-containing film formed on the silicon-containing film to a first temperature of 0° C. or less, and generating H 2 O 3 by a first process gas including hydrogen atoms and oxygen atoms. 2 The present invention executes a control of supplying O to a substrate, generating plasma from a first process gas by radio frequency waves to etch a carbon-containing film, setting a temperature of the substrate to a second temperature different from the first temperature, supplying a second process gas containing a gas containing hydrogen and fluorine or containing both a hydrogen-containing gas and a fluorine-containing gas to the substrate, and generating plasma from the second process gas by radio frequency waves to etch a silicon-containing film.

[0020] 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 given the same reference numerals, and duplicated explanations will be omitted. Unless otherwise specified, the positional relationship such as up, down, left, right, etc. will be described based on the positional relationship shown in the drawing. The dimensional ratio of the drawings does not indicate the actual ratio, and the actual ratio is not limited to the illustrated ratio.

[0021] <Configuration of Plasma Processing Apparatus 1> 1 is a diagram illustrating a schematic diagram of a plasma processing apparatus 1 according to an exemplary embodiment. The plasma processing apparatus 1 is a capacitively coupled plasma processing apparatus. A plasma processing method according to an exemplary embodiment of the present disclosure (hereinafter, also referred to as "the processing method") may be performed using the plasma processing apparatus 1.

[0022] The plasma processing apparatus 1 shown in FIG. 1 includes a chamber 10. The chamber 10 provides an internal space 10s therein. The chamber 10 includes a chamber body 12. The chamber body 12 has a substantially cylindrical shape. The chamber body 12 is formed of, for example, aluminum. A corrosion-resistant film is provided on the inner wall surface of the chamber body 12. The corrosion-resistant film may be formed of a ceramic such as aluminum oxide or yttrium oxide.

[0023] A passage 12p is formed in a sidewall of the chamber body 12. The substrate W is transferred between the internal space 10s and the outside of the chamber 10 through the passage 12p. The passage 12p is opened and closed by a gate valve 12g. The gate valve 12g is provided along the sidewall of the chamber body 12.

[0024] A support 13 is provided on the bottom of the chamber body 12. The support 13 is made of an insulating material. The support 13 has a generally cylindrical shape. The support 13 extends upward from the bottom of the chamber body 12 in the internal space 10s. The support 13 supports a substrate support 14. The substrate support 14 is configured to support a substrate W in the internal space 10s.

[0025] The substrate support 14 has a lower electrode 18 and an electrostatic chuck 20. The substrate support 14 may further have an electrode plate 16. The electrode plate 16 is made of a conductor such as aluminum and has a substantially disk-like shape. The lower electrode 18 is provided on the electrode plate 16. The lower electrode 18 is made of a conductor such as aluminum and has a substantially disk-like shape. The lower electrode 18 is electrically connected to the electrode plate 16.

[0026] The electrostatic chuck 20 is provided on the lower electrode 18. The substrate W is placed on the upper surface of the electrostatic chuck 20. The electrostatic chuck 20 has a body and an electrode. The body of the electrostatic chuck 20 has a substantially disk shape and is formed from a dielectric material. The electrode of the electrostatic chuck 20 is a film-like electrode and is provided in the body of the electrostatic chuck 20. The electrode of the electrostatic chuck 20 is connected to a DC power supply 20p via a switch 20s. When a voltage from the DC power supply 20p is applied to the electrode of the electrostatic chuck 20, an electrostatic attractive force is generated between the electrostatic chuck 20 and the substrate W. The substrate W is attracted to the electrostatic chuck 20 by the electrostatic attractive force and is held by the electrostatic chuck 20.

[0027] An edge ring 25 is disposed on the substrate support 14. The edge ring 25 is a ring-shaped member. The edge ring 25 may be made of silicon, silicon carbide, quartz, or the like. The substrate W is disposed on the electrostatic chuck 20 and within a region surrounded by the edge ring 25.

[0028] A flow path 18f is provided inside the lower electrode 18. A heat exchange medium (e.g., a coolant) is supplied to the flow path 18f from a chiller unit provided outside the chamber 10 via a pipe 22a. The heat exchange medium supplied to the flow path 18f is returned to the chiller unit via a pipe 22b. In the plasma processing apparatus 1, the temperature of the substrate W placed on the electrostatic chuck 20 is adjusted by heat exchange between the heat exchange medium and the lower electrode 18.

[0029] The plasma processing apparatus 1 is provided with a gas supply line 24. The gas supply line 24 supplies a heat transfer gas (for example, He gas) from a heat transfer gas supply mechanism to the gap between the upper surface of the electrostatic chuck 20 and the back surface of the substrate W.

[0030] The plasma processing apparatus 1 further includes an upper electrode 30. The upper electrode 30 is provided above the substrate support 14. The upper electrode 30 is supported on the upper part of the chamber body 12 via a member 32. The member 32 is made of an insulating material. The upper electrode 30 and the member 32 close the upper opening of the chamber body 12.

[0031] The upper electrode 30 may include a top plate 34 and a support 36. The bottom surface of the top plate 34 is the bottom surface on the side of the internal space 10s and defines the internal space 10s. The top plate 34 may be formed of a low-resistance conductor or semiconductor that generates little Joule heat. The top plate 34 has a plurality of gas discharge holes 34a penetrating the top plate 34 in its plate thickness direction.

[0032] The support 36 detachably supports the top plate 34. The support 36 is made of a conductive material such as aluminum. A gas diffusion chamber 36a is provided inside the support 36. The support 36 has a plurality of gas holes 36b extending downward from the gas diffusion chamber 36a. The plurality of gas holes 36b are connected to the plurality of gas discharge holes 34a, respectively. A gas inlet 36c is formed in the support 36. The gas inlet 36c is connected to the gas diffusion chamber 36a. A gas supply pipe 38 is connected to the gas inlet 36c.

[0033] A gas source group 40 is connected to the gas supply pipe 38 via a flow rate controller group 41 and a valve group 42. The flow rate controller group 41 and the valve group 42 configure a gas supply unit. The gas supply unit may further include a gas source group 40. The gas source group 40 includes a plurality of gas sources. The plurality of gas sources include sources of processing gases used in the present processing method. The flow rate controller group 41 includes a plurality of flow rate controllers. Each of the plurality of flow rate controllers in the flow rate controller group 41 is a mass flow controller or a pressure-controlled flow rate controller. The valve group 42 includes a plurality of opening and closing valves. Each of the plurality of gas sources in the gas source group 40 is connected to the gas supply pipe 38 via a corresponding flow rate controller in the flow rate controller group 41 and a corresponding opening and closing valve in the valve group 42.

[0034] In the plasma processing apparatus 1, a shield 46 is detachably provided along the inner wall surface of the chamber body 12 and the outer periphery of the support part 13. The shield 46 prevents reaction by-products from adhering to the chamber body 12. The shield 46 is formed by forming a corrosion-resistant film on the surface of a base material made of, for example, aluminum. The corrosion-resistant film may be made of a ceramic such as yttrium oxide.

[0035] A baffle plate 48 is provided between the support 13 and the side wall of the chamber body 12. The baffle plate 48 is formed, for example, by forming a corrosion-resistant film (a film of yttrium oxide or the like) on the surface of a member made of aluminum. A plurality of through holes are formed in the baffle plate 48. An exhaust port 12e is provided below the baffle plate 48 and at the bottom of the chamber body 12. An exhaust device 50 is connected to the exhaust port 12e via an exhaust pipe 52. The exhaust device 50 includes a pressure regulating valve and a vacuum pump such as a turbo molecular pump.

[0036] The plasma processing apparatus 1 includes a high-frequency power supply 62 and a bias power supply 64. The high-frequency power supply 62 is a power supply that generates high-frequency power HF. The high-frequency power HF has a first frequency suitable for generating plasma. The first frequency is, for example, a frequency within a range of 27 MHz to 100 MHz. The high-frequency power supply 62 is connected to the lower electrode 18 via a matching device 66 and the electrode plate 16. The matching device 66 has a circuit for matching the impedance of the load side (lower electrode 18 side) of the high-frequency power supply 62 to the output impedance of the high-frequency power supply 62. The high-frequency power supply 62 may be connected to the upper electrode 30 via the matching device 66. The high-frequency power supply 62 constitutes an example of a plasma generating unit.

