Patent Application
20250232954
An exemplary embodiment of the present disclosure relates to a plasma processing apparatus and a power supply system.
The specification of US2017/0125260A discloses a technique for controlling ions in plasma in an etching process.
A plasma processing apparatus in one exemplary aspect of the present disclosure includes a chamber; a substrate support that is disposed in the chamber and includes a lower electrode; an upper electrode that is disposed above the substrate support; a first radio frequency (RF) power supply configured to supply a first RF signal having a first RF frequency to the upper electrode or the lower electrode, in which the first RF signal has a first power level during a first period in each cycle, has a second power level during a second period after the first period in each cycle, has a third power level during a third period after the second period in each cycle, and has a fourth power level during a fourth period after the third period in each cycle, the second power level is less than the first power level, and the fourth power level has a zero power level; a second RF power supply configured to supply a second RF signal having a second RF frequency to the lower electrode, in which the second RF signal has a fifth power level during the first period in each cycle, has a sixth power level during the second period in each cycle, has a seventh power level during the third period in each cycle, and has an eighth power level during the fourth period in each cycle, and each of the fifth power level and the eighth power level have a zero power level; and a third RF power supply configured to supply a third RF signal having a third RF frequency to the lower electrode, in which the third RF signal has a ninth power level during the first period in each cycle, has a tenth power level during the second period in each cycle, has an eleventh power level during the third period in each cycle, and has a twelfth power level during the fourth period in each cycle, and each of the ninth power level, the tenth power level and the eleventh power level have a zero power level.
Hereinafter, each embodiment of the present disclosure will be described.
In one exemplary embodiment, there is provided a plasma processing apparatus including: a chamber; a substrate support that is disposed in the chamber and includes a lower electrode; an upper electrode that is disposed above the substrate support; a first RF power supply configured to supply a first RF signal having a first RF frequency to the upper electrode or the lower electrode, in which the first RF signal has a first power level during a first period in each cycle, has a second power level during a second period after the first period in each cycle, has a third power level during a third period after the second period in each cycle, and has a fourth power level during a fourth period after the third period in each cycle, the second power level is less than the first power level, and the fourth power level has a zero power level; a second RF power supply configured to supply a second RF signal having a second RF frequency to the lower electrode, in which the second RF signal has a fifth power level during the first period in each cycle, has a sixth power level during the second period in each cycle, has a seventh power level during the third period in each cycle, and has an eighth power level during the fourth period in each cycle, and each of the fifth power level and the eighth power level have a zero power level; and a third RF power supply configured to supply a third RF signal having a third RF frequency to the lower electrode, in which the third RF signal has a ninth power level during the first period in each cycle, has a tenth power level during the second period in each cycle, has an eleventh power level during the third period in each cycle, and has a twelfth power level during the fourth period in each cycle, and each of the ninth power level, the tenth power level and the eleventh power level have a zero power level.
In one exemplary embodiment, the third power level has a zero power level, and the seventh power level is greater than the sixth power level.
In one exemplary embodiment, the third power level is equal to the second power level, and the seventh power level is greater than the sixth power level.
In one exemplary embodiment, the third power level is greater than the second power level, and the seventh power level has a zero power level.
In one exemplary embodiment, the first RF frequency is larger than the second RF frequency, and the second RF frequency is larger than the third RF frequency.
In one exemplary embodiment, the third RF frequency is in a range of 300 kHz to 600 KHz.
In one exemplary embodiment, there is provided a plasma processing apparatus including: a chamber; a substrate support that is disposed in the chamber and includes a lower electrode; an upper electrode that is disposed above the substrate support; a first RF power supply configured to supply a first RF signal having a first RF frequency to the upper electrode or the lower electrode, in which the first RF signal has a first power level during a first period in each cycle, has a second power level during a second period after the first period in each cycle, has a third power level during a third period after the second period in each cycle, and has a fourth power level during a fourth period after the third period in each cycle, the second power level is less than the first power level, and the fourth power level has a zero power level; a second RF power supply configured to supply a second RF signal having a second RF frequency to the lower electrode, in which the second RF signal has a fifth power level during the first period in each cycle, has a sixth power level during the second period in each cycle, has a seventh power level during the third period in each cycle, and has an eighth power level during the fourth period in each cycle, and each of the fifth power level and the eighth power level have a zero power level; and a voltage pulse generator configured to apply a voltage pulse signal to the lower electrode, in which the voltage pulse signal has a first voltage level during the first period, the second period, and the third period in each cycle, and has a sequence of voltage pulses having a second voltage level during the fourth period in each cycle, and an absolute value of the second voltage level is larger than an absolute value of the first voltage level.
