JP2023020916A - Plasma processing method and plasma processing apparatus - Google Patents

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

SUMMARY Exemplary embodiments of the present disclosure relate to plasma processing methods and plasma processing apparatuses.

As a technique for suppressing the occurrence of bowing in etching, there is an etching method described in Patent Document 1.

JP 2019-179889 A

The present disclosure provides plasma processing methods that improve throughput.

In one exemplary embodiment of the present disclosure, a plasma processing method performed in a capacitively coupled plasma processing apparatus is provided. The plasma processing method comprises the steps of: preparing a substrate including a silicon-containing film and a carbon-containing film formed on the silicon-containing film; and setting the temperature of the substrate to a first temperature of 0° C. or lower. supplying H ₂ O to the substrate by a first process gas containing hydrogen atoms and oxygen atoms; 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; providing a process gas to the substrate; and generating a plasma from the second process gas by radio frequency to etch the silicon-containing film.

According to one exemplary embodiment of the present disclosure, a plasma processing method that improves throughput can be provided.

1 schematically shows a plasma processing apparatus 1 according to one exemplary embodiment; FIG. 4 is a timing chart showing an example of high frequency power HF and electrical bias; 4 is a partially enlarged view of another example of the substrate supporter 14 included in the plasma processing apparatus 1; FIG. 1 schematically illustrates a substrate processing system PS according to one exemplary embodiment; FIG. 2 is a diagram showing an example of a cross-sectional structure of a substrate W; FIG. It is a flow chart which shows an example of this processing method. It is a figure which shows an example of the cross-sectional structure of the board|substrate W during execution of process ST3. It is a figure which shows an example of the cross-sectional structure of the board|substrate W after completion|finish of process ST3. It is a figure which shows an example of the cross-sectional structure of the board|substrate W during execution of process ST4. It is a figure which shows an example of the cross-sectional structure of the board|substrate W after process ST4 is complete|finished. 4 is a graph showing measurement results of Experiment 1. FIG. 9 is a graph showing measurement results of Experiment 2. FIG.

Each embodiment of the present disclosure will be described below.

In one exemplary embodiment, a plasma processing method is provided. The plasma processing method is a plasma processing method performed in a plasma processing apparatus, comprising steps of preparing a substrate including a silicon-containing film and a carbon-containing film formed on the silicon-containing film; supplying H ₂ O to the substrate with a first process gas containing hydrogen atoms and oxygen atoms; generating a plasma from the first process gas with a radio frequency to produce carbon etching the containing film; setting the temperature of the substrate to a second temperature different from the first temperature; and generating a plasma from the second process gas by radio frequency to etch the silicon-containing film.

In one exemplary embodiment, a plasma processing apparatus includes a plasma processing chamber, a substrate support provided within the plasma processing chamber for supporting a substrate, and a substrate support facing the substrate support within the plasma processing chamber. and a provided top electrode, the step of providing the substrate includes placing the substrate on a substrate support, and the step of etching the carbon-containing film comprises applying radio frequency power to the substrate support or the top electrode, In a plasma processing chamber, generating a plasma from a first process gas to etch the carbon-containing film, the step of etching the silicon-containing film comprises applying radio frequency power to the substrate support or the upper electrode to generate the plasma. Generating a plasma from the second process gas in the process chamber to etch the silicon-containing film is included.

In one exemplary embodiment, a plasma processing apparatus includes a first plasma processing chamber and a second plasma processing chamber, and a first substrate support provided within the first plasma processing chamber for supporting a substrate. a first upper electrode disposed within the first plasma processing chamber opposite the first substrate support; and a second plasma processing chamber disposed within the second plasma processing chamber for supporting the substrate. a second substrate support and a second upper electrode disposed opposite the second substrate support in a second plasma processing chamber; The step of etching the carbon-containing film includes placing on a substrate support, applying radio frequency power to the first substrate support or the first upper electrode to produce a first substrate in a first plasma processing chamber. Generating a plasma from the process gas to etch the carbon-containing film, the plasma processing method further comprising transferring the substrate from the first substrate support to the second substrate support, and adjusting the temperature of the substrate to Setting the temperature to a second temperature different from the first temperature includes setting the temperature of the substrate to the second temperature in the second substrate support, and etching the silicon-containing film comprises: Generating a plasma from the second process gas in a second plasma processing chamber to etch the silicon-containing film by supplying radio frequency power to the substrate support or the second upper electrode.

In one exemplary embodiment, the plasma processing apparatus comprises a transfer chamber connected to the first plasma processing chamber and the second plasma processing chamber, wherein the transfer chamber has an internal pressure below atmospheric pressure to transfer the substrate. In the step of carrying out, the substrate is transferred from the first substrate supporter to the second substrate supporter via the transfer chamber.

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

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

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

In one exemplary embodiment, a plasma processing method is provided that is performed in a plasma processing apparatus having a plasma processing chamber. The plasma processing method comprises the steps of: supplying a carbon-containing gas into a plasma processing chamber; generating plasma from the carbon-containing gas by a high frequency to form a protective film on at least a portion of an inner wall of the plasma processing chamber; providing a substrate including a film and a carbon-containing film formed on the silicon-containing film in a plasma processing chamber; supplying ₂ O to the substrate; generating plasma from a first processing gas by radio frequency to etch the carbon-containing film; supplying a second process gas comprising a containing gas and a fluorine-containing gas to a substrate provided in a plasma processing chamber; and supplying a radio frequency to generate a plasma from the second process gas to form a silicon-containing film. and etching.

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

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

In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes at least one plasma processing chamber, a temperature control section for setting a temperature of a substrate in the at least one plasma processing chamber, and a gas configured to supply a gas into the at least one plasma processing chamber. a supply unit, a plasma generation unit configured to generate a plasma from a gas in at least one plasma processing chamber, and a control unit configured to control the temperature adjustment unit, the gas supply unit, and the plasma generation unit. The control unit sets the temperature of the substrate including the silicon-containing film and the carbon-containing film formed on the silicon-containing film to a first temperature of 0° C. or less, The process gas supplies H ₂ O to the substrate, the radio frequency generates a plasma from the first process gas to etch the carbon-containing film, and the temperature of the substrate is set to a second temperature different from the first temperature. , a second process gas comprising a gas containing hydrogen and fluorine, or comprising both a hydrogen-containing gas and a fluorine-containing gas, is supplied to the substrate, and a plasma is generated from the second process gas by radio frequency. , to control the etching of the silicon-containing film.

