JP2023027754A - Plasma processing apparatus and etching method - Google Patents

Abstract

To appropriately control the incident angle of ions in plasma with respect to an edge area of a substrate in plasma processing.SOLUTION: A plasma processing apparatus comprises: a substrate support that includes a lower electrode, an electrostatic chuck, and an edge ring; a drive device that moves the edge ring in the vertical direction; an upper electrode that is arranged above the substrate support; a source RF power supply that supplies source RF power to the upper electrode or the lower electrode; a bias RF power supply that supplies bias RF power to the lower electrode; at least one conductor that is in contact with the edge ring; a DC power supply that applies DC voltage having a negative polarity to the edge ring through the at least one conductor; an RF filter that is electrically connected between the at least one conductor and the DC power supply and includes at least one variable passive element; and a control unit that controls the drive device and the at least one variable passive element to adjust the incident angle of ions in plasma with respect to an edge area of a substrate.SELECTED DRAWING: Figure 16

Description

The present disclosure relates to a plasma processing apparatus and an etching method.

US Pat. No. 5,900,000 discloses a system for controlling ion flux directionality at the edge region in a plasma chamber. The system includes an RF generator configured to generate an RF signal, an impedance matching circuit for receiving the RF signal and generating a modified RF signal, and a plasma chamber. The plasma chamber includes an edge ring and a coupling ring that receives the modified RF signal. The coupling ring includes electrodes that receive the modified RF signal and electrodes that create capacitance with the edge ring to control the directionality of the ion flux.

JP 2017-228526 A

The technique according to the present disclosure appropriately controls the incident angle of ions in the plasma with respect to the edge region of the substrate in plasma processing.

A plasma processing apparatus according to one aspect of the present disclosure includes a plasma processing chamber and a substrate support arranged in the plasma processing chamber, wherein the substrate support includes a lower electrode, an electrostatic chuck, and the electrostatic chuck. a substrate support including an edge ring arranged to surround a substrate resting thereon; a drive configured to move the edge ring longitudinally; a top electrode disposed; a source RF power supply configured to supply source RF power to the top electrode or the bottom electrode to generate a plasma from gases in the plasma processing chamber; a bias RF power source configured to supply a bottom electrode; at least one conductor in contact with the edge ring; and configured to apply a negative DC voltage to the edge ring via the at least one conductor. an RF filter electrically connected between the at least one conductor and the DC power source and including at least one variable passive component; the driver and the at least one a controller configured to control a variable passive element to adjust the angle of incidence of ions in the plasma with respect to an edge region of a substrate placed on the electrostatic chuck.

According to the present disclosure, it is possible to appropriately control the incident angle of ions in the plasma with respect to the edge region of the substrate in plasma processing.

1 is a longitudinal sectional view showing the outline of the configuration of an etching apparatus according to this embodiment; FIG. FIG. 2 is a vertical cross-sectional view showing the outline of the configuration around the edge ring according to the present embodiment; FIG. 2 is a vertical cross-sectional view showing the outline of the configuration around the edge ring according to the present embodiment; FIG. 10 is an explanatory view showing changes in the shape of the sheath and tilting of the incident direction of ions due to wear of the edge ring; FIG. 10 is an explanatory view showing changes in the shape of the sheath and tilting of the incident direction of ions due to wear of the edge ring; FIG. 10 is an explanatory diagram showing changes in the shape of the sheath and occurrence of inclination of the incident direction of ions; FIG. 10 is an explanatory diagram showing changes in the shape of the sheath and occurrence of inclination of the incident direction of ions; FIG. 4 is an explanatory diagram showing an example of a tilt angle control method; FIG. 4 is an explanatory diagram showing an example of a tilt angle control method; FIG. 4 is an explanatory diagram showing an example of a tilt angle control method; FIG. 4 is an explanatory diagram showing an example of a tilt angle control method; FIG. 10 is a vertical cross-sectional view showing an outline of a configuration around an edge ring according to another embodiment; FIG. 4 is a vertical cross-sectional view showing an example of the configuration of a connecting portion; FIG. 4 is a vertical cross-sectional view showing an example of the configuration of a connecting portion; FIG. 4 is a vertical cross-sectional view showing an example of the configuration of a connecting portion; FIG. 4 is a vertical cross-sectional view showing an example of the configuration of a connecting portion; FIG. 4 is a vertical cross-sectional view showing an example of the configuration of a connecting portion; FIG. 4 is a vertical cross-sectional view showing an example of the configuration of a connecting portion; FIG. 4 is a vertical cross-sectional view showing an example of the configuration of a connecting portion; FIG. 4 is a vertical cross-sectional view showing an example of the configuration of a connecting portion; FIG. 4 is a vertical cross-sectional view showing an example of the configuration of a connecting portion; FIG. 4 is a vertical cross-sectional view showing an example of the configuration of a connecting portion; FIG. 4 is a vertical cross-sectional view showing an example of the configuration of a connecting portion; FIG. 4 is a vertical cross-sectional view showing an example of the configuration of a connecting portion; FIG. 4 is a vertical cross-sectional view showing an example of the configuration of a connecting portion; FIG. 4 is a plan view showing an example of a configuration of a connecting portion; FIG. 4 is a plan view showing an example of a configuration of a connecting portion; FIG. 4 is a plan view showing an example of a configuration of a connecting portion; FIG. 4 is an explanatory diagram schematically showing an example of a configuration of a connecting portion and a variable passive element; FIG. 4 is an explanatory diagram schematically showing an example of a configuration of a connecting portion and a variable passive element; FIG. 4 is an explanatory diagram schematically showing an example of a configuration of a connecting portion and a variable passive element; It is a longitudinal cross-sectional view which shows an example of a structure of a connection part and a drive device. It is a longitudinal cross-sectional view which shows an example of a structure of a connection part and a drive device. It is a longitudinal cross-sectional view which shows an example of a structure of a connection part and a drive device. It is a longitudinal cross-sectional view which shows an example of a structure of a connection part and a drive device. It is a longitudinal cross-sectional view which shows an example of a structure of a connection part and a drive device. It is a longitudinal cross-sectional view which shows an example of a structure of a connection part and a drive device. It is a longitudinal cross-sectional view which shows an example of a structure of a connection part and a drive device. It is a longitudinal cross-sectional view which shows an example of a structure of a connection part and a drive device. FIG. 10 is a vertical cross-sectional view showing an outline of a configuration around an edge ring according to another embodiment; FIG. 4 is an explanatory diagram showing an example of a tilt angle control method; FIG. 4 is an explanatory diagram showing an example of a tilt angle control method;

2. Description of the Related Art In a semiconductor device manufacturing process, a semiconductor wafer (hereinafter referred to as “wafer”) is subjected to plasma processing such as etching. In plasma processing, plasma is generated by exciting a processing gas, and the wafer is processed with the plasma.

Plasma processing is performed in a plasma processing apparatus. A plasma processing apparatus generally includes a chamber, a stage, and a radio frequency (RF) power supply. In one example, the radio frequency power supply comprises a first radio frequency power supply and a second radio frequency power supply. A first RF power supply provides first RF power to generate a plasma of the gas within the chamber. A second RF power supply supplies second RF power for biasing to the lower electrode to attract ions into the wafer. A stage is provided within the chamber. The stage has a lower electrode and an electrostatic chuck. In one example, an edge ring is arranged on the electrostatic chuck so as to surround the wafer placed on the electrostatic chuck. The edge ring is provided to improve plasma processing uniformity on the wafer.

The edge ring wears and the thickness of the edge ring decreases over time as the plasma treatment is performed. The reduced thickness of the edge ring changes the shape of the sheath above the edge ring and the edge region of the wafer. When the shape of the sheath changes in this way, the incident direction of ions in the edge region of the wafer is inclined with respect to the vertical direction. As a result, the recess formed in the edge region of the wafer is inclined with respect to the thickness direction of the wafer.

In order to form a concave portion extending in the thickness direction of the wafer in the edge region of the wafer, it is necessary to adjust the inclination of the incident direction of ions to the edge region of the wafer. Therefore, in order to control the incident direction of ions (ion flux directionality) to the edge region, a capacitance can be generated between the electrode of the coupling ring and the edge ring, as described in Patent Document 1, for example. Proposed.

However, even if an attempt is made to control the incident angle only by generating the above capacitance, the control range may be limited. In addition, it is desirable to suppress the replacement frequency of the edge ring due to wear, but there are cases where the incident angle of ions cannot be sufficiently controlled only by the generation of the above capacitance, and in such a case, the replacement frequency of the edge ring cannot be improved. .

The technique according to the present disclosure appropriately controls the tilt angle by making ions perpendicularly incident on the edge region of the substrate during etching.

Hereinafter, an etching apparatus and an etching method as a plasma processing apparatus according to this embodiment will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description.

<Etching device>
First, an etching apparatus according to this embodiment will be described. FIG. 1 is a vertical sectional view showing the outline of the structure of the etching apparatus 1. As shown in FIG. 2A and 2B are vertical cross-sectional views schematically showing the configuration around the edge ring. The etching apparatus 1 is a capacitive coupling type etching apparatus. The etching apparatus 1 etches a wafer W as a substrate.

As shown in FIG. 1, the etching apparatus 1 has a chamber 10 as a substantially cylindrical plasma processing chamber. Chamber 10 defines a processing space S within which a plasma is generated. The chamber 10 is made of aluminum, for example. Chamber 10 is connected to ground potential.

A stage 11 as a substrate support on which the wafer W is placed is housed inside the chamber 10 . The stage 11 has a lower electrode 12 , an electrostatic chuck 13 and an edge ring 14 . An electrode plate (not shown) made of, for example, aluminum may be provided on the lower surface side of the lower electrode 12 .

The lower electrode 12 is made of a conductive material such as a metal such as aluminum, and has a substantially disk shape.