In one exemplary embodiment, the third power level has a zero power level, and the seventh power level is greater than the sixth power level.
In one exemplary embodiment, the third power level is equal to the second power level, and the seventh power level is greater than the sixth power level.
In one exemplary embodiment, the third power level is greater than the second power level, and the seventh power level has a zero power level.
In one exemplary embodiment, the second voltage level has a negative polarity.
In one exemplary embodiment, the first voltage level has a zero voltage level.
In one exemplary embodiment, the sequence of the voltage pulses has a pulse frequency in a range of 300 kHz to 600 KHz.
In one exemplary embodiment, there is provided a plasma processing apparatus including: a chamber; a substrate support that is disposed in the chamber and includes a lower electrode; an upper electrode that is disposed above the substrate support; a first RF power supply configured to supply a first RF signal having a first RF frequency to the upper electrode or the lower electrode, in which the first RF frequency has a MHz band, the first RF signal has a first power level during a first period in each cycle, has a second power level during a second period after the first period in each cycle, has a third power level during a third period after the second period in each cycle, and has a fourth power level during a fourth period after the third period in each cycle, the second power level is less than the first power level, the third power level is greater than the second power level, and the fourth power level has a zero power level; and a second RF power supply configured to supply a second RF signal having a second RF frequency to the lower electrode, in which the second RF frequency has a kHz band, the second RF signal has a fifth power level during the first period in each cycle, has a sixth power level during the second period in each cycle, has a seventh power level during the third period in each cycle, and has an eighth power level during the fourth period in each cycle, each of the fifth power level and the seventh power level have a zero power level, and the eighth power level is equal to or greater than the sixth power level.
In one exemplary embodiment, the second RF signal has an RF frequency in a range of 300 kHz to 600 KHz.
In one exemplary embodiment, there is provided a plasma processing apparatus including: a chamber; a substrate support that is disposed in the chamber and includes a lower electrode; an upper electrode that is disposed above the substrate support; an RF power supply configured to supply an RF signal to the upper electrode or the lower electrode, in which the RF signal has a first power level during a first period in each cycle, has a second power level during a second period after the first period in each cycle, has a third power level during a third period after the second period in each cycle, and has a fourth power level during a fourth period after the third period in each cycle, the second power level is less than the first power level, the third power level is greater than the second power level, and the fourth power level has a zero power level; and a voltage pulse generator configured to apply a voltage pulse signal to the lower electrode, in which the voltage pulse signal has a first voltage level during the first period and the third period in each cycle, has a sequence of voltage pulses having a second voltage level during the second period in each cycle, and has a sequence of voltage pulses having the second voltage level or a third voltage level during the fourth period in each cycle, an absolute value of the second voltage level is larger than an absolute value of the first voltage level, and an absolute value of the third voltage level is larger than the absolute value of the second voltage level.
In one exemplary embodiment, there is provided a power supply system for use in a plasma processing apparatus, including: a first RF generator configured to generate a first RF signal having a first RF frequency, in which the first RF signal has a first power level during a first period in each cycle, has a second power level during a second period after the first period in each cycle, has a third power level during a third period after the second period in each cycle, and has a fourth power level during a fourth period after the third period in each cycle, the second power level is less than the first power level, and the fourth power level has a zero power level;
In one exemplary embodiment, there is provided a power supply system for use in a plasma processing apparatus, including: a first RF generator configured to generate a first RF signal having a first RF frequency, in which the first RF signal has a first power level during a first period in each cycle, has a second power level during a second period after the first period in each cycle, has a third power level during a third period after the second period in each cycle, and has a fourth power level during a fourth period after the third period in each cycle, the second power level is less than the first power level, and the fourth power level has a zero power level;
In one exemplary embodiment, there is provided a power supply system for use in a plasma processing apparatus, including: a first RF generator configured to generate a first RF signal having a first RF frequency, in which the first RF frequency has a MHz band, the first RF signal has a first power level during a first period in each cycle, has a second power level during a second period after the first period in each cycle, has a third power level during a third period after the second period in each cycle, and has a fourth power level during a fourth period after the third period in each cycle, the second power level is less than the first power level, the third power level is greater than the second power level, and the fourth power level has a zero power level; and a second RF generator configured to generate a second RF signal having a second RF frequency, in which the second RF frequency has a kHz band, the second RF signal has a fifth power level during the first period in each cycle, has a sixth power level during the second period in each cycle, has a seventh power level during the third period in each cycle, and has an eighth power level during the fourth period in each cycle, each of the fifth power level and the seventh power level have a zero power level, and the eighth power level is equal to or greater than the sixth power level.