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 denoted by the same reference numerals, and overlapping descriptions are omitted. Unless otherwise specified, positional relationships such as top, bottom, left, and right will be described based on the positional relationships shown in the drawings. The dimensional ratios in the drawings do not indicate the actual ratios, and the actual ratios are not limited to the illustrated ratios.

<Configuration of Plasma Processing Apparatus 1>
FIG. 1 schematically shows a plasma processing apparatus 1 according to one exemplary embodiment. The plasma processing apparatus 1 is a capacitively coupled plasma processing apparatus. A plasma processing method (hereinafter also referred to as “this processing method”) according to one exemplary embodiment of the present disclosure may be performed using the plasma processing apparatus 1 .

A plasma processing apparatus 1 shown in FIG. 1 includes a chamber 10 . Chamber 10 provides an interior space 10s therein. Chamber 10 includes a chamber body 12 . The chamber body 12 has a substantially cylindrical shape. The chamber body 12 is made of aluminum, for example. A corrosion-resistant film is provided on the inner wall surface of the chamber body 12 . Corrosion resistant membranes can be formed from ceramics such as aluminum oxide, yttrium oxide.

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

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

Substrate support 14 has a lower electrode 18 and an electrostatic chuck 20 . Substrate support 14 may further include an electrode plate 16 . The electrode plate 16 is made of a conductor such as aluminum and has a substantially disk shape. A 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 shape. Lower electrode 18 is electrically connected to electrode plate 16 .

An electrostatic chuck 20 is provided on the lower electrode 18 . A substrate W is placed on the upper surface of the electrostatic chuck 20 . The electrostatic chuck 20 has a body and electrodes. The main body of the electrostatic chuck 20 has a substantially disk shape and is made of a dielectric. The electrode of the electrostatic chuck 20 is a film-like electrode and is provided inside the main body of the electrostatic chuck 20 . Electrodes of the electrostatic chuck 20 are connected to a DC power supply 20p via a switch 20s. When a voltage is applied to the electrodes of the electrostatic chuck 20 from the DC power supply 20p, an electrostatic attractive force is generated between the electrostatic chuck 20 and the substrate W. As shown in FIG. The substrate W is attracted to the electrostatic chuck 20 by its electrostatic attraction and held by the electrostatic chuck 20 .

An edge ring 25 is arranged on the substrate support 14 . The edge ring 25 is a ring-shaped member. Edge ring 25 may be formed from silicon, silicon carbide, quartz, or the like. A substrate W is placed on the electrostatic chuck 20 and within the area surrounded by the edge ring 25 .

Inside the lower electrode 18, a channel 18f is provided. A heat exchange medium (for example, a refrigerant) is supplied to the flow path 18f from a chiller unit provided outside the chamber 10 through a pipe 22a. The heat exchange medium supplied to the flow path 18f is returned to the chiller unit via the 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 .

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

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 above the chamber body 12 via a member 32 . The member 32 is formed from 9 materials having insulating properties. Upper electrode 30 and member 32 close the upper opening of chamber body 12 .

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 can be made of a low-resistance conductor or semiconductor that generates little Joule heat. The top plate 34 has a plurality of gas discharge holes 34a passing through the top plate 34 in the plate thickness direction.

The support 36 detachably supports the top plate 34 . Support 36 is formed from a conductive material such as aluminum. A gas diffusion chamber 36 a 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 multiple gas holes 36b communicate with the multiple gas discharge holes 34a, respectively. The support 36 is formed with a gas introduction port 36c. The gas introduction port 36c is connected to the gas diffusion chamber 36a. A gas supply pipe 38 is connected to the gas inlet 36c.

A gas source group 40 is connected to the gas supply pipe 38 via a flow controller group 41 and a valve group 42 . The flow controller group 41 and the valve group 42 constitute a gas supply section. The gas supply section may further include a gas source group 40 . Gas source group 40 includes a plurality of gas sources. The plurality of gas sources includes sources of process gases used in the processing method. The flow controller group 41 includes a plurality of flow controllers. Each of the plurality of flow controllers in the flow controller group 41 is a mass flow controller or a pressure-controlled flow controller. The valve group 42 includes a plurality of open/close valves. Each of the plurality of gas sources of the gas source group 40 is connected to the gas supply pipe 38 via a corresponding flow controller of the flow controller group 41 and a corresponding opening/closing valve of the valve group 42 .

In the plasma processing apparatus 1 , a shield 46 is detachably provided along the inner wall surface of the chamber main body 12 and the outer circumference of the support portion 13 . Shield 46 prevents reaction by-products from adhering to chamber body 12 . The shield 46 is constructed, for example, by forming a corrosion-resistant film on the surface of a base material made of aluminum. Corrosion resistant membranes may be formed from ceramics such as yttrium oxide.

A baffle plate 48 is provided between the support portion 13 and the side wall of the chamber body 12 . The baffle plate 48 is constructed, for example, by forming a corrosion-resistant film (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 . Below the baffle plate 48 and at the bottom of the chamber body 12, an exhaust port 12e is provided. An exhaust device 50 is connected through an exhaust pipe 52 to the exhaust port 12e. The evacuation device 50 includes a pressure regulating valve and a vacuum pump such as a turbomolecular pump.

The plasma processing apparatus 1 includes a high frequency power source 62 and a bias power source 64 . A 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 plasma generation. The first frequency is, for example, a frequency within the range of 27 MHz to 100 MHz. A high frequency power supply 62 is connected to the lower electrode 18 via a matching box 66 and the electrode plate 16 . The matching device 66 has a circuit for matching the impedance on the load side (lower electrode 18 side) of the high frequency power supply 62 with 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 a matching device 66 . The high-frequency power supply 62 constitutes an example of a plasma generator.

A bias power supply 64 is a power supply that generates an electrical bias. A bias power supply 64 is electrically connected to the lower electrode 18 . The electrical bias has a second frequency. The second frequency is lower than the first frequency. The second frequency is, for example, a frequency within the range of 400 kHz-13.56 MHz. An electrical bias is applied to the substrate support 14 to attract ions to the substrate W when used with high frequency power HF. In one example, an electrical bias is applied to bottom electrode 18 . When an electrical 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 electrical bias may be applied to a bias electrode provided within the electrostatic chuck 20 (one example is the bias electrode 118 in FIG. 3).