[0037] The bias power supply 64 is a power supply that generates an electric bias. The bias power supply 64 is electrically connected to the lower electrode 18. The electric bias has a second frequency. The second frequency is lower than the first frequency. The second frequency is, for example, a frequency within a range of 400 kHz to 13.56 MHz. When the electric bias is used together with the high frequency power HF, it is applied to the substrate support 14 to attract ions to the substrate W. In one example, the electric bias is applied to the lower electrode 18. When the electric bias is applied to the lower electrode 18, the potential of the substrate W placed on the substrate support 14 fluctuates within a period defined by the second frequency. The electric bias may be applied to a bias electrode (in one example, the bias electrode 118 in FIG. 3) provided in the electrostatic chuck 20.

[0038] In one embodiment, the electric bias may be a high frequency power LF having a second frequency. When the high frequency power LF is used together with the high frequency power HF, it is used as a high frequency bias power for attracting ions to the substrate W. A bias power supply 64 configured to generate the high frequency power LF is connected to the lower electrode 18 via a matching box 68 and the electrode plate 16. The matching box 68 has a circuit for matching the impedance of the load side (lower electrode 18 side) of the bias power supply 64 to the output impedance of the bias power supply 64.

[0039] It is also possible to generate plasma using high frequency power LF without using high frequency power HF, that is, using only a single high frequency power. In this case, the frequency of the high frequency power LF may be a frequency higher than 13.56 MHz, for example, 40 MHz. In this case, the plasma processing apparatus 1 does not need to include the high frequency power supply 62 and the matching box 66. In this case, the bias power supply 64 constitutes an example of a plasma generating unit.

[0040] In another embodiment, the electrical bias may be a pulsed voltage. In this case, the bias power supply may be a DC power supply. The bias power supply may be configured to provide a pulsed voltage itself or may be configured to include a device for pulsing the voltage downstream of the bias power supply. In one example, the pulsed voltage is applied to the lower electrode 18 so as to generate a negative potential on the substrate W. The waveform of one or more pulse voltages included in each pulse of the electrical bias may be a square wave, a triangular wave, an impulse, or may have other waveforms.

[0041] The period of the pulse voltage is determined by the second frequency. The period of the pulse voltage includes two periods. The pulse voltage in one of the two periods is a negative voltage. The level (i.e., absolute value) of the voltage in one of the two periods is higher than the level (i.e., absolute value) of the voltage in the other of the two periods. The voltage in the other period may be either negative or positive. The level of the negative voltage in the other period may be greater than zero or may be zero. In this embodiment, the bias power supply 64 is connected to the lower electrode 18 via a low-pass filter and the electrode plate 16. Note that the bias power supply 64 may be connected to a bias electrode (in one example, the bias electrode 118 in FIG. 3) provided in the electrostatic chuck 20 instead of the lower electrode 18.

[0042] In one embodiment, the bias power supply 64 may provide a continuous wave of electrical bias to the lower electrode 18. That is, the bias power supply 64 may provide an electrical bias to the lower electrode 18 continuously.

[0043] In another embodiment, the bias power supply 64 may apply a pulse wave of an electric bias to the lower electrode 18. The pulse wave of the electric bias may be applied periodically to the lower electrode 18. The period of the pulse wave of the electric bias is defined by a third frequency. The third frequency is lower than the second frequency. The third frequency is, for example, 1 Hz or more and 200 kHz or less. In another example, the third frequency may be 5 Hz or more and 100 kHz or less.

[0044] The period of the pulse wave of the electric bias includes two periods, namely, an H period and an L period. The level of the electric bias in the H period (i.e., the level of the pulse of the electric bias) is higher than the level of the electric bias in the L period. That is, the pulse wave of the electric bias may be applied to the lower electrode 18 by increasing or decreasing the level of the electric bias. The level of the electric bias in the L period may be greater than zero. Alternatively, the level of the electric bias in the L period may be zero. That is, the pulse wave of the electric bias may be applied to the lower electrode 18 by alternately switching between supplying and stopping the supply of the electric bias to the lower electrode 18. Here, when the electric bias is a high frequency power LF, the level of the electric bias is the power level of the high frequency power LF. When the electric bias is a high frequency power LF, the level of the high frequency power LF in the pulse of the electric bias may be 2 kW or more. When the electric bias is a pulse wave of a negative polarity DC voltage, the level of the electric bias is the effective value of the absolute value of the negative polarity DC voltage. The duty ratio of the pulse wave of the electric bias, i.e., the proportion of the H period in the cycle of the pulse wave of the electric bias, is, for example, 1% or more and 80% or less. In another example, the duty ratio of the pulse wave of the electric bias may be 5% or more and 50% or less. Alternatively, the duty ratio of the pulse wave of the electric bias may be 50% or more and 99% or less. In addition, during the period in which the electric bias is supplied, the L period corresponds to the above-mentioned first period, and the H period corresponds to the above-mentioned second period. In addition, the level of the electric bias in the L period corresponds to the above-mentioned 0 or first level, and the level of the electric bias in the H period corresponds to the above-mentioned second level.

[0045] In one embodiment, the high frequency power source 62 may supply a continuous wave of high frequency power HF, i.e., the high frequency power source 62 may supply the high frequency power HF continuously.

[0046] In another embodiment, the high frequency power supply 62 may supply a pulse wave of high frequency power HF. The pulse wave of high frequency power HF may be supplied periodically. The period of the pulse wave of high frequency power HF is defined by a fourth frequency. The fourth frequency is lower than the second frequency. In one embodiment, the fourth frequency is the same as the third frequency. The period of the pulse wave of high frequency power HF includes two periods, namely, an H period and an L period. The power level of the high frequency power HF in the H period is higher than the power level of the high frequency power HF in the L period of the two periods. The power level of the high frequency power HF in the L period may be greater than zero or may be zero. Note that, among the periods during which the high frequency power HF is supplied, the L period corresponds to the third period described above, and the H period corresponds to the fourth period described above. Also, the level of the high frequency power HF in the L period corresponds to the 0 or third level described above, and the level of the electrical bias in the H period corresponds to the fourth level described above.

[0047] The period of the pulse wave of the high frequency power HF may be synchronized with the period of the pulse wave of the electric bias. The H period in the period of the pulse wave of the high frequency power HF may be synchronized with the H period in the period of the pulse wave of the electric bias. Alternatively, the H period in the period of the pulse wave of the high frequency power HF may not be synchronized with the H period in the period of the pulse wave of the electric bias. The time length of the H period in the period of the pulse wave of the high frequency power HF may be the same as or different from the time length of the H period in the period of the pulse wave of the electric bias. A part or the whole of the H period in the period of the pulse wave of the high frequency power HF may overlap with the H period in the period of the pulse wave of the electric bias.

[0048] FIG. 2 is a timing chart showing an example of the high frequency power HF and the electric bias. FIG. 2 shows an example in which pulse waves are used as both the high frequency power HF and the electric bias. In FIG. 2, the horizontal axis shows time. In FIG. 2, the vertical axis shows the power levels of the high frequency power HF and the electric bias. "L1" of the high frequency power HF indicates that the high frequency power HF is not supplied or is lower than the power level indicated by "H1". "L2" of the electric bias indicates that the electric bias is not supplied or is lower than the power level indicated by "H2". When the electric bias is a pulse wave of a negative polarity DC voltage, the level of the electric bias is the effective value of the absolute value of the negative polarity DC voltage. Note that the magnitude of the power levels of the high frequency power HF and the electric bias in FIG. 2 does not indicate a relative relationship between the two, and may be set arbitrarily. FIG. 2 shows an example in which the period of the high frequency power HF pulse wave is synchronized with the period of the electrical bias pulse wave, and the time lengths of the H and L periods of the high frequency power HF pulse wave are the same as the time lengths of the H and L periods of the electrical bias pulse wave.

