Plasma processing apparatus and etching method

Abstract

This invention provides a plasma processing apparatus and etching method, wherein the incident angle of ions in the plasma relative to the edge region of a substrate is appropriately controlled during plasma processing. The plasma processing apparatus comprises: a substrate support including a lower electrode, an electrostatic chuck, and an edge ring; a driving device for moving the edge ring longitudinally; an upper electrode disposed above the substrate support; a source radio frequency power supply for supplying source radio frequency power to the upper electrode or the lower electrode; a bias radio frequency power supply for supplying bias radio frequency power to the lower electrode; at least one conductor in contact with the edge ring; a DC power supply applying a negative DC voltage to the edge ring via the at least one conductor; a radio frequency filter electrically connected between the at least one conductor and the DC power supply, including at least one variable passive element; and a control unit for controlling the driving device and the at least one variable passive element to adjust the incident angle of ions in the plasma relative to the edge region of the substrate.

Description

Technical Field

[0001] This invention relates to a plasma treatment apparatus and an etching method. Prior Technology

[0002] Patent Document 1 discloses a system for controlling the directionality of an ion beam in an edge region within a plasma chamber. This system includes a radio frequency (RF) generator configured to generate an RF signal, an impedance matching circuit that receives the RF signal and generates a corrected RF signal, and a plasma chamber. The plasma chamber includes an edge ring and a coupling ring for receiving the corrected RF signal. The coupling ring includes electrodes for receiving the corrected RF signal and electrodes that generate capacitance between the coupling ring and the edge ring to control the directionality of the ion beam. [Known Technical Documents] [Patent Literature]

[0003] Patent Document 1: Japanese Patent Application Publication No. 2017-228526 Summary of the Invention

[0004] [The problem that this invention aims to solve]

[0005] The technology disclosed in this invention appropriately controls the incident angle of ions in the plasma relative to the edge region of the substrate during plasma processing. [Technical means to solve the problem]

[0006] A plasma processing apparatus according to an embodiment of the present invention includes: 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 surrounding a substrate mounted on the electrostatic chuck; a driving device for moving the edge ring longitudinally; an upper electrode disposed above the substrate support; a source radio frequency power supply for supplying source radio frequency power to the upper electrode or the lower electrode to generate plasma from gas within the plasma processing chamber; a bias radio frequency power supply for supplying bias radio frequency power to the lower electrode; at least one conductor in contact with the edge ring; a DC power supply for applying a negative DC voltage to the edge ring via the at least one conductor; a radio frequency filter electrically connected between the at least one conductor and the DC power supply, including at least one variable passive component; and a control unit for controlling the driving device and the at least one variable passive component to adjust the incident angle of ions in the plasma onto the edge region of the substrate mounted on the electrostatic chuck. [Effects of the Invention]

[0007] According to the present invention, the incident angle of ions in the plasma relative to the edge region of the substrate can be appropriately controlled during plasma processing. Simple Explanation of the Diagram

[0008] Figure 1 is a schematic longitudinal cross-sectional view showing the structure of the etching apparatus of this embodiment. Figure 2A is a schematic longitudinal cross-sectional view showing the composition of the periphery of the edge ring of this embodiment. Figure 2B is a longitudinal cross-sectional view showing the general structure of the periphery of the edge ring of this embodiment. Figure 3A is an illustration showing the changes in the shape of the sheath caused by the consumption of the edge rings and the tilting of the incident direction of ions. Figure 3B is an illustration showing the changes in the shape of the sheath caused by the consumption of the edge rings and the tilting of the incident direction of ions. Figure 4A is an illustration showing the changes in the shape of the sheath and the occurrence of the tilting of the incident direction of ions. Figure 4B is an illustration showing the changes in the shape of the sheath and the occurrence of the tilting of the incident direction of ions. Figure 5 is an explanatory diagram showing one example of a method for controlling the tilt angle. Figure 6 is an explanatory diagram showing one example of a method for controlling the tilt angle. Figure 7 is an explanatory diagram showing one example of a method for controlling the tilt angle. Figure 8 is an explanatory diagram showing one example of a method for controlling the tilt angle. Figure 9 is a schematic longitudinal cross-sectional view showing the composition of the periphery of the edge ring in another embodiment. Figure 10A shows a longitudinal sectional view of one example of the structure of the connecting part. Figure 10B is a longitudinal sectional view showing one example of the structure of the connecting part. Figure 10C shows a longitudinal sectional view of one example of the structure of the connecting part. Figure 10D shows a longitudinal sectional view of one example of the structure of the connecting part. Figure 10E shows a longitudinal sectional view of one example of the structure of the connecting part. Figure 10F shows a longitudinal sectional view of one example of the structure of the connecting part. Figure 11A shows a longitudinal sectional view of one example of the structure of the connecting part. Figure 11B is a longitudinal sectional view showing one example of the structure of the connecting part. Figure 11C shows a longitudinal sectional view of one example of the structure of the connecting part. Figure 11D shows a longitudinal sectional view of one example of the structure of the connecting part. Figure 11E shows a longitudinal sectional view of one example of the structure of the connecting part. Figure 11F shows a longitudinal sectional view of one example of the structure of the connecting part. Figure 11G shows a longitudinal cross-sectional view of one example of the structure of the connecting part. Figure 12A is a top view showing one example of the structure of the connecting part. Figure 12B is a top view showing one example of the configuration of the connecting part. Figure 12C is a top view showing one example of the configuration of the connecting part. Figure 13A is an explanatory diagram illustrating one example of the configuration of the connecting part and the variable passive element. Figure 13B is an explanatory diagram illustrating one example of the configuration of the connecting part and the variable passive element. Figure 13C is an explanatory diagram illustrating one example of the configuration of the connecting part and the variable passive element. Figure 14A shows a longitudinal sectional view of an example of the configuration of the connecting part and the drive device. Figure 14B shows a longitudinal sectional view of one example of the configuration of the connecting part and the drive device. Figure 14C shows a longitudinal sectional view of an example of the configuration of the connecting part and the drive device. Figure 14D shows a longitudinal sectional view of an example of the configuration of the connecting part and the drive device. Figure 15A shows a longitudinal sectional view of one example of the configuration of the connecting part and the drive device. Figure 15B is a longitudinal sectional view showing an example of the configuration of the connecting part and the drive device. Figure 15C shows a longitudinal sectional view of an example of the configuration of the connecting part and the drive device. Figure 15D shows a longitudinal sectional view of an example of the configuration of the connecting part and the drive device. Figure 16 is a schematic longitudinal cross-sectional view showing the composition of the periphery of the edge ring in another embodiment. Figure 17 is an explanatory diagram showing one example of a method for controlling the tilt angle. Figure 18 is an explanatory diagram showing one example of a method for controlling the tilt angle. Implementation

[0009] In the manufacturing process of semiconductor devices, plasma processing such as etching is performed on semiconductor wafers (hereinafter referred to as "wafers"). In plasma processing, plasma is generated by exciting processing gases, and the wafer is processed by the plasma.

[0010] Plasma processing is performed in a plasma processing apparatus. A plasma processing apparatus generally includes a chamber, a platform, and a radio frequency (RF) power supply. In one example, the RF power supply includes a first RF power supply and a second RF power supply. The first RF power supply provides first RF power to generate plasma gas within the chamber. The second RF power supply provides second RF power for biasing the lower electrode to guide ions into the wafer. The platform is disposed within the chamber. The platform includes a lower electrode and an electrostatic chuck. In one example, an edge ring is disposed on the electrostatic chuck to surround the wafer mounted on the chuck. The edge ring is provided to improve the uniformity of plasma processing on the wafer.

[0011] As the plasma processing time progresses, the edge ring is consumed, and its thickness decreases. If the edge ring thickness decreases, the shape of the sheath layer above the edge ring and the wafer edge region changes. If the sheath layer shape changes in this way, the incident direction of ions in the wafer edge region is tilted longitudinally. As a result, the recesses formed in the wafer edge region are tilted relative to the wafer thickness direction.

[0012] In order to form a recess extending along the thickness direction of the wafer in the edge region, the tilt of the incident direction of ions toward the edge region of the wafer must be adjusted. Therefore, in order to control the incident direction of ions toward the edge region (the directionality of the ion beam), for example, as proposed in Patent Document 1 above, a capacitance is generated between the electrode of the coupling ring and the edge ring.

[0013] However, even if the angle of incidence is controlled solely by generating the aforementioned capacitance, the control range is still limited. Furthermore, while it is desirable to suppress the replacement frequency of the edge rings that are consumed, the angle of incidence of ions cannot be adequately controlled solely by generating the aforementioned capacitance, and this situation cannot improve the replacement frequency of the edge rings.

[0014] The technique disclosed in this invention appropriately controls the tilt angle by vertically incidenting ions into the edge region of the substrate during etching.

[0015] The following description, with reference to the drawings, describes the etching apparatus and etching method as a plasma treatment apparatus according to this embodiment. Furthermore, in this specification and the drawings, elements having substantially the same functional configuration are given the same reference numerals, thereby omitting redundant descriptions.

[0016] <Etching Device> First, the etching apparatus of this embodiment will be described. Figure 1 is a schematic longitudinal cross-sectional view showing the configuration of the etching apparatus 1. Figures 2A and 2B are schematic longitudinal cross-sectional views showing the configuration of the periphery of the edge ring. The etching apparatus 1 is a capacitively coupled type etching apparatus. In the etching apparatus 1, etching is performed on the wafer W, which serves as the substrate.

[0017] As shown in Figure 1, the etching apparatus 1 has a slightly cylindrical chamber 10 that serves as a plasma processing chamber. Inside the chamber 10, a plasma-generating processing space S is drawn in the center. The chamber 10 is, for example, made of aluminum. The chamber 10 is connected to a ground potential.

[0018] Inside the chamber 10, a platform 11 serving as a substrate support for holding the wafer W is housed. The platform 11 includes a lower electrode 12, an electrostatic chuck 13, and an edge ring 14. Alternatively, an electrode plate (not shown) made of aluminum may be provided on the bottom surface of the lower electrode 12.