In one embodiment, the electrical bias may be high frequency power LF having a second frequency. The radio frequency power LF is used as radio frequency bias power for drawing ions into the substrate W when used together with the radio frequency power HF. A bias power supply 64 configured to generate high frequency power LF is connected to the lower electrode 18 via a matcher 68 and the electrode plate 16 . The matching device 68 has a circuit for matching the impedance on the load side (lower electrode 18 side) of the bias power supply 64 with the output impedance of the bias power supply 64 .

Plasma may be generated using the high-frequency power LF instead of the 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 greater than 13.56 MHz, for example 40 MHz. Also, 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 plasma generator.

In another embodiment, the electrical bias may be a pulsed voltage (pulse 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 downstream of the bias power supply to pulse the voltage. In one example, a pulse voltage is applied to the bottom electrode 18 such that the substrate W has a negative potential. The waveform indicated by the one or more pulse voltages included in each pulse of the electrical bias may be a square wave, a triangular wave, an impulse, or have other waveforms. good.

A period of the pulse voltage is defined by the second frequency. A period of the pulse voltage includes two periods. A pulse voltage in one of the two periods is a negative voltage. The voltage level (ie absolute value) in one of the two periods is higher than the voltage level (ie absolute value) 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, bias power supply 64 is connected to lower electrode 18 through low pass filter and electrode plate 16 . The bias power supply 64 may be connected to a bias electrode provided inside the electrostatic chuck 20 instead of the lower electrode 18 (eg, the bias electrode 118 in FIG. 3).

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

In another embodiment, bias power supply 64 may apply a pulsed wave of electrical bias to bottom electrode 18 . A pulse wave of electrical bias may be applied to the lower electrode 18 periodically. The period of the electrical bias pulse wave is defined by the 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 other examples, the third frequency may be greater than or equal to 5 Hz and less than or equal to 100 kHz.

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

In one embodiment, the RF power supply 62 may provide a continuous wave of RF power HF. That is, the high frequency power supply 62 may continuously supply the high frequency power HF.

In another embodiment, the high frequency power supply 62 may supply a pulsed wave of high frequency power HF. A pulsed wave of high frequency power HF may be supplied periodically. The period of the pulse wave of the high frequency power HF is defined by the 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, H period and 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. Of the periods during which the high-frequency power HF is supplied, the L period corresponds to the above-described third period, and the H period corresponds to the above-described fourth period. Also, the level of the high-frequency power HF during the L period corresponds to the above-described 0 or third level, and the level of the electrical bias during the H period corresponds to the above-described fourth level.

The cycle of the pulse wave of the high frequency power HF may be synchronized with the cycle of the pulse wave of the electrical 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 cycle of the pulse wave of the high frequency power HF may not be synchronized with the H period in the cycle of the pulse wave of the electrical bias. The time length of the H period in the cycle 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 cycle of the pulse wave of the electrical bias. Part or all of the H period in the cycle of the pulse wave of the high frequency power HF may overlap with the H period in the cycle of the pulse wave of the electrical bias.

FIG. 2 is a timing chart showing an example of high frequency power HF and electrical 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 indicates time. In FIG. 2, the vertical axis indicates the power level of the high frequency power HF and the electrical 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". The electrical bias "L2" indicates that the electrical bias is not applied or is lower than the power level indicated by "H2". When the electrical bias is a negative DC voltage pulse wave, the level of the electrical bias is the effective value of the absolute value of the negative DC voltage. The power levels of the high-frequency power HF and the electric bias shown in FIG. 2 do not indicate a relative relationship between the two, and may be set arbitrarily. FIG. 2 shows that the period of the pulse wave of the high frequency power HF is synchronized with the period of the pulse wave of the electrical bias, the time length of the H period and the L period of the pulse wave of the high frequency power HF, and the pulse wave of the electrical bias. This is an example in which the time lengths of the H period and the L period are the same.

Returning to FIG. 1, the description continues. The plasma processing apparatus 1 further includes a power supply 70 . A power supply 70 is connected to the upper electrode 30 . In one example, power supply 70 may be configured to supply DC voltage or low frequency power to 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. A DC voltage or low frequency power may be supplied as a pulse wave or as a continuous wave. In this embodiment, positive ions existing within the internal space 10s are drawn into the upper electrode 30 and collide with it. Secondary electrons are thus 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. Secondary electrons also contribute to an improvement in plasma density. In addition, since the charged state of the substrate W is neutralized by the irradiation of the secondary electrons, the straightness of the ions into the recesses formed by etching is enhanced. Furthermore, if the upper electrode 30 is made of a silicon-containing material, collisions with positive ions will release silicon together with secondary electrons. The released silicon combines with oxygen in the plasma and deposits on the mask as a silicon oxide compound to function as a protective film. As described above, the supply of DC voltage or low-frequency power to the upper electrode 30 not only improves the selectivity, but also provides effects such as suppression of abnormal shapes in concave portions formed by etching and improvement of the etching rate.

When plasma processing is performed in the plasma processing apparatus 1, gas is supplied from the gas supply unit to the internal space 10s. 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 electrical bias. The generated high-frequency electric field generates plasma from the gas in the internal space 10s.

The plasma processing apparatus 1 may further include a controller 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, a signal input/output interface, and the like. The controller 80 controls each part of the plasma processing apparatus 1 . In the control unit 80 , the operator can use the input device to input commands for managing the plasma processing apparatus 1 . In addition, the control unit 80 can visualize and display the operation status of the plasma processing apparatus 1 using the display device. Furthermore, the storage unit stores control programs and recipe data. The control program is executed by the processor in order to perform various processes in the plasma processing apparatus 1. FIG. The processor executes a control program and controls each part of the plasma processing apparatus 1 according to recipe data. In one exemplary embodiment, part or all of the controller 80 may be provided as part of the configuration of the apparatus external to the plasma processing apparatus 1 .

FIG. 3 is a partially enlarged view of another example of the substrate supporter 14 included in the plasma processing apparatus 1. FIG. Substrate support 14 includes electrode plate 16 , bottom electrode 18 and electrostatic chuck 20 . The upper surface of the electrostatic chuck 20 has a substrate support surface 111a, which is a central area for supporting the substrate W, and an annular area 111b for supporting the edge ring 25. As shown in FIG. The annular region 111b surrounds the substrate support surface 111a. The substrate W is placed on the substrate support surface 111a, and the edge ring 25 is placed on the annular region 111b so as to surround the substrate W on the substrate support surface 111a. An electrostatic chuck 20 is placed on the lower electrode 18 . The upper surface of the electrostatic chuck 20 has a substrate supporting surface that supports the substrate W. As shown in FIG.

