Power modules, power supply devices, and substrate processing devices

Abstract

This invention relates to a power supply module, a power supply device, and a substrate processing device. The invention provides a power supply module capable of maintaining in-phase first bias RF power and second bias RF power while maintaining stable impedance matching, as well as a power supply device and a substrate processing device including the same. The power supply module according to the invention, which generates RF (radio frequency) power in a plasma-utilizing substrate processing device, includes: a main RF power supply supplying main RF power having a first frequency to a metal plate located inside a support unit supporting a substrate; a first bias RF power supply supplying first bias RF power having a second frequency lower than the first frequency to a first bias electrode located inside the support unit; and a second bias RF power supply supplying second bias RF power having a third frequency offset relative to the second frequency to a second bias electrode disposed at the edge of the support unit.

Description

Technical Field

[0001] This invention relates to a power supply module that utilizes plasma to generate RF (radio frequency) power, as well as a power supply device and a substrate processing device including the power supply module. Background Technology

[0002] Semiconductor (or display) manufacturing processes are processes used to manufacture semiconductor devices on substrates (e.g., wafers), including processes such as exposure, evaporation, etching, ion implantation, and cleaning. To perform these processes, cleanrooms in semiconductor manufacturing plants are equipped with semiconductor manufacturing equipment that performs the processes on substrates fed into the equipment.

[0003] Plasma processing is performed by placing a substrate in the lower part of a plasma processing space and applying RF (radio frequency) power to electrodes located in the lower or upper part of the processing space along with the supply of processing gas for plasma processing.

[0004] Along with the main RF power used to generate and maintain the plasma, bias RF power for modulating the energy of ions in the plasma is supplied from the center and edge of the substrate. For precise plasma control in the center and edge regions of the substrate, a first bias RF power supply supplies first bias RF power to a first bias electrode in the center region, and a second bias RF power supply supplies second bias RF power to a second bias electrode in the edge region. A first matching device for impedance matching is provided between the first bias RF power supply and the first bias electrode, and a second matching device for impedance matching is provided between the second bias RF power supply and the second bias electrode.

[0005] Typically, the first bias RF power and the second bias RF power can have different frequencies. However, recently, with the application of high-power RF bias power in manufacturing processes, research is underway to supply RF power with the same frequency and synchronized with each other to the first and second bias electrodes to prevent arcing. However, it has been confirmed that if the first and second bias powers are supplied synchronously, the impedance matching in the first and second matching circuits becomes unstable. Therefore, a method is needed to maintain the impedance matching stably while keeping the first and second bias RF powers in phase. Summary of the Invention

[0006] The present invention provides a power supply module that can maintain the in-phase state of the first bias RF power and the second bias RF power while maintaining stable impedance matching, as well as a power supply device and a substrate processing device including the same.

[0007] A power supply module for generating RF (radio frequency) power in a plasma-utilizing substrate processing apparatus according to the present invention includes: a main RF power supply supplying main RF power having a first frequency to a metal plate located inside a support unit of a supporting substrate; a first bias RF power supply supplying first bias RF power having a second frequency lower than the first frequency to a first bias electrode located inside the support unit; and a second bias RF power supply supplying second bias RF power having a third frequency offset relative to the second frequency to a second bias electrode disposed at the edge of the support unit. The first bias RF power and the second bias RF power are supplied according to a pulse signal having the same frequency and duty cycle. The phases of the first bias RF power and the second bias RF power are controlled such that within a unit pulse of the pulse signal, the phases of the first bias RF power and the second bias RF power are the same at at least one time point.

[0008] In an embodiment of the present invention, the offset may be 1% of the second frequency.

[0009] In an embodiment of the present invention, the first frequency may be 40MHz to 60MHz, the second frequency may be 400kHz, and the third frequency may be, for example, 396kHz to 404kHz.

[0010] In an embodiment of the present invention, the frequency of the pulse signal may be 10 kHz and the duty cycle of the pulse signal may be 20%.

[0011] In an embodiment of the present invention, the first bias RF power and the second bias RF power may be synchronized at the start time of the pulse signal.

[0012] In an embodiment of the present invention, the frequency of the pulse signal may be 5 kHz and the duty cycle of the pulse signal may be 20%.