[0019] The lower electrode 12 is made of a conductive material, such as aluminum, and has a slightly rounded plate shape.

[0020] Alternatively, platform 11 may also include a temperature control module configured to adjust at least one of the electrostatic chuck 13, edge ring 14, and wafer W to a desired temperature. The temperature control module may also include a heater, a flow path, or a combination thereof, allowing temperature-regulating media such as refrigerant or heat transfer gas to flow through the flow path.

[0021] In one example, a flow path 15a is formed inside the lower electrode 12. A temperature-regulating medium is supplied to the flow path 15a from a quench unit (not shown) located outside the chamber 10 via an inlet pipe 15b. The temperature-regulating medium supplied to the flow path 15a returns to the quench unit via an outlet flow path 15c. Within the flow path 15a, by circulating a temperature-regulating medium, such as cooling water, the electrostatic chuck 13, the edge ring 14, and the wafer W can be cooled to the desired temperature.

[0022] An electrostatic chuck 13 is disposed on the lower electrode 12. In one example, the electrostatic chuck 13 can hold the wafer W and the edge ring 14 together by electrostatic force. The top surface of the central portion of the electrostatic chuck 13 is formed to be higher than the top surface of the edge portion. The top surface of the central portion of the electrostatic chuck 13 becomes the wafer mounting surface for placing the wafer W; in one example, the top surface of the edge portion of the electrostatic chuck 13 becomes the edge ring mounting surface for placing the edge ring 14.

[0023] In one example, a first electrode 16a for adsorbing and holding the wafer W is provided at the center of the electrostatic chuck 13. A second electrode 16b for adsorbing and holding the edge ring 14 is provided at the edge of the electrostatic chuck 13. The electrostatic chuck 13 has a configuration that clamps the electrodes 16a and 16b between insulating materials made of insulating material.

[0024] A DC voltage from a DC power supply (not shown) is applied to the first electrode 16a. The resulting electrostatic force attracts and holds the wafer W to the top surface of the center portion of the electrostatic chuck 13. Similarly, a DC voltage from a DC power supply (not shown) is applied to the second electrode 16b. In one example, the resulting electrostatic force attracts and holds the edge ring 14 to the top surface of the edge portion of the electrostatic chuck 13.

[0025] In this embodiment, the central portion of the electrostatic chuck 13 where the first electrode 16a is disposed is integrated with the edge portion where the second electrode 16b is disposed; however, the central portion and the edge portion can also be separate components. Furthermore, both the first electrode 16a and the second electrode 16b can be unipolar or bipolar.

[0026] Furthermore, in this 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 of holding the edge ring 14 is not limited to this one. For example, the edge ring 14 can also be attracted and held by an adsorption sheet, or the edge ring 14 can also be clamped and held. Alternatively, the edge ring 14 can also be held by its own weight.

[0027] The edge ring 14 is a ring-shaped component configured to surround the wafer W placed on the top surface of the central portion of the electrostatic chuck 13. The edge ring 14 is provided to improve the uniformity of etching. Therefore, the edge ring 14 is made of a material appropriately selected for etching and has electrical conductivity, for example, it can be made of Si or SiC.

[0028] The platform 11, constructed as described above, is fastened to a slightly cylindrical support member 17 located at the bottom of the chamber 10. The support member 17 is made of an insulator, for example, ceramic or quartz.

[0029] A spray head 20 is disposed above the platform 11, facing the platform 11. The spray head 20 includes an electrode plate 21 disposed facing the processing space S, and an electrode support 22 disposed above the electrode plate 21. The electrode plate 21 functions as an upper electrode paired with the lower electrode 12. As described later, when the first radio frequency power supply 50 is electrically coupled to the lower electrode 12, the spray head 20 is connected to ground potential. Furthermore, the spray head 20 is supported on the upper part (ceiling surface) of the chamber 10 via an insulating shielding member 23.

[0030] On the electrode plate 21, a plurality of gas outlets 21a are formed for supplying the processing gas delivered from the gas diffusion chamber 22a (described later) to the processing space S. The electrode plate 21 is, for example, made of a conductor or semiconductor with low resistivity that generates little Joule heat.

[0031] The electrode support 22 supports the electrode plate 21 in a detachable manner. The electrode support 22 may have, for example, a plasma-resistant film formed on the surface of a conductive material such as aluminum. This film may be formed by anodizing or a ceramic film such as yttrium oxide. A gas diffusion chamber 22a is formed inside the electrode support 22. A plurality of gas flow holes 22b communicating with the gas outlet 21a are formed from the gas diffusion chamber 22a. Furthermore, a gas inlet hole 22c connected to the gas supply pipe 33 (described later) is formed in the gas diffusion chamber 22a.

[0032] In addition, the gas supply source group 30 that supplies the processing gas to the gas diffusion chamber 22a is connected to the electrode support 22 via the flow control machine group 31, the valve group 32, the gas supply pipe 33, and the gas inlet port 22c.

[0033] The gas supply source group 30 includes multiple gas supply sources required for etching. The flow control machine group 31 includes multiple flow controllers, and the valve group 32 includes multiple valves. Each of the multiple flow controllers in the flow control machine group 31 is a mass flow controller or a pressure-controlled flow controller. In the etching apparatus 1, the processing gas selected from one or more gas supply sources from the gas supply source group 30 is supplied to the gas diffusion chamber 22a via the flow control machine group 31, the valve group 32, the gas supply pipe 33, and the gas inlet port 22c. Then, the processing gas supplied to the gas diffusion chamber 22a is dispersed in a spray-like manner into the processing space S via the gas flow port 22b and the gas outlet 21a.

[0034] A baffle 40 is provided at the bottom of chamber 10, between the inner wall of chamber 10 and support member 17. The baffle 40 is constructed, for example, by coating aluminum with a ceramic such as yttrium oxide. A plurality of through holes are formed in the baffle 40. The processing space S communicates with the exhaust port 41 via the baffle 40. For example, an exhaust device 42, such as a vacuum pump, is connected to the exhaust port 41, and the pressure within the processing space S can be reduced by the exhaust device 42.

[0035] In addition, a wafer W loading / unloading inlet 43 is formed on the side wall of chamber 10, and the loading / unloading outlet 43 can be opened and closed by a gate valve 44.

[0036] As shown in Figures 1 and 2, the etching apparatus 1 further includes a first radio frequency power supply 50 as a source radio frequency power supply, a second radio frequency power supply 51 as a bias radio frequency power supply, and a matching unit 52. The first radio frequency power supply 50 and the second radio frequency power supply 51 are coupled to the lower electrode 12 via the matching unit 52.

[0037] The first RF power supply 50 generates RF power HF, which is the source of RF power for plasma generation, and supplies this RF power HF to the lower electrode 12. The RF power HF can be a frequency in the range of 27MHz to 100MHz, and in one example, it is 40MHz. The first RF power supply 50 is coupled to the lower electrode 12 via the first matching circuit 53 of the matching unit 52. The first matching circuit 53 is a circuit used to match the output impedance of the first RF power supply 50 with the input impedance of the load side (lower electrode 12 side). Alternatively, the first RF power supply 50 may not be electrically coupled to the lower electrode 12, and may be coupled to the spray head 20 of the upper electrode via the first matching circuit 53. In addition, a pulse power supply configured to apply a pulse voltage other than RF power to the lower electrode 12 may be used instead of the first RF power supply 50. This pulse power supply is the same as the pulse power supply used later to replace the second RF power supply 51.

[0038] The second RF power supply 51 generates RF power LF, which is used to introduce ions into the wafer W as a bias RF power, and supplies this RF power LF to the lower electrode 12. The RF power LF can be in the frequency range of 400kHz to 13.56MHz, and in one example, it is 400kHz. The second RF power supply 51 is coupled to the lower electrode 12 via the second matching circuit 54 of the matching circuit 52. The second matching circuit 54 is a circuit used to match the output impedance of the second RF power supply 51 with the input impedance of the load side (lower electrode 12 side). Alternatively, instead of the second RF power supply 51, a pulsed power supply configured to apply a pulsed voltage other than RF power to the lower electrode 12 can be used. Here, the pulsed voltage is a pulsed voltage whose magnitude changes periodically. The pulsed power supply can also be a DC power supply. The pulsed power supply can be configured to apply a pulsed voltage itself, or it can be configured to have a device for pulsed voltage on the downstream side. In one example, a pulsed voltage is applied to the lower electrode 12 to generate a negative potential on the wafer W. The pulse voltage can be a rectangular wave, a triangular wave, a pulse wave, or other waveforms. The frequency of the pulse voltage (pulse frequency) can also be in the range of 100kHz to 2MHz. In addition, the aforementioned radio frequency power LF or pulse voltage can also be supplied or applied to the bias electrode disposed inside the electrostatic chuck 13.

[0039] The etching apparatus 1 further includes a first variable passive element 60 and a second variable passive element 61. Starting from the edge ring 14 side, the first variable passive element 60 and the second variable passive element 61 are arranged sequentially. The second variable passive element 61 is connected to ground potential. That is, the second variable passive element 61 is not separately connected to the first RF power supply 50 and the second RF power supply 51.

[0040] In one example, at least one of the first variable passive element 60 and the second variable passive element 61 has variable impedance. The first variable passive element 60 and the second variable passive element 61 can be, for example, either an inductor or a capacitor. Furthermore, not limited to inductors or capacitors, any variable impedance element such as a diode can achieve the same function regardless of its configuration. Those skilled in the art can also appropriately design the number and position of the first variable passive element 60 and the second variable passive element 61. Furthermore, it is not necessary for the elements themselves to be variable; for example, a plurality of elements with fixed impedance values ​​can be used, and a switching circuit can be used to switch the combination of elements with fixed values ​​to make the impedance variable. Additionally, those skilled in the art can appropriately design the circuit configurations of these first variable passive elements 60 and second variable passive elements 61 respectively.