Electrostatic chuck 20 includes chuck electrode 120 and bias electrode 118 therein. The chuck electrode 120 has an electrode 120 a provided between the substrate supporting surface 111 a and the lower electrode 18 . The electrode 120a may be a planar electrode corresponding to the shape of the substrate support surface 111a. Chuck electrode 120 may also include electrodes 120 b and 120 c provided between edge ring 25 and bottom electrode 18 . Electrodes 120 b and 120 c may be annular electrodes corresponding to the shape of ring assembly 112 . The electrode 120c is provided outside the electrode 120b. The electrodes 120b and 120c may constitute a bipolar electrostatic chuck. Also, the electrodes 120a, 120b and 120c may be integrally constructed. The DC power supply 20p may be configured to apply different DC voltages to the electrodes 120a, 120b and 120c, respectively, and may be configured to apply the same DC voltage.

Bias electrode 118 has an electrode 118 a provided between electrode 120 a (or substrate support surface 111 a ) and bottom electrode 18 . Electrode 118a may be a planar electrode corresponding to the shape of substrate support surface 111a and/or electrode 120a. Also, the bias electrode 118 may have an electrode 118 b provided between the edge ring 25 and the lower electrode 18 . Also, although not shown, the substrate supporter 14 may include a temperature control module configured to control at least one of the electrostatic chuck 114, the ring assembly 112, and the substrate to a target temperature. The temperature control module may include heaters, heat transfer media, flow paths, or combinations thereof. A heat transfer fluid, such as brine or gas, flows through the channel. Further, the substrate supporter 14 has 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. may contain

<Configuration of substrate processing system PS>
FIG. 4 schematically illustrates a substrate processing system PS according to one exemplary embodiment. This processing method may be performed using the substrate processing system PS.

The substrate processing system PS includes substrate processing modules PM1 to PM6 (hereinafter also collectively referred to as “substrate processing modules PM”), a transfer module TM, and load lock modules LLM1 and LLM2 (hereinafter collectively referred to as “load lock modules”). module LLM"), loader module LM, and load ports LP1 to LP3 (hereinafter collectively referred to as "load port LP"). The controller CT controls each component of the substrate processing system PS to perform predetermined processing on the substrate W. FIG.

The substrate processing module PM performs processing such as etching processing, trimming processing, film forming processing, annealing processing, doping processing, lithography processing, cleaning processing, and ashing processing on the substrate W therein. A part of the substrate processing module PM may be a measurement module, and may measure the film thickness of the film formed on the substrate W, the dimension of the pattern formed on the substrate W, and the like. A plasma processing apparatus 1 shown in FIG. 1 is an example of a substrate processing module PM.

The transport module TM has a transport device that transports the substrate W, and transports 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 arranged adjacent to the transfer module TM. The transfer module TM, the substrate processing module PM, and the load lock module LLM are spatially isolated or connected by an openable/closable gate valve (eg, the gate valve 12g in FIG. 1).

The load lock modules LLM1 and LLM2 are provided between the transport module TM and the loader module LM. The load lock module LLM can switch its internal pressure to atmospheric pressure or vacuum. The load lock module LLM transfers the substrate W from the atmospheric pressure loader module LM to the vacuum transfer module TM, and transfers the substrate W from the vacuum transfer module TM to the atmospheric pressure loader module LM.

The loader module LM has a transport device that transports the substrate W, and transports the substrate W between the load lock module LLM and the load board LP. A FOUP (Front Opening Unified Pod) capable of accommodating, for example, 25 substrates W or an empty FOUP can be placed inside the load port LP. 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. Also, the loader module LM takes out the substrate W from the load lock module LLM and transports it to the FOUP in the load board LP.

The controller CT controls each component of the substrate processing system PS to perform predetermined processing on the substrate W. FIG. The controller CT stores a recipe in which process procedures, process conditions, transfer conditions, etc. are set, and controls each component of the substrate processing system PS so as to perform a predetermined process on the substrate W according to the recipe. to control. The controller CT may have the function of part or all of the controller 80 of the plasma processing apparatus 1 shown in FIG.

<Example of substrate W>
FIG. 5 is a diagram showing an example of the cross-sectional structure of the substrate W. As shown in FIG. The substrate W is an example of a substrate to which this 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 a base film UF and a mask film MK. As shown in FIG. 5, the substrate W may be formed by laminating a base film UF, a silicon-containing film SF, a carbon-containing film CF, and a mask film MK in this order.

The underlying film UF may be, for example, a silicon wafer or an organic film, dielectric film, metal film, semiconductor film, or the like formed on the silicon wafer. The base film UF may be a laminated film configured by laminating a plurality of films.

The silicon-containing film SF may be a SiO-containing film. The silicon-containing film SF is, for example, a multilayer film in which a silicon oxide film and a silicon nitride film are alternately laminated. The silicon-containing film SF may be a silicon oxide film (SiOx film), silicon nitride film, silicon oxynitride film (SiON film), or Si-ARC film. The silicon-containing film SF may include a SiGe film and a polycrystalline silicon film. The silicon-containing film SF may be a multilayer film configured by alternately stacking silicon oxide films and polycrystalline silicon films.

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, in one example, may be an organic film.

The base film UF, silicon-containing film SF and/or carbon-containing film CF may be formed by a CVD method, a spin coating method, or the like. The base film UF and/or the silicon-containing film SF may be a flat film or a film having unevenness.

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 above the silicon-containing film SF and surrounded by side walls of the mask film MK. That is, in FIG. 5, the upper surface of the carbon-containing film CF has a region covered with the mask film MK and a region exposed at the bottom of the opening OP.

The opening OP may have any shape in plan view of the substrate W (when the substrate W is viewed from the top to the bottom in FIG. 5). The shape may be, for example, circular, linear, or a combination of circular and linear. The mask film MK may have a plurality of sidewalls, and the plurality of sidewalls may define the plurality of openings OP. The plurality of openings OP may each have a linear shape and may 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.

The mask film MK is, for example, a silicon-containing film. The silicon-containing film, in one example, may be a SiON film. Also, the mask film MK may 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. Metal-containing films may include, for example, tungsten, tungsten carbide, and titanium nitride. The mask film MK may be formed by CVD, spin coating, or the like. The opening OP may be formed by etching the mask film MK. The mask film MK may be formed by lithography.