[0013] In an embodiment of the present invention, the first bias RF power and the second bias RF power may be synchronized at the midpoint of the pulse signal.

[0014] According to the present invention, while the frequencies of the first bias RF power supplied to the bias electrode and the second bias RF power supplied to the edge electrode ring are offset, the phase within a unit pulse of the pulse signal is controlled to be the same, thereby maintaining the in-phase state of the first bias RF power and the second bias RF power while keeping the impedance matching stable. Attached Figure Description

[0015] Figure 1 A schematic structure of the substrate processing apparatus according to the present invention is shown.

[0016] Figure 2 The waveforms are shown when the first bias RF power and the second bias RF power have frequencies at which offset occurs.

[0017] Figure 3 The waveforms are shown when the first bias RF power and the second bias RF power are synchronized at the initial time point of the unit pulse.

[0018] Figure 4a as well as Figure 4b The waveforms are shown when the first bias RF power and the second bias RF power are synchronized at the initial and intermediate time points of the unit pulse.

[0019] (Explanation of reference numerals in the attached diagram)

[0020] 10: Substrate processing apparatus

[0021] 100: Cavity

[0022] 200: Support unit

[0023] 210: Dielectric board

[0024] 214: First bias electrode

[0025] 220: Metal plate

[0026] 260: Focusing ring

[0027] 270: Second bias electrode

[0028] 275: Insulating ring

[0029] 280: Coverage Ring

[0030] 300: Nozzle assembly

[0031] 400: Gas Supply Unit

[0032] 500: Power supply equipment

[0033] 505: Power Module

[0034] 510: Main RF Power Supply

[0035] 512: First Matcher

[0036] 514: First RF Filter

[0037] 520: First bias RF power supply

[0038] 522: Second Matcher

[0039] 524: Second RF Filter

[0040] 530: Second bias RF power supply

[0041] 532: Third Matcher

[0042] 534: Third RF Filter Detailed Implementation

[0043] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art to which this invention pertains can readily implement it. The present invention can be implemented in various different ways and is not limited to the embodiments described herein.

[0044] To clearly illustrate the invention, irrelevant parts have been omitted, and the same or similar components are marked with the same reference numerals throughout the specification.

[0045] Furthermore, in multiple embodiments, the same reference numerals are used to describe only representative embodiments of the constituent elements having the same structure, while in other embodiments only structures different from the representative embodiments are described.

[0046] In the specification as a whole, when a part is described as being "connected (or combined)" with other parts, it includes not only the case of "direct connection (or combination)" but also the case of "indirect connection (or combination)" where other components are placed in between. Furthermore, when a part is described as "including" a constituent element, unless otherwise stated otherwise, it means that other constituent elements may be included, rather than excluding them.

[0047] Unless otherwise defined, all terms used herein, including technical or scientific terms, shall have the same meaning as commonly understood by one of ordinary knowledge in the art to which this invention pertains. Terms such as those defined in commonly used dictionaries shall be interpreted as having the same meaning as in the relevant technical context, and shall not be ideally or excessively interpreted as having a formal meaning unless expressly defined in this application.

[0048] Figure 1A schematic structure of a substrate processing apparatus 10 according to the present invention is shown. The substrate processing apparatus 10 processes a substrate W using plasma. The substrate processing apparatus 10 includes a cavity 100, a support unit 200, a nozzle assembly 300, a gas supply unit 400, a power supply device 500, and a baffle unit 600.

[0049] The cavity 100 has a processing space 102 for performing substrate processing. The cavity 100 is provided in a sealed shape. The cavity 100 can be made of a conductive material. For example, the cavity 100 can be made of a material including metal. The cavity 100 can be made of aluminum. The cavity 100 can be grounded. An exhaust port 104 is formed on the bottom surface of the cavity 100. The exhaust port 104 is connected to an exhaust line 106. The exhaust line 106 is connected to a pump (not shown). Reaction byproducts generated during the process and gases remaining in the internal space of the cavity 100 can be discharged to the outside through the exhaust line 106. The internal pressure of the cavity 100 is reduced to a predetermined pressure through the exhaust process. Alternatively, a separate pressure reducing component (not shown) can be provided to reduce the internal pressure of the processing space 102 to a predetermined pressure.