Note that the stage 11 may include a temperature control module configured to control at least one of the electrostatic chuck 13, the edge ring 14, and the wafer W to a desired temperature. The temperature control module may include heaters, channels, or a combination thereof. A temperature control medium such as a refrigerant or a heat transfer gas flows through the flow path.

In one example, a channel 15 a is formed inside the lower electrode 12 . A temperature control medium is supplied to the flow path 15a from a chiller unit (not shown) provided outside the chamber 10 through an inlet pipe 15b. The temperature control medium supplied to the channel 15a returns to the chiller unit through the outlet channel 15c. The electrostatic chuck 13, the edge ring 14, and the wafer W can be cooled to a desired temperature by circulating a temperature control medium such as cooling water in the flow path 15a.

The electrostatic chuck 13 is provided on the lower electrode 12 . In one example, the electrostatic chuck 13 is a member that can attract and hold both the wafer W and the edge ring 14 by electrostatic force. The electrostatic chuck 13 is formed such that the upper surface of the central portion is higher than the upper surface of the peripheral portion. The upper surface of the central portion of the electrostatic chuck 13 serves as a wafer mounting surface on which the wafer W is mounted. In one example, the upper surface of the peripheral portion of the electrostatic chuck 13 serves as an edge ring mounting surface on which the edge ring 14 is mounted. face.

In one example, a first electrode 16 a for attracting and holding the wafer W is provided in the central portion inside the electrostatic chuck 13 . A second electrode 16 b for attracting and holding the edge ring 14 is provided at the peripheral portion inside the electrostatic chuck 13 . The electrostatic chuck 13 has a configuration in which electrodes 16a and 16b are sandwiched between insulating materials made of an insulating material.

A DC voltage from a DC power source (not shown) is applied to the first electrode 16a. The wafer W is attracted and held on the upper surface of the central portion of the electrostatic chuck 13 by the electrostatic force generated thereby. Similarly, a DC voltage from a DC power supply (not shown) is applied to the second electrode 16b. In one example, the edge ring 14 is attracted and held on the upper surface of the peripheral portion of the electrostatic chuck 13 by the electrostatic force generated thereby.

In this embodiment, the central portion of the electrostatic chuck 13 where the first electrode 16a is provided and the peripheral portion where the second electrode 16b is provided are integrated. may be separate. Both the first electrode 16a and the second electrode 16b may be monopolar or bipolar.

In the present embodiment, the edge ring 14 is electrostatically attracted to the electrostatic chuck 13 by applying a DC voltage to the second electrode 16b, but the method for holding the edge ring 14 is not limited to this. For example, the edge ring 14 may be held by suction using a suction sheet, or the edge ring 14 may be clamped and held. Alternatively, the edge ring 14 may be held by its own weight.

The edge ring 14 is an annular member arranged so as to surround the wafer W placed on the upper surface of the central portion of the electrostatic chuck 13 . The edge ring 14 is provided to improve etch uniformity. For this reason, the edge ring 14 is made of a material appropriately selected according to etching, has conductivity, and can be made of Si or SiC, for example.

The stage 11 configured as described above is fastened to a substantially cylindrical support member 17 provided at the bottom of the chamber 10 . The support member 17 is made of an insulator such as ceramic or quartz.

A shower head 20 is provided above the stage 11 so as to face the stage 11 . The shower head 20 has an electrode plate 21 arranged facing the processing space S and an electrode support 22 provided above the electrode plate 21 . The electrode plate 21 functions as the lower electrode 12 and a pair of upper electrodes. When the first high-frequency power supply 50 is electrically coupled to the lower electrode 12 as will be described later, the showerhead 20 is connected to ground potential. The shower head 20 is supported on the top (ceiling surface) of the chamber 10 via an insulating shielding member 23 .

The electrode plate 21 is formed with a plurality of gas ejection ports 21a for supplying the processing space S with a processing gas sent from a gas diffusion chamber 22a, which will be described later. The electrode plate 21 is made of, for example, a conductor or semiconductor that generates little Joule heat and has low electrical resistivity.

The electrode support 22 detachably supports the electrode plate 21 . The electrode support 22 has a structure in which a plasma-resistant film is formed on the surface of a conductive material such as aluminum. This membrane can be an anodized membrane or a ceramic membrane such as yttrium oxide. A gas diffusion chamber 22 a is formed inside the electrode support 22 . A plurality of gas flow holes 22b are formed from the gas diffusion chamber 22a to communicate with the gas ejection port 21a. A gas introduction hole 22c connected to a gas supply pipe 33, which will be described later, is formed in the gas diffusion chamber 22a.

A gas supply source group 30 for supplying a processing gas to the gas diffusion chamber 22a is connected to the electrode support 22 via a flow control device group 31, a valve group 32, a gas supply pipe 33, and a gas introduction hole 22c. It is

The gas supply source group 30 has a plurality of types of gas supply sources necessary for etching. The flow control device group 31 includes a plurality of flow controllers, and the valve group 32 includes a plurality of valves. Each of the plurality of flow controllers of the flow controller group 31 is a mass flow controller or a pressure-controlled flow controller. In the etching apparatus 1, processing gas from one or more gas supply sources selected from the gas supply source group 30 is supplied through the flow control device group 31, the valve group 32, the gas supply pipe 33, and the gas introduction hole 22c. It is supplied to the gas diffusion chamber 22a. The processing gas supplied to the gas diffusion chamber 22a is dispersed in the processing space S in the form of a shower through the gas flow hole 22b and the gas ejection port 21a.

A baffle plate 40 is provided at the bottom of the chamber 10 and between the inner wall of the chamber 10 and the support member 17 . The baffle plate 40 is made of, for example, an aluminum material coated with ceramics such as yttrium oxide. A plurality of through holes are formed in the baffle plate 40 . The processing space S communicates with an exhaust port 41 through the baffle plate 40 . An exhaust device 42 such as a vacuum pump, for example, is connected to the exhaust port 41 so that the inside of the processing space S can be depressurized by the exhaust device 42 .

A loading/unloading port 43 for the wafer W is formed in the side wall of the chamber 10 , and the loading/unloading port 43 can be opened and closed by a gate valve 44 .

As shown in FIGS. 1 and 2, the etching apparatus 1 further has a first high frequency power supply 50 as a source RF power supply, a second high frequency power supply 51 as a bias RF power supply, and a matching box 52 . A first high frequency power supply 50 and a second high frequency power supply 51 are coupled to the lower electrode 12 via a matching box 52 .

The first high-frequency power supply 50 generates high-frequency power HF, which is source RF power for plasma generation, and supplies the high-frequency power HF to the lower electrode 12 . The high frequency power HF may have a frequency in the range of 27 MHz to 100 MHz, and in one example is 40 MHz. A first high frequency power supply 50 is coupled to the lower electrode 12 via a first matching circuit 53 of a matching box 52 . The first matching circuit 53 is a circuit for matching the output impedance of the first high-frequency power supply 50 and the input impedance on the load side (lower electrode 12 side). Note that the first high-frequency power supply 50 may not be electrically coupled to the lower electrode 12 , and may be coupled to the showerhead 20 , which is the upper electrode, via the first matching circuit 53 . Further, instead of the first high-frequency power supply 50, a pulse power supply configured to apply a pulse voltage other than high-frequency power to the lower electrode 12 may be used. This pulse power source is the same as the pulse power source used in place of the second high-frequency power source 51, which will be described later.

The second high-frequency power supply 51 generates high-frequency power LF, which is bias RF power for drawing ions into the wafer W, and supplies the high-frequency power LF to the lower electrode 12 . The high frequency power LF may have a frequency in the range of 400 kHz to 13.56 MHz, and in one example is 400 kHz. A second high-frequency power supply 51 is coupled to the lower electrode 12 via a second matching circuit 54 of a matching box 52 . The second matching circuit 54 is a circuit for matching the output impedance of the second high-frequency power supply 51 and the input impedance on the load side (lower electrode 12 side). A pulse power source configured to apply a pulse voltage other than high frequency power to the lower electrode 12 may be used instead of the second high frequency power source 51 . Here, the pulse voltage is a pulse-like voltage whose magnitude changes periodically. The pulse power supply may be a DC power supply. A pulsed power supply may be configured such that the power supply itself applies a pulsed voltage, or it may be configured with a device downstream to pulse the voltage. In one example, the pulse voltage is applied to the lower electrode 12 such that the wafer W has a negative potential. The pulse voltage may be square, triangular, impulse, or have other waveforms. The frequency of the pulse voltage (pulse frequency) may be within the range of 100 kHz to 2 MHz. The high-frequency power LF or pulse voltage may be supplied or applied to a bias electrode provided inside the electrostatic chuck 13 .

The etching apparatus 1 further has a first variable passive element 60 and a second variable passive element 61 . The first variable passive element 60 and the second variable passive element 61 are arranged in this order from the edge ring 14 side. The second variable passive element 61 is connected to ground potential. That is, the second variable passive element 61 is not connected to each of the first high frequency power supply 50 and the second high frequency power supply 51 .

In one example, at least one of the first variable passive element 60 and the second variable passive element 61 is configured to have variable impedance. The first variable passive element 60 and the second variable passive element 61 may be, for example, either coils (inductors) or capacitors (capacitors). In addition, the same function can be achieved with any variable impedance element such as a diode, not limited to a coil or a capacitor. The number and positions of the first variable passive element 60 and the second variable passive element 61 can also be appropriately designed by those skilled in the art. Furthermore, the element itself does not need to be variable. For example, a plurality of elements having fixed impedance values may be provided, and a switching circuit may be used to switch the combination of the fixed value elements to vary the impedance. The circuit configurations of the first variable passive element 60 and the second variable passive element 61 can be appropriately designed by those skilled in the art.