<Example of this processing method>
FIG. 6 is a flow chart showing an example of this processing method. The processing method includes a step of precoating the inner wall of the chamber (ST1), a step of preparing the substrate (ST2), a step of etching the carbon-containing film (ST3), and a step of etching the silicon-containing film (ST4). 1 or 4 controls each part of the plasma processing apparatus 1 to perform the present processing method on the substrate W shown in FIG. 5 will be described as an example. do. Each step included in this processing method can be performed by an inductively coupled plasma processing apparatus or a capacitively coupled plasma processing apparatus. In one example, steps ST1 to ST4 can be performed in a capacitively coupled plasma processing apparatus. In one example, steps ST1 to ST3 may be performed by an inductively coupled plasma processing apparatus, and step ST4 may be performed by an inductively coupled plasma processing apparatus. An antenna is an example of an upper electrode in an inductively coupled plasma processing apparatus.

(Step ST1: Precoating of inner wall of chamber)
In step ST<b>1 , a protective film is formed on at least 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, the gas supply unit of the plasma processing apparatus 1 supplies a processing gas containing a carbon-containing gas into the chamber 10 . The carbon-containing gas, in one example, includes one or more of CO, _CO2 , COS, and hydrocarbons as precursors. Hydrocarbons are _CH4 , _C2H2 , _{C3H6 ,} and the _like . A high frequency power supply 62 then supplies high frequency power HF to the electrode or upper electrode 30 included in the substrate support 14 . Thereby, an electric field is generated between the upper electrode 30 and the substrate supporter 14, and plasma is generated from the processing gas (including the carbon-containing gas) in the internal space 10s. Thereby, a carbon-containing film is deposited on at least a portion of the inner wall of the chamber 10 to form a protective film on at least a portion of the inner wall of the chamber 10 . Note that a reaction by-product in the etching process of step ST3 may form part of the protective film.

(Process ST2: Preparation of substrate)
In step ST2, a substrate W is prepared in the internal space 10s of the chamber 10. As shown in FIG. In the internal space 10 s , the substrate W is placed on the upper surface of the substrate support 14 (the surface facing the upper electrode 30 ) and held on the substrate support 14 by the electrostatic chuck 20 . At least part of the process of forming each configuration of the substrate W may be performed within the interior 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 the step ST3 of etching the carbon-containing film (and the step ST4 of etching the silicon-containing film). That is, the opening OP and the recess RC, which will be described later, may be formed continuously within 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 the step ST2, (b) the step ST3 and (c) the step ST4 are successively performed in the same chamber, the mask film MK is removed in the step ST4. may be removed. Further, after all or part of each component of the substrate W is formed in an apparatus or chamber (including other substrate processing modules PM of the substrate processing system PS in FIG. 4) outside the plasma processing apparatus 1, the substrate W may be carried into the internal space 10 s of the plasma processing apparatus 1 and placed on the upper surface of the substrate support 14 .

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

In step ST31, the temperature of the substrate W is set to the first temperature. The first temperature may be 0° C. or lower. Also, the first temperature may be −30° C. or lower, for example. Setting the temperature of the substrate W to the first temperature means directly measuring the temperature of the substrate W and adjusting the temperature of the substrate W so that the temperature of the substrate W reaches the first temperature. Not limited. 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. As another example, setting the temperature of the substrate W to the first temperature means 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. including setting to Also, “setting” the temperature includes inputting, selecting, or storing the temperature in the controller 80 .

In step ST<b>32 , the gas supply unit supplies the first processing gas into the chamber 10 . In this embodiment, the carbon-containing film CF may be an amorphous carbon film, and the first processing gas may contain H ₂ O gas. Also, the first processing gas may contain Ar gas. When the H ₂ O gas is supplied into the chamber 10 , H ₂ O molecules are physically adsorbed on the surface of the substrate W. As shown in FIG. The surface on which H ₂ O molecules are adsorbed includes the portion of the upper surface of the carbon-containing film CF that is exposed in the opening OP of the mask film MK (see FIG. 5). If the amorphous carbon film contains a predetermined proportion or more of hydrogen atoms, the first processing gas may contain an oxygen-containing gas together with the H ₂ O gas or instead of the H ₂ O gas. The oxygen-containing gas, in one example, may be _O2 gas. Note that the first processing gas may include multiple gases capable of generating H ₂ O gas within the chamber 10 . In one example, the multiple gases may be H ₂ gas and O ₂ gas.

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. FIG. The high frequency power HF has a first frequency suitable for plasma generation. The first frequency may be, for example, a frequency within the range of 27 MHz to 100 MHz. Also, the high frequency power HF may be supplied to the upper electrode 30 or the bias electrode 118 . Bias power supply 64 also provides an electrical bias to bias electrode 118 . The electrical bias may be a pulse wave (see Figure 2). Each pulse included in the electrical bias may comprise high frequency power LF or a pulsed voltage. An electrical bias may also be supplied to the bottom electrode 18 .

When the first processing gas is supplied into the chamber 10 and plasma is generated within the chamber 10, the H ₂ O molecules adsorbed on the upper surface of the carbon-containing film CF are included in the carbon-containing film CF. The carbon-containing film CF is etched by reacting with the amorphous carbon.

FIG. 7 is a diagram showing an example of the cross-sectional structure of the substrate W during execution of step ST3. As shown in FIG. 7, H ₂ O molecules adsorbed on the upper surface of the carbon-containing film CF through the openings OP of the mask film MK react with the amorphous carbon contained in the carbon-containing film CF to form A recess RC is formed. The recess RC is defined by the side walls of the carbon-containing film CF and the bottom surface BT. When the recesses RC are formed in the carbon-containing film CF, H ₂ O molecules are physically adsorbed to the bottom surface BT, and the carbon-containing film CF is further etched using the adsorbed H ₂ O molecules as an etchant. That is, the depth of the recess RC is increased.

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

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

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

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

In step ST<b>42 , the gas supply section supplies the second processing gas into the chamber 10 . The second process gas may include a gas containing both hydrogen and fluorine. A gas containing both hydrogen and fluorine, in one example, may be hydrogen fluoride (HF) gas. Gases containing both hydrogen and fluorine may include C _x H _y F _z (where x, y and z are integers of 1 or greater; hereinafter also referred to as “hydrofluorocarbons”).

