JP2012174682A - Plasma processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma processing device which allows the processing of a large-size substrate.SOLUTION: A plasma processing device according to the invention comprises: a chamber; a gas supply part for supplying required gas to inside the chamber; a first electrode which is disposed in the chamber and to which high frequency power is applied; capacitor parts formed above the first electrode and electrically connected with the first electrode; and a plurality of second electrodes formed above the capacitor parts and electrically connected with the capacitor parts.

Description

  The present invention relates to a plasma processing apparatus, and more particularly to a plasma processing apparatus for a large substrate.

  In recent years, a liquid crystal display panel or a solar cell panel uses a method of producing many panels at a time in order to mass-produce them at a low cost. The individual size of a liquid crystal display panel or solar cell panel has a standard of several tens of centimeters, but in order to manufacture this at once, the manufacturing process manufactures one large panel and then divides it into several panels. Manufactured. Recently, a panel of at least 3 m has been manufactured on one side of one unit panel used in the manufacturing process.

  In manufacturing such a large panel, various processes using plasma are included as in the existing semiconductor manufacturing process. Examples of the process using plasma include etching, chemical vapor deposition (CVD), and sputtering (Sputtering). However, when a plasma process is applied to a large panel in a liquid crystal display panel or a solar cell panel, various problems may occur unlike a semiconductor manufactured in a relatively small size.

  A plasma processing apparatus used for manufacturing a liquid crystal display panel or a solar cell panel mainly employs inductively coupled plasma (ICP) and two-frequency superposed parallel plate plasma (CCP). However, since it is difficult to generate a uniform plasma and the cost is high, inductively coupled plasma is not used for a panel having a size of 2 m or more. In the case of parallel plate plasma, since the apparatus is simple and it is relatively easy to form a uniform plasma, it is currently used for manufacturing a panel having a side of 2 m or more. However, as the manufacturing equipment becomes larger and larger, when manufacturing panels having a size of 3 m or more, the plasma density becomes non-uniform even in parallel plate plasma. A non-uniform defect occurs, causing a serious problem.

US Pat. No. 7,661,388 JP 2008-042117 A JP 2008-042115 A Japanese Patent No. 429876

  The present invention has been made in view of the above problems, and an object thereof is to provide a plasma processing apparatus capable of processing a large substrate.

  A plasma processing apparatus according to an embodiment of the present invention includes a chamber, a gas supply unit that supplies a necessary gas in the chamber, a first electrode that is disposed in the chamber and to which high-frequency power is applied, and the first electrode And a plurality of second electrodes formed on the capacitor unit and electrically connected to the capacitor unit.

  The capacitor unit may include a plurality of rated capacitors.

  The capacitor unit may include a plurality of variable capacitors that can be adjusted outside the chamber.

  Each of the variable capacitors may include a vacuum capacitor.

  The capacitor part may include a ceramic, and the ceramic may have different thicknesses depending on positions in order to correct a plasma density.

  In addition, the ceramic may include a porous ceramic in which a large number of holes through which an inflowing gas can move are formed.

  In addition, a gas introduction part that penetrates the first electrode may be further included, and the gas supplied by the gas introduction part may be diffused through the porous ceramic, and a plasma chemical vapor deposition method may be used for the target substrate.

  The second electrode may further include a gas hole and be formed from a honeycomb structure.

  A plasma processing apparatus according to an embodiment of the present invention includes a chamber, a gas supply unit that supplies a necessary gas in the chamber, a first electrode that is disposed in the chamber and to which high-frequency power is applied, and is separated from the chamber. And a baffle plate formed around the first electrode, and a controller for adjusting a density of plasma generated at the periphery of the first electrode.

  The baffle plate may be disposed inside the chamber and spaced from the side wall of the chamber, and the adjusting unit may be disposed between the side wall of the chamber and the baffle plate.

  The adjusting unit may include a dielectric.

  The adjusting unit may include a low pass filter.

  The low-pass filter may block a plasma generation frequency and pass a frequency used for bias.

  A plasma processing apparatus according to an embodiment of the present invention includes a chamber, a gas supply unit that supplies a necessary gas into the chamber, a first electrode that is disposed in the chamber and to which high-frequency power is applied, and the first electrode And a resistance portion for reducing the high-frequency power moving from the first electrode.

  Further, the resistance portion may include a metal having a resistivity of 2.0 μ / cm or more.

  Moreover, you may comprise the said resistance part from one metal among iron, nickel, cobalt, and platinum.

  The resistance unit may include a semiconductor whose resistivity can be adjusted.

  The resistor may include boron nitride ceramic.

  According to the present invention, the capacity can be set by installing a separate capacitor depending on the position of the plasma generation electrode, and the sheath capacity generated between the plasma generation electrode and the plasma surface can be maintained uniformly. Therefore, it is possible to provide a plasma processing apparatus that can generate plasma uniformly and suppress nonuniformity in plasma processing of a large substrate.

  Further, according to the present invention, it is possible to suppress a non-uniform phenomenon that occurs at the side surface portion of the target substrate by inserting a high-impedance adjusting portion between the chamber and the baffle plate. The adjustment unit can provide a plasma processing apparatus that prevents the plasma density near the sidewall of the chamber from being bent by using a low dielectric constant dielectric or a low-pass filter.

  In addition, according to the present invention, by forming a resistor on the surface of the plasma generation electrode, a standing wave formed by mixing two different waveforms in which the high frequency power source is attenuated by the resistor and moves in both directions is mixed. Occurrence can be prevented. Therefore, it is possible to provide a plasma processing apparatus that suppresses non-uniformity in voltage generated at each electrode position and thereby forms uniform plasma.