In one exemplary embodiment, there is provided a power supply system for use in a plasma processing apparatus, including: an RF generator configured to generate an RF signal, in which the RF signal has a first power level during a first period in each cycle, has a second power level during a second period after the first period in each cycle, has a third power level during a third period after the second period in each cycle, and has a fourth power level during a fourth period after the third period in each cycle, the second power level is less than the first power level, the third power level is greater than the second power level, and the fourth power level has a zero power level; and a voltage pulse generator configured to generate a voltage pulse signal, in which the voltage pulse signal has a first voltage level during the first period and the third period in each cycle, has a sequence of voltage pulses having a second voltage level during the second period in each cycle, and has a sequence of voltage pulses having the second voltage level or a third voltage level during the fourth period in each cycle, an absolute value of the second voltage level is larger than an absolute value of the first voltage level, and an absolute value of the third voltage level is larger than the absolute value of the second voltage level.
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 will be given the same reference numerals, and repeated descriptions will be omitted. Unless otherwise specified, a positional relationship such as up, down, left, and right will be described based on a positional relationship illustrated in the drawings. A dimensional ratio in the drawings does not indicate an actual ratio, and the actual ratio is not limited to the ratio illustrated in the drawings.
The plasma generator 12 is configured to form a plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be a capacitively coupled plasma (CCP), an inductively coupled plasma (ICP), an electron-cyclotron-resonance plasma (ECR plasma), a helicon wave plasma (HWP), a surface wave plasma (SWP), or the like. Further, various types of plasma generators including an alternating current (AC) plasma generator and a direct current (DC) plasma generator may be used. In an embodiment, an AC signal (AC power) used in the AC plasma generator has a frequency in the range of 100 kHz to 10 GHz. Therefore, the AC signal includes an RF signal and a microwave signal. In an embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.
The controller 2 processes a computer-executable instruction that causes the plasma processing apparatus 1 to execute various steps described in the present disclosure. The controller 2 may be configured to control each element of the plasma processing apparatus 1 such that the various steps described here are executed. In an embodiment, a part or the entirety of the controller 2 may be included in the plasma processing apparatus 1. The controller 2 may include a processor 2a1, a storage 2a2, and a communication interface 2a3. The controller 2 is realized by, for example, a computer 2a. The processor 2a1 may be configured to read out a program from the storage 2a2 and to execute the read-out program to perform various control operations. This program may be stored in the storage 2a2 in advance, or may be acquired through a medium when necessary. The acquired program is stored in the storage 2a2, is read out from the storage 2a2, and executed by the processor 2a1. The medium may be various storage media readable by the computer 2a or may be a communication line connected to the communication interface 2a3. The processor 2a1 may be a central processing unit (CPU). The storage 2a2 may include a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 through a communication line such as a local area network (LAN).
Hereinafter, a configuration example of the capacitively coupled plasma processing apparatus as an example of the plasma processing apparatus 1 will be described.
The capacitively coupled plasma processing apparatus 1 includes the plasma processing chamber 10, the gas supply 20, a power supply system 30, and the exhaust system 40. In addition, the plasma processing apparatus 1 includes the substrate support 11 and a gas introduction unit. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes a showerhead 13. The substrate support 11 is disposed in the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In an embodiment, the showerhead 13 configures at least a part of a ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, a side wall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from a housing of the plasma processing chamber 10.
The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a center region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of the substrate W. The annular region 111b of the main body 111 surrounds the center region 111a of the main body 111 in plan view. The substrate W is disposed on the center region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 such that the ring assembly 112 surrounds the substrate W on the center region 111a of the main body 111. Therefore, the center region 111a is also referred to as a substrate support surface for supporting the substrate W, and the annular region 111b is also referred to as a ring support surface for supporting the ring assembly 112.