[0050] A heater (not shown) is provided on the wall of cavity 100. The heater heats the wall of cavity 100. The heater is electrically connected to a heating power source (not shown). The heater generates heat by resisting the current applied from the heating power source. The heat generated by the heater is transferred to the internal space. The processing space 102 is maintained at a predetermined temperature by the heat generated by the heater. The heater is provided with a hot wire in the shape of a coil. Multiple heaters may be provided on the wall of cavity 100.

[0051] The liner 110 prevents damage to the inner wall of the cavity 100 during the process. The liner 110 prevents dopants generated during the process from being deposited onto the inner wall. The liner 110 can be made of aluminum. The liner 110 protects the inner surface of the cavity 100. During the process gas excitation process, an arc discharge may occur inside the cavity 100. Arc discharge can damage the cavity 100. The liner 110 protects the inner surface of the cavity 100 from damage caused by arc discharge.

[0052] The support unit 200 is located inside the cavity 100. The support unit 200 supports the substrate W within the processing space 102. The support unit 200 can provide an electrostatic chuck for adsorbing the substrate W using electrostatic force. The support unit 200 may include a dielectric plate 210, a metal plate 220, an insulating plate 230, a lower cover 240, a lower dielectric plate 250, a focusing ring 260, a second bias electrode 270, an insulating ring 275, and a cover ring 280.

[0053] A substrate W is placed on the upper part of the dielectric plate 210. The dielectric plate 210 is provided in a circular plate shape. The dielectric plate 210 may be provided with a dielectric substance. The dielectric plate 210 may be made of ceramic material.

[0054] An adsorption electrode 212 is embedded inside the dielectric plate 210 to use electrostatic force to press the substrate W tightly against the dielectric plate 210. The adsorption electrode 212 is a metal disk. The adsorption electrode 212 is electrically connected to a DC power supply 540. The adsorption electrode 212 can be connected to the DC power supply 540 via a DC power cable 546. An electrostatic force is generated on the substrate W by the DC voltage supplied from the DC power supply 540 to the adsorption electrode 212. In addition, a heater layer (not shown) for heating the substrate W can be disposed inside the dielectric plate 210.

[0055] A first bias electrode 214 is embedded inside the dielectric plate 210. The first bias electrode 214 is a metal disk. The first bias electrode 214 is electrically connected to a first bias RF power supply 520. The first bias electrode 214 can be connected to the first bias RF power supply 520 via a first bias RF power cable 526. A bias voltage provided from the first bias RF power supply 520 is applied to the first bias electrode 214, and during plasma processing by the bias voltage, the interior of the cavity 100 maintains a voltage for regulating ion energy.

[0056] A metal plate 220 is provided below the dielectric plate 210. The metal plate 220 may be in a circular plate shape. The metal plate 220 is made of a conductive material. The metal plate 220 may be made of aluminum (Al). A cooling fluid passage 222 and a temperature regulating fluid passage 224 may be formed inside the metal plate 220. The metal plate 220 may be connected to the main RF power supply 510 via an RF power cable 516. Alternatively, an RF voltage supplied from the main RF power supply 510 may be applied to the metal plate 220 to generate plasma. A first matching unit 512 and a first RF filter 514 may be connected to the output of the main RF power supply 510.

[0057] Coolant for cooling substrate W can flow through cooling fluid passage 224. Cooling fluid can be supplied from cooling fluid supply source 710 to cooling fluid passage 222 through cooling fluid supply pipe 712.

[0058] The heat transfer fluid can flow through the temperature regulating fluid passage 224 to maintain a uniform temperature distribution across the entire area of ​​the substrate W. An inert gas (e.g., He) can be used as the heat transfer fluid. Cooling fluid can be supplied from the temperature regulating fluid supply source 720 to the temperature regulating fluid passage 224 through the temperature regulating fluid supply pipe 722.

[0059] An insulating plate 230 is disposed below the metal plate 220. The insulating plate 230 is made of an insulating material. A lower cover 240 supports the insulating plate 230. The lower cover 240 may be provided to be attached to the lower edge of the insulating plate 230. The lower cover 240 may have a cylindrical shape with openings at the top and bottom. The lower cover 240 may be made of an insulating material. A lower dielectric plate 250 is disposed below the lower cover 240. The lower dielectric plate 250 is disposed below the lower cover 240 and supports the lower cover 240.