The hydrofluorocarbon _, in one example, is at least one of _CH2F2 , _CHF3 , or _CH3F . Hydrofluorocarbons may contain more than one carbon. Hydrofluorocarbons may also contain three carbons, or four carbons. _{Hydrofluorocarbons are , for example , C2HF5 , C2H2F4 , C2H3F3 , C2H4F2 , C3HF7 , C3H2F2 , C3H2F6} , 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 . may be at least one. In one example, the carbon- _containing gas _{is at} least one selected from _the group consisting of _C3H2F4 and _C4H2F6 . C _x H _y F _z may be linear or cyclic.

The second process gas may contain both a hydrogen-containing gas and a fluorine-containing gas. Hydrogen-containing gases, in one example, may include _{H2 , NH3} , _H2O , _H2O2 or hydrocarbons ( _CH4 , _{C3H6 ,} etc.). In addition, the fluorine-containing gas may include, for example, _NF3 , _SF6 , _WF6 , _XeF2 or _CuFv (where u and _v are integers of 1 or more; hereinafter also referred to as "fluorocarbons"). The fluorocarbon _, in _one example _, is at least one of _CF4 , _C3F8 , _C4F6 , or _C4F8 .

The second process gas, in one example, may further include a carbon-containing gas. Carbon-containing gases include C _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 is an integer of 1 or more.). C _a H _b can be, in one example, CH ₄ or C ₃ H ₆ or the like. C _c F _d may be CF ₄ , C ₃ F ₈ , C ₄ F ₆ or C ₄ F ₈ or the like, in one example. _CHeFf , in one example, may be _CH2F2 , _{CHF3 , CH3F} , or the like _.

When the second processing gas is supplied into the chamber 10, the etchant contained in the second processing gas is physically adsorbed on the surface of the substrate W. FIG. The etchant may be hydrogen fluoride (HF), atomic hydrogen and/or atomic fluorine, in one example. The surface on which the etchant is adsorbed includes the portion of the upper surface of the silicon-containing film SF that is exposed in the recess RC (see FIG. 8).

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

A phosphorus-containing gas is a gas that contains phosphorus-containing molecules. The phosphorus-containing molecule may be an oxide such as tetraphosphorus decaoxide ( _P4O10 ), tetraphosphorus octaoxide ( _P4O8 ), tetraphosphorus hexaoxide _{( P4O6} ), _and the like _. Tetraphosphorus decaoxide is sometimes referred to as diphosphorus pentoxide _{( P2O5} ). Phosphorus-containing molecules include phosphorus trifluoride ( _PF3 ), phosphorus pentafluoride ( _PF5 ), phosphorus trichloride ( _PCl3 ), phosphorus pentachloride ( _PCl5 ), phosphorus tribromide ( _PBr3 ), pentaodorous Halides (phosphorus halides) such as phosphorus iodide (PBr ₅ ) and phosphorus iodide (PI ₃ ) may also be used. That is, the molecule containing phosphorus 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 the halogen element. The phosphorus-containing molecule may be a phosphoryl halide such as phosphoryl fluoride ( _POF3 ), phosphoryl chloride ( _POCl3 ), phosphoryl bromide ( _POBr3 ). Phosphorus-containing molecules _include phosphine ( _PH3 ), calcium phosphide ( _Ca3P2 , etc.), phosphoric acid _{( H3PO4} ), sodium phosphate ( _Na3PO4 ), hexafluorophosphoric acid ( _HPF6 ) _, etc. can be Phosphorus-containing molecules may be fluorophosphines (H _g PF _h ). Here, the sum of g and h is 3 or 5. Examples of fluorophosphines include HPF ₂ and H ₂ PF ₃ . The process gas may contain, as the at least one phosphorus-containing molecule, one or more of the phosphorus-containing molecules described above. For example, the process gas can include at least one of _PF3 , _PCl3 , _PF5 , _PCl5 , _POCl3 , _PH3 , _PBr3 , or _PBr5 as the at least one phosphorus-containing molecule. Note that when each phosphorus-containing molecule contained in the process gas is liquid or solid, each phosphorus-containing molecule can be vaporized by heating or the like and supplied into the chamber 10 . Also, the nitrogen-containing gas may be, for example, a gas containing at least one selected from the group consisting of NH ₃ , NF ₃ and N ₂ . The nitrogen-containing gas may also be a combination of gases in which NH ₃ is produced at the chamber 10 or substrate W surface.

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. FIG. The high frequency power HF has a first frequency suitable for plasma generation. The first frequency may be, for example, a frequency within the range of 27 MHz to 100 MHz. Also, the high frequency power HF may be supplied to the upper electrode 30 or the bias electrode 118 . Bias power supply 64 also provides an electrical bias to bias electrode 118 . The electrical bias may be a pulse wave (see Figure 2). Each pulse included in the electrical bias may comprise high frequency power LF or a pulsed voltage. An electrical bias may also be supplied to the bottom electrode 18 . The level of the electrical bias power supplied in step ST43 (for example, the effective value of the electrical bias power or the effective value of the absolute value of the DC voltage) is higher than the level of the electrical bias power supplied in step ST32. High is fine.

When the second processing gas is supplied into the chamber 10 and 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 produce silicon. Containment film SF is etched.

FIG. 9 is a diagram showing an example of the cross-sectional structure of the substrate W during execution of step ST4. As shown in FIG. 9, the etchant adsorbed on 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 the recess RC in the silicon-containing film SF. The recess RC is defined by the side walls and the 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 is physically adsorbed to the bottom surface BT, and the adsorbed etchant further etches the silicon-containing film SF. That is, the depth of the recess RC is increased.

FIG. 10 is a diagram showing an example of the cross-sectional structure of the substrate W after step ST4 is completed. As shown in FIG. 10, etching is performed in step ST4, and when the recess RC reaches the underlying film UF (that is, when the surface of the underlying film UF is exposed in the recess RC), the step ST4 ends. In step ST4, part of the base film UF may be etched. That is, in step ST4, part of the base film UF may be over-etched in the depth direction of the recess RC.

Experiments conducted to evaluate this treatment method are described below. The present disclosure is not limited in any way by the following experiments.

(Experiment 1)
Experiment 1 is an experiment relating to step ST3 (see FIG. 6) of this processing method. In Experiment 1, the amorphous carbon film formed on the substrate W was etched using the plasma processing apparatus 1 under the following conditions. An amorphous carbon film is an example of a carbon-containing film.

Processing gas: H ₂ O gas, Ar gas Set temperature: -70°C to 0°C
Chamber pressure: 25mTorr
High frequency power HF: 60MHz/100W
High frequency power LF: 3.2MHz/1000W

In Experiment 1, the amorphous carbon film was etched while changing the temperature of the substrate supporter 14, and the adsorption amount and etching rate of H ₂ O molecules in the internal space 10s of the chamber 10 were measured during the etching of the amorphous carbon film.