In an embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 may function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed in the ceramic member 1111a. The ceramic member 1111a has the center region 111a. In an embodiment, the ceramic member 1111a also has the annular region 111b. Another member that surrounds the electrostatic chuck 1111 may have the annular region 111b, such as an annular electrostatic chuck or an annular insulating member. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. Further, at least one RF/DC electrode coupled to an RF power supply 31 and/or a DC power supply 32, which will be described later, may be disposed in the ceramic member 1111a. In this case, at least one RF/DC electrode functions as the lower electrode. In a case where a bias RF signal and/or a DC signal, which will be described later, are supplied to at least one RF/DC electrode, the RF/DC electrode is also referred to as a bias electrode. The conductive member of the base 1110 and at least one RF/DC electrode may function as lower electrodes.
The ring assembly 112 includes one or a plurality of annular members. In an embodiment, one or the plurality of annular members includes one or a plurality of edge rings and at least one cover ring. The edge ring is formed of a conductive material or an insulating material, and the cover ring is formed of an insulating material.
In addition, the substrate support 11 may include a temperature-controlled module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature-controlled module may include a heater, a heat transfer medium, a flow passage 1110a, or a combination thereof. A heat transfer fluid such as brine or a gas flows in the flow passage 1110a. In an embodiment, the flow passage 1110a is formed in the base 1110, and one or a plurality of heaters is disposed in the ceramic member 1111a of the electrostatic chuck 1111. Further, the substrate support 11 may include a heat transfer gas supply configured to supply the heat transfer gas to a gap between a back surface of the substrate W and the center region 111a.
The showerhead 13 is configured to introduce at least one processing gas from the gas supply 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and gas introduction ports 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the gas introduction ports 13c. In addition, the showerhead 13 includes at least one upper electrode. In addition to the showerhead 13, the gas introduction unit may include one or a plurality of side gas injectors (SGI) attached to one or a plurality of opening portions formed on the side wall 10a.
The gas supply 20 may include at least one gas source 21 and at least one flow rate controller 22. In an embodiment, the gas supply 20 is configured to supply at least one processing gas to the showerhead 13 from each corresponding gas source 21 through each corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Further, the gas supply 20 may include at least one flow modulation device that modulates or pulses a flow of at least one processing gas.
The power supply system 30 includes an RF power supply 31 that is coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode and/or at least one upper electrode. As a result, a plasma is formed from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 may function as at least a part of the plasma generator 12. Further, by supplying the bias RF signal to at least one lower electrode, a bias potential is generated in the substrate W, and an ion component in the formed plasma can be drawn into the substrate W.
In an embodiment, the RF power supply 31 includes a first RF generator 31a and a second RF generator 31b. The first RF generator 31a is coupled to at least one lower electrode and/or at least one upper electrode via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma formation. In an embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHZ. In an embodiment, the first RF generator 31a may be configured to generate source RF signals having different frequencies. The generated one or plurality of source RF signals is supplied to at least one lower electrode and/or at least one upper electrode.
The second RF generator 31b is coupled to at least one lower electrode via at least one impedance matching circuit and is configured to generate the bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In an embodiment, the bias RF signal has a frequency smaller than the frequency of the source RF signal. In an embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In an embodiment, the second RF generator 31b may be configured to generate bias RF signals having different frequencies. The generated one or plurality of bias RF signals is supplied to at least one lower electrode. In addition, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.
In addition, the power supply system 30 may include a DC power supply 32 that is coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In an embodiment, the first DC generator 32a is connected to at least one lower electrode, and is configured to generate the first DC signal. The generated first DC signal is applied to at least one lower electrode. In an embodiment, the second DC generator 32b is connected to at least one upper electrode and is configured to generate a second DC signal. The generated second DC signal is applied to at least one upper electrode.
In various embodiments, the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and/or at least one upper electrode. The voltage pulse may have a pulse waveform having a rectangular shape, a trapezoidal shape, a triangular shape, or a combination thereof. In an embodiment, a waveform generator for generating the sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Therefore, the first DC generator 32a and the waveform generator configure the voltage pulse generator. In a case where the second DC generator 32b and the waveform generator configure the voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulse may have a positive polarity or a negative polarity. In addition, the sequence of voltage pulses may include one or a plurality of positive voltage pulses and one or a plurality of negative voltage pulses in one cycle. The first and second DC generators 32a and 32b may be provided in addition to the RF power supply 31, and the first DC generator 32a may be provided instead of the second RF generator 31b.