[0060] The edge of the support unit 200 is configured with a ring assembly consisting of multiple rings. The ring assembly includes a focusing ring 260, an insulating ring 275 having a second bias electrode 270 inside, and a cover ring 280.

[0061] A focusing ring 260 is provided to surround the dielectric substrate 210. The focusing ring 260 may be made of silicon to concentrate ions generated during the plasma processing onto the substrate W. A cover ring 280 is formed outside the focusing ring 260 to surround the focusing ring 260. The cover ring 280 may be made of quartz.

[0062] The second bias electrode 270 may be provided with a conductive metal material. The second bias electrode 270 is provided in the form of a ring. The second bias electrode 270 may be referred to as a coupling ring. The second bias electrode 270 can be electrically connected to the second bias RF power supply 530 via a second bias power cable 536. The second bias RF power supply 530 can provide second bias RF power to the second bias electrode 270. The second bias RF power supply 530 can regulate ion energy in the edge region of the substrate W by applying the second bias RF power to the second bias electrode 270.

[0063] An insulating ring 275 is provided to surround the second bias electrode 270. The insulating ring 275 may be made of an insulating material. The insulating ring 275 is located below the focusing ring 260. The insulating ring 275 and the cover ring 280 surround the outer side of the support unit 200 to electrically insulate the periphery of the ring assembly.

[0064] The nozzle assembly 300 is located above the support unit 200. The nozzle assembly 300 includes a nozzle 320 and a gas distribution plate 310. The nozzle 320 can be provided as a plate with a constant or variable thickness. The cross-section of the nozzle 320 can be provided to have the same shape and cross-sectional area as the dielectric plate 210. A plurality of gas supply holes 322 are formed in the nozzle 320. The gas supply holes 322 can be formed vertically through the top and bottom of the nozzle 320. The nozzle 320 can be grounded.

[0065] A gas distribution plate 310 is disposed above the nozzle 320. The gas distribution plate 310 can be attached to the top of the cavity 100. The gas distribution plate 310 allows the gas supplied from above to diffuse. The gas distribution plate 310 may have an air inlet 312. The air inlet 312 may be formed at a position corresponding to the aforementioned gas supply hole 322. The air inlet 312 may communicate with the gas supply hole 322. Gas supplied from above the nozzle assembly 300 can be sequentially supplied to the lower part of the nozzle 320 through the air inlet 312 and the gas supply hole 322. The gas distribution plate 310 may be made of metal. An upper ring 330 is configured to surround the nozzle 320 and the periphery of the gas distribution plate 310. The upper ring 330 may be provided as a circular ring. The upper ring 330 may be made of quartz.

[0066] The gas supply unit 400 supplies gas into the cavity 100. The gas supplied by the gas supply unit 400 can be excited into a plasma state by a plasma source. The gas supply unit 400 includes a gas supply source 410, a gas supply line 420, and a gas supply port 430. The gas supply port 430 is located at the upper center of the cavity 100. The gas supply port 430 supplies process gas to the gas distribution plate 310. The gas supply line 420 connects the gas supply port 430 and the gas supply source 410. The gas supply line 420 supplies the process gas stored in the gas supply source 410 to the gas supply port 430. A valve (not shown) can be installed on the gas supply line 420. The valve can open and close the gas supply line 420 to regulate the flow rate of the process gas supplied through the gas supply line 420.

[0067] A baffle unit 600 is located between the inner wall of the cavity 100 and the support unit 200. The baffle unit 600 is provided in an annular shape. Multiple through holes are formed in the baffle unit 600. Gas supplied to the cavity 100 is exhausted to the exhaust port 104 through the through holes of the baffle unit 600. The gas flow can be controlled according to the shape of the baffle unit 600 and the shape of the through holes.