As shown in FIGS. 1, 2A and 2B, the etching apparatus 1 further comprises a driving device 70 for vertically moving the edge ring 14 . The drive device 70 has a lifter pin 71 that supports the edge ring 14 and moves in the vertical direction, and a drive source 72 that moves the lifter pin 71 in the vertical direction.

The lifter pins 71 extend vertically from the bottom surface of the edge ring 14 and penetrate through the electrostatic chuck 13 , the lower electrode 12 , the support member 17 and the bottom of the chamber 10 . A seal is provided between the lifter pin 71 and the chamber 10 to seal the interior of the chamber 10 . At least the surface of the lifter pin 71 may be made of an insulating material.

The drive source 72 is provided outside the chamber 10 . The drive source 72 incorporates, for example, a motor, and moves the lifter pins 71 in the vertical direction. That is, the driving device 70 moves the edge ring 14 vertically between a state where it is placed on the electrostatic chuck 13 as shown in FIG. 2A and a state where it is separated from the electrostatic chuck 13 as shown in FIG. 2B. It is configured so that it can move freely.

A controller 100 is provided in the etching apparatus 1 described above. The control unit 100 is, for example, a computer having a CPU, memory, etc., and has a program storage unit (not shown). A program for controlling etching in the etching apparatus 1 is stored in the program storage unit. The program may be recorded in a computer-readable storage medium and installed in the control unit 100 from the storage medium. Moreover, the storage medium may be temporary or non-temporary.

<Etching method>
Next, etching performed using the etching apparatus 1 configured as described above will be described.

First, the wafer W is loaded into the chamber 10 and placed on the electrostatic chuck 13 . Thereafter, by applying a DC voltage to the first electrode 16a of the electrostatic chuck 13, the wafer W is electrostatically attracted to and held by the electrostatic chuck 13 by Coulomb force. After loading the wafer W, the inside of the chamber 10 is depressurized to a desired degree of vacuum by the exhaust device 42 .

Next, a processing gas is supplied from the gas supply source group 30 to the processing space S through the showerhead 20 . Further, the first high-frequency power source 50 supplies high-frequency power HF for plasma generation to the lower electrode 12 to excite the processing gas and generate plasma. At this time, the high-frequency power LF for attracting ions may be supplied from the second high-frequency power supply 51 . Then, the wafer W is etched by the action of the generated plasma.

When finishing the etching, first, the supply of the high frequency power HF from the first high frequency power supply 50 and the supply of the processing gas from the gas supply source group 30 are stopped. Further, when the high-frequency power LF is being supplied during etching, the supply of the high-frequency power LF is also stopped. Next, the supply of the heat transfer gas to the back surface of the wafer W is stopped, and the electrostatic chuck 13 stops holding the wafer W by attraction.

After that, the wafer W is unloaded from the chamber 10, and a series of etchings for the wafer W is completed.

In etching, plasma may be generated by using only the high frequency power LF from the second high frequency power supply 51 without using the high frequency power HF from the first high frequency power supply 50 .

<Tilt angle control method>
Next, a method for controlling the tilt angle in the etching described above will be described. The tilt angle is the inclination (angle) of the recess formed by etching in the edge region of the wafer W with respect to the thickness direction of the wafer W. FIG. The tilt angle is substantially the same as the inclination of the incident direction of ions to the edge region of the wafer W with respect to the vertical direction (incident angle of ions). In the following description, the radially inner side (center side) with respect to the thickness direction (longitudinal direction) of the wafer W is referred to as the inner side, and the radially outer direction with respect to the thickness direction of the wafer W is referred to as the outer side. It says.

3A and 3B are explanatory diagrams showing changes in the shape of the sheath and occurrence of inclination of the incident direction of ions due to consumption of the edge ring. The edge ring 14 shown in solid lines in FIG. 3A shows the edge ring 14 in its unworn state. The edge ring 14 indicated by a dotted line indicates the edge ring 14 whose thickness has decreased due to wear. Further, the sheath SH indicated by a solid line in FIG. 3A represents the shape of the sheath SH when the edge ring 14 is in a non-consumed state. A sheath SH indicated by a dotted line represents the shape of the sheath SH when the edge ring 14 is in a worn state. Further, the arrows in FIG. 3A indicate the incident direction of the ions when the edge ring 14 is in a worn state.

In one example, as shown in FIG. 3A, the shape of the sheath SH remains flat above the wafer W and the edge ring 14 when the edge ring 14 is in a non-consumed condition. Therefore, the ions are incident on the entire surface of the wafer W in a substantially vertical direction (longitudinal direction). Therefore, the tilt angle is 0 (zero) degrees.

On the other hand, when the edge ring 14 is worn and its thickness is reduced, the thickness of the sheath SH is reduced in the edge region of the wafer W and above the edge ring 14, and the shape of the sheath SH changes into a downward convex shape. As a result, the incident direction of ions with respect to the edge region of the wafer W is inclined with respect to the vertical direction. In the following description, a phenomenon in which a concave portion formed by etching is inclined toward the inner side when the incident direction of ions is inclined radially inward (toward the center) with respect to the vertical direction is referred to as inner tilt. In FIG. 3B, the incident direction of ions is inclined toward the inner side by an angle θ1, and the concave portion is also inclined toward the inner side by θ1. The cause of inner tilt is not limited to wear of the edge ring 14 described above. For example, when the bias voltage generated in the edge ring 14 is lower than the voltage on the wafer W side, the inner tilt occurs in the initial state. Further, for example, the initial state of the edge ring 14 may be intentionally adjusted to be inner tilt, and the tilt angle may be corrected by adjusting the driving amount of the driving device 70, which will be described later.

4A and 4B, the thickness of the sheath SH is greater in the edge region of the wafer W and above the edge ring 14 than in the central region of the wafer W, and the shape of the sheath SH is upwardly convex. It may become For example, when the bias voltage generated in the edge ring 14 is high, the shape of the sheath SH may be upwardly convex. Arrows in FIG. 4A indicate incident directions of ions. In the following description, a phenomenon in which a concave portion formed by etching is inclined to the outer side when the incident direction of ions is inclined radially outward with respect to the vertical direction is referred to as outer tilt. In FIG. 4B, the incident direction of ions is inclined toward the outer side by an angle of θ2, and the concave portion is also inclined toward the outer side by an angle of θ2.

The tilt angle is controlled in the etching apparatus 1 of the present embodiment. Specifically, the tilt angle is controlled by adjusting at least the drive amount of the drive source 72 of the drive device 70 (the drive amount of the edge ring 14) or the impedance of the second variable passive element 61 to control the ion incident angle. It is done by controlling. In the following embodiment, the case of adjusting the impedance of the second variable passive element 61 will be described, but the impedance of the first variable passive element 60 may be adjusted, or the impedance of the variable passive elements 60 and 61 may be adjusted. Both impedances may be adjusted.

[Adjustment of drive amount]
First, the case of adjusting the driving amount of the driving device 70 will be described. FIG. 5 is an explanatory diagram showing the relationship between the driving amount of the driving device 70 and the correction angle of the tilt angle (hereinafter referred to as "tilt correction angle"). The vertical axis in FIG. 5 indicates the tilt correction angle, and the horizontal axis indicates the driving amount of the driving device 70 . As shown in FIG. 5, the tilt correction angle increases as the driving amount of the driving device 70 increases.

The control unit 100, for example, uses a predetermined function or table to determine the wear amount of the edge ring 14 (the amount of decrease from the initial value of the thickness of the edge ring 14) estimated from the etching process conditions (for example, processing time). , to set the driving amount of the driving device 70 . That is, the control unit 100 determines the driving amount of the driving device 70 by inputting the wear amount of the edge ring 14 to the function or referring to the table using the wear amount of the edge ring 14 .

The amount of consumption of the edge ring 14 is the etching time of the wafer W, the number of processed wafers W, the thickness of the edge ring 14 measured by the measuring instrument, the change in the mass of the edge ring 14 measured by the measuring instrument, and the thickness of the edge ring 14 measured by the measuring instrument. changes in the electrical properties around the edge ring 14 (e.g., voltage and current values at any point around the edge ring 14) measured by a measuring instrument, or the electrical properties of the edge ring 14 measured by a measuring instrument (e.g., edge It may be estimated based on a change in the resistance value of the ring 14 or the like. Further, the driving amount of the driving device 70 may be increased according to the etching time of the wafer W or the number of wafers W to be processed, regardless of the consumption amount of the edge ring 14 . Further, the driving amount of the driving device 70 may be increased according to the etching time of the wafer W weighted by the high-frequency power and the number of wafers W to be processed.

A specific method for controlling the tilt angle by adjusting the driving amount of the driving device 70 as described above will be described. First, the edge ring 14 is placed on the electrostatic chuck 13 . At this time, for example, above the edge region of the wafer W and the edge ring 14, the sheath shape is flat and the tilt angle is 0 (zero) degrees.

Next, the wafer W is etched. As the etching is performed over time, the edge ring 14 is consumed and its thickness is reduced. Then, as shown in FIG. 3A, the thickness of the sheath SH is reduced above the edge region of the wafer W and the edge ring 14, and the tilt angle changes toward the inner side.

Therefore, the driving amount of the driving device 70 is adjusted. Specifically, the driving amount of the driving device 70 is increased according to the amount of wear of the edge ring 14 to raise the edge ring 14 . As a result, the tilt correction angle increases as shown in FIG. 5, and the tilt angle inclined toward the inner side can be changed toward the outer side. That is, the shape of the sheath above the edge ring 14 and the edge region of the wafer W is controlled, the inclination of the incident direction of ions to the edge region of the wafer W is reduced, and the tilt angle is controlled. Then, when the edge ring 14 is raised based on the driving amount set by the control unit 100 as described above, the tilt correction angle is adjusted to the target angle θ3, and the tilt angle is corrected to 0 (zero) degree. be able to. As a result, over the entire region of the wafer W, recesses substantially parallel to the thickness direction of the wafer W are formed.