[0041] As shown in Figures 1, 2A, and 2B, the etching apparatus 1 further includes a drive device 70 for longitudinally moving the edge ring 14. The drive device 70 includes a lifting pin 71 that supports the longitudinal movement of the edge ring 14 and a drive source 72 that moves the lifting pin 71 longitudinally.

[0042] A lifting pin 71 extends longitudinally from the bottom surface of the edge ring 14, passing through the electrostatic chuck 13, the lower electrode 12, the support member 17, and the bottom of the chamber 10. The lifting pin 71 is sealed to the chamber 10 to enclose its interior. At least its surface may be formed of an insulating material.

[0043] The drive source 72 is located outside the chamber 10. The drive source 72, for example, has a built-in motor that moves the lifting pin 71 longitudinally. That is, by means of the drive device 70, the edge ring 14 is configured to move arbitrarily longitudinally between the state where it is placed on the electrostatic chuck 13 as shown in FIG. 2A and the state where it is separated from the electrostatic chuck 13 as shown in FIG. 2B.

[0044] A control unit 100 is provided in the etching apparatus 1 described above. The control unit 100, for example, is a computer equipped with a CPU (Central Processing Unit) and memory, and includes a program storage unit (not shown). The program storage unit stores a program for controlling the etching process of the etching apparatus 1. Alternatively, the program can be recorded on a computer-readable recording medium and installed onto the control unit 100. Furthermore, the recording medium can be either transient or non-transient.

[0045] <Etching Method> Next, the etching performed using the etching apparatus 1 configured as described above will be explained.

[0046] First, wafer W is moved into chamber 10 and placed on electrostatic chuck 13. Then, by applying a DC voltage to the first electrode 16a of electrostatic chuck 13, wafer W is electrostatically attracted and held in place by Coulomb force. Furthermore, after wafer W is moved in, the vacuum level inside chamber 10 is reduced to the desired vacuum level using exhaust device 42.

[0047] Next, processing gas is supplied from the gas supply source group 30 to the processing space S via the spray head 20. Furthermore, radio frequency power HF for plasma generation is supplied to the lower electrode 12 by the first radio frequency power supply 50 to excite the processing gas and generate plasma. At this time, radio frequency power LF for iontophoresis can also be supplied by the second radio frequency power supply 51. Then, the generated plasma is used to etch the wafer W.

[0048] At the end of etching, firstly, the supply of radio frequency power HF from the first radio frequency power supply 50 and the supply of processing gas from the gas supply source group 30 are stopped. Furthermore, if radio frequency power LF is supplied during etching, the supply of radio frequency power LF is also stopped. Next, the supply of heat transfer gas to the back side of the wafer W is stopped, and the adsorption and holding of the wafer W by the electrostatic chuck 13 is stopped.

[0049] Subsequently, wafer W is removed from chamber 10, ending a series of etching processes on wafer W.

[0050] In addition, during etching, there are also cases where the RF power HF from the first RF power source 50 is not used, but only the RF power LF from the second RF power source 51 is used to generate plasma.

[0051] <Tilt Angle Control Method> Next, the method for controlling the tilt angle in the above etching process will be explained. The tilt angle refers to the degree of tilt (angle) of the recess formed by etching in the edge region of wafer W relative to the thickness direction of wafer W. The tilt angle is approximately the same as the angle of tilt (ion incident angle) relative to the longitudinal direction of ion incidence towards the edge region of wafer W. Furthermore, in the following explanation, the direction radially inward (center side) relative to the thickness direction (longitudinal direction) of wafer W is referred to as the inner side; the direction radially outward relative to the thickness direction of wafer W is referred to as the outer side.

[0052] Figures 3A and 3B are explanatory diagrams showing the changes in the shape of the sheath and the tilting of the ion incident direction caused by the consumption of the edge ring. In Figure 3A, the edge ring 14 shown by the solid line represents the edge ring 14 in the state without consumption. The edge ring 14 shown by the dashed line represents the edge ring 14 whose thickness has decreased due to consumption. Furthermore, the sheath SH shown by the solid line in Figure 3A shows the shape of the sheath SH when the edge ring 14 is not consumed. The sheath SH shown by the dashed line shows the shape of the sheath SH when the edge ring 14 is consumed. Further, in Figure 3A, the arrows indicate the ion incident direction when the edge ring 14 is consumed.

[0053] As shown in Figure 3A, in one example where the edge ring 14 is not consumed, the shape of the sheath SH remains flat above the wafer W and the edge ring 14. Therefore, ions are injected into the entire surface of the wafer W in a slightly perpendicular direction (longitudinal). Thus, the tilt angle becomes 0 (zero) degrees.

[0054] On the other hand, if the edge ring 14 is consumed, its thickness decreases, and the thickness of the sheath layer SH in the edge region of wafer W and above the edge ring 14 becomes smaller, causing the shape of the sheath layer SH to change to a downward convex shape. As a result, the incident direction of ions relative to the edge region of wafer W tilts longitudinally. In the following description, the phenomenon that the recess formed by etching tilts inward when the incident direction of ions is tilted radially inward (towards the center side) relative to the longitudinal direction is called inner tilt. In Figure 3B, the incident direction of ions tilts inward by an angle θ1, and the recess also tilts inward by θ1. The cause of inner tilt is not limited to the consumption of the edge ring 14. For example, if the bias voltage generated by the edge ring 14 is lower than the voltage on the wafer W side, it will be inner tilt in the initial state. In addition, for example, there are cases where the edge ring 14 is intentionally adjusted to tilt inward in its initial state, and the tilt angle is corrected by adjusting the driving amount of the drive device 70 described later.

[0055] Additionally, as shown in Figures 4A and 4B, the thickness of the sheath layer SH may increase relative to the central region of wafer W, in the edge region of wafer W and above the edge ring 14, causing the sheath layer SH to have an upward convex shape. For example, when the bias voltage generated by the edge ring 14 is high, the shape of the sheath layer SH may become an upward convex shape. In Figure 4A, the arrows indicate the incident direction of the ions. In the following description, the phenomenon that the recess formed by etching tilts outward when the incident direction of the ions is tilted radially outward relative to the longitudinal direction is called outward tilting. In Figure 4B, the incident direction of the ions tilts outward by an angle θ2, and the recess also tilts outward by θ2.

[0056] In the etching apparatus 1 of this embodiment, the tilt angle is controlled. Specifically, at least the driving amount of the driving source 72 of the driving device 70 (the driving amount of the edge ring 14) or the impedance of the second variable passive element 61 is adjusted to control the incident angle of the ions, thereby controlling the tilt angle. Furthermore, although the following embodiment describes the case of adjusting the impedance of the second variable passive element 61, the impedance of the first variable passive element 60 can also be adjusted, or the impedances of both variable passive elements 60 and 61 can also be adjusted.

[0057] [Adjustment of Driving Forces] First, the adjustment of the drive amount of the drive device 70 will be explained. Figure 5 is an explanatory diagram showing the relationship between the drive amount of the drive device 70 and the tilt correction angle (hereinafter referred to as the "tilt correction angle"). The vertical axis of Figure 5 shows the tilt correction angle, and the horizontal axis shows the drive amount of the drive device 70. As shown in Figure 5, if the drive amount of the drive device 70 is increased, the tilt correction angle increases.

[0058] The control unit 100, for example, uses a predetermined function or table to set the drive amount of the drive device 70 based on the consumption amount of the edge ring 14 estimated from the etching process conditions (e.g., processing time) (the reduction amount calculated from the initial value of the thickness of the edge ring 14). That is, the control unit 100 determines the drive amount of the drive device 70 by inputting the consumption amount of the edge ring 14 into the above-mentioned function, or by referring to the above-mentioned table using the consumption amount of the edge ring 14.

[0059] Alternatively, the consumption of edge ring 14 can be estimated based on the etching time of wafer W, the number of wafers processed by wafer W, the thickness of edge ring 14 measured by a measuring instrument, the change in the mass of edge ring 14 measured by a measuring instrument, the change in the peripheral electrical characteristics of edge ring 14 (e.g., voltage and current values ​​at any point on the periphery of edge ring 14) measured by a measuring instrument, or the change in the electrical characteristics of edge ring 14 (e.g., resistance value of edge ring 14) measured by a measuring instrument. Furthermore, the driving intensity of driving device 70 can be increased independently of the consumption of edge ring 14, based on the etching time of wafer W and the number of wafers processed by wafer W. Further, the driving intensity of driving device 70 can also be increased by weighting the etching time of wafer W and the number of wafers processed by wafer W using radio frequency power.

[0060] The specific method for adjusting the drive amount of the drive device 70 to control the tilt angle as described above will be explained. First, the edge ring 14 is placed on the electrostatic chuck 13. At this time, for example, in the edge region of the wafer W and above the edge ring 14, the sheath shape is made flat and the tilt angle is 0 (zero) degrees.

[0061] Next, the wafer W is etched. As the etching process continues, the edge ring 14 is consumed, and its thickness decreases. As a result, as shown in FIG3A, the thickness of the sheath layer SH decreases in the edge region of the wafer W and above the edge ring 14, and the tilt angle changes inward.

[0062] Therefore, the driving amount of the driving device 70 is adjusted. Specifically, based on the consumption of the edge ring 14, the driving amount of the driving device 70 is increased, causing the edge ring 14 to rise. As shown in FIG. 5, the tilt correction angle can be increased, changing the tilt angle that tilts inward to outward. That is, by controlling the shape of the edge ring 14 and the sheath above the edge region of the wafer W, the tilt of ions towards the incident direction of the edge region of the wafer W is reduced, and the tilt angle is controlled. Then, if the edge ring 14 is raised according to the driving amount set by the control unit 100 as described above, the tilt correction angle can be adjusted to the target angle θ3, correcting the tilt angle to 0 (zero) degrees. As a result, a concave portion slightly parallel to the thickness direction of the wafer W is formed, covering the entire area of ​​the wafer W.