[0049] Returning to FIG. 1, the description will be continued. The plasma processing apparatus 1 further includes a power supply 70. The power supply 70 is connected to the upper electrode 30. In one example, the power supply 70 may be configured to supply a DC voltage or low-frequency power to the upper electrode 30 during plasma processing. For example, the power supply 70 may supply a negative DC voltage to the upper electrode 30, or may periodically supply low-frequency power. The DC voltage or low-frequency power may be supplied as a pulse wave or a continuous wave. In this embodiment, positive ions present in the internal space 10s are attracted to the upper electrode 30 and collide with it. As a result, secondary electrons are emitted from the upper electrode 30. The emitted secondary electrons modify the mask film MK and improve the etching resistance of the mask film MK. In addition, the secondary electrons contribute to improving the plasma density. In addition, the charged state of the substrate W is neutralized by irradiation of the secondary electrons, so that the straightness of the ions into the recesses formed by etching is improved. Furthermore, when the upper electrode 30 is made of a silicon-containing material, the collision of the positive ions causes silicon to be emitted together with secondary electrons. The emitted silicon combines with oxygen in the plasma to form a silicon oxide compound that is deposited on the mask and functions as a protective film. As described above, the supply of a DC voltage or low-frequency power to the upper electrode 30 not only improves the selectivity, but also suppresses shape abnormalities in the recesses formed by etching, improves the etching rate, and other effects.

[0050] When plasma processing is performed in the plasma processing apparatus 1, a gas is supplied from a gas supply unit to the internal space 10s. In addition, a high-frequency electric field is generated between the upper electrode 30 and the lower electrode 18 by supplying high-frequency power HF and / or an electric bias. The generated high-frequency electric field generates plasma from the gas in the internal space 10s.

[0051] The plasma processing apparatus 1 may further include a control unit 80. The control unit 80 may be a computer including a processor, a storage unit such as a memory, an input device, a display device, an input / output interface for signals, and the like. The control unit 80 controls each unit of the plasma processing apparatus 1. In the control unit 80, an operator can use the input device to input commands and the like to manage the plasma processing apparatus 1. In addition, the control unit 80 can visualize and display the operating status of the plasma processing apparatus 1 using the display device. Furthermore, the storage unit stores a control program and recipe data. The control program is executed by the processor to execute various processes in the plasma processing apparatus 1. The processor executes the control program and controls each unit of the plasma processing apparatus 1 according to the recipe data. In one exemplary embodiment, a part or all of the control unit 80 may be provided as a part of the configuration of an external device of the plasma processing apparatus 1.

[0052] 3 is a partially enlarged view of another example of the substrate support 14 included in the plasma processing apparatus 1. The substrate support 14 includes an electrode plate 16, a lower electrode 18, and an electrostatic chuck 20. The upper surface of the electrostatic chuck 20 has a substrate support surface 111a which is a central region for supporting the substrate W, and an annular region 111b for supporting the edge ring 25. The annular region 111b surrounds the substrate support surface 111a. The substrate W is disposed on the substrate support surface 111a, and the edge ring 25 is disposed on the annular region 111b so as to surround the substrate W on the substrate support surface 111a. The electrostatic chuck 20 is disposed on the lower electrode 18. The upper surface of the electrostatic chuck 20 has a substrate support surface for supporting the substrate W.

[0053] The electrostatic chuck 20 includes a chuck electrode 120 and a bias electrode 118 therein. The chuck electrode 120 has an electrode 120a provided between the substrate support surface 111a and the lower electrode 18. The electrode 120a may be a planar electrode corresponding to the shape of the substrate support surface 111a. The chuck electrode 120 may also have electrodes 120b and 120c provided between the edge ring 25 and the lower electrode 18. The electrodes 120b and 120c may be annular electrodes corresponding to the shape of the ring assembly 112. The electrode 120c is provided outside the electrode 120b. The electrodes 120b and 120c may form a bipolar electrostatic chuck. The electrodes 120a, 120b, and 120c may also be integrally formed. The DC power supply 20p may be configured to apply different DC voltages to the electrodes 120a, 120b, and 120c, respectively, or may be configured to apply the same DC voltage to the electrodes 120a, 120b, and 120c.

[0054] The bias electrode 118 includes an electrode 118a provided between the electrode 120a (or the substrate support surface 111a) and the lower electrode 18. The electrode 118a may be a planar electrode corresponding to the shape of the substrate support surface 111a and / or the electrode 120a. The bias electrode 118 may include an electrode 118b provided between the edge ring 25 and the lower electrode 18. Although not shown, the substrate support 14 may include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 114, 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 path, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path. The substrate support 14 may include a heat transfer gas supply unit configured to supply a heat transfer gas between the back surface of the substrate W and the substrate support surface 111a and / or between the edge ring 25 and the annular region 111b.

[0055] <Configuration of the Substrate Processing System PS> 4 is a schematic diagram of a substrate processing system PS according to an exemplary embodiment, the processing method may be performed using the substrate processing system PS.

[0056] The substrate processing system PS includes substrate processing modules PM1 to PM6 (hereinafter collectively referred to as "substrate processing modules PM"), a transfer module TM, load lock modules LLM1 and LLM2 (hereinafter collectively referred to as "load lock modules LLM"), a loader module LM, and load ports LP1 to LP3 (hereinafter collectively referred to as "load ports LP"). A control unit CT controls each component of the substrate processing system PS to perform a predetermined process on a substrate W.

[0057] The substrate processing module PM performs processes such as etching, trimming, film formation, annealing, doping, lithography, cleaning, and ashing on the substrate W. A part of the substrate processing module PM may be a measurement module, which may measure the thickness of a film formed on the substrate W or the dimensions of a pattern formed on the substrate W. The plasma processing apparatus 1 shown in FIG. 1 is an example of the substrate processing module PM.

[0058] The transfer module TM has a transfer device for transferring a substrate W, and transfers the substrate W between the substrate processing modules PM or between the substrate processing module PM and the load lock module LLM. The substrate processing module PM and the load lock module LLM are disposed adjacent to the transfer module TM. The transfer module TM, the substrate processing module PM, and the load lock module LLM are spatially isolated from or connected to each other by an openable / closable gate valve (for example, the gate valve 12g in FIG. 1).

[0059] The load lock modules LLM1 and LLM2 are provided between the transfer module TM and the loader module LM. The load lock module LLM can switch its internal pressure between atmospheric pressure and vacuum. The load lock module LLM transfers the substrate W from the loader module LM, which is at atmospheric pressure, to the transfer module TM, which is at vacuum, and also transfers the substrate W from the transfer module TM, which is at vacuum, to the loader module LM, which is at atmospheric pressure.

[0060] The loader module LM has a transport device for transporting the substrate W, and transports the substrate W between the load lock module LLM and the load board LP. Inside the load port LP, for example, a FOUP (Front Opening Unified Pod) capable of storing 25 substrates W or an empty FOUP can be placed. The loader module LM takes out the substrate W from the FOUP in the load port LP and transports it to the load lock module LLM. The loader module LM also takes out the substrate W from the load lock module LLM and transports it to the FOUP in the load board LP.

[0061] The controller CT controls each component of the substrate processing system PS to perform a predetermined process on the substrate W. The controller CT stores a recipe in which a process procedure, process conditions, transport conditions, etc. are set, and controls each component of the substrate processing system PS to perform the predetermined process on the substrate W according to the recipe. The controller CT may also have some or all of the functions of the controller 80 of the plasma processing apparatus 1 shown in FIG.

[0062] <An example of the substrate W> 5 is a diagram showing an example of a 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 a silicon-containing film SF and a carbon-containing film CF. The substrate W may have an undercoat film UF and a mask film MK. As shown in FIG. 5, the substrate W may be formed by stacking an undercoat film UF, a silicon-containing film SF, a carbon-containing film CF, and a mask film MK in this order.