The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at a bottom portion of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 10s is adjusted by the pressure regulating valve. The vacuum pump may include a turbo molecular pump, a dry pump, or a combination thereof.
As illustrated in
In an embodiment, the first RF power supply 200 is electrically connected to the upper electrode and is configured to generate a first RF signal. The generated first RF signal is supplied to the upper electrode. The first RF power supply 200 may include a first RF generator. In an embodiment, the first RF signal has a frequency of a MHz band. In an embodiment, the first RF signal has a frequency in a range of 40 MHz to 150 MHz. In an embodiment, the first RF signal may have a frequency in a range of 80 MHz to 120 MHz.
As illustrated in
In an embodiment, the first RF signal (HF) has a first power level P1 in the first period T1 in each cycle, has a second power level P2 during the second period T2 in each cycle, has a third power level P3 during the third period T3 in each cycle, and has a fourth power level P4 during the fourth period T4 in each cycle. In an embodiment, the first power level P1 and the second power level P2 may be greater than the zero power level, and the first period T1 and the second period T2 may be in a state (ON state) in which the first RF signal (HF) is supplied to the upper electrode. The second power level P2 may be less than the first power level P1. In an embodiment, each of the third power level P3 and the fourth power level P4 is a zero power level, and the third period T3 and the fourth period T4 may be in a state in which the first RF signal (HF) is not supplied to the upper electrode (OFF state).
In an embodiment, as illustrated in
In an embodiment, as illustrated in
In an embodiment, as illustrated in
In an embodiment, as illustrated in
The plasma processing performed using the plasma processing apparatus 1 includes an etching process of etching a film on the substrate W using plasma. In an embodiment, the plasma processing is executed by the controller 2.
First, the substrate W is carried into the chamber 10 by a transport arm, is placed on the substrate support 11 by a lifter, and is held by suction on the substrate support 11 as illustrated in
Next, the processing gas is supplied to the showerhead 13 by the gas supply 20, and is supplied from the showerhead 13 to the plasma processing space 10s. The processing gas supplied at this time includes a gas that generates an active species required for the etching process of the substrate W.
In an embodiment, the first RF signal (HF) is supplied to the upper electrode by the first RF power supply 200. The second RF signal (LF) and the third RF signal (LF2) are supplied to the lower electrode by the second RF power supply 201 and the third RF power supply 202. In this case, the atmosphere in the plasma processing space 10s is exhausted from the gas exhaust port 10e, and the inside of the plasma processing space 10s may be depressurized to a predetermined pressure. As a result, plasma is formed in the plasma processing space 10s, and the substrate W is subjected to the etching process.
In an embodiment, as illustrated in
During the first period T1 in an embodiment, only the first RF signal (HF) is supplied, and thus, on the substrate W in the plasma processing space 10s, the ion flux is high and the ion energy is low.
The example illustrated in
In an embodiment, during the second period T2 in the plasma processing, as illustrated in
In an embodiment, during the second period T2, as illustrated in
In an embodiment, during the third period T3 in the plasma processing, as illustrated in
In an embodiment, during the third period T3, as illustrated in
During the fourth period T4 in the plasma processing, as illustrated in
During the fourth period T4, as illustrated in
According to the present exemplary embodiment, the plasma processing apparatus 1 includes the first RF power supply 200 that supplies the first RF signal (HF) to the upper electrode, the second RF power supply 201 that supplies the second RF signal (LF) to the lower electrode, and the third RF power supply 202 that supplies the third RF signal (LF2) to the lower electrode. The first RF signal (HF) has the first power level P1 during the first period T1 in each cycle, has the second power level P2 less than the first power level P1 during the second period T2 in each cycle, has the third power level P3 during the third period T3 in each cycle, and has the fourth power level P4 of the zero power level during the fourth period T4 in each cycle. The second RF signal (LF) has the fifth power level P5 having the zero power level during the first period T1 in each cycle, has the sixth power level P6 during the second period T2 in each cycle, has the seventh power level P7 during the third period T3 in each cycle, and has the eighth power level P8 having the zero power level during the fourth period T4 in each cycle. The third RF signal (LF2) has the ninth power level P9 having the zero power level during the first period T1 in each cycle, has the tenth power level P10 having the zero power level during the second period T2 in each cycle, has the eleventh power level P11 having the zero power level during the third period T3 in each cycle, and the twelfth power level P12 during the fourth period T4 in each cycle. Accordingly, since the RF signals of three frequencies can be supplied at a predetermined power level in each of the periods T1 to T4 in each cycle, the ion energy and the ion flux of the generated plasma can be independently controlled, respectively. As a result, it is possible to improve the controllability of plasma formed on the substrate.