[0063] [Impedance Adjustment] Next, the adjustment of the impedance of the second variable passive element 61 will be explained. Figure 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 of Figure 6 shows the tilt correction angle, and the horizontal axis shows the impedance of the second variable passive element 61. As shown in Figure 6, if the impedance of the second variable passive element 61 is increased, the tilt correction angle increases. However, in the example shown in Figure 6, the tilt correction angle increases by increasing the impedance; but depending on the configuration of the second variable passive element 61, the tilt correction angle can also be decreased by increasing the impedance. The relationship between impedance and tilt correction angle depends on the design of the second variable passive element 61 and is therefore not limited.

[0064] Similar to setting the drive amount of the drive device 70, the control unit 100 sets the impedance of the second variable passive element 61 based on the consumption of the edge ring 14. The control unit 100 changes the voltage generated in the edge ring 14 by changing the impedance of the second variable passive element 61.

[0065] In the etching apparatus 1, if the edge ring 14 is consumed, the second variable passive element 61 is controlled to the impedance set by the control unit 100. This controls the shape of the sheath layer above the edge region of the wafer W, reducing the tilt of ions towards the edge region of the wafer W and controlling the tilt angle. Thus, as shown in Figure 6, the tilt correction angle can be adjusted to the target angle θ3, making the tilt angle 0 (zero) degrees.

[0066] [Adjustment of driving force and impedance] Next, the adjustment of the combination of the drive amount of the drive device 70 and the impedance of the second variable passive element 61 will be explained. Figure 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 of Figure 7 shows the tilt correction angle, and the horizontal axis shows the impedance of the second variable passive element 61.

[0067] As shown in Figure 7, firstly, the impedance of the second variable passive element 61 is adjusted to correct the tilt angle. Next, if the impedance reaches a predetermined value, such as the upper limit, the drive amount of the drive device 70 is adjusted to change the tilt correction angle to the target angle θ3, making the tilt angle 0 degrees. This reduces the number of impedance and drive amount adjustments, simplifying the application of tilt angle control.

[0068] Here, the resolution of tilt angle correction resulting from impedance adjustment and the resolution of tilt angle correction resulting from drive quantity adjustment depend on the performance of the second variable passive element 61 and the drive device 70, respectively. The resolution of tilt angle correction is the amount of tilt angle correction in a single adjustment of impedance or drive quantity. Furthermore, for example, if the resolution of the second variable passive element 61 is higher than the resolution of the drive device 70, in this embodiment, the overall resolution of tilt angle correction can be improved by adjusting the impedance of the second variable passive element 61 to correct the tilt angle.

[0069] As described above, in this embodiment, the range of tilt angle adjustment 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 appropriately adjusted, thus enabling uniform etching.

[0070] Furthermore, for example, in cases where the tilt angle is controlled solely by the impedance of the second variable passive element 61, if the impedance reaches the upper limit of the control range of the variable passive element 61, the edge ring 14 must be replaced. Regarding this, in this embodiment, by adjusting the drive amount of the drive device 70, the adjustment range of the tilt angle can be increased without replacing the edge ring 14. Therefore, the replacement interval of the edge ring 14 can be lengthened, suppressing its replacement frequency.

[0071] Furthermore, this embodiment simplifies the application of tilt angle control and improves the resolution of tilt angle correction. In addition, it increases the variability of tilt angle control application.

[0072] Furthermore, in the example shown in Figure 7, although the impedance adjustment and the drive amount adjustment are performed once each, and the tilt correction angle is adjusted to the target angle θ3, the number of times these impedance adjustments and drive amount adjustments are performed is not limited to this configuration. For example, as shown in Figure 8, the impedance adjustment and the drive amount adjustment can be performed multiple times each. In this case, the same effect as in this embodiment can also be obtained.

[0073] Furthermore, in the examples shown in Figures 7 and 8, although the adjustment of the driving amount of the drive device 70 is performed after the adjustment of the impedance of the second variable passive element 61, this order can also be reversed. In this case, firstly, the driving amount of the drive device 70 is adjusted to correct the tilt angle. At this time, if the driving amount of the drive device 70 is too large, a discharge will occur between the wafer W and the edge ring 14. Therefore, the driving amount of the drive device 70 is limited. Therefore, next, if the driving amount reaches a predetermined value, such as an upper limit value, the impedance of the second variable passive element 61 is adjusted to adjust the tilt correction angle to the target angle θ3, so that the tilt angle becomes 0 (zero) degrees. In this case, the same effect as in this embodiment can also be obtained.

[0074] Furthermore, in the above-described embodiment, although the impedance adjustment of the second variable passive element 61 and the drive amount adjustment of the drive device 70 are performed separately, the impedance adjustment and the drive amount adjustment can also be performed simultaneously.

[0075] <Another implementation form> Here, as mentioned above, the frequency of the radio frequency power (biased radio frequency power) LF supplied from the second radio frequency power supply 51 is 400kHz to 13.56MHz, but preferably below 5MHz. When etching is performed on the wafer W with a high aspect ratio, high ion energy is required to achieve the vertical shape of the etched pattern. Therefore, after careful examination by the inventors, it was discovered that by keeping the frequency of the radio frequency power LF below 5MHz, the tracking ability of ions to changes in the radio frequency electric field is improved, and the controllability of ion energy is enhanced.

[0076] On the other hand, if the frequency of the RF power LF is a low frequency below 5MHz, the effect of making the impedance of the second variable passive element 61 variable is reduced. That is, the controllability of the tilt angle resulting from adjusting the impedance of the second variable passive element 61 is reduced. For example, in Figures 2A and 2B, when the electrical connection between the edge ring 14 and the second variable passive element 61 is non-contact or capacitively coupled, even if the impedance of the second variable passive element 61 is adjusted, the tilt angle cannot be properly controlled. Therefore, in this embodiment, the edge ring 14 is directly electrically connected to the second variable passive element 61.

[0077] The edge ring 14 is directly electrically connected to the second variable passive element 61 via the connecting portion. The edge ring 14 contacts the connecting portion, allowing direct current to flow through the connecting portion. Hereinafter, an example of the structure of the connecting portion (hereinafter referred to as the "contact structure") will be described.

[0078] As shown in Figure 9, the connecting portion 200, which serves as a conductor, includes a conductive structure 201 and a conductive elastic member 202. The conductive structure 201 connects the edge ring 14 to the second variable passive element 61 via the 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 top surface of the lower electrode 12, in contact with the conductive elastic member 202.

[0079] A conductive elastic member 202 is disposed, for example, in the space formed between the edge ring 14 and the electrostatic chuck 13. The conductive elastic member 202 and the conductive structure 201 are in contact with the bottom surface of the edge ring 14. Furthermore, the conductive elastic member 202 is made of a conductor, such as a metal. The construction of the conductive elastic member 202 is not particularly limited; examples are shown in Figures 10A to 10F. Figures 10A to 10C show examples of conductive elastic members 202 using an elastomer.

[0080] As shown in Figure 10A, a leaf spring biased longitudinally can be used in the conductive elastic member 202. As shown in Figure 10B, a helical spring wound in a spiral shape and extending horizontally can be used in the conductive elastic member 202. As shown in Figure 10C, a spring wound in a spiral shape and extending longitudinally can be used in the conductive elastic member 202. These conductive elastic members 202 are elastic bodies, and their elastic force acts longitudinally. Through this elastic force, the conductive elastic member 202 makes close contact with the bottom surfaces of the conductive structure 201 and the edge ring 14 with a desired contact pressure, electrically connecting the conductive structure 201 and the edge ring 14.

[0081] As shown in Figure 10D, a pin that moves longitudinally via a drive mechanism (not shown) can be used in the conductive elastic member 202. In this case, by raising the conductive elastic member 202, the conductive elastic member 202 is brought into close contact with the bottom surfaces of the conductive structure 201 and the edge ring 14, respectively. Then, by adjusting the pressure exerted by the conductive elastic member 202 during longitudinal movement, the conductive elastic member 202 is brought into close contact with the bottom surfaces of the conductive structure 201 and the edge ring 14 with the desired contact pressure.

[0082] As shown in Figure 10E, a lead wire can be used to connect the conductive structure 201 to the edge ring 14 in the conductive elastic member 202. One end of the lead wire is bonded to the conductive structure 201, and the other end is bonded to the bottom surface of the edge ring 14. This bonding of the lead wire can be achieved by making ohmic contact with the bottom surface of either the conductive structure 201 or the edge ring 14; for example, the lead wire can be fused or crimped. In the case where a lead wire is used in the conductive elastic member 202, the conductive elastic member 202 contacts the bottom surfaces of both the conductive structure 201 and the edge ring 14, electrically connecting the conductive structure 201 and the edge ring 14.

[0083] In the above cases, when using any of the conductive elastic members 202 shown in Figures 10A to 10E, the edge ring 14 can be directly electrically connected to the second variable passive element 61 via the connecting portion 200 as shown in Figure 9. Therefore, the frequency of the radio frequency power LF can be made to be low frequency below 5MHz, which can improve the controllability of ion energy.

[0084] Furthermore, when adjusting the drive amount of the drive device 70 to control the tilt angle, the adjusted drive amount can be reduced in the setting portion of the connection portion 200. As a result, discharge between the wafer W and the edge ring 14 can be suppressed. Further, as described above, by adjusting the drive amount of the drive device 70 and the impedance of the second variable passive element 61, the adjustment range of the tilt angle can be increased, and the tilt angle can be controlled to the desired value.

[0085] Furthermore, in the above-described embodiment, although the conductive elastic member 202 includes, for example, the leaf spring shown in FIG10A, the helical spring shown in FIG10B, the spring shown in FIG10C, the pin shown in FIG10D, and the lead wire shown in FIG10E, these can also be used in combination.

[0086] Alternatively, in the connecting portion 200 of the above embodiment, as shown in FIG10F, a conductive film 203 may be provided between the conductive elastic member 202 and the edge ring 14 of the connecting portion 200. For example, a metal film may be used for the conductive film 203. The conductive film 203 is provided at least in the portion of the bottom surface of the edge ring 14 that contacts the conductive elastic member 202. The conductive film 203 may also be provided on the entire bottom surface of the edge ring 14, or a plurality of conductive films 203 may be configured in a near-ring shape. In either case, the resistance generated by the contact of the conductive elastic member 202 can be suppressed by the conductive film 203, allowing the edge ring 14 to be appropriately connected to the second variable passive element 61.