[0063] The undercoat film UF may be, for example, a silicon wafer, an organic film formed on a silicon wafer, a dielectric film, a metal film, a semiconductor film, etc. The undercoat film UF may be a laminated film formed by laminating a plurality of films.

[0064] The silicon-containing film SF may be a SiO-containing film. In one example, the silicon-containing film SF is a multilayer film in which silicon oxide films and silicon nitride films are alternately stacked. The silicon-containing film SF may be a silicon oxide film (SiOx film), a silicon nitride film, a silicon oxynitride film (SiON film), or a Si-ARC film. The silicon-containing film SF may include a SiGe film or a polycrystalline silicon film. The silicon-containing film SF may be a multilayer film in which silicon oxide films and polycrystalline silicon films are alternately stacked.

[0065] The carbon-containing film CF is, for example, an amorphous carbon film. When the carbon-containing film CF is an amorphous carbon film, the amorphous carbon may be amorphous carbon containing hydrogen. The carbon-containing film CF may be, for example, an organic film.

[0066] The undercoat film UF, the silicon-containing film SF and / or the carbon-containing film CF may be formed by a CVD method, a spin coating method, etc. The undercoat film UF and / or the silicon-containing film SF may be a flat film or may be a film having irregularities.

[0067] The mask film MK is formed on the silicon-containing film SF. The mask film MK defines at least one opening OP on the silicon-containing film SF. The opening OP is a space on the silicon-containing film SF and is surrounded by the sidewall of the mask film MK. That is, in FIG. 5, the upper surface of the carbon-containing film CF has a region covered by the mask film MK and a region exposed at the bottom of the opening OP.

[0068] The openings OP may have any shape in a plan view of the substrate W (when the substrate W is viewed from top to bottom in FIG. 5). The shape may be, for example, a circle, a line, or a combination of a circle and a line. The mask film MK may have a plurality of side walls that define a plurality of openings OP. The plurality of openings OP may each have a line shape and be arranged at regular intervals to form a line and space pattern. Also, the plurality of openings OP may each have a hole shape and form an array pattern.

[0069] The mask film MK is, for example, a silicon-containing film. The silicon-containing film may be, for example, a SiON film. The mask film MK may also be an organic film or a metal-containing film. The organic film may be, for example, a spin-on carbon film (SOC), an amorphous carbon film, or a photoresist film. The metal-containing film may contain, for example, tungsten, tungsten carbide, or titanium nitride. The mask film MK may be formed by a CVD method, a spin coating method, or the like. The opening OP may be formed by etching the mask film MK. The mask film MK may also be formed by lithography.

[0070] <An example of this processing method> FIG. 6 is a flow chart showing an example of the present processing method. The present processing method includes a step of pre-coating the inner wall of the chamber (ST1), a step of preparing a substrate (ST2), a step of etching a carbon-containing film (ST3), and a step of etching a silicon-containing film (ST4). In the following, a case where the control unit 80 shown in FIG. 1 or the control unit CT shown in FIG. 4 controls each unit of the plasma processing apparatus 1 to execute the present processing method on the substrate W shown in FIG. 5 will be described as an example. Each step included in the present processing method may be performed in an inductively coupled plasma processing apparatus or a capacitively coupled plasma processing apparatus. In one example, the steps ST1 to ST4 may be performed in a capacitively coupled plasma processing apparatus. In another example, the steps ST1 to ST3 may be performed in an inductively coupled plasma processing apparatus, and the step ST4 may be performed in an inductively coupled plasma processing apparatus. In an inductively coupled plasma processing apparatus, an antenna is an example of an upper electrode.

[0071] (Step ST1: Pre-coating the inner walls of the chamber) In step ST1, a protective film is formed on at least a part of the inner wall of the chamber 10 of the plasma processing apparatus 1. The protective film may be a carbon-containing film. First, a gas supply unit of the plasma processing apparatus 1 supplies a process gas containing a carbon-containing gas into the chamber 10. The carbon-containing gas may contain, for example, CO, CO 2 , COS, and one or more of hydrocarbons. Hydrocarbons include CH4 , C 2 H 2 , C 3 H 6 etc. Then, the high frequency power supply 62 supplies high frequency power HF to the electrode included in the substrate support 14 or the upper electrode 30. As a result, an electric field is generated between the upper electrode 30 and the substrate support 14, and plasma is generated from the processing gas (including a carbon-containing gas) in the internal space 10s. As a result, a carbon-containing film is deposited on at least a part of the inner wall of the chamber 10, and a protective film is formed on at least a part of the inner wall of the chamber 10. Note that a reaction by-product in the etching process in step ST3 may form part of the protective film.

[0072] (Step ST2: Preparation of the substrate) In step ST2, the substrate W is prepared in the internal space 10s of the chamber 10. In the internal space 10s, the substrate W is placed on the upper surface (the surface facing the upper electrode 30) of the substrate support 14, and is held on the substrate support 14 by the electrostatic chuck 20. At least a part of the process for forming each component of the substrate W may be performed in the internal space 10s. In one example, the step of etching the mask film MK to form the opening OP may be performed in the same chamber as step ST3 of etching the carbon-containing film (and step ST4 of etching the silicon-containing film). That is, the opening OP and the recess RC described later may be formed successively in the same chamber. The chamber may be a chamber included in a capacitively coupled plasma processing apparatus. When (a) the step of forming the opening OP, which is a part of step ST2, (b) step ST3, and (c) step ST4 are performed successively in the same chamber, the mask film MK may be removed in step ST4. In addition, after all or part of each component of the substrate W is formed in an apparatus or chamber external to the plasma processing apparatus 1 (including other substrate processing modules PM of the substrate processing system PS in Figure 4), the substrate W may be loaded into the internal space 10s of the plasma processing apparatus 1 and placed on the upper surface of the substrate support 14.

[0073] (Step ST3: Etching of carbon-containing film) In step ST3, the carbon-containing film CF is etched. Step ST3 includes a step of setting the temperature of the substrate W to a first temperature (ST31), a step of supplying a first process gas (ST32), and a step of generating plasma (ST33).

[0074] In step ST31, the temperature of the substrate W is set to a first temperature. The first temperature may be 0° C. or lower. In addition, the first temperature may be −30° C. or lower, for example. Note that setting the temperature of the substrate W to the first temperature is not limited to directly measuring the temperature of the substrate W and adjusting the temperature of the substrate W so that the temperature of the substrate W becomes the first temperature. As an example, setting the temperature of the substrate W to the first temperature includes setting the temperature of the substrate support 14 on which the substrate W is placed to the first temperature. In addition, as another example, setting the temperature of the substrate W to the first temperature includes setting the temperature of the substrate support 14 to a temperature different from the first temperature so that the temperature of the substrate W becomes the first temperature. In addition, “setting” the temperature includes inputting, selecting, or storing the temperature in the control unit 80.

[0075] In step ST32, the gas supply unit supplies a first process gas into the chamber 10. In this embodiment, the carbon-containing film CF is an amorphous carbon film, and the first process gas is H 2 The first process gas may include O gas. The first process gas may include Ar gas. 2 When O gas is supplied into the chamber 10, H 2 O molecules are physically adsorbed on the surface of the substrate W. 2 The surface on which the O molecules are adsorbed includes a portion of the upper surface of the carbon-containing film CF that is exposed at the opening OP of the mask film MK (see FIG. 5). When the amorphous carbon film contains hydrogen atoms at a predetermined ratio or more, the first process gas is H 2 With O gas or H 2 Instead of O gas, an oxygen-containing gas may be included. In one example, the oxygen-containing gas is O 2 The first process gas may be H 2The gas may include a plurality of gases capable of generating O gas. In one example, the plurality of gases may include H 2 Gas and O 2 It may be a gas.