[0068] The power supply unit 500 supplies RF power to the support unit 200 for generating and controlling plasma. The power supply unit 500 may include a power module 505 comprising a main RF power supply 510, a first bias RF power supply 520, and a second bias RF power supply 530, and matching transformers 512, 522, and 532 connected to the output of the power module 505, and RF filters 514, 524, and 534 connected between the matching transformers 512, 522, and 532 and the support unit 200. Although not shown, a controller may be incorporated for controlling each RF power supply 510, 520, and 530 of the power module 505. The controller may control the output power, frequency, phase, and amplitude of each RF power supply 510, 520, and 530. The controller may generate control signals for controlling each RF power supply 510, 520, and 530. The controller may include at least one processor and a memory.

[0069] The power module 505 supplies RF power to the support unit 200. The power module 505 includes a main RF power supply 510, a first bias RF power supply 520, and a second bias RF power supply 530. The power module 505 may also include a pulse wave power supply for generating pulse signals. The pulse wave power supply can provide the same pulse wave signal to both the first bias RF power supply 520 and the second bias RF power supply 530.

[0070] The main RF power supply 510 supplies main RF power to the metal plate 220 via RF power cable 516. A first matching unit 512 and a first RF filter 514 can be connected between the main RF power supply 510 and the metal plate 220. The main RF power supply 510 generates main RF power for generating and maintaining the plasma. The frequency (first frequency) of the main RF power generated by the main RF power supply 510 is approximately 40 MHz to 60 MHz.

[0071] A first bias RF power supply 520 supplies first bias RF power to a first bias electrode 214 via a first bias RF power cable 526. A second matching unit 522 and a second RF filter 524 can be connected between the first bias RF power supply 520 and the first bias electrode 214. During plasma processing, the first bias RF power supply 520 generates first bias RF power for ion energy regulation near the center of the substrate W. The frequency (second frequency) of the first bias RF power is approximately 400 kHz.

[0072] The second bias RF power supply 530 supplies second bias RF power to the second bias electrode 270 via the second bias RF power cable 536. A third matching unit 532 and a third filter 534 can be connected between the second bias RF power supply 530 and the second bias electrode 270. During plasma processing, the second bias RF power supply 530 generates second bias RF power near the edge of the substrate W for ion energy regulation. For example, the frequency (third frequency) of the second bias RF power can be approximately 396 kHz. Figures 2 to 4b The following example uses a second bias RF power frequency (third frequency) of 396 kHz as an example, but the scope of the invention is not limited thereto. The second bias RF power frequency (third frequency) can be in the range of 396 kHz to 404 kHz. The third frequency can be set within a unit pulse level without violating the synchronization with the second frequency.

[0073] Each matching unit 512, 522, and 532 adjusts the impedance of the power supply path to maximize the transfer of RF power supplied from each power module 505 to the plasma. Each matching unit 512, 522, and 532 may include at least one impedance element (e.g., a capacitor or an inductor). The impedance element may have a fixed impedance or a variable impedance. The first matching unit 512 is connected to the output of the main RF power supply 510. The second matching unit 522 is connected to the output of the first bias RF power supply 520. The third matching unit 532 is connected to the output of the second bias RF power supply 530.

[0074] RF filters 514, 524, and 534 allow specific frequency components to pass through and block other frequency components in the power supply path. RF filters 514, 524, and 534 can block unwanted noise or interference signals that may be included in the RF signal. RF filters 514, 524, and 534 can block reflected or abnormal signals to protect the matching circuits 512, 522, and 532, as well as the RF power supplies 510, 520, and 530 of the power module 505. Each RF filter 514, 524, and 534 may include at least one impedance element (e.g., a capacitor or an inductor). The impedance element may have a fixed impedance or a variable impedance.

[0075] In the power supply device 500 according to the invention, independently operating bias RF power supplies 520 and 530 supply bias RF power to the first bias electrode 214 and the second bias electrode 270, respectively. Typically, the first bias RF power supplied by the first bias RF power supply 520 and the second bias RF power supplied by the second bias RF power supply 530 have the same frequency and amplitude. This is to prevent plasma sheath control caused by the first bias RF power and the second bias RF power, as well as arcing caused by voltage difference.