According to the present exemplary embodiment, during the first period T1 in each cycle, only the first RF signal (HF) having a high frequency is supplied, whereby it is possible to promote the formation of the protective film on the film on the substrate W while suppressing the etching of the film on the substrate W in a state in which the ion flux is high and the ion energy is low. During the second period T2 in each cycle, by supplying the first RF signal (HF) having a lower power level than the first period T1 and supplying the second RF signal (LF) having a medium frequency, thereby lowering the ion flux and increasing the ion energy, the formation of the protective film can be continued while suppressing the formation of the protective film on the substrate W, the ions can be drawn, and the etching of the film on the substrate W can be advanced. During the third period T3 in each cycle, by supplying the second RF signal (LF) having a higher power level than the second period T2, both the ion flux and the ion energy are increased, and the drawing of ions is further strengthened while a strong protective film is formed on the film on the substrate W, and the etching of the film on the substrate W can be promoted. As a result, the etching of the etched film can be advanced while suppressing the spread of the opening hole of the mask film. In addition, during the third period T3, the power levels of the first RF signal (HF) and the second RF signal (RF) are adjusted, and thus a balance between the action of formation of the protective film and the etching action by ions can be adjusted. During the fourth period T4 in each cycle, the third RF signal (LF2) having a low frequency is supplied, and thus the ions can be strongly drawn in a state in which the ion flux is low and the ion energy is high. As a result, the perpendicularity of the ions with respect to the substrate W can be increased, and the etching of the etched film can be promoted. As a result, it is suppressed that the diameter of the bottom portion of the hole formed in the etched film is decreased, a part of the width of the hole in the etched film is narrowed, and the corner portion of the mask film is obliquely cut. Therefore, an etching shape is improved.
In the first embodiment, as illustrated in
In the first embodiment, as illustrated in
In the first embodiment, as illustrated in
In the first embodiment, the first period T1, the second period T2, the third period T3, and the fourth period T4 in each cycle may be continuously performed, or a period (OFF period) in which all of the first RF signal (HF), the second RF signal (LF), and the third RF signal (LF2) are stopped may be provided between the first period T1 and the second period T2, between the second period T2 and the third period T3, and between the third period T3 and the fourth period T4. The first RF signal (HF) may be supplied to the lower electrode instead of the upper electrode.
In the first embodiment, as illustrated in
The voltage pulse generator 300 is configured to be electrically connected to the lower electrode and to generate the voltage pulse signal. The generated voltage pulse signal is applied to the lower electrode. As illustrated in
In an embodiment, the first voltage level V1 has the zero voltage level. In an embodiment, the sequence of the voltage pulses has a pulse frequency in a range of 300 kHz to 600 kHz. An absolute value of the second voltage level V2 may be larger than an absolute value of the first voltage level V1. In an embodiment, the second voltage level V2 has a negative polarity. The supply and the power level of the first RF signal (HF) and the second RF signal (LF) may be the same as those in the first embodiment illustrated in
During the fourth period T4 in an embodiment, since the voltage pulse signal (DC) is applied, the ion energy is increased on the substrate W in the plasma processing space 10s as compared with the first period T1, the second period T2, and the third period T3. As a result, during the fourth period T4, the ions are strongly drawn to the substrate W side, and the etched film EF is etched. In this case, the ions are drawn perpendicularly to the substrate W, and the ions reach a bottom portion of a hole of the etched film EF, and a hole diameter of the bottom portion is secured. In addition, it is suppressed that a corner portion of the mask film MF is obliquely cut, and a side wall of the mask film MF or the etched film EF is swollen. The present aspect in which the voltage pulse signal (DC) is applied by the voltage pulse generator 300 may be applied to all the first embodiment illustrated in
As illustrated in
In an embodiment, the first RF power supply 400 is electrically connected to the upper electrode and is configured to generate the first RF signal (RF signal of a MHz band). The generated first RF signal is supplied to the upper electrode. In an embodiment, the first RF signal has a frequency in a range of 40 MHz to 150 MHz. In an embodiment, the first RF signal may have a frequency in a range of 80 MHz to 120 MHz.