[Impedance adjustment]
Next, the case of adjusting the impedance of the second variable passive element 61 will be described. FIG. 6 is an explanatory diagram showing the relationship between the impedance of the second variable passive element 61 and the tilt correction angle. The vertical axis in FIG. 6 indicates the tilt correction angle, and the horizontal axis indicates the impedance of the second variable passive element 61 . As shown in FIG. 6, increasing the impedance of the second variable passive element 61 increases the tilt correction angle. In the example shown in FIG. 6, the tilt correction angle is increased by increasing the impedance. It is also possible to The relationship between the impedance and the tilt correction angle depends on the design of the second variable passive element 61 and is not limited.

The control unit 100 sets the impedance of the second variable passive element 61 based on the wear amount of the edge ring 14 in the same manner as setting the drive amount of the drive device 70 described above. The control unit 100 changes the voltage generated in the edge ring 14 by changing the impedance of the second variable passive element 61 .

In the etching apparatus 1 , when the edge ring 14 is worn out, the second variable passive element 61 is controlled to the impedance set by the control section 100 . Thereby, the shape of the sheath above the edge ring 14 and the edge region of the wafer W is controlled, the inclination of the incident direction of ions to the edge region of the wafer W is reduced, and the tilt angle is controlled. Then, as shown in FIG. 6, the tilt correction angle can be adjusted to the target angle θ3 to set the tilt angle to 0 (zero) degree.

[Adjustment of driving amount and impedance]
Next, a case will be described in which the driving amount of the driving device 70 and the impedance of the second variable passive element 61 are combined and adjusted. FIG. 7 is an explanatory diagram showing the relationship between the drive amount of the drive device 70, the impedance of the second variable passive element 61, and the tilt correction angle. The vertical axis in FIG. 7 indicates the tilt correction angle, and the horizontal axis indicates the impedance of the second variable passive element 61 .

As shown in FIG. 7, first, the impedance of the second variable passive element 61 is adjusted to correct the tilt angle. Next, when the impedance reaches a predetermined value, for example, the upper limit value, the drive amount of the drive device 70 is adjusted, the tilt correction angle is adjusted to the target angle θ3, and the tilt angle is set to 0 (zero) degrees. . In this case, it is possible to reduce the number of times of impedance adjustment and drive amount adjustment, thereby simplifying the operation of tilt angle control.

Here, the resolution of the tilt angle correction by adjusting the impedance and the resolution of the tilt angle correction by adjusting the driving amount depend on the performance of the second variable passive element 61 and the driving device 70, respectively. The resolution of tilt angle correction is the amount of tilt angle correction in one adjustment of impedance or driving amount. Then, for example, when the resolution of the second variable passive element 61 is higher than the resolution of the driving device 70, in the present embodiment, the impedance of the second variable passive element 61 is adjusted to correct the tilt angle. resolution of tilt angle correction can be improved.

As described above, according to this embodiment, the adjustment range of the tilt angle can be increased by adjusting the impedance of the second variable passive element 61 and the driving amount of the driving device 70 . Therefore, the tilt angle can be appropriately controlled, that is, the incident direction of ions can be adjusted appropriately, so etching can be performed uniformly.

Further, when the tilt angle is controlled only by the impedance of the second variable passive element 61, for example, the edge ring 14 needs to be replaced when the impedance reaches the upper limit of the control range of the variable passive element 61. In this regard, in the present embodiment, the adjustment range of the tilt angle can be increased by adjusting the driving amount of the driving device 70 without exchanging the edge ring 14 . Therefore, the replacement interval of the edge ring 14 can be lengthened, and the replacement frequency can be suppressed.

Moreover, according to the present embodiment, it is possible to improve the resolution of tilt angle correction while simplifying the operation of tilt angle control. In addition, it is possible to increase variations in the operation of tilt angle control.

In the example shown in FIG. 7, the impedance adjustment and the drive amount adjustment are each performed once to adjust the tilt correction angle to the target angle θ3. It is not limited to this. For example, as shown in FIG. 8, the impedance adjustment and the drive amount adjustment may each be performed multiple times. Even in such a case, the same effects as in the present embodiment can be obtained.

In the examples shown in FIGS. 7 and 8, the impedance of the second variable passive element 61 is adjusted and then the driving amount of the driving device 70 is adjusted, but this order may be reversed. In such a case, first, the driving amount of the driving device 70 is adjusted to correct the tilt angle. At this time, if the driving amount of the driving device 70 is excessively increased, discharge occurs between the wafer W and the edge ring 14 . Therefore, the driving amount of the driving device 70 is limited. Therefore, next, when the driving amount reaches a predetermined value, for example, the upper limit value, the impedance of the second variable passive element 61 is adjusted, the tilt correction angle is adjusted to the target angle θ3, and the tilt angle is reduced to 0 ( zero) degrees. Even in such a case, the same effects as in the present embodiment can be obtained.

In the above embodiment, the impedance adjustment of the second variable passive element 61 and the driving amount of the driving device 70 are adjusted separately, but the impedance adjustment and the driving amount adjustment may be performed at the same time.

<Other embodiments>
As described above, the frequency of the high frequency power (bias RF power) LF supplied from the second high frequency power supply 51 is 400 kHz to 13.56 MHz, preferably 5 MHz or less. When etching the wafer W with a high aspect ratio, high ion energy is required to achieve a vertical shape of the pattern after etching. Therefore, as a result of intensive studies by the present inventors, it was found that by setting the frequency of the high-frequency power LF to 5 MHz or less, the ability of ions to follow changes in the high-frequency electric field is improved, and the controllability of ion energy is improved.

On the other hand, if the frequency of the high-frequency power LF is set to a low frequency of 5 MHz or less, the effect of making the impedance of the second variable passive element 61 variable may decrease. That is, the controllability of the tilt angle by adjusting the impedance of the second variable passive element 61 may deteriorate. For example, in FIGS. 2A and 2B, if the electrical connection between the edge ring 14 and the second variable passive element 61 is non-contact or capacitive coupling, even if the impedance of the second variable passive element 61 is adjusted, Tilt angle cannot be properly controlled. Therefore, in this embodiment, the edge ring 14 and the second variable passive element 61 are electrically connected directly.

The edge ring 14 and the second variable passive element 61 are directly electrically connected via the connecting portion. The edge ring 14 and the connecting portion are in contact and direct current is conducted through the connecting portion. An example of the structure of the connecting portion (hereinafter sometimes referred to as "contact structure") will be described below.

As shown in FIG. 9, the connecting portion 200 as a conductor has a conductive structure 201 and a conductive elastic member 202 . A conductive structure 201 connects the edge ring 14 and the second variable passive element 61 via a conductive elastic member 202 . Specifically, the conductive structure 201 has one end connected to the second variable passive element 61 and the other end exposed on the upper surface of the lower electrode 12 and in contact with the conductive elastic member 202 .

The conductive elastic member 202 is provided in a space formed between the edge ring 14 and the electrostatic chuck 13, for example. The conductive elastic member 202 contacts the conductive structure 201 and the lower surface of the edge ring 14 respectively. Also, the conductive elastic member 202 is made of a conductor such as metal. The configuration of the conductive elastic member 202 is not particularly limited, but an example is shown in each of FIGS. 10A to 10F. 10A to 10C are examples in which an elastic body is used as the conductive elastic member 202. FIG.

As shown in FIG. 10A, the conductive elastic member 202 may be a plate spring biased in the vertical direction. As shown in FIG. 10B, the conductive elastic member 202 may be a coil spring that is spirally wound and extends horizontally. As shown in FIG. 10C, the conductive elastic member 202 may be a spirally wound spring that extends in the vertical direction. These conductive elastic members 202 are elastic bodies, and elastic force acts in the vertical direction. Due to this elastic force, the conductive elastic member 202 is brought into close contact with the lower surfaces of the conductive structure 201 and the edge ring 14 with a desired contact pressure, and the conductive structure 201 and the edge ring 14 are electrically connected.

As shown in FIG. 10D, the conductive elastic member 202 may be a pin that is vertically moved by a drive mechanism (not shown). In this case, the conductive elastic member 202 is brought into close contact with the conductive structure 201 and the bottom surface of the edge ring 14 by lifting the conductive elastic member 202 . By adjusting the pressure applied when the conductive elastic member 202 moves in the vertical direction, the conductive elastic member 202 is brought into close contact with the conductive structure 201 and the lower surface of the edge ring 14 with a desired contact pressure.

A wire connecting the conductive structure 201 and the edge ring 14 may be used as the conductive elastic member 202 as shown in FIG. 10E. The wire is bonded at one end to the conductive structure 201 and at the other end to the bottom surface of the edge ring 14 . The bonding of this wire may be in ohmic contact with the conductive structure 201 or the underside of the edge ring 14, by way of example, the wire is welded or crimped. When a wire is used as the conductive elastic member 202 in this manner, the conductive elastic member 202 contacts the conductive structure 201 and the lower surface of the edge ring 14 respectively, and the conductive structure 201 and the edge ring 14 are electrically connected. connected to

10A to 10E, the edge ring 14 and the second variable passive element 61 can be electrically connected via the connecting portion 200 as shown in FIG. can be connected directly to Therefore, the frequency of the high-frequency power LF can be set to a low frequency of 5 MHz or less, and controllability of ion energy can be improved.

Further, when the tilt angle is controlled by adjusting the drive amount of the drive device 70, the drive amount to be adjusted can be suppressed to a small amount by the provision of the connecting portion 200. FIG. As a result, the occurrence of discharge between wafer W and edge ring 14 can be suppressed. Furthermore, as described above, by adjusting the driving amount of the driving device 70 and the impedance of the second variable passive element 61, the tilt angle adjustment range can be widened and the tilt angle can be controlled to a desired value. can.