[0076] In step ST33, the high frequency power supply 62 supplies high frequency power HF to the lower electrode 18 to generate plasma in the chamber 10. The high frequency power HF has a first frequency suitable for generating plasma. The first frequency may be, for example, a frequency in the range of 27 MHz to 100 MHz. The high frequency power HF may be supplied to the upper electrode 30 or the bias electrode 118. The bias power supply 64 supplies an electric bias to the bias electrode 118. The electric bias may be a pulse wave (see FIG. 2). Each pulse included in the electric bias may include high frequency power LF or a pulse voltage. The electric bias may be supplied to the lower electrode 18.

[0077] When the first process gas is supplied into the chamber 10 and plasma is generated in the chamber 10, the H adsorbed on the upper surface of the carbon-containing film CF is 2 The O molecules react with the amorphous carbon contained in the carbon-containing film CF, and the carbon-containing film CF is etched.

[0078] 7 is a diagram showing an example of a cross-sectional structure of the substrate W during step ST3. As shown in FIG. 7, H adsorbed on the upper surface of the carbon-containing film CF through the opening OP of the mask film MK. 2 The O molecules react with the amorphous carbon contained in the carbon-containing film CF to form a recess RC in the carbon-containing film CF. The recess RC is defined by the sidewall and bottom surface BT of the carbon-containing film CF. When the recess RC is formed in the carbon-containing film CF, H 2 O molecules physically adsorb on the bottom surface BT, and the adsorbed H 2 The carbon-containing film CF is further etched using the O molecules as an etchant, i.e., the depth of the recess RC becomes deeper.

[0079] Fig. 8 is a diagram showing an example of the cross-sectional structure of the substrate W after completion of step ST3. As shown in Fig. 8, etching is performed in step ST3, and when the recess RC reaches the silicon-containing film SF (i.e., when the surface of the silicon-containing film SF is exposed in the recess RC), step ST3 is completed. Note that, in step ST3, a part of the silicon-containing film SF may be etched. That is, in step ST3, a part of the silicon-containing film SF may be over-etched in the depth direction of the recess RC.

[0080] (Step ST4: Etching of silicon-containing film) Next, in step ST4, the silicon-containing film SF is etched. Step ST4 includes a step of setting the temperature of the substrate W to a second temperature (ST41), a step of supplying a second process gas (ST42), and a step of generating plasma (ST43).

[0081] The process ST4 may be performed in the same chamber 10 as the chamber in which the process ST3 was performed. That is, after the process ST3 is performed in the chamber 10 of the plasma processing apparatus 1, the process ST4 may be performed while the substrate W is placed on the substrate support 14 of the same chamber 10. The process ST4 may be performed in a chamber different from the chamber 10 in which the process ST3 was performed. In one example, after the process ST3 is performed in the chamber 10 of the plasma processing apparatus 1, the substrate W may be transported to a chamber different from the chamber 10, and placed on the substrate support of the different chamber, and the process ST4 may be performed. When the substrate W is transported from the chamber 10 in which the process ST3 was performed to the different chamber, the transport path of the substrate W may be kept in vacuum (in one example, a pressure lower than atmospheric pressure). In addition, the different chamber may be a chamber of another processing module PM included in the substrate processing system PS. In this case, a transport module TM (see FIG. 4) may transport the substrate W from the plasma processing apparatus 1 to the other processing module PM. In one example, the substrate processing system PS may include a processing module PM that performs a process ST3 and a processing module PM that performs a process ST4. In one example, the processing module PM that performs a process ST3 may be an inductively coupled plasma processing apparatus, and the processing module PM that performs a process ST4 may be a capacitively coupled plasma processing apparatus.

[0082] In step ST41, the temperature of the substrate W is set to a second temperature. The second temperature may be lower than the first temperature. When the second temperature is lower than the first temperature, the second temperature may be, for example, −50° C. or lower. Also, the second temperature may be higher than the first temperature. For example, when the second process gas contains an adsorption promoting gas as described below, the second temperature may be 20° C. or lower.

[0083] In step ST42, the gas supply unit supplies a second process gas into the chamber 10. The second process gas may include a gas containing both hydrogen and fluorine. In one example, the gas containing both hydrogen and fluorine may be hydrogen fluoride (HF) gas. The gas containing both hydrogen and fluorine may be Cx H y F z (x, y, and z are integers of 1 or more. Hereinafter, they may be referred to as "hydrofluorocarbons").

[0084] One example of a hydrofluorocarbon is CH 2 F 2 , CHF 3 , or C.H. 3 F. Hydrofluorocarbons may contain two or more carbons. Hydrofluorocarbons may also contain three or four carbons. Hydrofluorocarbons include, for example, C 2 HF 5 , C 2 H 2 F 4 , C 2 H 3 F 3 , C 2 H 4 F 2 , C 3 HF 7 , C 3 H 2 F 2 , C 3 H 2 F 6 , C 3 H 2 F 4 , C 3 H 3 F 5 , C 4 H 5 F 5 , C 4 H 2 F 6 , C 5 H 2 F 10 and cC 5 H 3 F 7 In one example, the carbon-containing gas may be at least one selected from the group consisting of C 3 H 2 F 4 and C 4 H 2 F 6 At least one selected from the group consisting ofx H y F z may be linear or cyclic.

[0085] The second process gas may include both a hydrogen-containing gas and a fluorine-containing gas. In one example, the hydrogen-containing gas is H 2 , N.H. 3 , H 2 O, H 2 O 2 or hydrocarbons (CH 4 , C 3 H 6 In one example, the fluorine-containing gas may include NF 3 ,SCIENCE FICTION 6 , W.F. 6 , XeF 2 Or C u F v (u and v are integers of 1 or more. Hereinafter, also referred to as "fluorocarbons"). In one example, the fluorocarbon is CF 4 , C 3 F 8 , C 4 F 6 , or C 4 F 8 At least one of the following.

[0086] The second process gas may further include a carbon-containing gas, in one example. a H b (a and b are integers of 1 or more), C c F d (c and d are integers of 1 or more) and CH e F f (e and f are integers of 1 or more). a H b In one example, 4 Or C 3 H 6 etc. are fine. C c F d In one example, CF 4 , C 3 F 8 , C 4 F 6Or C 4 F 8 etc. are fine. CH e F f In one example, 2 F 2 , CHF 3 or CH 3 It may be F etc.

[0087] When the second process gas is supplied into the chamber 10, an etchant contained in the second process gas is physically adsorbed onto the surface of the substrate W. The etchant may be, for example, hydrogen fluoride (HF), hydrogen atoms, and / or fluorine atoms. The surface onto which the etchant is adsorbed includes the portion of the upper surface of the silicon-containing film SF that is exposed at the recess RC (see FIG. 8).

[0088] The second process gas may further include other gases. For example, the other gases may be a gas that promotes adsorption of the etchant on the surface of the silicon-containing film SF (hereinafter, also referred to as an "adsorption promoting gas"). For example, when the second temperature is higher than the first temperature, the second process gas may include an adsorption promoting gas. For example, the adsorption promoting gas may be a phosphorus-containing gas or a nitrogen-containing gas.