[0087] The connecting portion 200 in the above embodiment should have a configuration that protects the conductive elastic member 202 from plasma when the edge ring 14 is raised by the driving device 70. Figures 11A to 11G show examples of plasma countermeasures for the conductive elastic member 202.

[0088] Alternatively, as shown in Figure 11A, protrusions 14a and 14b can be provided on the bottom surface of the edge ring 14, protruding downwards from the bottom surface. In the illustrated example, protrusion 14a is located radially inner to the conductive elastic member 202, and protrusion 14b is located radially outer to the conductive elastic member 202. That is, the conductive elastic member 202 is located in the recess formed by the protrusions 14a and 14b. In this case, the protrusions 14a and 14b can suppress plasma from winding back to the conductive elastic member 202, thus protecting the conductive elastic member 202.

[0089] Furthermore, in the example of Figure 11A, although protrusions 14a and 14b are provided on the bottom surface of the edge ring 14, the shape for suppressing plasma swirling is not limited to this form and can be determined according to the etching apparatus 1. In addition, the shape of the edge ring 14 can be determined in such a way that the edge ring 14 can be appropriately moved longitudinally by the drive device 70.

[0090] Alternatively, as shown in Figure 11B, an additional edge ring 210 can be provided inside the conductive elastic member 202 between the edge ring 14 and the electrostatic chuck 13. The additional edge ring 210 is formed of an insulating material. The additional edge ring 210 is configured as a member separate from the lower electrode 12, for example, having a circular shape. In this case, by adding the edge ring 210, plasma can be prevented from winding back to the conductive elastic member 202, thus protecting the conductive elastic member 202.

[0091] Alternatively, as shown in Figure 11C, the protrusion 14a of the edge ring 14 shown in Figure 11A and the additional edge ring 210 shown in Figure 11B can be provided. In this case, the protrusion 14a and the additional edge ring 210 can further suppress plasma entanglement and protect the conductive elastic member 202.

[0092] Alternatively, as shown in Figure 11D, the protrusions 14a and 14b of the edge ring 14 shown in Figure 11A, and the additional edge ring 210 shown in Figure 11B can be provided. The conductive elastic member 202 contacts the protrusion 14b. Furthermore, the additional edge ring 210 is provided between the protrusions 14a and 14b. In this case, the protrusions 14a and 14b and the additional edge ring 210 form a curved structure, which can further suppress plasma entanglement and protect the conductive elastic member 202.

[0093] Alternatively, as shown in Figure 11E, the edge ring 14 can be divided into an upper edge ring 140 and a lower edge ring 141. The upper edge ring 140 corresponds to the edge ring disclosed in this invention, and the lower edge ring 141 corresponds to the additional edge ring disclosed in this invention. The upper edge ring 140 can move arbitrarily in the longitudinal direction by means of the driving device 70. The lower edge ring 141 does not move in the longitudinal direction. The conductive elastic member 202 is provided in contact with the bottom surface of the upper edge ring 140 and the top surface of the lower edge ring 141. The conductive structure 201 is connected to the lower edge ring 141. In this case, the upper edge ring 140 is directly electrically connected to the second variable passive element 61 through the conductive elastic member 202, the lower edge ring 141, and the conductive structure 201.

[0094] On the bottom surface of the upper edge ring 140, a protrusion 140a is provided at the outermost periphery, protruding downward from the bottom surface. On the top surface of the lower edge ring 141, a protrusion 141a is provided at the innermost periphery, protruding upward from the top surface. In this case, the protrusions 140a and 141a can prevent plasma from winding back to the conductive elastic member 202, thus protecting the conductive elastic member 202.

[0095] Figure 11F is a variation of Figure 11E. In the example shown in Figure 11E, the conductive structure 201 is connected to the lower edge ring 141, but in the example shown in Figure 11F, one end of the conductive structure 201 is exposed on the top surface of the lower electrode 12 and contacts the conductive elastic member 220. The conductive elastic member 220 is provided on the radially outer side of the electrostatic chuck 13, forming a space between the bottom surface of the lower edge ring 141 and the top surface of the lower electrode 12. That is, the conductive elastic member 220 and the bottom surface of the lower edge ring 141 are in contact with the conductive structure 201. In this case, the upper edge ring 140 is directly electrically connected to the second variable passive element 61 via the conductive elastic member 202, the lower edge ring 141, the conductive elastic member 220, and the conductive structure 201. In this example, the protrusions 140a and 141a can also suppress plasma from winding back to the conductive elastic member 202, thus protecting the conductive elastic member 202.

[0096] Figure 11G is a variation of Figure 11E. In the example shown in Figure 11E, the conductive elastic member 202 is disposed on the top surface of the lower edge ring 141, but in the example shown in Figure 11G, the conductive elastic member 202 is disposed on the top surface of the lower electrode 12. The conductive elastic member 202 and the bottom surface of the upper edge ring 140 are in contact with the conductive structure 201. One end of the conductive structure 201 is exposed on the top surface of the electrostatic chuck 13 and is in contact with the conductive elastic member 202. In this case, the upper edge ring 140 is directly electrically connected to the second variable passive element 61 via the conductive elastic member 202 and the conductive structure 201. In this example, the protrusions 140a and 141a can also suppress plasma from winding back to the conductive elastic member 202, thus protecting the conductive elastic member 202.

[0097] Alternatively, in the above embodiments, the configurations shown in Figures 11A to 11G can be used in combination. Furthermore, in the connecting portion 200, a plasma-resistant coating can be applied to the surface of the conductive elastic member 202, except for the portion in contact with the edge ring 14. In this case, the conductive elastic member 202 can be protected from plasma.

[0098] Next, the top view configuration of the conductive elastic member 202 will be described. Figures 12A to 12C show examples of planar configurations of the conductive elastic member 202. As shown in Figures 12A and 12B, the connecting portion 200 may also include a plurality of conductive elastic members 202; the plurality of conductive elastic members 202 are provided at equal intervals on a circle concentric with the edge ring 14. In the example of Figure 12A, the conductive elastic member 202 is provided at 8 locations; in Figure 12B, the conductive elastic member 202 is provided at 24 locations. Furthermore, as shown in Figure 12C, the conductive elastic member 202 may also be provided in a ring shape on a circle concentric with the edge ring 14.

[0099] From the viewpoint of uniformly performing etching to achieve a uniform shape of the sheath (the viewpoint of process uniformity), it is preferable to arrange the conductive elastic member 202 in a ring shape for the edge ring 14, as shown in FIG12C, so that the contact with the edge ring 14 is uniformly performed on the circumference. Furthermore, from the same viewpoint of process uniformity, in the case of setting a plurality of conductive elastic members 202 as shown in FIGS. 12A and 12B, it is also preferable to arrange these plurality of conductive elastic members 202 at equal intervals around the edge ring 14, so that the contact points with the edge ring 14 are arranged in a point-symmetric manner. Moreover, compared to the example of FIG12A, it is preferable to increase the number of conductive elastic members 202, as in the example of FIG12B, and to make it closer to a ring shape as shown in FIG12C. In addition, the number of conductive elastic members 202 is not particularly limited; to ensure symmetry, it is preferable to have three or more, for example, three to 36.

[0100] However, in terms of device configuration, in order to avoid interference with other components, it is difficult to make the conductive elastic member 202 ring-shaped or to increase the number of conductive elastic members 202. Therefore, the planar arrangement of the conductive elastic member 202 can also be appropriately set in view of the conditions for processing uniformity, the constraints of device configuration, etc.

[0101] Next, the relationship between the connecting part 200, the first variable passive element 60, and the second variable passive element 61 will be explained. Figures 13A to 13C show examples of the configuration of the connecting part 200, the first variable passive element 60, and the second variable passive element 61, respectively.

[0102] As shown in Figure 13A, for example, when one of each of the eight conductive elastic members 202 (first variable passive element 60 and second variable passive element 61) is provided, the connection portion 200 can also include a relay member 230. Furthermore, although Figure 13A illustrates the case where the relay member 230 is provided in the connection portion 200 shown in Figure 12A, the relay member 230 can also be provided in the connection portion 200 shown in either Figure 12B or Figure 12C. In addition, a plurality of relay members 230 can also be provided.

[0103] The relay member 230 is arranged in a ring shape on a circle concentric 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 structure 201a via the conductive elastic member 202. That is, starting from the relay member 230, eight conductive structures 201a extend radially in top view and are respectively connected to eight conductive elastic members 202. In addition, 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.

[0104] In this case, for example, even if the second variable passive element 61 is not positioned at the center of the edge ring 14, the electrical characteristics (arbitrary voltage and current values) of the relay member 230 can still be uniformly applied around the circumference, and the electrical characteristics of each of the eight conductive elastic members 202 can be further uniformized. As a result, etching can be performed uniformly, and the shape of the sheath can be made uniform.

[0105] As shown in Figure 13B, for example, for eight conductive elastic members 202, a plurality of, for example, eight first variable passive elements 60 can be provided, and one second variable passive element 61 can be provided. In this way, the number of first variable passive elements 60 can be appropriately set according to the number of conductive elastic members 202. Alternatively, in the example of Figure 13B, a relay member 230 can also be provided.

[0106] As shown in Figure 13C, for example, for the eight conductive elastic members 202, a plurality of, for example, eight first variable passive elements 60 and a plurality of, for example, eight second variable passive elements 61 can be provided. In this way, the number of second variable passive elements 61 with variable impedance can be appropriately set for the number of conductive elastic members 202. In the example of Figure 13C, a relay member 230 can also be provided.

[0107] Furthermore, by providing multiple second variable passive elements 61 with variable impedance, the electrical characteristics of each of the multiple conductive elastic members 202 can be controlled independently. As a result, the electrical characteristics of each of the multiple conductive elastic members 202 can be homogenized, thereby improving the uniformity of processing.