10A, the coil spring shown in FIG. 10B, the spring shown in FIG. 10C, the pin shown in FIG. 10D, and the pin shown in FIG. Although wires are exemplified, these may be used in combination.

In the connection portion 200 of the above embodiment, a conductive film 203 is provided between the conductive elastic member 202 and the edge ring 14 of the connection portion 200 as shown in FIG. 10F. may A metal film, for example, is used for the conductive film 203 . The conductive film 203 is provided on at least a portion of the lower surface of the edge ring 14 with which the conductive elastic member 202 contacts. The conductive film 203 may be provided on the entire lower surface of the edge ring 14, or a plurality of conductive films 203 may be provided in a nearly annular shape as a whole. In either case, the conductive film 203 can suppress the resistance due to the contact of the conductive elastic member 202, and the edge ring 14 and the second variable passive element 61 can be appropriately connected.

The connecting portion 200 of the above embodiment preferably has a configuration in which the conductive elastic member 202 is protected from plasma when the edge ring 14 is lifted by the driving device 70 . 11A to 11G each show an example of plasma countermeasures of the conductive elastic member 202. FIG.

As shown in FIG. 11A, the lower surface of the edge ring 14 may be provided with protrusions 14a and 14b projecting downward from the lower surface. In the illustrated example, the protrusion 14 a is provided radially inside the conductive elastic member 202 , and the protrusion 14 b is provided radially outward of the conductive elastic member 202 . That is, the conductive elastic member 202 is provided in the recess formed by the protrusions 14a and 14b. In this case, the protrusions 14a and 14b can prevent the plasma from flowing toward the conductive elastic member 202, and the conductive elastic member 202 can be protected.

In the example of FIG. 11A, the projections 14a and 14b are provided on the lower surface of the edge ring 14, but the shape for suppressing the wraparound of plasma is not limited to this, and may be determined according to the etching apparatus 1. FIG. Also, the shape of the edge ring 14 may be determined so that the edge ring 14 can be properly moved vertically by the drive device 70 .

An additional edge ring 210 may be provided inside the conductive elastic member 202 between the edge ring 14 and the electrostatic chuck 13 as shown in FIG. 11B. Additional edge ring 210 is formed of an insulating material. The additional edge ring 210 is provided separately from the lower electrode 12 and has, for example, an annular shape. In such a case, the additional edge ring 210 can prevent the plasma from flowing toward the conductive elastic member 202 and protect the conductive elastic member 202 .

As shown in FIG. 11C, both the protrusion 14a of the edge ring 14 shown in FIG. 11A and the additional edge ring 210 shown in FIG. 11B may be provided. In such a case, the protruding portion 14a and the additional edge ring 210 can further suppress the wraparound of the plasma, and the conductive elastic member 202 can be protected.

As shown in FIG. 11D, both the projections 14a, 14b of the edge ring 14 shown in FIG. 11A and the additional edge ring 210 shown in FIG. 11B may be provided. The conductive elastic member 202 contacts the projection 14b. again. An additional edge ring 210 is provided between the projections 14a, 14b. In this case, the protrusions 14a and 14b and the additional edge ring 210 form a labyrinth structure, which can further suppress the wraparound of plasma and protect the conductive elastic member 202. FIG.

The edge ring 14 may be split into an upper edge ring 140 and a lower edge ring 141 as shown in FIG. 11E. The upper edge ring 140 corresponds to the edge ring in this disclosure, and the lower edge ring 141 corresponds to the additional edge ring in this disclosure. The upper edge ring 140 is vertically movable by the driving device 70 . The lower edge ring 141 does not move vertically. The conductive elastic member 202 is provided in contact with the lower surface of the upper edge ring 140 and the upper surface of the lower edge ring 141 . Conductive structure 201 is connected to lower edge ring 141 . In such case, the upper edge ring 140 and the second variable passive element 61 are directly electrically connected via the conductive elastic member 202 , the lower edge ring 141 and the conductive structure 201 .

A protrusion 140a that protrudes downward from the lower surface of the upper edge ring 140 is provided on the outermost periphery of the lower surface of the upper edge ring 140 . A protrusion 141a is provided on the upper surface of the lower edge ring 141 at the innermost peripheral portion thereof so as to protrude upward from the upper surface. In such a case, the protrusions 140a and 141a can prevent the plasma from flowing toward the conductive elastic member 202, and the conductive elastic member 202 can be protected.

FIG. 11F is a modification of FIG. 11E. In the example shown in FIG. 11E, the conductive structure 201 was connected to the lower edge ring 141, whereas in the example shown in FIG. contact member 220; The conductive elastic member 220 is provided in a space formed between the lower surface of the lower edge ring 141 and the upper surface of the lower electrode 12 on the radially outer side of the electrostatic chuck 13 . That is, the conductive elastic member 220 contacts the lower surface of the lower edge ring 141 and the conductive structure 201 . In such a case, the upper edge ring 140 and the second variable passive element 61 are directly electrically connected via the conductive elastic member 202, the lower edge ring 141, the conductive elastic member 220 and the conductive structure 201. . Also in this example, the protrusions 140a and 141a can prevent the plasma from flowing toward the conductive elastic member 202, and the conductive elastic member 202 can be protected.

FIG. 11G is a modification of FIG. 11E. In the example shown in FIG. 11E, the conductive elastic member 202 is provided on the upper surface of the lower edge ring 141, but in the example shown in FIG. 11G, the conductive elastic member 202 is provided on the upper surface of the lower electrode 12. The conductive elastic member 202 contacts the lower surface of the upper edge ring 140 and the conductive structure 201 . One end of the conductive structure 201 is exposed on the upper surface of the electrostatic chuck 13 and contacts the conductive elastic member 202 . In such case, the upper edge ring 140 and the second variable passive element 61 are directly electrically connected via the conductive elastic member 202 and the conductive structure 201 . Also in this example, the protrusions 140a and 141a can prevent the plasma from flowing toward the conductive elastic member 202, and the conductive elastic member 202 can be protected.

In addition, in the above embodiments, the configurations shown in FIGS. 11A to 11G may be used in combination. Also, in the connection portion 200, plasma-resistant coating may be applied to the portion of the surface of the conductive elastic member 202 other than the portion in contact with the edge ring 14. FIG. In such a case, the conductive elastic member 202 can be protected from plasma.

Next, the arrangement of the conductive elastic member 202 in plan view will be described. 12A to 12C each show an example of planar arrangement of the conductive elastic member 202. FIG. As shown in FIGS. 12A and 12B, the connecting portion 200 may include a plurality of conductive elastic members 202, and the plurality of conductive elastic members 202 may be provided concentrically with the edge ring 14 at equal intervals. In the example of FIG. 12A, the conductive elastic members 202 are provided at 8 locations, and in FIG. 12B, the conductive elastic members 202 are provided at 24 locations. Alternatively, as shown in FIG. 12C, the conductive elastic member 202 may be annularly provided concentrically with the edge ring 14 .

From the viewpoint of performing uniform etching and uniformizing the shape of the sheath (from the viewpoint of process uniformity), as shown in FIG. It is preferred that the contact with the is made uniformly on the circumference. Also, from the viewpoint of process uniformity, even when a plurality of conductive elastic members 202 are provided as shown in FIG. 12A and FIG. It is preferable that the contact points with respect to the edge ring 14 are arranged point-symmetrically. Furthermore, it is better to increase the number of conductive elastic members 202 as in the example of FIG. 12B as compared to the example of FIG. 12A so as to approach the ring shape as shown in FIG. 12C. Although the number of conductive elastic members 202 is not particularly limited, it is preferable that the number is 3 or more in order to ensure symmetry, and the number may be 3 to 36, for example.

However, it may be difficult to make the conductive elastic member 202 annular or to increase the number of the conductive elastic members 202 in order to avoid interference with other members in terms of the device configuration. Therefore, the planar arrangement of the conductive elastic member 202 may be appropriately set in consideration of the conditions for uniform process and the restrictive conditions on the apparatus configuration.

Next, the relationship between the connecting portion 200 and the first variable passive element 60 and the second variable passive element 61 will be described. 13A to 13C schematically show examples of configurations of the connecting portion 200, the first variable passive element 60 and the second variable passive element 61, respectively.

As shown in FIG. 13A, for example, when one first variable passive element 60 and one second variable passive element 61 are provided for eight conductive elastic members 202, the connecting portion 200 is a relay member. 230 may also be included. 13A illustrates a case where the relay member 230 is provided in the connection portion 200 shown in FIG. 12A, the relay member 230 can be provided in the connection portion 200 shown in either FIG. 12B or FIG. 12C. . Also, a plurality of relay members 230 may be provided.

The relay member 230 is annularly provided concentrically with the edge ring 14 in the conductive structure 201 between the conductive elastic member 202 and the second variable passive element 61 . The relay member 230 is connected to the conductive elastic member 202 by the conductive structure 201a. That is, eight conductive structures 201a radially extend from the relay member 230 in plan view and are connected to the eight conductive elastic members 202, respectively. Also, the relay member 230 is connected to the second variable passive element 61 via the first variable passive element 60 through the conductive structure 201b.

In such a case, for example, even if the second variable passive element 61 is not arranged at the center of the edge ring 14, the electrical characteristics (arbitrary voltage and current values) of the relay member 230 can be made uniform on the circumference. Furthermore, the electrical characteristics of each of the eight conductive elastic members 202 can be made uniform. As a result, etching can be performed uniformly, and the shape of the sheath can be made uniform.

As shown in FIG. 13B, for example, eight conductive elastic members 202 are provided with a plurality of, for example, eight first variable passive elements 60, and one second variable passive element 61 is provided. good too. In this manner, the number of first variable passive elements 60 can be appropriately set with respect to the number of conductive elastic members 202 . In addition, the relay member 230 may be provided also in the example of FIG. 13B.