[0089] A phosphorus-containing gas is a gas that contains phosphorus-containing molecules. 4 O 10 ), tetraphosphorus octoxide (P 4 O 8 ), tetraphosphorus hexaoxide (P 4 O 6 ) and other oxides. 2 O 5 Phosphorus-containing molecules are sometimes called phosphorus trifluoride (PF 3 ), phosphorus pentafluoride (PF 5 ), phosphorus trichloride (PCl 3 ), phosphorus pentachloride (PCl 5 ), phosphorus tribromide (PBr 3 ), phosphorus pentabromide (PBr 5 ), phosphorus iodide (PI 3The phosphorus-containing molecule may be a halide (phosphorus halide) such as phosphorus fluoride (POF). That is, the phosphorus-containing molecule may contain fluorine as a halogen element, such as phosphorus fluoride. Alternatively, the phosphorus-containing molecule may contain a halogen element other than fluorine as a halogen element. The phosphorus-containing molecule may be phosphoryl fluoride (POF 3 ), phosphoryl chloride (POCl 3 ), phosphoryl bromide (POBr 3 The phosphorus-containing molecule may be a phosphoryl halide such as a phosphine (PH 3 ), calcium phosphide (Ca 3 P 2 etc.), phosphoric acid (H 3 PO 4 ), Sodium phosphate (Na 3 PO 4 ), hexafluorophosphate (HPF 6 ) and the like. Phosphorus-containing molecules include fluorophosphines (H g PF h ) where the sum of g and h is 3 or 5. Fluorophosphines include HPF 2 , H 2 PF 3 The treatment gas may include one or more of the above phosphorus-containing molecules as the at least one phosphorus-containing molecule. For example, the treatment gas may include PF 3 , PCl 3 , P.F. 5 , PCl 5 , POCl 3 , PH 3 , PBr 3 , or PBr 5 In addition, when each phosphorus-containing molecule contained in the processing gas is liquid or solid, each phosphorus-containing molecule may be vaporized by heating or the like and supplied into the chamber 10. In addition, the nitrogen-containing gas may be, for example, NH 3 , N.F. 3 Or N 2 The nitrogen-containing gas may be a gas containing at least one selected from the group consisting of NH 3 may be a combination of gases produced.

[0090] In step ST43, the high frequency power supply 62 supplies high frequency power HF to the lower electrode 18 to generate plasma in the chamber 10. The high frequency power HF has a first frequency suitable for generating plasma. The first frequency may be, for example, a frequency in the range of 27 MHz to 100 MHz. The high frequency power HF may be supplied to the upper electrode 30 or the bias electrode 118. The bias power supply 64 supplies an electric bias to the bias electrode 118. The electric bias may be a pulse wave (see FIG. 2). Each pulse included in the electric bias may include high frequency power LF or a pulse voltage. The electric bias may be supplied to the lower electrode 18. The power level of the electric bias supplied in step ST43 (for example, the effective value of the power of the electric bias or the effective value of the absolute value of the DC voltage) may be higher than the power level of the electric bias supplied in step ST32.

[0091] When the second process gas is supplied into the chamber 10 and a plasma is generated in the chamber 10, the etchant adsorbed on the upper surface of the silicon-containing film SF reacts with the silicon-containing film SF to etch the silicon-containing film SF.

[0092] 9 is a diagram showing an example of a cross-sectional structure of the substrate W during the execution of step ST4. As shown in FIG. 9, the etchant adsorbed onto the upper surface of the silicon-containing film SF through the opening OP and the recess RC reacts with the silicon-containing film SF to further form a recess RC in the silicon-containing film SF. The recess RC is defined by the sidewalls and bottom surface BT of the carbon-containing film CF and the silicon-containing film SF. When the recess RC is formed in the silicon-containing film SF, the etchant physically adsorbs onto the bottom surface BT, and the silicon-containing film SF is further etched by the adsorbed etchant. That is, the depth of the recess RC becomes deeper.

[0093] Fig. 10 is a diagram showing an example of the cross-sectional structure of the substrate W after completion of step ST4. As shown in Fig. 10, etching is performed in step ST4, and when the recess RC reaches the base film UF (i.e., when the surface of the base film UF is exposed at the recess RC), step ST4 is completed. Note that, in step ST4, a part of the base film UF may be etched. In other words, in step ST4, a part of the base film UF may be over-etched in the depth direction of the recess RC.

[0094] The following describes experiments carried out to evaluate the present treatment method, but the present disclosure is not limited to the following experiments.

[0095] (Experiment 1) Experiment 1 is an experiment related to step ST3 (see FIG. 6) of the present processing method. In Experiment 1, an amorphous carbon film formed on a substrate W was etched under the following conditions using a plasma processing apparatus 1. The amorphous carbon film is an example of a carbon-containing film. Processing gas: H 2 O gas, Ar gas Setting temperature: -70℃~0℃ Chamber pressure: 25mTorr High frequency power HF: 60MHz / 100W High frequency power LF:3.2MHz / 1000W In experiment 1, the temperature of the substrate support 14 was changed to etch the amorphous carbon film, and the H 2 The amount of adsorbed O molecules and the etching rate were measured.

[0096] FIG. 11 is a graph showing the measurement results of Experiment 1. In FIG. 11, the horizontal axis indicates the temperature (° C.) of the substrate support 14, and the vertical axis indicates the etching rate of the amorphous carbon film. As shown in FIG. 11, the etching rate of the amorphous carbon film increases when the temperature of the substrate support 14 increases from about −30° C. That is, when the temperature of the substrate support 14 is about −30° C. or lower,2 The amount of O molecules physically adsorbed on the substrate W increases, and therefore the amount of H 2 It was found that the amount of O molecules consumed as an etchant increased, resulting in an increase in the etching rate.

[0097] (Experiment 2) Experiment 2 is an experiment related to step ST4 (see FIG. 6) of the present processing method. In Experiment 2, a silicon oxide film formed on a substrate W was etched using the plasma processing apparatus 1 under the following conditions. Processing gas: HF (hydrogen fluoride) gas, Ar gas, Setting temperature: -70℃~0℃ Chamber pressure: 25mTorr High frequency power HF: 60MHz / 100W High frequency power LF: 3MHz / 1000W In experiment 2, the temperature of the substrate support 14 was changed, the silicon oxide film was etched, and the etching rate of the silicon oxide film was measured.

[0098] FIG. 12 is a graph showing the measurement results of Experiment 2. In FIG. 12, the horizontal axis indicates the temperature (°C) of the substrate support 14. The vertical axis indicates the etching rate of the silicon oxide film. As shown in FIG. 12, the etching rate of the silicon oxide film increases when the temperature of the substrate support 14 is about -40°C. In other words, it was found that when the temperature of the substrate support 14 is about -40°C or lower, the amount of HF (or hydrogen atoms and fluorine atoms) physically adsorbed to the substrate W increases, and therefore the amount of HF (or hydrogen atoms and fluorine atoms) consumed as an etchant in etching the silicon oxide film increases, thereby increasing the etching rate.

[0099] According to an exemplary embodiment of the present disclosure, in both the etching process of the carbon-containing film (in one example, an amorphous carbon film) and the etching process of the silicon-containing film (in one example, a laminated film of a silicon oxide film and a silicon nitride film), the etching process is performed by physically adsorbing an etchant as molecules to a substrate. This allows the etching process of the carbon-containing film and the etching process of the silicon-containing film to be performed consecutively in the same chamber of a capacitively coupled plasma processing apparatus. Therefore, according to this exemplary embodiment, the throughput of the etching process can be improved.

[0100] According to one exemplary embodiment of the present disclosure, in an etching process for a carbon-containing film, an etchant, H 2 O molecules are physically adsorbed onto the substrate, which allows etching of carbon-containing films at high etching rates without the need to generate high-density plasma.

[0101] According to one exemplary embodiment of the present disclosure, when a predetermined etching process and an etching process using a corrosive gas such as hydrogen fluoride are performed consecutively in the same chamber, at least a part of the inner wall of the chamber can be pre-coated with a protective film before the predetermined etching process. This makes it possible to suppress corrosion of the inner wall of the chamber in the etching process using hydrogen fluoride or the like. As a result, it is possible to suppress contamination inside the chamber caused by corrosion of the inner wall of the chamber.

[0102] Although various exemplary embodiments have been described above, various additions, omissions, substitutions, and modifications may be made without being limited to the above-described exemplary embodiments. Also, elements in different embodiments can be combined to form other embodiments. For example, each step of the processing method may be performed using a plasma processing apparatus using any plasma source, such as a capacitively coupled plasma processing apparatus, an inductively coupled plasma processing apparatus, a microwave plasma processing apparatus, an ECR plasma processing apparatus, etc. Also, it will be understood that various embodiments of the present disclosure are described herein for illustrative purposes, and various modifications may be made without departing from the scope and spirit of the present disclosure. Therefore, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the appended claims.