11 is a graph showing the measurement results of Experiment 1. FIG. In FIG. 11, the horizontal axis represents the temperature (° C.) of the substrate supporter 14 . The vertical axis represents 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 is about -30.degree. That is, when the temperature of the substrate support 14 is about −30° C. or less, the amount of H ₂ O molecules physically adsorbed to the substrate W increases, and therefore the H ₂ O molecules become an etchant in the etching of the amorphous carbon film. It was found that the etching rate increased as the amount consumed increased.

(Experiment 2)
Experiment 2 is an experiment relating to step ST4 (see FIG. 6) of this processing method. In Experiment 2, the plasma processing apparatus 1 was used to etch the silicon oxide film formed on the substrate W under the following conditions.

Processing gas: HF (hydrogen fluoride) gas, Ar gas,
Set temperature: -70°C to 0°C
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 to etch the silicon oxide film, and the etching rate of the silicon oxide film was measured.

12 is a graph showing the measurement results of Experiment 2. FIG. In FIG. 12, the horizontal axis represents the temperature (° C.) of the substrate supporter 14 . The vertical axis represents 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.degree. That is, 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 thus the HF in etching the silicon oxide film increases. (or hydrogen atoms and fluorine atoms) were found to etch and consume an increased amount, resulting in an increase in the etching rate.

According to one exemplary embodiment of the present disclosure, an etching process for a carbon-containing film (in one example, an amorphous carbon film) and an etching process for a silicon-containing film (in one example, a laminated film of a silicon oxide film and a silicon nitride film). In both, the etchant is physically adsorbed to the substrate as molecules to perform the etching process. Thereby, the etching process for the carbon-containing film and the etching process for the silicon-containing film can be continuously performed in the same chamber in the capacitively coupled plasma processing apparatus. Therefore, according to this exemplary embodiment, the throughput of the etching process can be improved.

According to one exemplary embodiment of the present disclosure, the etchant H ₂ O molecules are physically adsorbed to the substrate during the etching process of the carbon-containing film. As a result, the carbon-containing film can be etched at a high etching rate without generating high-density plasma.

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 continuously performed in the same chamber, the predetermined etching process At least part of the inner wall of the chamber can be pre-coated with a protective film prior to . Thereby, corrosion of the inner wall of the chamber can be suppressed in the etching process using hydrogen fluoride or the like. As a result, contamination inside the chamber caused by corrosion of the inner wall of the chamber can be suppressed.

While various exemplary embodiments have been described above, various additions, omissions, substitutions, and modifications may be made without being limited to the exemplary embodiments described above. Also, elements from different embodiments can be combined to form other embodiments. For example, each step of the present processing method may be performed using a plasma processing apparatus using an arbitrary plasma source, such as capacitively coupled plasma, inductively coupled plasma, microwave plasma, and ECR plasma. Also, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various changes can 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 a true scope and spirit being indicated by the following claims.

The present disclosure may also include the following embodiments.

(Appendix 1)
A plasma processing method performed in a plasma processing apparatus,
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 below 0°C;
supplying H ₂ O to the substrate with a first process gas comprising hydrogen atoms and oxygen atoms;
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 comprising a gas containing hydrogen and fluorine, or comprising both a hydrogen-containing gas and a fluorine-containing gas;
generating plasma from the second processing gas by radio frequency to etch the silicon-containing film.

(Appendix 2)
The plasma processing apparatus is
a plasma processing chamber;
a substrate support provided in the plasma processing chamber for supporting a substrate;
an upper electrode provided opposite to the substrate support in the plasma processing chamber;
providing the substrate includes placing the substrate on the substrate support;
The step of etching the carbon-containing film includes supplying high frequency power to the substrate support or the upper electrode to generate plasma from the first processing gas in the plasma processing chamber to etch the carbon-containing film. including the step of
The step of etching the silicon-containing film includes supplying high frequency power to the substrate support or the upper electrode to generate plasma from the second processing gas in the plasma processing chamber to etch the silicon-containing film. The plasma processing method according to Appendix 1, comprising the step of

(Appendix 3)
The plasma processing apparatus is
a first plasma processing chamber and a second plasma processing chamber;
a first substrate support within the first plasma processing chamber for supporting a substrate;
a first upper electrode disposed within the first plasma processing chamber opposite the first substrate support;
a second substrate support within the second plasma processing chamber for supporting a substrate;
a second upper electrode disposed opposite the second substrate support in the second plasma processing chamber;
providing the substrate includes placing the substrate on the first substrate support;
The step of etching the carbon-containing film includes supplying high frequency power to the first substrate support or the first upper electrode to generate plasma from the first processing gas in the first plasma processing chamber. forming and etching the carbon-containing film;
the plasma processing method further comprising 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 in the second substrate support;
The step of etching the silicon-containing film includes supplying high frequency power to the second substrate support or the second upper electrode to generate plasma from the second processing gas in the second plasma processing chamber. 2. The plasma processing method of claim 1, comprising forming and etching the silicon-containing film.

(Appendix 4)
The plasma processing apparatus comprises a transfer chamber connected to the first plasma processing chamber and the second plasma processing chamber, wherein an internal pressure of the transfer chamber is lower than atmospheric pressure,
3. The plasma processing method according to appendix 3, wherein in the step of transferring the substrate, the substrate is transferred from the first substrate supporter to the second substrate supporter via the transfer chamber.

(Appendix 5)
5. The plasma processing method according to any one of appendices 1 to 4, wherein the second temperature is lower than the first temperature.

(Appendix 6)
5. The plasma processing method according to any one of appendices 1 to 4, wherein the second temperature is higher than the first temperature.

(Appendix 7)
7. The plasma processing method according to any one of appendices 1 to 6, wherein the carbon-containing film is an amorphous carbon film.

(Appendix 8)
A plasma processing method performed 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 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 that includes a silicon-containing film and a carbon-containing film formed on the silicon-containing film;
providing a first process gas comprising hydrogen atoms and oxygen atoms into the plasma processing chamber to provide H ₂ O to the substrate;
generating a plasma from the first process gas by radio frequency to etch the carbon-containing 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;
and a step of supplying a high frequency wave to generate plasma from the second processing gas to etch the silicon-containing film.