As illustrated in
In an embodiment, the first RF signal (HF) has the first power level P1 during the first period T1 in each cycle, has the second power level P2 during the second period T2 in each cycle, has the third power level P3 during the third period T3 in each cycle, and has the fourth power level P4 during the fourth period T4 in each cycle. In an embodiment, the first power level P1 and the third power level P3 may be greater than the zero power level, and the first period T1 and the third period T3 may be in a state (ON state) in which the first RF signal (HF) is supplied to the upper electrode. The second power level P2 may be less than the first power level P1, and the third power level P3 may be greater than the second power level P2. In an embodiment, the fourth power level P4 may be the zero power level, and the fourth period T4 may be in a state (OFF state) in which the first RF signal (HF) is not supplied to the upper electrode. The third power level P3 may be the same as or less than the first power level P1.
In an embodiment, as illustrated in
In an embodiment, as illustrated in
In an embodiment, during the first period T1 in the plasma processing, as illustrated in
In an embodiment, during the second period T2 in the plasma processing, as illustrated in
In an embodiment, during the third period T3 in the plasma processing, as illustrated in
In an embodiment, during the fourth period T4 in the plasma processing, as illustrated in
According to the present exemplary embodiment, the plasma processing apparatus 1 has the first RF power supply 400 that supplies the first RF signal (HF) having the RF frequency of MHz band to the upper electrode, and the second RF power supply 401 that supplies the second RF signal (LF2) having the RF frequency of kHz band to the lower electrode. The first RF signal (HF) has the first power level P1 during the first period T1 in each cycle, has the second power level P2 less than the first power level P1 during the second period T2 in each cycle, has the third power level P3 greater than the second power level P2 during the third period T3 in each cycle, and has the fourth power level P4 of the zero power level during the fourth period T4 in each cycle. The second RF signal (LF2) has the fifth power level P5 having the zero power level during the first period T1 in each cycle, has the sixth power level P6 during the second period T2 in each cycle, has the seventh power level P7 having the zero power level during the third period T3 in each cycle, and has the eighth power level P8 equal to or larger than the sixth power level P6 during the fourth period T4 in each cycle. Accordingly, in each of the periods T1 to T4 in each cycle, the RF signals having two frequencies of the MHz band and the kHz band can be supplied at a predetermined power level, and thus the ion energy and the ion flux of the generated plasma can be independently controlled, respectively. As a result, it is possible to improve the controllability of plasma formed on the substrate.
In the second embodiment, the second power level P2 and the sixth power level P6 may be the zero power level. In the second embodiment, the first period T1, the second period T2, the third period T3, and the fourth period T4 in each cycle may be continuously performed, or a period (OFF period) in which all of the first RF signal (HF) and the second RF signal (LF2) are stopped may be provided between the first period T1 and the second period T2, between the second period T2 and the third period T3, and between the third period T3 and the fourth period T4. The first RF signal (HF) may be supplied to the lower electrode instead of the upper electrode.
In the second embodiment, as illustrated in
The voltage pulse generator 500 is electrically connected to the lower electrode and is configured to generate the voltage pulse signal. The generated voltage pulse signal is applied to the lower electrode. As illustrated in
In an embodiment, the first voltage level V1 has the zero voltage level. In an embodiment, the sequence of the voltage pulses having the second voltage level V2 has a pulse frequency in a range of 300 kHz to 600 kHz. An absolute value of the second voltage level V2 may be larger than an absolute value of the first voltage level V1. In an embodiment, the sequence of the voltage pulses having the third voltage level V3 has a pulse frequency in a range of 300 kHz to 600 KHz. The absolute value of the third voltage level V3 may be larger than the absolute value of the second voltage level V2. In an embodiment, the second voltage level V2 and the third voltage level V3 have the negative polarity. The supply of the first RF signal (HF) and the power level may be the same as those in the second embodiment illustrated in
During the second period T2 in an embodiment, since the voltage pulse signal (DC) having the second voltage level V2 is applied to the lower electrode, the ion energy is increased as compared with during the first period T1 on the substrate W in the plasma processing space 10s. As a result, during the second period T2, ions are drawn to the substrate W side. As a result, the protective film PF is formed, and the etched film EF is etched. In an embodiment, the higher the absolute value of the second voltage level V2, the more the etching of the etched film EF is promoted.