As shown in FIG. 13C, for example, eight conductive elastic members 202 are provided with a plurality of first variable passive elements 60, for example eight, and a plurality of second variable passive elements 61, for example eight. may have been Thus, the number of the second variable passive elements 61 with variable impedance can be appropriately set with respect to the number of the conductive elastic members 202 . Also in the example of FIG. 13C, a relay member 230 may be provided.

By providing a plurality of second variable passive elements 61 with variable impedance, it is possible to control the electrical characteristics of the plurality of conductive elastic members 202 individually and independently. As a result, the electrical characteristics of each of the plurality of conductive elastic members 202 can be made uniform, and the uniformity of the process can be improved.

Next, as a contact structure for the edge ring 14, examples other than the examples shown in FIGS. 9 and 10A to 10F will be described. 14A to 14D and 15A to 15D respectively show other examples of the configuration of the connecting portion.

14A to 14D each show an example in which the lifter pin 300 of the driving device 70 is made of an insulating material, and the connecting portion 310 as a conductor is provided inside the lifter pin 300. FIG.

As shown in FIG. 14A, the drive device 70 may have lifter pins 300 instead of the lifter pins 71 of the above embodiment. The lifter pins 300 extend vertically from the bottom surface of the edge ring 14 and pass through the electrostatic chuck 13 , the lower electrode 12 , the support member 17 and the bottom of the chamber 10 . A seal is provided between the lifter pin 300 and the chamber 10 to seal the interior of the chamber 10 . Lifter pins 300 are made of an insulating material. Also, the lifter pin 300 is configured to be vertically movable by a drive source 72 provided outside the chamber 10 .

Inside the lifter pin 300, a connecting portion 310, which is a conductive wire extending in the longitudinal direction, is provided. The connecting portion 310 directly connects the edge ring 14 and the lifter pin 300 and connects the edge ring 14 and the second variable passive element 61 . Specifically, the connecting portion 310 has one end connected to the second variable passive element 61 and the other end exposed on the upper surface of the lifter pin 300 and in contact with the lower surface of the edge ring 14 .

As shown in FIGS. 14B and 14C, the connecting portion 310 provided inside the lifter pin 300 may have a conductive structure 311 and a conductive elastic member 312 . A conductive structure 311 connects the edge ring 14 and the second variable passive element 61 via a conductive elastic member 312 . Specifically, the conductive structure 311 has one end connected to the second variable passive element 61 and the other end exposed in the upper space inside the lifter pin 300 to contact the conductive elastic member 312 .

The conductive elastic member 312 is installed in the upper space inside the lifter pin 300 . The conductive elastic member 312 contacts the conductive structure 311 and the lower surface of the edge ring 14 respectively. Also, the conductive elastic member 312 is made of a conductor such as metal, for example. Although the configuration of the conductive elastic member 312 is not particularly limited, for example, a leaf spring having elasticity that is vertically biased may be used as shown in FIG. and edge ring 14 may be used. Alternatively, the conductive elastic member 312 may be the coil spring shown in FIG. 10B, the spring shown in FIG. 10C, the pin shown in FIG. 10D, or the like. In such a case, the edge ring 14 and the second variable passive element 61 are directly electrically connected via the conductive elastic member 312 and the conductive structure 311 .

As shown in FIG. 14D , the lifter pin 300 has a hollow cylindrical shape with open upper and lower surfaces, and the connecting portion 310 provided inside the lifter pin 300 is a conductive structure (first conductive structure) 311 In addition to the conductive elastic member 312, another conductive structure (second conductive structure) 313 may be provided. A conductive structure 313 is provided on the inner surface of the lifter pin 300 . The conductive structure 313 may be, for example, a metal film or a metal cylinder.

Conductive structure 311 is connected to the bottom end of conductive structure 313 . A conductive elastic member 312 is connected to the upper end of the conductive structure 313 . In such a case, the edge ring 14 and the second variable passive element 61 are directly electrically connected via the conductive elastic member 312 , the conductive structure 313 and the conductive structure 311 .

14A to 14D, the edge ring 14 and the second variable passive element 61 can be directly and electrically connected via the connection portion 310. FIG. Therefore, the frequency of the high-frequency power LF can be set to a low frequency of 5 MHz or less, and controllability of ion energy can be improved.

In addition, since the connection part 310 of the above embodiment is provided inside the lifter pin 300 formed of an insulating material, it does not have to be protected from plasma.

15A to 15D each show an example in which the lifter pins 400 of the driving device 70 are made of a conductive material, and the lifter pins 400 themselves constitute the connecting portion.

As shown in FIG. 15A, the drive device 70 may have lifter pins 400 instead of the lifter pins 71 and 300 of the above embodiment. The lifter pins 400 extend vertically from the bottom surface of the edge ring 14 and pass through the electrostatic chuck 13 , the lower electrode 12 , the support member 17 and the bottom of the chamber 10 . A seal is provided between the lifter pin 400 and the chamber 10 to seal the interior of the chamber 10 . Lifter pins 400 are formed of a conductive material. Further, the lifter pin 400 is configured to be vertically movable by a drive source 72 provided outside the chamber 10 .

A conductive structure 410 is connected to the lower end of the lifter pin 400 . Conductive structure 410 is connected to second variable passive element 61 . In such case, the edge ring 14 and the second variable passive element 61 are directly electrically connected via the lifter pins 400 and the conductive structure 410 .

The lifter pins 400 preferably have a structure that protects them from plasma when the edge ring 14 is lifted by the driving device 70 . 15B-15C each show an example of the lifter pin 400 plasma protection.

As shown in FIG. 15B, an additional edge ring 210 shown in FIG. 11B may be provided inside the lifter pins 400 on the upper surface of the bottom electrode 12 . In such a case, the additional edge ring 210 can prevent the plasma from flowing toward the lifter pins 400 and protect the lifter pins 400 . Note that the configuration for suppressing the wraparound of plasma is not limited to this, and any one of the configurations shown in FIGS. 11A and 11C to 11G may be applied.

As shown in FIG. 15C, the outer surface of the lifter pin 400 may be provided with an insulating member 401 having plasma resistance. The insulating member 401 may be, for example, an insulator film or an insulator cylinder. In this case, the insulating member 401 can protect the lifter pins 400 from the plasma. 15B, the insulating member 401 shown in FIG. 15C may be further provided.

In any case shown in FIGS. 15A to 15C, the edge ring 14 and the second variable passive element 61 can be directly electrically connected via the lifter pin 400. FIG. Therefore, the frequency of the high-frequency power LF can be set to a low frequency of 5 MHz or less, and controllability of ion energy can be improved.

15A to 15C, the lifter pin 400 itself constitutes the connecting portion, but as shown in FIG. 15D, the connecting portion 420 as a conductor may be further provided inside the lifter pin 400. FIG. The connection part 420 may have a conductive structure 421 and a conductive elastic member 422 . A conductive structure 421 connects the edge ring 14 and the second variable passive element 61 via a conductive elastic member 422 . Specifically, the conductive structure 421 has one end connected to the second variable passive element 61 and the other end exposed in the upper space inside the lifter pin 400 to contact the conductive elastic member 422 . In addition, the conductive structure 410 is included in the conductive structure 421 .

The conductive elastic member 422 is installed in the upper space inside the lifter pin 400 . The conductive elastic member 422 contacts the conductive structure 421 and the lower surface of the edge ring 14 respectively. The conductive elastic member 422 is made of a conductor such as metal. Although the configuration of the conductive elastic member 422 is not particularly limited, for example, a leaf spring biased in the vertical direction shown in FIG. 10A may be used. Alternatively, the coil spring shown in FIG. 10B, the spring shown in FIG. 10C, the pin shown in FIG. 10D, the wire shown in FIG. 10E, or the like may be used. In such a case, the edge ring 14 and the second variable passive element 61 are directly electrically connected via the conductive elastic member 422 and the conductive structure 421 in addition to the lifter pin 400 . In addition, since resistance due to contact between the lifter pin 400 and the conductive elastic member 422 can be suppressed, the edge ring 14 and the second variable passive element 61 can be connected more appropriately.

<Other embodiments>
In the etching apparatus 1 of the above embodiment, a direct current (DC) power supply 62, a switching unit 63, a first RF filter 64, and a second RF filter 65 are further provided as shown in FIG. good too. A first RF filter 64 and a second RF filter 65 are provided in place of the first variable passive element 60 and the second variable passive element 61, respectively. The first RF filter 64, the second RF filter 65, the switching unit 63, and the DC power supply 62 are arranged in this order from the edge ring 14 side. That is, the DC power supply 62 is electrically connected to the edge ring 14 via the switching unit 63, the second RF filter 65, and the first RF filter 64. Incidentally, in this embodiment, the DC power supply 62 is connected to the ground potential.

The DC power supply 62 is a power supply that generates a negative DC voltage to be applied to the edge ring 14 . Also, the DC power supply 62 is a variable DC power supply, and can adjust the level of the DC voltage.

The switching unit 63 is configured to be able to stop the application of the DC voltage from the DC power supply 62 to the edge ring 14 . The circuit configuration of the switching unit 63 can be appropriately designed by those skilled in the art.

The first RF filter 64 and the second RF filter 65 are filters that attenuate high frequency power. The first RF filter 64 attenuates, for example, 40 MHz high frequency power from the first high frequency power supply 50 . The second RF filter 65 attenuates, for example, 400 kHz high frequency power from the second high frequency power supply 51 .