[0076] However, when the first bias RF power and the second bias RF power are supplied at the same frequency and in phase, impedance matching instability may occur in the second matching circuit 522 and the third matching circuit 532 due to mutual interference. To solve the impedance matching problem, the second frequency of the first bias RF power output from the first bias RF power supply 520 and the third frequency of the second bias RF power output from the second bias RF power supply 530 can be made slightly different. In other words, the third frequency is offset relative to the second frequency. If such a frequency offset occurs, the impedance matching instability problem is solved.

[0077] Figure 2 The waveforms are shown when the first bias RF power and the second bias RF power have frequencies at which offset occurs. Figure 2 When the frequency of the first bias RF power (second frequency) is 400kHz and the frequency of the second bias RF power (third frequency) is 396kHz, and a frequency offset of 4kHz occurs, the waveforms RF2 and RF3 of the first bias RF power are compared. The frequency offset between the first and second bias RF power can be set to 1% of the operating frequency. For example, the frequency of the second bias RF power (third frequency) can be offset by 1% of the frequency of the first bias RF power (second frequency).

[0078] Reference Figure 2 Two waveforms, RF2 and RF3, are initially in-phase, but after a certain period of time become either out-of-phase or have a phase difference. At this point, it becomes difficult to control the plasma sheath, and arcing due to the voltage difference may occur. In this paper, in-phase means that the two signals oscillate in the same phase or within the error range. When they are not in-phase, the two signals can become out-of-phase, either with a phase difference exceeding the error range or with a phase difference of 180 degrees.

[0079] This invention provides a power supply method that applies frequency shifting to both a first bias RF power supply and a second bias RF power supply while maintaining in-phase operation. According to the invention, the first bias RF power supply and the second bias RF power supply are supplied based on pulse signals having the same frequency and duty cycle. That is, the first bias RF power supply and the second bias RF power supply can be synchronized with the same pulse signal. The pulse signal is a signal that switches between a low (or off) state and a high (or on) state with a constant period. The low state is when the pulse signal is close to zero, and the high state is when the pulse signal has a maximum amplitude sufficiently large than zero. The frequency of the pulse signal is the number of times the same pulse signal repeats per unit time, and is the reciprocal of the period. The duty cycle of the pulse signal is the time during which the pulse signal is in the high state within one period.

[0080] The first bias RF power and the second bias RF power can be supplied synchronously with the pulse signal. That is, the first bias RF power supply 520 and the second bias RF power supply 530 output the first bias RF power and the second bias RF power according to the same pulse signal. The first bias RF power and the second bias RF power are supplied when the pulse signal is high, and are not supplied and are cut off when the pulse signal is low. In other words, the first bias RF power supply 520 and the second bias RF power supply 530 output the first bias RF power and the second bias RF power when the pulse signal is high, and do not output and are cut off when the pulse signal is low.

[0081] According to the present invention, the control is such that the phases of the first bias RF power and the second bias RF power are the same at at least one time point within a unit pulse of the pulse signal. The first bias RF power can adjust the phase of the signal when the first bias RF power is supplied according to the pulse signal. The second bias RF power can adjust the phase of the signal when the second bias RF power is supplied according to the pulse signal.

[0082] For example, the first bias RF power and the second bias RF power can be synchronized at the start time of the pulse signal. Figure 3 The waveforms are shown when the first bias RF power and the second bias RF power are synchronized at the initial time point T0 of the unit pulse. Figure 3 In the example, the frequency of the first bias RF power (second frequency) RF2 is 400kHz, the frequency of the second bias RF power (third frequency) RF3 is 396kHz, the frequency of the pulse signal is 10kHz, and the duty cycle of the pulse signal is 20%.

[0083] exist Figure 3In this process, a unit pulse P1 forming a pulse envelope consists of eight 400kHz waveforms. If the 400kHz and 396kHz waveforms are synchronized at the start time of unit pulse P1, they remain in phase within the unit pulse. The initial time point of unit pulse P1 is marked as T0, the middle time point as T1, and the end time point as T2. When a pulse period is 100μs (100%), the first unit pulse P1 is held for 20μs (20%), and then the pulse signal is low for the remaining 80μs (80%). During this time, the first bias RF power and the second bias RF power are not output.