During the fourth period T4 in an embodiment, since the voltage pulse signal (DC) having the second voltage level V2 or the third voltage level V3 is applied to the lower electrode, the ion energy is increased as compared with the first period T1 and the third period T3 on the substrate W in the plasma processing space 10s. As a result, during the fourth period T4, the ions are strongly drawn to the substrate W side, and the etched film EF is etched. In this case, the ions are drawn perpendicularly to the substrate W, and the ions reach a bottom portion of a hole of the etched film EF, and a hole diameter of the bottom portion is secured. In addition, it is suppressed that a corner portion of the mask film MF is obliquely cut, and a side wall of the mask film MF or the etched film EF is swollen. In an embodiment, the larger the absolute value of the second voltage level V2 or the third voltage level V3, the more the etching of the etched film EF is promoted.
For example, in the embodiments described above, while the capacitively coupled plasma apparatus is illustratively described, the present disclosure is not limited thereto, and may be applied to other plasma apparatuses. For example, an inductively coupled plasma apparatus may be used instead of the capacitively coupled plasma apparatus. In this case, the inductively coupled plasma apparatus includes an antenna and a lower electrode. The lower electrode is disposed in the substrate support, and the antenna is disposed above the upper portion of or above the chamber. In an embodiment, the first RF power supply 200 is electrically connected to the antenna, and the second RF power supply 201 and the third RF power supply 202 are electrically connected to the lower electrode. The voltage pulse generator 300 may be applied instead of the third RF power supply 202. In addition, in an embodiment, the first RF power supply 400 is electrically connected to the antenna, and the second RF power supply 401 is electrically connected to the lower electrode. The voltage pulse generator 500 may be applied instead of the second RF power supply 401. In this way, the first RF power supplies 200 and 400 are electrically connected to the upper electrode of the capacitively coupled plasma apparatus or the antenna of the inductively coupled plasma apparatus. That is, the first RF power supplies 200 and 400 are coupled to the plasma processing chamber 10.
The embodiments of the present disclosure further include the following aspects.
A plasma processing apparatus including:
The plasma processing apparatus according to Addendum 1, in which
The plasma processing apparatus according to Addendum 1, in which
The plasma processing apparatus according to Addendum 1, in which
The plasma processing apparatus according to any one of Addenda 1 to 4, in which
The plasma processing apparatus according to any one of Addenda 1 to 5, in which the third RF frequency is in a range of 300 kHz to 600 KHz.
A plasma processing apparatus including:
The plasma processing apparatus according to Addendum 7, in which
The plasma processing apparatus according to Addendum 7, in which
The plasma processing apparatus according to Addendum 7, in which
The plasma processing apparatus according to any one of Addenda 7 to 10, in which the second voltage level has a negative polarity.
The plasma processing apparatus according to any one of Addenda 7 to 11, in which the first voltage level has a zero voltage level.
The plasma processing apparatus according to any one of Addenda 7 to 12, in which the sequence of the voltage pulses has a pulse frequency in a range of 300 kHz to 600 kHz.
The plasma processing apparatus according to Addendum 14, in which the second RF signal has an RF frequency in a range of 300 kHz to 600 KHz.
A plasma processing apparatus including:
A power supply system for use in a plasma processing apparatus, including:
A power supply system for use in a plasma processing apparatus, including:
A power supply system for use in a plasma processing apparatus, including:
A power supply system for use in a plasma processing apparatus, including:
Each of the above-described embodiments is described for the purpose of description, and is not intended to limit the scope of the present disclosure. Each of the above embodiments may be modified in various ways without departing from the scope and purpose of the present disclosure. For example, some configuration elements in one embodiment can be added to other embodiments. In addition, some configuration elements in one embodiment can be replaced with corresponding configuration elements in another embodiment.
According to one exemplary embodiment of the present disclosure, it is possible to provide a technique for improving the controllability of plasma formed on a substrate.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-156980 | Sep 2022 | JP | national |
This application is a bypass continuation application of international application No. PCT/JP2023/032799 having an international filing date of Sep. 8, 2023 and designating the United States, the international application being based upon and claiming the benefit of priority from Japanese Patent Application No. 2022-156980, filed on Sep. 29, 2022, the entire contents of each are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2023/032799 | Sep 2023 | WO |
| Child | 19093832 | US |