In one example, the second RF filter 65 has a variable impedance. That is, the second RF filter 65 includes at least one variable passive element and has variable impedance. A variable passive element may be, for example, either a coil (inductor) or a capacitor (capacitor). In addition, the same function can be achieved with any variable impedance element such as a diode, not limited to a coil or a capacitor. The number and positions of the variable passive elements can also be appropriately designed by those skilled in the art. Furthermore, the element itself does not need to be variable. For example, a plurality of elements having fixed impedance values may be provided, and a switching circuit may be used to switch the combination of the fixed value elements to vary the impedance. The circuit configurations of the second RF filter 65 and the first RF filter 64 can be appropriately designed by those skilled in the art.

The etching apparatus 1 may further include a measuring device (not shown) for measuring the self-bias voltage of the edge ring 14 (or the self-bias voltage of the lower electrode 12 or wafer W). The configuration of the measuring instrument can be appropriately designed by those skilled in the art.

Next, a method of controlling the tilt angle using the etching apparatus 1 of this embodiment will be described. In this embodiment, the DC voltage from the DC power supply 62 is adjusted in addition to the adjustment of the drive amount of the drive device 70 and the adjustment of the impedance of the second RF filter 65 in the above embodiment. That is, at least two selected from the group consisting of the driving amount of the driving device 70, the impedance of the second RF filter 65, and the DC voltage from the DC power supply 62 are adjusted to control the tilt angle. 17 and 18 each show an example of a tilt angle control method in this embodiment.

In the example shown in FIG. 17, first, the impedance of the second RF filter 65 is adjusted to correct the tilt angle. Next, when the impedance reaches a predetermined value, for example, the upper limit, the DC voltage from the DC power supply 62 is adjusted, the tilt correction angle is adjusted to the target angle θ3, and the tilt angle is set to 0 (zero) degrees. do.

In the DC power supply 62, the DC voltage applied to the edge ring 14 is set to a negative voltage whose absolute value is the sum of the absolute value of the self-bias voltage Vdc and the set value ΔV, that is, −(|Vdc|+ΔV). be done. The self-bias voltage Vdc is the self-bias voltage of the wafer W, and is applied to the lower electrode 12 when one or both of the high-frequency powers are supplied and the DC voltage from the DC power supply 62 is not applied to the lower electrode 12. is the self-bias voltage of The set value ΔV is given by the control section 100 .

The control unit 100 sets the impedance of the second RF filter 65 from the amount of wear of the edge ring 14 in the same manner as setting the drive amount of the driving device 70 and setting the impedance of the second RF filter 65 in the above embodiment. do. Determine the set value ΔV.

In determining the set value ΔV, the control unit 100 determines the difference between the initial thickness of the edge ring 14 and the thickness of the edge ring 14 actually measured using a measuring device such as a laser measuring device or a camera. may be used as the amount of consumption. Alternatively, the wear amount of the edge ring 14 may be estimated from a change in the mass of the edge ring 14 measured by a measuring instrument such as a mass meter. Alternatively, the control unit 100 may estimate the wear amount of the edge ring 14 from specific parameters using another predetermined function or table for determining the set value ΔV. This particular parameter can be any of the self-bias voltage Vdc, the peak value Vpp of the high frequency power HF or the high frequency power LF, the load impedance, the edge ring 14 or electrical characteristics around the edge ring 14, and the like. The electrical property of the edge ring 14 or the periphery of the edge ring 14 may be any of the voltage, current value, resistance value including the edge ring 14, etc. of the edge ring 14 or any point around the edge ring 14 . Another function or table is predetermined to define the relationship between specific parameters and the amount of edge ring 14 wear. In order to estimate the amount of wear of the edge ring 14, the measurement conditions for estimating the amount of wear, that is, the high frequency power HF, the high frequency power LF, and the processing space S and the flow rate of the processing gas supplied to the processing space S, the etching apparatus 1 is operated. Then, the specific parameter is acquired, and by inputting the specific parameter to the other function or by referring to the table using the specific parameter, the wear amount of the edge ring 14 is calculated. identified.

In the etching apparatus 1, a DC voltage is applied from the DC power supply 62 to the edge ring 14 during etching, that is, during a period in which one or both of the high frequency power HF and the high frequency power LF are supplied. Thereby, the shape of the sheath above the edge ring 14 and the edge region of the wafer W is controlled, the inclination of the incident direction of ions to the edge region of the wafer W is reduced, and the tilt angle is controlled. As a result, over the entire region of the wafer W, recesses substantially parallel to the thickness direction of the wafer W are formed.

More specifically, during etching, the self-bias voltage Vdc is measured by a meter (not shown). A DC voltage is applied to the edge ring 14 from the DC power supply 62 . The value of the DC voltage applied to the edge ring 14 is -(|Vdc|+ΔV) as described above. |Vdc| is the absolute value of the measured value of the self-bias voltage Vdc obtained by the measuring instrument immediately before, and ΔV is the set value determined by the control unit 100 . The DC voltage applied to the edge ring 14 is determined from the self-bias voltage Vdc thus measured during etching. Then, even if the self-bias voltage Vdc changes, the DC voltage generated by the DC power supply 62 is corrected, and the tilt angle is appropriately corrected.

Further, in the example shown in FIG. 17, instead of the impedance of the second RF filter 65, the driving amount of the driving device 70 may be adjusted. That is, the tilt angle may be corrected by adjusting the driving amount of the driving device 70 and the DC voltage from the DC power supply 62 .

In the example shown in FIG. 18, first, the impedance of the second RF filter 65 is adjusted to correct the tilt angle. Next, when the impedance reaches a predetermined value, for example, an upper limit value, the DC voltage from the DC power supply 62 is adjusted to correct the tilt angle.

Here, if the absolute value of the DC voltage is too high, discharge will occur between the wafer W and the edge ring 14 . Therefore, the DC voltage that can be applied to the edge ring 14 is limited, and even if the tilt angle is controlled only by adjusting the DC voltage, the control range is limited.

Therefore, when the absolute value of the DC voltage reaches a predetermined value, for example, the upper limit value, the drive amount of the drive device 70 is adjusted, the tilt correction angle is adjusted to the target angle θ3, and the tilt angle is reduced to 0 (zero). degree.

As described above, according to the present embodiment, in addition to adjusting the impedance of the second RF filter 65 and adjusting the driving amount of the driving device 70, the tilt angle is adjusted by adjusting the DC voltage from the DC power supply 62. The adjustment range of can be increased. Therefore, the tilt angle can be appropriately controlled, that is, the incident direction of ions can be adjusted appropriately, so etching can be performed uniformly.

In controlling the tilt angle, the adjustment of the impedance of the second RF filter 65, the adjustment of the driving amount of the driving device 70, and the combination of the DC voltage from the DC power supply 62 can be arbitrarily designed.

Also, although the adjustment of the impedance of the second RF filter 65, the adjustment of the driving amount of the driving device 70, and the DC voltage from the DC power supply 62 are individually performed, these adjustments may be performed simultaneously.

In the above embodiment, the DC power supply 62 is connected to the edge ring 14 via the switching unit 63, the second RF filter 65, and the first RF filter 64, but the DC voltage is applied to the edge ring 14. The power supply system to apply is not limited to this. For example, the DC power supply 62 may be electrically connected to the edge ring 14 via the switching unit 63 , the second RF filter 65 , the first RF filter 64 and the bottom electrode 12 . In such a case, bottom electrode 12 and edge ring 14 are directly electrically coupled and the self-bias voltage of edge ring 14 is the same as the self-bias voltage of bottom electrode 12 .

Here, when the lower electrode 12 and the edge ring 14 are directly electrically coupled, the sheath thickness above the edge ring 14 cannot be adjusted due to, for example, the capacitance below the edge ring 14 determined by the hardware structure. Outer tilt can occur even when no voltage is applied. In this respect, in the present disclosure, the tilt angle can be controlled by adjusting the DC voltage from the DC power supply 62, the impedance of the second RF filter 65, and the drive amount of the drive device 70. By changing the angle toward the inner side, the tilt angle can be adjusted to 0 (zero) degree.

Although the impedance of the second RF filter 65 is variable in the above embodiment, the impedance of the first RF filter 64 may be variable, or the impedance of both the RF filters 64 and 65 may be variable. may In such cases, the first RF filter 64 includes at least one variable passive element. Also, in the above embodiment, two RF filters 64 and 65 are provided for the DC power supply 62, but the number of RF filters is not limited to this, and may be, for example, one. In the above embodiments, the second RF filter 65 (first RF filter 64) includes at least one variable passive element to make the impedance variable, but the configuration for making the impedance variable is limited to this. not. For example, a variable or fixed impedance RF filter may be connected to a device capable of adjusting the impedance of the RF filter. In other words, the variable impedance RF filter may be composed of an RF filter and a device connected to the RF filter and capable of varying the impedance of the RF filter. Also, although the RF filter includes at least one variable passive element to make the impedance variable, it is also possible to use an RF filter whose impedance is not variable and provide the variable passive element outside the RF filter.

<Other embodiments>
In the above embodiment, according to the wear amount of the edge ring 14, the driving amount of the driving device 70 is adjusted, the impedance of the second variable passive element 61 (second RF filter 65) is adjusted, Although the DC voltage is adjusted, the driving amount, the impedance, and the DC voltage adjustment timing are not limited to this. For example, the drive amount, impedance, and DC voltage may be adjusted according to the processing time of the wafer W. FIG. Alternatively, for example, the processing time of the wafer W and predetermined parameters such as high-frequency power may be combined to determine the adjustment timing of the drive amount, impedance, and DC voltage.

<Other embodiments>
Although the etching apparatus 1 of the above embodiment is a capacitive coupling type etching apparatus, the etching apparatus to which the present disclosure is applied is not limited to this. For example, the etching device may be an inductively coupled etching device.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The embodiments described above may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

Embodiments of the present disclosure further include the following aspects.