[0084] The 400kHz first bias RF power and the 396kHz second bias RF power can remain in phase within a single unit pulse P1. Then, at the initial time T0 of the second unit pulse P2, the first and second bias RF powers are synchronized. During the second unit pulse P2, the 400kHz first bias RF power and the 396kHz second bias RF power can also remain in phase. By maintaining phase between the 400kHz first bias RF power and the 396kHz second bias RF power throughout the entire pulse signal period, impedance matching stability can be ensured while simultaneously controlling the plasma sheath and preventing arcing.

[0085] In another example, the first bias RF power and the second bias RF power can be synchronized at the midpoint of the pulse signal. Figure 4a as well as Figure 4b The waveforms are shown when the first bias RF power and the second bias RF power are synchronized at the initial and intermediate time points of the unit pulse. Figure 4a as well as Figure 4b In the example, the frequency of the first bias RF power (second frequency) RF2 is 400kHz, the frequency of the second bias RF power (third frequency) RF3 is 396kHz, the frequency of the pulse signal is 5kHz, and the duty cycle of the pulse signal is 20%.

[0086] Figure 4a This illustrates the synchronization of the first bias RF power and the second bias RF power at the initial time point T0 of the unit pulse P1. Figure 4b This illustrates the synchronization of the first bias RF power and the second bias RF power at the midpoint T1 of the unit pulse P1. Figure 4a In this context, a unit pulse P1 consists of sixteen 400kHz waveforms, ten of which are 400kHz and ten of which are 396kHz, after which the state of being out of phase occurs.

[0087] This can be achieved by adjusting the waveforms of the first bias RF power and the phase of the second bias RF power waveform, such as... Figure 4b In this way, the 400kHz waveform and the 396kHz waveform are synchronized at the midpoint T1 of the unit pulse P1. If the 400kHz waveform and the 396kHz waveform are synchronized at the midpoint T1, then the 400kHz waveform and the 396kHz waveform can be kept in phase throughout the entire region of the unit pulse P1.

[0088] That is, the first bias RF power and the second bias RF power are synchronized at the midpoint T1 of the unit pulse P1, so that the 400kHz first bias RF power and the 396kHz second bias RF power can remain in phase within the unit pulse P1. Subsequently, through a similar process, the 400kHz first bias RF power and the 396kHz second bias RF power remain in phase throughout the entire pulse signal period, thus ensuring impedance matching stability while controlling the plasma sheath and preventing arcing.

[0089] This embodiment and the accompanying drawings are merely illustrative of a portion of the technical concept included in this invention. It is obvious that variations and specific embodiments that can be readily derived by those skilled in the art within the scope of the technical concept included in the specification and drawings of this invention are all included within the scope of the claims of this invention.

[0090] Therefore, the concept of the present invention should not be limited to the illustrated embodiments, not only to the appended claims, but also to any equivalent or modified versions thereof.

Claims

1. A power module that generates RF power in a plasma-based substrate processing apparatus, wherein, The power module includes: The main RF power supply supplies main RF power with a first frequency to the metal plate located inside the support unit of the support substrate; A first bias RF power supply supplies first bias RF power with a second frequency lower than the first frequency to a first bias electrode located inside the support unit; and A second bias RF power supply supplies second bias RF power with a third frequency offset relative to the second frequency to a second bias electrode disposed at the edge of the support unit. The first bias RF power and the second bias RF power are supplied according to pulse signals with the same frequency and duty cycle. The control is such that the phases of the first bias RF power and the second bias RF power are the same at at least one time point within a unit pulse of the pulse signal.

2. The power module according to claim 1, wherein, The offset is 1% of the second frequency.

3. The power module according to claim 1, wherein, The first frequency is 40MHz to 60MHz. The second frequency is 400kHz. The third frequency is 396kHz to 404kHz.

4. The power module according to claim 3, wherein, The frequency of the pulse signal is 10kHz. The duty cycle of the pulse signal is 20%.

5. The power supply module according to claim 1, wherein, The first bias RF power and the second bias RF power are synchronized at the start time of the pulse signal.

6. The power supply module according to claim 3, wherein, The frequency of the pulse signal is 5kHz. The duty cycle of the pulse signal is 20%.

7. The power module according to claim 1, wherein, The first bias RF power and the second bias RF power are synchronized at the midpoint of the pulse signal.