[0108] Next, as for the contact structure of the edge ring 14, examples other than those shown in Figures 9 and 10A to 10F will be described. Figures 14A to 14D and Figures 15A to 15D show other examples of the connection configuration.

[0109] Figures 14A to 14D show examples of lifting pins 300 formed of insulating material for drive devices 70, with connecting portions 310 serving as conductors provided inside the lifting pins 300.

[0110] As shown in Figure 14A, the drive device 70 can also replace the lifting pin 71 in the above embodiment, and includes a lifting pin 300. The lifting pin 300 extends longitudinally from the bottom surface of the edge ring 14, passing through the electrostatic chuck 13, the lower electrode 12, the support member 17, and the bottom of the chamber 10. The lifting pin 300 is sealed to the chamber 10 to seal its interior. The lifting pin 300 is made of insulating material. Furthermore, the lifting pin 300 can be moved arbitrarily longitudinally by a drive source 72 located outside the chamber 10.

[0111] Inside the lifting pin 300, a conductive lead extending longitudinally is provided, namely a connecting part 310. The connecting part 310 directly connects the edge ring 14 to the lifting pin 300 and connects the edge ring 14 to the second variable passive element 61. Specifically, the connecting part 310 has one end connected to the second variable passive element 61, and the other end exposed on the top surface of the lifting pin 300 and in contact with the bottom surface of the edge ring 14.

[0112] As shown in Figures 14B and 14C, the connecting portion 310 disposed inside the lifting pin 300 may also have a conductive structure 311 and a conductive elastic member 312. The conductive structure 311 connects the edge ring 14 to the second variable passive element 61 via the 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 lifting pin 300, contacting the conductive elastic member 312.

[0113] A conductive elastic member 312 is disposed in the upper space inside the lifting pin 300. The conductive elastic member 312 contacts the bottom surface of the conductive structure 311 and the edge ring 14. Furthermore, the conductive elastic member 312 is made of a conductor such as metal. The construction of the conductive elastic member 312 is not particularly limited; for example, a longitudinally biased elastic leaf spring can be used as shown in FIG. 14B, or a lead wire connecting the conductive structure 311 and the edge ring 14 can be used as shown in FIG. 14C. Alternatively, a helical spring as shown in FIG. 10B, a spring as shown in FIG. 10C, or a pin as shown in FIG. 10D can be used in the conductive elastic member 312. In these cases, the edge ring 14 is directly electrically connected to the second variable passive element 61 via the conductive elastic member 312 and the conductive structure 311.

[0114] As shown in Figure 14D, the lifting pin 300 can also be a hollow cylindrical shape with openings at the top and bottom surfaces. The connecting portion 310 located inside the lifting pin 300, in addition to having a conductive structure (first conductive structure) 311 and a conductive elastic member 312, also has another conductive structure (second conductive structure) 313. The conductive structure 313 is located on the inner side of the lifting pin 300. The conductive structure 313 can be, for example, a metal film or a metal cylinder.

[0115] The lower ends of conductive structure 311 and conductive structure 313 are connected. The upper ends of conductive elastic member 312 and conductive structure 313 are connected. In this case, the edge ring 14 is directly electrically connected to the second variable passive element 61 via conductive elastic member 312, conductive structure 313, and conductive structure 311.

[0116] In all cases where any of the connection portions 310 shown in Figures 14A to 14D is used, the edge ring 14 can be directly electrically connected to the second variable passive element 61 via the connection portion 310. Therefore, the frequency of the radio frequency power LF can be made low-frequency, below 5MHz, which can improve the controllability of ion energy.

[0117] Furthermore, the connecting part 310 in the above embodiment is located inside the lifting pin 300 formed of insulating material, and therefore may not have a structure to protect it from plasma.

[0118] Figures 15A to 15D show examples of lifting pins 400 of the drive device 70 made of conductive material, whereby the lifting pin 400 itself constitutes a connecting part.

[0119] As shown in Figure 15A, the drive device 70 can also replace the lifting pins 71 and 300 in the above embodiments, and includes a lifting pin 400. The lifting pin 400 extends longitudinally from the bottom surface of the edge ring 14, passing through the electrostatic chuck 13, the lower electrode 12, the support member 17, and the bottom of the chamber 10. The lifting pin 400 is sealed to the chamber 10 to seal its interior. The lifting pin 400 is made of a conductive material. Furthermore, the lifting pin 400 can be moved arbitrarily longitudinally by a drive source 72 located outside the chamber 10.

[0120] A conductive structure 410 is connected to the lower end of the lifting pin 400. The conductive structure 410 is connected to the second variable passive element 61. In this case, the edge ring 14 is directly electrically connected to the second variable passive element 61 via the lifting pin 400 and the conductive structure 410.

[0121] The aforementioned lifting pin 400 should preferably have a configuration that protects the edge ring 14 from plasma when it is raised by the drive device 70. Figures 15B and 15C show examples of plasma countermeasures for the lifting pin 400.

[0122] As shown in Figure 15B, an additional edge ring 210 as shown in Figure 11B can also be provided on the top surface of the electrostatic chuck 13, inside the lifting pin 400. In this case, the additional edge ring 210 can suppress plasma from winding back to the lifting pin 400, thus protecting the lifting pin 400. Furthermore, the configuration for suppressing plasma winding is not limited to this form; any of the configurations shown in Figures 11A, 11C, and 11G can also be used.

[0123] As shown in Figure 15C, an insulating member 401 with plasma resistance can also be provided on the outer side of the lifting pin 400. The insulating member 401 can be, for example, an insulating film or an insulating cylinder. In this case, the insulating member 401 can protect the lifting pin 400 from plasma. Alternatively, the insulating member 401 shown in Figure 15C can be further provided in the configuration shown in Figure 15B.

[0124] In any of the cases shown in Figures 15A to 15C, the edge ring 14 can be directly electrically connected to the second variable passive element 61 via the lifting pin 400. Therefore, the frequency of the radio frequency power LF can be set to a low frequency below 5MHz, improving the controllability of ion energy.

[0125] Furthermore, although the lifting pin 400 itself constitutes a connecting portion in Figures 15A-15C, as shown in Figure 15D, a connecting portion 420 serving as a conductor can also be further provided inside the lifting pin 400. The connecting portion 420 may also include a conductive structure 421 and a conductive elastic member 422. The conductive structure 421 connects the edge ring 14 to the second variable passive element 61 via the 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 lifting pin 400, contacting the conductive elastic member 422. Additionally, the aforementioned conductive structure 410 is included within the conductive structure 421.

[0126] A conductive elastic member 422 is disposed in the upper space inside the lifting pin 400. The conductive elastic member 422 contacts both the conductive structure 421 and the bottom surface of the edge ring 14. Furthermore, the conductive elastic member 422 is made of a conductor, such as metal. The construction of the conductive elastic member 422 is not particularly limited; for example, a longitudinally biasing leaf spring as shown in FIG. 10A can be used. Alternatively, a helical spring as shown in FIG. 10B, a spring as shown in FIG. 10C, a pin as shown in FIG. 10D, or a lead wire as shown in FIG. 10E can also be used. In these cases, the edge ring 14 and the second variable passive element 61 are directly electrically connected, not only via the lifting pin 400 but also via the conductive elastic member 422 and the conductive structure 421. Furthermore, the resistance generated by the contact between the lifting pin 400 and the conductive elastic member 422 can be suppressed, thus allowing for a more appropriate connection between the edge ring 14 and the second variable passive element 61.

[0127] <Another implementation form> In the etching apparatus 1 of the above embodiment, as shown in FIG16, a DC (Direct Current) power supply 62, a switching unit 63, a first RF filter 64, and a second RF filter 65 may be further provided. The first RF filter 64 and the second RF filter 65 are respectively provided in place of the first variable passive element 60 and the second variable passive element 61. Starting from the edge ring 14 side, the first RF filter 64, the second RF filter 65, the switching unit 63, and the DC power supply 62 are arranged sequentially. 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. In addition, in this embodiment, the DC power supply 62 is connected to the ground potential.

[0128] The DC power supply 62 is a power source that generates a negative DC voltage applied to the edge ring 14. Furthermore, the DC power supply 62 is a variable DC power supply, allowing adjustment of the DC voltage level.

[0129] The switching unit 63 can stop the application of DC voltage from the DC power supply 62 to the edge ring 14. Furthermore, those skilled in the art can appropriately design the circuit configuration of the switching unit 63.

[0130] The first RF filter 64 and the second RF filter 65 are filters that attenuate RF power. The first RF filter 64, for example, attenuates RF power of 40 MHz from the first RF power supply 50. The second RF filter 65, for example, attenuates RF power of 400 kHz from the second RF power supply 51.

[0131] In one example, the second RF filter 65 has variable impedance. That is, the second RF filter 65 includes at least one variable passive element, thus having variable impedance. The variable passive element can be, for example, either an inductor or a capacitor. Furthermore, it is not limited to inductors or capacitors; any variable impedance element, such as a diode, can achieve the same function. Those skilled in the art can also appropriately design the number and position of the variable passive elements. Furthermore, it is not necessary for the element itself to be variable; for example, it can have a plurality of elements with fixed impedance values, and a switching circuit can be used to switch the combination of elements with fixed values ​​to make the impedance variable. Additionally, those skilled in the art can appropriately design the circuit configurations of this second RF filter 65 and the aforementioned first RF filter 64.

[0132] Furthermore, the etching apparatus 1 may also be equipped with 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 the wafer W). Additionally, those skilled in the art can appropriately design the configuration of the measuring device.

[0133] Next, the method for controlling the tilt angle using the etching apparatus 1 of this embodiment will be described. In this embodiment, in addition to adjusting the drive amount of the drive device 70 and the impedance of the second RF filter 65 as described in the previous embodiment, the DC voltage from the DC power supply 62 is adjusted. That is, at least two of the following are adjusted to control the tilt angle: the drive amount of the drive device 70, the impedance of the second RF filter 65, and the DC voltage from the DC power supply 62. Figures 17 and 18 show examples of the tilt angle control method of this embodiment.