(Appendix 1)
a plasma processing chamber;
A substrate support disposed within the plasma processing chamber, the substrate support including a lower electrode, an electrostatic chuck, and an edge ring disposed to surround the substrate placed on the electrostatic chuck. a substrate support comprising
a drive configured to move the edge ring longitudinally;
a top electrode positioned above the substrate support;
a source RF power supply configured to supply source RF power to the upper electrode or the lower electrode to generate a plasma from gases in the plasma processing chamber;
a bias RF power supply configured to supply bias RF power to the bottom electrode;
at least one conductor in contact with the edge ring;
a DC power supply configured to apply a negative DC voltage to the edge ring via the at least one conductor;
an RF filter electrically connected between the at least one conductor and the DC power source and comprising at least one variable passive element;
a controller configured to control the drive and the at least one variable passive element to adjust the angle of incidence of ions in the plasma with respect to an edge region of a substrate mounted on the electrostatic chuck; ,
plasma processing apparatus.

(Appendix 2)
The driving device
lifter pins configured to support the edge ring;
2. The plasma processing apparatus of claim 1, comprising a drive source configured to move the lifter pins longitudinally.

(Appendix 3)
The plasma processing apparatus according to appendix 2, wherein at least the surface of the lifter pin is made of an insulating material.

(Appendix 4)
the at least one conductor comprises a conductive wire extending longitudinally within the lifter pin;
4. The plasma processing apparatus of Claim 3, wherein one end of the conductive wire is in contact with the edge ring.

(Appendix 5)
4. The plasma processing apparatus according to appendix 3, wherein the at least one conductor includes a conductive elastic member in contact with the edge ring.

(Appendix 6)
6. The plasma processing apparatus according to appendix 5, wherein the conductive elastic member is arranged within the lifter pin.

(Appendix 7)
6. The plasma processing apparatus according to appendix 5, wherein the conductive elastic member is arranged between the edge ring and the electrostatic chuck.

(Appendix 8)
Clause 8. The plasma processing apparatus of Clause 7, further comprising an additional edge ring positioned between the edge ring and the electrostatic chuck.

(Appendix 9)
9. The plasma processing apparatus according to appendix 8, wherein the additional edge ring is made of an insulating material and arranged inside the conductive elastic member.

(Appendix 10)
10. The plasma processing apparatus according to appendix 9, wherein the edge ring has a protrusion on its lower surface.

(Appendix 11)
the additional edge ring is made of a conductive material;
9. The plasma processing apparatus according to appendix 8, wherein the conductive elastic member is arranged between the edge ring and the additional edge ring.

(Appendix 12)
12. The plasma processing apparatus according to any one of appendices 1 to 11, wherein said edge ring has at least one conductive film in contact with said at least one conductor.

(Appendix 13)
12. The plasma processing apparatus according to any one of appendices 1 to 11, wherein the at least one conductor includes a plurality of conductors arranged at regular intervals along the circumferential direction of the edge ring in plan view.

(Appendix 14)
12. The plasma processing apparatus according to any one of appendices 1 to 11, wherein the edge ring has conductivity.

(Appendix 15)
a plasma processing chamber;
a substrate support disposed within the plasma processing chamber, the substrate support including an electrostatic chuck and an edge ring disposed to surround a substrate mounted on the electrostatic chuck; a substrate support;
a drive configured to move the edge ring longitudinally;
an RF power supply configured to generate RF power to generate a plasma from gases in the plasma processing chamber;
at least one conductor in contact with the edge ring;
at least one variable passive element electrically connected to the at least one conductor;
a controller configured to control the drive and the at least one variable passive element to adjust the angle of incidence of ions in the plasma with respect to an edge region of a substrate mounted on the electrostatic chuck; ,
plasma processing apparatus.

(Appendix 16)
The driving device
lifter pins configured to support the edge ring;
16. The plasma processing apparatus of Clause 15, comprising a drive source configured to move the lifter pins longitudinally.

(Appendix 17)
17. The plasma processing apparatus according to appendix 16, wherein at least a surface of the lifter pin is made of an insulating material.

(Appendix 18)
the at least one conductor comprises a conductive wire extending longitudinally within the lifter pin;
18. The plasma processing apparatus of Claim 17, wherein one end of the conductive wire is electrically and physically connected to the edge ring.

(Appendix 19)
An etching method using a plasma processing apparatus,
The plasma processing apparatus is
a plasma processing chamber;
a substrate support disposed within the plasma processing chamber, the substrate support including an electrostatic chuck and an edge ring disposed to surround a substrate mounted on the electrostatic chuck; a substrate support;
at least one conductor electrically and physically connected to the edge ring;
at least one variable passive element electrically connected to the at least one conductor;
with
The etching method is
(a) placing a substrate on the electrostatic chuck;
(b) generating a plasma from gases in the plasma processing chamber;
(c) etching the substrate with the generated plasma;
(d) adjusting an incident angle of ions in the plasma with respect to an edge region of the substrate, the adjusting step comprising:
(d1) moving the edge ring vertically;
(d2) tuning the at least one variable passive element;
a step comprising
A method of etching, comprising:

1 etching device 10 chamber 11 stage 12 lower electrode 13 electrostatic chuck 14 edge ring 21 electrode plate 50 first high frequency power supply 51 second high frequency power supply 62 DC power supply 64 first RF filter 65 second RF filter 70 driving device 100 control unit 200 connection unit 310 connection unit 420 connection unit W wafer

Claims (19)

a plasma processing chamber;
A substrate support disposed within the plasma processing chamber, the substrate support including a lower electrode, an electrostatic chuck, and an edge ring disposed to surround the substrate placed on the electrostatic chuck. a substrate support comprising
a drive configured to move the edge ring longitudinally;
a top electrode positioned above the substrate support;
a source RF power supply configured to supply source RF power to the upper electrode or the lower electrode to generate a plasma from gases in the plasma processing chamber;
a bias RF power supply configured to supply bias RF power to the bottom electrode;
at least one conductor in contact with the edge ring;
a DC power supply configured to apply a negative DC voltage to the edge ring via the at least one conductor;
an RF filter electrically connected between the at least one conductor and the DC power source and comprising at least one variable passive element;
a controller configured to control the drive and the at least one variable passive element to adjust the angle of incidence of ions in the plasma with respect to an edge region of a substrate mounted on the electrostatic chuck; ,
plasma processing apparatus. The driving device
lifter pins configured to support the edge ring;
and a drive source configured to move the lifter pins longitudinally. 3. The plasma processing apparatus according to claim 2, wherein at least a surface of said lifter pin is made of an insulating material. the at least one conductor comprises a conductive wire extending longitudinally within the lifter pin;
4. The plasma processing apparatus of claim 3, wherein one end of said conductive wire is in contact with said edge ring. 4. The plasma processing apparatus of claim 3, wherein said at least one conductor includes a conductive elastic member in contact with said edge ring. 6. The plasma processing apparatus according to claim 5, wherein said conductive elastic member is arranged within said lifter pin. 6. The plasma processing apparatus according to claim 5, wherein said conductive elastic member is arranged between said edge ring and said electrostatic chuck. 8. The plasma processing apparatus of claim 7, further comprising an additional edge ring positioned between said edge ring and said electrostatic chuck. 9. The plasma processing apparatus according to claim 8, wherein said additional edge ring is made of an insulating material and arranged inside said conductive elastic member. 10. The plasma processing apparatus of claim 9, wherein said edge ring has a protrusion on its lower surface. the additional edge ring is made of a conductive material;
9. The plasma processing apparatus according to claim 8, wherein said conductive elastic member is arranged between said edge ring and said additional edge ring. The plasma processing apparatus according to any one of claims 1 to 11, wherein said edge ring has at least one conductive film in contact with said at least one conductor. The plasma processing apparatus according to any one of claims 1 to 11, wherein said at least one conductor includes a plurality of conductors arranged at regular intervals along the circumferential direction of said edge ring in plan view. The plasma processing apparatus according to any one of claims 1 to 11, wherein said edge ring has conductivity. a plasma processing chamber;
a substrate support disposed within the plasma processing chamber, the substrate support including an electrostatic chuck and an edge ring disposed to surround a substrate mounted on the electrostatic chuck; a substrate support;
a drive configured to move the edge ring longitudinally;
an RF power supply configured to generate RF power to generate a plasma from gases in the plasma processing chamber;
at least one conductor in contact with the edge ring;
at least one variable passive element electrically connected to the at least one conductor;
a controller configured to control the drive and the at least one variable passive element to adjust the angle of incidence of ions in the plasma with respect to an edge region of a substrate mounted on the electrostatic chuck; ,
plasma processing apparatus. The driving device
lifter pins configured to support the edge ring;
16. The plasma processing apparatus of claim 15, comprising a drive source configured to move the lifter pins longitudinally. 17. The plasma processing apparatus according to claim 16, wherein at least a surface of said lifter pin is made of an insulating material. the at least one conductor comprises a conductive wire extending longitudinally within the lifter pin;
18. The plasma processing apparatus of claim 17, wherein one end of said conductive wire is electrically and physically connected to said edge ring. An etching method using a plasma processing apparatus,
The plasma processing apparatus is
a plasma processing chamber;
a substrate support disposed within the plasma processing chamber, the substrate support including an electrostatic chuck and an edge ring disposed to surround a substrate mounted on the electrostatic chuck; a substrate support;
at least one conductor electrically and physically connected to the edge ring;
at least one variable passive element electrically connected to the at least one conductor;
with
The etching method is
(a) placing a substrate on the electrostatic chuck;
(b) generating a plasma from gases in the plasma processing chamber;
(c) etching the substrate with the generated plasma;
(d) adjusting an incident angle of ions in the plasma with respect to an edge region of the substrate, the adjusting step comprising:
(d1) moving the edge ring vertically;
(d2) tuning the at least one variable passive element;
a step comprising
A method of etching, comprising:

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