8. A power supply device for supplying RF power in a plasma-utilizing substrate processing apparatus, wherein, The power supply device includes: The main RF power supply supplies main RF power with a first frequency to the metal plate inside the support unit of the support substrate; The first matching unit is connected to the output terminal of the main RF power supply; A first RF filter is connected between the first matching unit and the metal plate; A first bias RF power supply supplies first bias RF power with a second frequency lower than the first frequency to a first bias electrode located inside the support unit; The second matching unit is connected to the output of the first bias RF power supply; A second RF filter is connected between the second matching unit and the first bias electrode; The second bias RF power supply supplies second bias RF power with a third frequency offset relative to the second frequency to the second bias electrode disposed at the edge of the support unit; A third matching unit is connected to the output of the second bias RF power supply; and A third RF filter is connected between the third matching unit and the second bias electrode; The first bias RF power and the second bias RF power are supplied according to pulse signals with the same frequency and duty cycle. The control is such that the phases of the first bias RF power and the second bias RF power are the same at at least one time point within a unit pulse of the pulse signal.

9. The power supply device according to claim 8, wherein, The offset is 1% of the second frequency.

10. The power supply device according to claim 8, wherein, The first frequency is 40MHz to 60MHz. The second frequency is 400kHz. The third frequency is 396kHz to 404kHz.

11. The power supply device according to claim 10, wherein, The frequency of the pulse signal is 10kHz. The duty cycle of the pulse signal is 20%.

12. The power supply device according to claim 8, wherein, The first bias RF power and the second bias RF power are synchronized at the start time of the pulse signal.

13. The power supply device according to claim 10, wherein, The frequency of the pulse signal is 5kHz. The duty cycle of the pulse signal is 20%.

14. The power supply device according to claim 8, wherein, The first bias RF power and the second bias RF power are synchronized at the midpoint of the pulse signal.

15. A substrate processing apparatus utilizing plasma, wherein, The substrate processing apparatus includes: The cavity forms the processing space for the substrate; A support unit is located in the lower part of the cavity; and The power supply device is electrically connected to the support unit. The support unit includes: A dielectric plate that supports the substrate below and has a first bias electrode inside; A metal plate is located below the dielectric plate; An insulating ring is disposed on the outside of the metal plate and has a second bias electrode inside; A focusing ring, disposed above the insulating ring; and A cover ring is disposed outside the focusing ring. The power supply device includes: A main RF power supply supplies main RF power with a first frequency to the metal plate located inside the support unit supporting the substrate; The first matching unit is connected to the output terminal of the main RF power supply; A first RF filter is connected between the first matching unit and the metal plate; A first bias RF power supply supplies the metal plate with a second frequency that is lower than the first frequency; The second matching unit is connected to the output of the first bias RF power supply; A second RF filter is connected between the second matching unit and the first bias electrode; The second bias RF power supply supplies second bias RF power with a third frequency offset relative to the second frequency to the edge electrodes disposed on the outer side of the metal plate; The third matching unit is connected to the output of the second bias RF power supply; A third RF filter is connected between the third matching unit and the edge electrode; and A pulse wave generator provides pulse signals with the same frequency and duty cycle to the first bias RF power supply and the second bias RF power supply. The first bias RF power and the second bias RF power are supplied according to the pulse signal. The control is such that the phases of the first bias RF power and the second bias RF power are the same at at least one time point within a unit pulse of the pulse signal.

16. The substrate processing apparatus according to claim 15, wherein, The first frequency is 40MHz to 60MHz. The second frequency is 400kHz. The third frequency is 396kHz to 404kHz.

17. The substrate processing apparatus according to claim 16, wherein, The frequency of the pulse signal is 10kHz. The duty cycle of the pulse signal is 20%.

18. The substrate processing apparatus according to claim 15, wherein, The first bias RF power and the second bias RF power are synchronized at the start or middle time point of the pulse signal.

19. The substrate processing apparatus according to claim 15, wherein, The frequency of the pulse signal is 5kHz. The duty cycle of the pulse signal is 20%.

20. The substrate processing apparatus according to claim 15, wherein, The first bias RF power and the second bias RF power are synchronized at the midpoint of the pulse signal.

Images