[0134] In the example shown in Figure 17, firstly, the impedance of the second RF filter 65 is adjusted to correct the tilt angle. Then, if the impedance reaches a predetermined value, such as the upper limit, the DC voltage from the DC power supply 62 is adjusted to adjust the tilt correction angle to the target angle θ3, making the tilt angle 0 (zero) degrees.

[0135] In the DC power supply 62, the DC voltage applied to the edge ring 14 is set to be the voltage with the absolute value of the self-bias voltage Vdc and the set value ΔV as the negative polarity of its absolute value, that is, it is set to -(|Vdc|+ΔV). The self-bias voltage Vdc is the self-bias voltage of the wafer W, which supplies RF power to one or both of them, and is the self-bias voltage of the lower electrode 12 when no DC voltage from the DC power supply 62 is applied to the lower electrode 12. The set value ΔV is given by the control unit 100.

[0136] The control unit 100, similar to the setting of the drive quantity of the drive device 70 and the setting of the impedance of the second RF filter 65 in the above embodiment, sets the impedance of the second RF filter 65 based on the consumption of the edge ring 14. The set value ΔV is determined.

[0137] In determining the setpoint ΔV, the control unit 100 may use the difference between the initial thickness of the edge ring 14 and the thickness of the edge ring 14 measured by a measuring instrument such as a laser measuring instrument or a camera as the consumption of the edge ring 14. Alternatively, the consumption of the edge ring 14 may be estimated from the change in the mass of the edge ring 14 measured by a measuring instrument such as a mass meter. Or, the control unit 100 may use a pre-determined function or table to estimate the consumption of the edge ring 14 from specific parameters in order to determine the setpoint ΔV. These specific parameters may be any one of the following: self-bias voltage Vdc, the peak value Vpp of the RF power HF or RF power LF, load impedance, or the peripheral electrical characteristics of the edge ring 14. The peripheral electrical characteristics of the edge ring 14 may be any one of the following: voltage, current, or resistance value including the edge ring 14 at any point around the edge ring 14. Another function or table is predetermined to determine the relationship between specific parameters and the consumption of edge ring 14. To estimate the consumption of edge ring 14, before actual etching or during maintenance of etching apparatus 1, etching apparatus 1 is operated under the settings for estimating consumption, namely, RF power HF, RF power LF, pressure within processing space S, and flow rate of processing gas supplied to processing space S. Then, the aforementioned specific parameters are obtained, and the consumption of edge ring 14 is indicated by inputting these specific parameters into the aforementioned function or by referring to the aforementioned table using these specific parameters.

[0138] In the etching apparatus 1, during etching, that is, during the supply of radio frequency power (RF power HF and RF power LF) or both, a DC voltage is applied to the edge ring 14 from the DC power supply 62. This controls the shape of the sheath layer above the edge ring 14 and the edge region of the wafer W, reduces the tilt of ions towards the edge region of the wafer W, and controls the tilt angle. As a result, a recess is formed covering the entire area of ​​the wafer W, slightly parallel to the thickness direction of the wafer W.

[0139] More specifically, during etching, the self-bias voltage Vdc is measured using a measuring instrument (not shown). Furthermore, 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, as described above, -(|Vdc|+ΔV). |Vdc| is the absolute value of the self-bias voltage Vdc measured immediately preceding it by the measuring instrument; ΔV is a set value determined by the control unit 100. Thus, the DC voltage applied to the edge ring 14 is determined by the self-bias voltage Vdc measured during etching. In this way, 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 adjusted.

[0140] Furthermore, in the example shown in Figure 17, the impedance of the second RF filter 65 can also be replaced to adjust the driving amount of the drive device 70. That is, the driving amount of the drive device 70 and the DC voltage from the DC power supply 62 can also be adjusted to correct the tilt angle.

[0141] In the example shown in Figure 18, firstly, the impedance of the second RF filter 65 is adjusted to correct the tilt angle. Then, if the impedance reaches a predetermined value, such as the upper limit, the DC voltage from the DC power supply 62 is adjusted to correct the tilt angle.

[0142] Here, if the absolute value of the DC voltage is too high, a discharge will occur between the wafer W and the edge ring 14. Therefore, there is a limit to the DC voltage that can be applied to the edge ring 14, and even if an attempt is made to control the tilt angle solely by adjusting the DC voltage, the control range is still limited.

[0143] Therefore, if the absolute value of the DC voltage reaches a predetermined value, such as the upper limit, the driving amount of the drive device 70 is adjusted to adjust the tilt correction angle to the target angle θ3, so that the tilt angle becomes 0 (zero) degrees.

[0144] As described above, in this embodiment, in addition to adjusting the impedance of the second RF filter 65 and the driving amount of the driving device 70, the adjustment range of the tilt angle can be increased by adjusting the DC voltage from the DC power supply 62. Therefore, the tilt angle can be appropriately controlled, that is, the incident direction of the ions can be appropriately adjusted, so etching can be performed uniformly.

[0145] Furthermore, when controlling the tilt angle, the impedance adjustment of the second RF filter 65, the drive quantity adjustment of the drive device 70, and the combination of DC voltage from the DC power supply 62 can be arbitrarily designed.

[0146] Furthermore, although the impedance adjustment of the second radio frequency filter 65, the drive quantity adjustment of the drive device 70, and the DC voltage adjustment from the DC power supply 62 are performed separately, these adjustments can also be performed simultaneously.

[0147] 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. However, the power supply system applying DC voltage to the edge ring 14 is not limited to this embodiment. For example, the DC power supply 62 may also 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 lower electrode 12. In this case, the lower electrode 12 and the edge ring 14 are directly electrically coupled, and the self-bias voltage of the edge ring 14 becomes the same as the self-bias voltage of the lower electrode 12.

[0148] Here, when the lower electrode 12 is directly electrically coupled to the edge ring 14, for example, due to the capacitance under the edge ring 14 determined by the hardware structure, the sheath thickness on the edge ring 14 cannot be adjusted, and the object may tilt outward even without a DC voltage applied. Regarding this point, in this invention, 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. Therefore, by changing the tilt angle inward, the tilt angle can be adjusted to 0 (zero) degrees.

[0149] Furthermore, in the above embodiment, although the second RF filter 65 has variable impedance, the first RF filter 64 can also have variable impedance, or both RF filters 64 and 65 can have variable impedance. In this case, the first RF filter 64 includes at least one variable passive element. Moreover, in the above embodiment, although two RF filters 64 and 65 are provided for the DC power supply 62, the number of RF filters is not limited to this configuration; for example, it can be one. Furthermore, in the above embodiment, although the second RF filter 65 (first RF filter 64) includes at least one variable passive element to make its impedance variable, the configuration for making the impedance variable is not limited to this configuration. For example, a device that makes the impedance of a RF filter variable or fixed impedance can be connected to it. That is, a RF filter that makes its impedance variable can also be composed of a RF filter and a device connected to it that makes its impedance variable. In addition, although the RF filter can include at least one variable passive element to make its impedance variable, it is also possible to use an RF filter with non-variable impedance and to set the variable passive element outside the RF filter.

[0150] <Another implementation form> In the above embodiment, the drive quantity of the drive device 70, the impedance of the second variable passive element 61 (second RF filter 65), and the DC voltage from the DC power supply 62 are adjusted according to the consumption of the edge ring 14. However, the timing of the adjustment of the drive quantity, impedance, and DC voltage is not limited to this embodiment. For example, the drive quantity, impedance, and DC voltage can also be adjusted according to the processing time of the wafer W. Alternatively, the timing of the adjustment of the drive quantity, impedance, and DC voltage can be determined by combining the processing time of the wafer W with predetermined parameters such as RF power.

[0151] <Another implementation form> The etching apparatus 1 described above is a capacitively coupled etching apparatus, but the etching apparatus used in this invention is not limited to this form. For example, the etching apparatus can also be an inductively coupled etching apparatus.

[0152] The embodiments disclosed herein are for illustrative purposes only and are not intended to limit the invention. The aforementioned embodiments may also be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended patent application.

[0153] The embodiments of the present invention further include the following forms.

[0154] (Note 1) A plasma treatment apparatus, comprising: Plasma treatment chamber; A substrate support is disposed within the plasma processing chamber. The substrate support includes a lower electrode, an electrostatic chuck, and an edge ring surrounding the substrate mounted on the electrostatic chuck. The drive mechanism moves the edge ring longitudinally; The upper electrode is positioned above the substrate support. A source radio frequency power supply provides radio frequency power to the upper electrode or the lower electrode in order to generate plasma from the gas in the plasma processing chamber; A bias RF power supply provides bias RF power to the lower electrode. At least one conductor is in contact with the edge ring; A DC power supply applies 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 supply, includes at least one variable passive element; and The control unit controls the drive device and the at least one variable passive element to adjust the incident angle of the ions in the plasma onto the edge region of the substrate placed on the electrostatic chuck.

[0155] (Note 2) As described in Note 1, the plasma treatment apparatus, wherein, The drive unit includes: Lifting pins support the edge ring; and The driving source causes the lifting pin to move longitudinally.

[0156] (Note 3) As described in Note 2, the plasma treatment apparatus, wherein, The lifting pin, at least its surface, is formed of insulating material.

[0157] (Note 4) As described in Note 3, the plasma treatment apparatus, wherein, The at least one conductor is contained within the lifting pin and is a conductive lead extending longitudinally. One end of the conductive lead is in contact with the edge ring.

[0158] (Note 5) As described in Note 3, the plasma treatment apparatus, wherein, The at least one conductor includes a conductive elastic member in contact with the edge ring.

[0159] (Note 6) As described in Note 5, the plasma treatment apparatus, in which, The conductive elastic component is disposed within the lifting pin.

[0160] (Note 7) As described in Note 5, the plasma treatment apparatus, in which, The conductive elastic member is disposed between the edge ring and the electrostatic chuck.