[0103] The present disclosure may also include the following embodiments.

[0104] (Appendix 1) A plasma processing method performed in a plasma processing apparatus, comprising: providing a substrate including a silicon-containing film and a carbon-containing film formed on the silicon-containing film; setting the temperature of the substrate to a first temperature that is equal to or less than 0° C.; The first process gas contains hydrogen atoms and oxygen atoms. 2 supplying O to the substrate; generating a plasma from the first process gas by radio frequency waves and etching the carbon-containing film; setting the temperature of the substrate to a second temperature different from the first temperature; supplying a second process gas to the substrate, the second process gas comprising a hydrogen-containing gas and a fluorine-containing gas, or both a hydrogen-containing gas and a fluorine-containing gas; generating a plasma from the second process gas by radio frequency and etching the silicon-containing film; A plasma processing method comprising:

[0105] (Appendix 2) The plasma processing apparatus includes: a plasma processing chamber; a substrate support disposed within the plasma processing chamber and supporting a substrate; an upper electrode provided in the plasma processing chamber facing the substrate support; Equipped with providing the substrate includes placing the substrate on the substrate support; the step of etching the carbon-containing film includes the step of supplying a high frequency wave to the substrate support or the upper electrode to generate plasma from the first process gas in the plasma processing chamber and etching the carbon-containing film; 2. The plasma processing method of claim 1, wherein the step of etching the silicon-containing film includes the step of supplying a high frequency to the substrate support or the upper electrode to generate plasma from the second processing gas in the plasma processing chamber, and etching the silicon-containing film.

[0106] (Appendix 3) The plasma processing apparatus includes: a first plasma processing chamber and a second plasma processing chamber; a first substrate support disposed within the first plasma processing chamber and configured to support a substrate; a first upper electrode disposed in the first plasma processing chamber and facing the first substrate support; a second substrate support disposed within the second plasma processing chamber and configured to support a substrate; a second upper electrode disposed in the second plasma processing chamber and facing the second substrate support; Equipped with providing the substrate includes placing the substrate on the first substrate support; the step of etching the carbon-containing film includes the step of supplying a high frequency wave to the first substrate support or the first upper electrode to generate plasma from the first processing gas in the first plasma processing chamber, and etching the carbon-containing film; The plasma processing method further includes a step of transferring the substrate from the first substrate support to the second substrate support, setting the temperature of the substrate to a second temperature different from the first temperature includes setting the temperature of the substrate to the second temperature on the second substrate support; 2. The plasma processing method of claim 1, wherein the step of etching the silicon-containing film includes the step of supplying a high frequency to the second substrate support or the second upper electrode to generate plasma from the second processing gas in the second plasma processing chamber, and etching the silicon-containing film.

[0107] (Appendix 4) The plasma processing apparatus includes a transfer chamber connected to the first plasma processing chamber and the second plasma processing chamber, and an internal pressure of the transfer chamber is lower than atmospheric pressure; 4. The plasma processing method according to claim 3, wherein in the step of transporting the substrate, the substrate is transported from the first substrate support to the second substrate support via the transport chamber.

[0108] (Appendix 5) 5. The plasma processing method according to claim 1, wherein the second temperature is lower than the first temperature.

[0109] (Appendix 6) 5. The plasma processing method according to claim 1, wherein the second temperature is higher than the first temperature.

[0110] (Appendix 7) 7. The plasma processing method according to claim 1, wherein the carbon-containing film is an amorphous carbon film.

[0111] (Appendix 8) 1. A plasma processing method carried out in a plasma processing apparatus having a plasma processing chamber, comprising: providing a carbon-containing gas into the plasma processing chamber; generating a plasma from the carbon-containing gas by radio frequency waves to form a protective film on at least a portion of an inner wall of the plasma processing chamber; providing a substrate in the plasma processing chamber, the substrate including a silicon-containing film and a carbon-containing film formed on the silicon-containing film; A first process gas containing atomic hydrogen and atomic oxygen is supplied into the plasma processing chamber to form a first process gas having atomic hydrogen and atomic oxygen. 2 supplying O to the substrate; generating a plasma from the first process gas by radio frequency waves and etching the carbon-containing film; supplying a second process gas comprising a hydrogen-containing gas and a fluorine-containing gas, or a second process gas comprising a hydrogen-containing gas and a fluorine-containing gas, to the substrate provided in the plasma processing chamber; generating a plasma from the second process gas by supplying a high frequency wave to etch the silicon-containing film; A plasma processing method comprising:

[0112] (Appendix 9) setting the temperature of the substrate to a first temperature; setting the temperature of the substrate to a second temperature different from the first temperature; Further comprising: In the step of etching the carbon-containing film, the carbon-containing film is etched after the substrate is set to the first temperature; 9. The plasma processing method according to claim 8, wherein in the step of etching the silicon-containing film, the SiO film is etched after the substrate is set to the second temperature.

[0113] (Appendix 10) 10. The plasma processing method according to claim 8, wherein the protective film is a carbon-containing film.

[0114] (Appendix 11) 11. The plasma processing method according to claim 1, wherein the plasma processing apparatus is a capacitively coupled plasma processing apparatus.

[0115] (Appendix 12) at least one plasma processing chamber; a temperature regulator for setting a temperature of the substrate in the at least one plasma processing chamber; a gas supply configured to supply gas into the at least one plasma processing chamber; a plasma generating unit configured to generate a plasma from a gas in the at least one plasma processing chamber; a control unit configured to control the temperature adjustment unit, the gas supply unit, and the plasma generation unit; Equipped with The control unit is Setting a temperature of a substrate including a silicon-containing film and a carbon-containing film formed on the silicon-containing film to a first temperature that is equal to or lower than 0° C.; The first process gas contains hydrogen atoms and oxygen atoms. 2 supplying O to the substrate; generating a plasma from the first process gas by radio frequency to etch the carbon-containing film; setting the temperature of the substrate to a second temperature different from the first temperature; supplying a second process gas to the substrate, the second process gas comprising a hydrogen-containing gas and a fluorine-containing gas, or both a hydrogen-containing gas and a fluorine-containing gas; a plasma processing apparatus that performs control to generate plasma from the second process gas by using high frequency waves and etch the silicon-containing film.

[0116] (Appendix 13) 1. A plasma processing system comprising a first plasma processing apparatus having a first plasma processing chamber and a second plasma processing apparatus having a second plasma processing chamber, a temperature adjustment unit that sets a temperature of a substrate disposed in the first plasma processing chamber and the second plasma processing chamber; a gas supply configured to supply gas into the first plasma processing chamber and into the second plasma processing chamber; an inductively coupled plasma generating unit coupled to the first plasma processing chamber; a capacitively coupled plasma generating unit coupled to the second plasma processing chamber; a control unit configured to control the temperature adjustment unit, the gas supply unit, the inductively coupled plasma generation unit, and the capacitively coupled plasma generation unit; Equipped with The control unit is placing a substrate including a silicon-containing film and a carbon-containing film formed on the silicon-containing film in the first plasma processing chamber; setting the temperature of the substrate to a first temperature that is equal to or less than 0° C.; The first process gas contains hydrogen atoms and oxygen atoms. 2 supplying O to the substrate; generating a plasma from the first process gas by radio frequency to etch the carbon-containing film; placing the substrate with the etched carbon-containing film in the second plasma processing chamber; setting the temperature of the substrate to a second temperature different from the first temperature; supplying a second process gas to the substrate, the second process gas comprising a hydrogen-containing gas and a fluorine-containing gas, or both a hydrogen-containing gas and a fluorine-containing gas; A plasma processing system that performs control to generate a plasma from the second process gas by radio frequency to etch the silicon-containing film. [Explanation of symbols]