(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;
etching the carbon-containing film, wherein 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.

(Appendix 10)
10. The plasma processing method according to appendix 8 or 9, wherein the protective film is a carbon-containing film.

(Appendix 11)
11. The plasma processing method according to any one of appendices 1 to 10, wherein the plasma processing apparatus is a capacitively coupled plasma processing apparatus.

(Appendix 12)
at least one plasma processing chamber;
a temperature adjuster for setting the 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 generator configured to generate a plasma from a gas within 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;
The control unit
setting the temperature of the substrate including the silicon-containing film and the carbon-containing film formed on the silicon-containing film to a first temperature of 0° C. or lower;
supplying H ₂ O to the substrate with a first process gas containing hydrogen atoms and oxygen atoms;
generating 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 comprising a gas containing hydrogen and fluorine, or comprising both a hydrogen-containing gas and a fluorine-containing gas;
A plasma processing apparatus that controls etching of the silicon-containing film by generating plasma from the second processing gas by a high frequency.

(Appendix 13)
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, comprising:
a temperature adjustment unit for setting temperatures of substrates arranged 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 generator coupled to the first plasma processing chamber;
a capacitively coupled plasma generator 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;
The control unit
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 of 0° C. or lower;
supplying H ₂ O to the substrate with a first process gas containing hydrogen atoms and oxygen atoms;
generating 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 comprising a gas containing hydrogen and fluorine, or comprising both a hydrogen-containing gas and a fluorine-containing gas;
A plasma processing system that controls etching of the silicon-containing film by generating a plasma from the second process gas via radio frequency.

Reference Signs List 1 plasma processing apparatus 10 chamber 13 support 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 controller group 50 Exhaust device 62 High frequency power supply 64 Bias power supply 80 Control unit 114 Electrostatic chuck 118 Bias Electrodes, BT... Bottom, CF... Carbon-containing film, CT... Control part, MK... Mask film, PM... Substrate processing module, RC... Concave part, SF... Silicon-containing film, TM... Transfer module, UF... Underlying film, W... substrate

Claims (13)

A plasma processing method performed in a plasma processing apparatus,
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 below 0°C;
supplying H ₂ O to the substrate with a first process gas comprising hydrogen atoms and oxygen atoms;
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 comprising a gas containing hydrogen and fluorine, or comprising both a hydrogen-containing gas and a fluorine-containing gas;
generating plasma from the second processing gas by radio frequency to etch the silicon-containing film. The plasma processing apparatus is
a plasma processing chamber;
a substrate support provided in the plasma processing chamber for supporting a substrate;
an upper electrode provided opposite to the substrate support in the plasma processing chamber;
providing the substrate includes placing the substrate on the substrate support;
The step of etching the carbon-containing film includes supplying high frequency power to the substrate support or the upper electrode to generate plasma from the first processing gas in the plasma processing chamber to etch the carbon-containing film. including the step of
The step of etching the silicon-containing film includes supplying high frequency power to the substrate support or the upper electrode to generate plasma from the second processing gas in the plasma processing chamber to etch the silicon-containing film. 2. The plasma processing method of claim 1, comprising the step of: The plasma processing apparatus is
a first plasma processing chamber and a second plasma processing chamber;
a first substrate support within the first plasma processing chamber for supporting a substrate;
a first upper electrode disposed within the first plasma processing chamber opposite the first substrate support;
a second substrate support within the second plasma processing chamber for supporting a substrate;
a second upper electrode disposed opposite the second substrate support in the second plasma processing chamber;
providing the substrate includes placing the substrate on the first substrate support;
The step of etching the carbon-containing film includes supplying high frequency power to the first substrate support or the first upper electrode to generate plasma from the first processing gas in the first plasma processing chamber. forming and etching the carbon-containing film;
the plasma processing method further comprising 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 in the second substrate support;
The step of etching the silicon-containing film includes supplying high frequency power to the second substrate support or the second upper electrode to generate plasma from the second processing gas in the second plasma processing chamber. 2. The plasma processing method of claim 1, comprising forming and etching said silicon-containing film. The plasma processing apparatus comprises a transfer chamber connected to the first plasma processing chamber and the second plasma processing chamber, wherein 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 transferring said substrate, said substrate is transferred from said first substrate supporter to said second substrate supporter via said transfer chamber. 2. The plasma processing method according to claim 1, wherein said second temperature is lower than said first temperature. 2. The plasma processing method according to claim 1, wherein said second temperature is higher than said first temperature. 2. The plasma processing method according to claim 1, wherein said carbon-containing film is an amorphous carbon film. A plasma processing method performed 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 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 that includes a silicon-containing film and a carbon-containing film formed on the silicon-containing film;
providing a first process gas comprising hydrogen atoms and oxygen atoms into the plasma processing chamber to provide H ₂ O to the substrate;
generating a plasma from the first process gas by radio frequency to etch the carbon-containing 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;
and a step of supplying a high frequency wave to generate plasma from the second processing gas to etch the silicon-containing film. 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;
etching the carbon-containing film, wherein 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 etching said silicon-containing film, said SiO film is etched after said substrate is set to said second temperature. 9. The plasma processing method according to claim 8, wherein said protective film is a carbon-containing film. 11. The plasma processing method according to claim 1, wherein said plasma processing apparatus is a capacitively coupled plasma processing apparatus. at least one plasma processing chamber;
a temperature adjuster for setting the 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 generator configured to generate a plasma from a gas within 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;
The control unit
setting the temperature of the substrate including the silicon-containing film and the carbon-containing film formed on the silicon-containing film to a first temperature of 0° C. or lower;
supplying H ₂ O to the substrate with a first process gas containing hydrogen atoms and oxygen atoms;
generating 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 comprising a gas containing hydrogen and fluorine, or comprising both a hydrogen-containing gas and a fluorine-containing gas;
A plasma processing apparatus that controls etching of the silicon-containing film by generating plasma from the second processing gas by a high frequency. 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, comprising:
a temperature adjustment unit for setting temperatures of substrates arranged 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 generator coupled to the first plasma processing chamber;
a capacitively coupled plasma generator 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;
The control unit
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 of 0° C. or lower;
supplying H ₂ O to the substrate with a first process gas containing hydrogen atoms and oxygen atoms;
generating 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 comprising a gas containing hydrogen and fluorine, or comprising both a hydrogen-containing gas and a fluorine-containing gas;
A plasma processing system that controls etching of the silicon-containing film by generating a plasma from the second process gas via radio frequency.

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