[0161] (Note 8) As described in Note 7, the plasma treatment apparatus, wherein, It also features an additional edge ring, which is positioned between the edge ring and the electrostatic chuck.

[0162] (Note 9) As described in Note 8, the plasma treatment apparatus, in which, The additional edge ring, formed of an insulating material, is positioned further inside the conductive elastic member.

[0163] (Note 10) As described in Note 9, the plasma treatment apparatus, in which, The edge ring has a protrusion on its bottom surface.

[0164] (Note 11) As described in Note 8, the plasma treatment apparatus, in which, The additional edge ring is formed of a conductive material; The conductive elastic member is disposed between the edge ring and the additional edge ring.

[0165] (Note 12) As described in any of Notes 1 to 11, the plasma processing apparatus, wherein, The edge ring has at least one conductive film in contact with the at least one conductor.

[0166] (Note 13) As described in any of Notes 1 to 11, the plasma processing apparatus, wherein, The at least one conductor comprises a plurality of conductors arranged at equal intervals along the circumference of the edge ring when viewed from above.

[0167] (Note 14) As described in any of Notes 1 to 11, the plasma processing apparatus, wherein, The edge ring is conductive.

[0168] (Note 15) A plasma treatment apparatus, comprising: Plasma treatment chamber; A substrate support is disposed within the plasma processing chamber. The substrate support includes an electrostatic chuck and an edge ring surrounding the substrate mounted on the electrostatic chuck. The drive mechanism moves the edge ring longitudinally; Radio frequency (RF) power supply, used to generate RF power by producing plasma from the gas within the plasma processing chamber; At least one conductor is in contact with the edge ring; At least one variable passive element, and electrically connected to the at least one conductor; and The control unit controls the drive device and the at least one variable passive element to adjust the incident angle of the ions in the plasma onto the edge region of the substrate placed on the electrostatic chuck.

[0169] (Note 16) As described in Note 15, the plasma processing apparatus, wherein, The drive unit includes: Lifting pins support the edge ring; and The driving source causes the lifting pin to move longitudinally.

[0170] (Note 17) As described in Note 16, the plasma processing apparatus, wherein, The lifting pin, at least its surface, is formed of insulating material.

[0171] (Note 18) As described in Note 17, the plasma processing apparatus, wherein, The at least one conductor is contained within the lifting pin and is a conductive lead extending longitudinally. One end of the conductive lead is electrically and physically connected to the edge ring.

[0172] (Note 19) An etching method using a plasma treatment device, The plasma processing device includes: Plasma treatment chamber; A substrate support is disposed within the plasma processing chamber. The substrate support includes an electrostatic chuck and an edge ring surrounding the substrate mounted on the electrostatic chuck. At least one conductor is electrically and physically connected to the edge ring; and At least one variable passive element is electrically connected to the at least one conductor; The etching method includes the following steps: (a) The substrate is placed on the electrostatic chuck; (b) Plasma is generated from the gas within the plasma processing chamber; (c) Etching the substrate with the generated plasma; and (d) Adjust the incident angle of the ions in the plasma at the edge region of the substrate; The adjustment process includes the following steps: (d1) Move the edge ring longitudinally; and (d2) Adjust the at least one variable passive element.

[0173] 1: Etching device 10: Chamber 11: Platform 12: Lower electrode 13: Electrostatic chuck 14,210: Edge ring 14a, 14b, 140a, 141a: Protrusions 15a:Flow path 15b:Inlet piping 15c:Exit flow path 16a: Electrode 1 16b: Second electrode 17: Supporting components 20: Spray head 21: Electrode plate 21a: Gas ejection outlet 22: Electrode support 22a: Gas diffusion chamber 22b: Gas flow hole 22c: Gas inlet port 23: Insulating shielding components 30: Gas supply source group 31: Flow control machine group 32: Valve Group 33: Gas supply pipe 40: baffle 41: Exhaust port 42: Exhaust device 43:Move out entrance 44: Gate valve 50: First RF power supply 51: Second RF power supply 52: Matcher 53: First Matching Circuit 54: Second Matching Circuit 60: First Variable Passive Element 61: Second Variable Passive Element 62: DC power supply 63: Switching Unit 64: First RF Filter 65: Second RF Filter 70: Drive unit 71,300,400: Lifting pins 72: Driver Source 100: Control Department 140: Upper edge ring 141: Lower edge ring 200, 310, 420: Connecting parts 201,201a,201b,311,313,410,421: Conductive Structure 202,220,312,422: Conductive elastic components 203: Conductive film 230: Relay component 401: Insulating components S: Processing space SH: Sheath W: Wafer

Claims

1. A plasma processing apparatus, comprising: 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 surrounding a substrate mounted on the electrostatic chuck; a driving device for raising the edge ring; a source radio frequency power supply for supplying source radio frequency power to generate plasma from gas within the plasma processing chamber; a bias radio frequency power supply for supplying bias radio frequency power to the lower electrode; at least one conductor in contact with the edge ring after it has been raised by the driving device; a DC power supply for applying a DC voltage to the edge ring via the at least one conductor; a radio frequency filter electrically connected between the at least one conductor and the DC power supply, including at least one variable passive element; and a control unit for controlling the driving device and the at least one variable passive element to adjust the incident angle of ions in the plasma onto the edge region of the substrate mounted on the electrostatic chuck.

2. The plasma treatment apparatus as claimed in claim 1, wherein, The at least one conductor maintains the connection between the edge ring and the DC power supply in response to the rise of the edge ring.

3. The plasma treatment apparatus as claimed in claim 1, wherein, At least one conductor deforms due to the rise of the edge ring.

4. The plasma treatment apparatus as described in claim 3, wherein, The at least one conductor includes a conductive elastic member in contact with the edge ring.

5. The plasma treatment apparatus as claimed in claim 1, wherein, The drive unit includes: a lifting pin that supports the edge ring; and a drive source that raises the lifting pin.

6. The plasma treatment apparatus as claimed in claim 5, wherein, The lifting pin, at least its surface, is formed of insulating material.

7. The plasma treatment apparatus as claimed in claim 6, wherein, The at least one conductor is contained within the lifting pin and is a conductive lead extending longitudinally; one end of the conductive lead is in contact with the edge ring.

8. The plasma treatment apparatus as claimed in claim 6, wherein, The at least one conductor includes a conductive elastic member in contact with the edge ring.

9. The plasma treatment apparatus as claimed in claim 8, wherein, The conductive elastic component is disposed within the lifting pin.

10. The plasma treatment apparatus as claimed in claim 8, wherein, The conductive elastic member is disposed between the edge ring and the electrostatic chuck.

11. The plasma treatment apparatus as claimed in claim 10, wherein, It also includes an additional edge ring disposed between the edge ring and the electrostatic chuck.

12. The plasma processing apparatus as claimed in claim 11, wherein, The additional edge ring is formed of insulating material and is positioned further inside the conductive elastic member.

13. The plasma processing apparatus as claimed in claim 12, wherein, The edge ring has a protrusion on its bottom surface.

14. The plasma processing apparatus as claimed in claim 11, wherein, The additional edge ring is formed of a conductive material; the conductive elastic member is disposed between the edge ring and the additional edge ring.

15. A plasma processing apparatus as described in any of claims 1 to 14, wherein, The edge ring has at least one conductive film in contact with the at least one conductor.

16. The plasma processing apparatus of any one of claims 1 to 14, wherein, The at least one conductor comprises a plurality of conductors arranged at equal intervals along the circumference of the edge ring when viewed from above.

17. A plasma processing apparatus as described in any of claims 1 to 14, wherein, The edge ring is conductive.

18. A plasma processing apparatus, comprising: a plasma processing chamber; a substrate support disposed within the plasma processing chamber, the substrate support including an electrostatic chuck and an edge ring surrounding a substrate mounted on the electrostatic chuck; a driving device for raising the edge ring; a radio frequency power supply for generating radio frequency power to generate plasma from gas within the plasma processing chamber; at least one conductor in contact with the edge ring after it has been raised by the driving device; at least one variable passive element electrically connected to the at least one conductor; and a control unit for controlling the driving device and the at least one variable passive element to adjust the incident angle of ions in the plasma onto an edge region of the substrate mounted on the electrostatic chuck.

19. The plasma processing apparatus of claim 18 further includes: a DC power supply that applies a DC voltage to the edge ring via the at least one conductor; the at least one conductor that maintains the edge ring in contact with the DC power supply in response to the rise of the edge ring.

20. The plasma processing apparatus as claimed in claim 18, wherein, At least one conductor deforms due to the rise of the edge ring.

21. The plasma processing apparatus as claimed in claim 20, wherein, The at least one conductor includes a conductive elastic member in contact with the edge ring.

22. The plasma processing apparatus as claimed in claim 18, wherein, The drive unit includes: a lifting pin that supports the edge ring; and a drive source that raises the lifting pin.

23. The plasma processing apparatus as claimed in claim 22, wherein, The lifting pin, at least its surface, is formed of insulating material.

24. The plasma processing apparatus as claimed in claim 23, wherein, The at least one conductor is contained within the lifting pin and is a conductive lead extending longitudinally; one end of the conductive lead is electrically and physically connected to the edge ring.

25. An etching method utilizing a plasma processing apparatus; the plasma processing apparatus comprising: a plasma processing chamber; a substrate support disposed within the plasma processing chamber, the substrate support including an electrostatic chuck and an edge ring surrounding a substrate mounted on the electrostatic chuck; at least one conductor electrically and physically connected to the edge ring; and at least one variable passive element electrically connected to the at least one conductor; the etching method comprising the steps of: (a) placing a substrate on the electrostatic chuck; (b) generating plasma from a gas within the plasma processing chamber; (c) etching the substrate with the generated plasma; and (d) adjusting the incident angle of ions in the plasma onto an edge region of the substrate; the adjustment step comprising the steps of: raising the edge ring to maintain contact between the at least one conductor and the edge ring; and adjusting the at least one variable passive element.

Images