[0117] 1...plasma processing apparatus, 10...chamber, 13...supporting portion, 14...substrate support, 16...electrode plate, 18...lower electrode, 20...electrostatic chuck, 24...gas supply line, 25...edge ring, 30...upper electrode, 38...gas supply pipe, 40...gas source group, 41...flow rate controller group, 50...exhaust device, 62...high frequency power supply, 64...bias power supply, 80...control portion, 114...electrostatic chuck, 118...bias electrode, BT...bottom surface, CF...carbon-containing film, CT...control portion, MK...mask film, PM...substrate processing module, RC...recess, SF...silicon-containing film, TM...transfer module, UF...undercoat film, W...substrate

Claims

1. A plasma processing method performed in a plasma processing apparatus, comprising: providing a substrate including a silicon-containing film and an amorphous carbon film formed on the silicon-containing film; setting the temperature of the substrate to a first temperature that is equal to or less than 0° C.; The first process gas contains hydrogen atoms and oxygen atoms. ２ supplying O to the substrate; physically adsorbing the H2O onto the surface of the substrate; generating plasma from the first process gas by high frequency waves and etching the amorphous carbon film; setting the temperature of the substrate to a second temperature different from the first temperature; supplying a second process gas to the substrate, the second process gas comprising a hydrogen-containing gas and a fluorine-containing gas, or both a hydrogen-containing gas and a fluorine-containing gas; generating a plasma from the second process gas by radio frequency waves and etching the silicon-containing film; A plasma processing method comprising:

2. The plasma processing apparatus includes: a plasma processing chamber; a substrate support disposed within the plasma processing chamber and supporting a substrate; an upper electrode provided in the plasma processing chamber facing the substrate support; Equipped with providing the substrate includes placing the substrate on the substrate support; the step of etching the amorphous carbon film includes the step of supplying a high frequency wave to the substrate support or the upper electrode to generate plasma from the first processing gas in the plasma processing chamber, and etching the amorphous carbon film; 2. The plasma processing method according to claim 1, wherein the step of etching the silicon-containing film includes the step of supplying a high frequency wave to the substrate support or the upper electrode to generate plasma from the second process gas in the plasma processing chamber, and etching the silicon-containing film.

3. The plasma processing apparatus includes: a first plasma processing chamber and a second plasma processing chamber; a first substrate support disposed within the first plasma processing chamber and configured to support a substrate; a first upper electrode disposed in the first plasma processing chamber and facing the first substrate support; a second substrate support disposed within the second plasma processing chamber and configured to support a substrate; a second upper electrode disposed in the second plasma processing chamber and facing the second substrate support; Equipped with providing the substrate includes placing the substrate on the first substrate support; the step of etching the amorphous carbon film includes a step of supplying a high frequency wave to the first substrate support or the first upper electrode to generate plasma from the first processing gas in the first plasma processing chamber, and etching the amorphous carbon film; The plasma processing method further includes a step of transferring the substrate from the first substrate support to the second substrate support, setting the temperature of the substrate to a second temperature different from the first temperature includes setting the temperature of the substrate to the second temperature on the second substrate support; 2. The plasma processing method of claim 1, wherein the step of etching the silicon-containing film includes the step of supplying a high frequency to the second substrate support or the second upper electrode to generate plasma from the second process gas in the second plasma processing chamber, and etching the silicon-containing film.

4. The plasma processing apparatus includes a transfer chamber connected to the first plasma processing chamber and the second plasma processing chamber, the internal pressure of the transfer chamber being lower than atmospheric pressure; 4. The plasma processing method according to claim 3, wherein in the step of transporting the substrate, the substrate is transported from the first substrate support to the second substrate support via a transport chamber.

5. The plasma processing method of claim 1 , wherein the second temperature is lower than the first temperature.

6. The plasma processing method of claim 1 , wherein the second temperature is higher than the first temperature.

7. The plasma processing method according to claim 1 , wherein the amorphous carbon film is an amorphous carbon film.

8. 1. A plasma processing method carried out in a plasma processing apparatus having a plasma processing chamber, comprising: providing a carbon-containing gas into the plasma processing chamber; generating a plasma from the carbon-containing gas by radio frequency waves to form a protective film on at least a portion of an inner wall of the plasma processing chamber; providing a substrate in the plasma processing chamber, the substrate including a silicon-containing film and an amorphous carbon film formed on the silicon-containing film; A first process gas containing atomic hydrogen and atomic oxygen is supplied into the plasma processing chamber to form a first process gas having atomic hydrogen and atomic oxygen. ２ supplying O to the substrate; physically adsorbing the HO on a surface of the substrate; generating plasma from the first process gas by high frequency waves and etching the amorphous carbon film; supplying a second process gas comprising a hydrogen- and fluorine-containing gas or a hydrogen-containing gas and a fluorine-containing gas to the substrate provided in the plasma processing chamber; generating a plasma from the second process gas by supplying a high frequency wave to etch the silicon-containing film; A plasma processing method comprising:

9. setting the temperature of the substrate to a first temperature; setting the temperature of the substrate to a second temperature different from the first temperature; Further comprising: In the step of etching the amorphous carbon film, the amorphous carbon film is etched after the substrate is set to the first temperature; 9. The plasma processing method of claim 8, wherein in the step of etching the silicon-containing film, the silicon-containing film is etched after the substrate is set to the second temperature.

10. 9. The plasma processing method according to claim 8, wherein the protective film is an amorphous carbon film.

11. The plasma processing method according to claim 1 , wherein the plasma processing apparatus is a capacitively coupled plasma processing apparatus.

12. at least one plasma processing chamber; a temperature regulator for setting a temperature of a substrate in the at least one plasma processing chamber; a gas supply configured to supply gas into the at least one plasma processing chamber; a plasma generating portion configured to generate a plasma from a gas in the at least one plasma processing chamber; a control unit configured to control the temperature adjustment unit, the gas supply unit, and the plasma generation unit; Equipped with The control unit is setting a temperature of a substrate including a silicon-containing film and an amorphous carbon film formed on the silicon-containing film to a first temperature that is equal to or lower than 0° C.; The first process gas contains hydrogen atoms and oxygen atoms. ２ supplying O to the substrate; The H 2 O is physically adsorbed on the surface of the substrate; generating a plasma from the first processing gas by using a high frequency wave to etch the amorphous carbon film; setting the temperature of the substrate to a second temperature different from the first temperature; supplying a second process gas to the substrate, the second process gas comprising a hydrogen-containing gas and a fluorine-containing gas, or both a hydrogen-containing gas and a fluorine-containing gas; a plasma processing apparatus that performs control to generate plasma from the second process gas by using high frequency waves and etch the silicon-containing film.

13. 1. A plasma processing system comprising a first plasma processing apparatus having a first plasma processing chamber and a second plasma processing apparatus having a second plasma processing chamber, a temperature adjusting unit that sets a temperature of a substrate disposed in the first plasma processing chamber and the second plasma processing chamber; a gas supply configured to supply gas into the first plasma processing chamber and into the second plasma processing chamber; an inductively coupled plasma generating unit coupled to the first plasma processing chamber; a capacitively coupled plasma generating unit coupled to the second plasma processing chamber; a control unit configured to control the temperature adjustment unit, the gas supply unit, the inductively coupled plasma generation unit, and the capacitively coupled plasma generation unit; Equipped with The control unit is placing a substrate including a silicon-containing film and an amorphous carbon film formed on the silicon-containing film in the first plasma processing chamber; setting the temperature of the substrate to a first temperature that is equal to or less than 0° C.; The first process gas contains hydrogen atoms and oxygen atoms. ２ supplying O to the substrate; The H 2 O is physically adsorbed on the surface of the substrate; generating a plasma from the first processing gas by using a high frequency wave to etch the amorphous carbon film; placing the substrate on which the amorphous carbon film has been etched in the second plasma processing chamber; setting the temperature of the substrate to a second temperature different from the first temperature; supplying a second process gas to the substrate, the second process gas comprising a hydrogen-containing gas and a fluorine-containing gas, or both a hydrogen-containing gas and a fluorine-containing gas; The plasma processing system performs control to generate a plasma from the second process gas by radio frequency to etch the silicon-containing film.

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