It is a block diagram which shows the plasma processing apparatus which concerns on one Embodiment of this invention. FIG. 2 is an enlarged partial configuration diagram illustrating a portion A of FIG. 1. It is a block diagram which shows the flow of the electromagnetic wave of the conventional plasma processing apparatus. It is a graph which shows distribution of an electromagnetic wave with the electrode of the plasma processing apparatus of FIG.1 and FIG.3. It is a graph which shows distribution of an electromagnetic wave with the electrode of the plasma processing apparatus of FIG.1 and FIG.3. It is a graph which shows distribution of an electromagnetic wave with the electrode of the plasma processing apparatus of FIG.1 and FIG.3. It is a graph which shows distribution of an electromagnetic wave with the electrode of the plasma processing apparatus of FIG.1 and FIG.3. It is a graph which shows distribution of an electromagnetic wave with the electrode of the plasma processing apparatus of FIG.1 and FIG.3. It is a graph which shows distribution of an electromagnetic wave with the electrode of the plasma processing apparatus of FIG.1 and FIG.3. It is a graph which shows distribution of an electromagnetic wave with the electrode of the plasma processing apparatus of FIG.1 and FIG.3. It is a graph which shows distribution of an electromagnetic wave with the electrode of the plasma processing apparatus of FIG.1 and FIG.3. It is a block diagram which shows the electrode part of the plasma processing apparatus which concerns on other embodiment of this invention. It is a block diagram which shows the electrode part of the plasma processing apparatus which concerns on other embodiment of this invention. It is a top view which shows the 2nd electrode of the plasma processing apparatus which concerns on other embodiment of this invention. It is a top view which shows the 2nd electrode of the plasma processing apparatus which concerns on other embodiment of this invention. It is a top view which shows the 2nd electrode of the plasma processing apparatus which concerns on other embodiment of this invention. It is a top view which shows the 2nd electrode of the plasma processing apparatus which concerns on other embodiment of this invention. It is a block diagram which shows the electrode part of the plasma processing apparatus which concerns on other embodiment of this invention. It is a top view which shows the 2nd electrode of the electrode part of FIG. It is a block diagram which shows the plasma processing apparatus which concerns on other embodiment of this invention. It is an expansion partial block diagram which shows the B section of FIG. It is an expansion partial block diagram which shows the B section of FIG. It is a block diagram which shows the plasma processing apparatus which concerns on other embodiment of this invention. It is a graph which shows the distribution of the electromagnetic wave according to an electrode in the conventional plasma processing apparatus and the plasma processing apparatus of FIG. It is a graph which shows the distribution of the electromagnetic wave according to an electrode in the conventional plasma processing apparatus and the plasma processing apparatus of FIG. It is a graph which shows the distribution of the electromagnetic wave according to an electrode in the conventional plasma processing apparatus and the plasma processing apparatus of FIG. It is a graph which shows the distribution of the electromagnetic wave according to an electrode in the conventional plasma processing apparatus and the plasma processing apparatus of FIG.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a configuration diagram of a plasma processing apparatus according to an embodiment of the present invention. FIG. 2 is an enlarged partial configuration diagram showing a portion A of FIG.

  Referring to FIG. 1, a plasma processing apparatus 1000 according to an embodiment of the present invention includes a chamber 140, a gas supply unit 150, a first electrode 110, a plurality of capacitors 130, and a plurality of second electrodes 120. The interior of the chamber 140 is a space where plasma for plasma processing is formed. The gas supply unit 150 supplies necessary gas inside the chamber 140. A gas supply port 141 and a gas discharge port 142 are formed in the chamber 140 and connected to the gas supply unit 150 through the gas supply port 141. The pressure is adjusted by the gas supply of the gas supply unit 150. A radio frequency (RF) power supply unit 160 and an adjustment circuit 161 for adjusting the radio frequency power supply unit 160 are installed outside the chamber 140. The high frequency power supply unit 160 supplies high frequency power (RF Power) into the chamber 140. The adjustment circuit 161 controls the high frequency power supplied to the chamber interior 140. The adjustment circuit 161 is electrically connected to the supply electrode 112, and the supply electrode 112 is electrically connected to the first electrode 110. Accordingly, high frequency power is supplied to the first electrode 110.

  Although not shown in the drawing, the supply electrode 112 has a chuck for fixing an electrode formed thereon and a substrate to be processed, a cooling device, and a film forming gas for chemical vapor deposition (CVD). A supply unit or the like is formed. In the case of an etching apparatus, gas is drawn through the gas supply port 141 and diffused into the chamber 140. This gas is diffused into the ground electrode 170 and is uniformly supplied toward the target substrate 10 through a number of shower heads formed on the ground electrode 170. When a gas is supplied into the chamber 140, the pressure is adjusted to be constant, and a high frequency power source is supplied to the first electrode 110, the plasma 20 is generated.

  A plurality of capacitors 130 are formed on the first electrode 110. Each of the plurality of capacitors 130 is electrically connected to the second electrode 120, and the entire area of the plurality of second electrodes 120 is formed to be substantially the same as the area of the first electrode 110. The target substrate 10 for plasma processing is mounted on the second electrode 120. The plasma 20 is formed on the target substrate 10 mounted on the second electrode 120 so that various plasma treatments can be performed.

  In the plasma processing, a plasma sheath is formed between the plasma 20 and the target substrate 10. The plasma sheath is a capacitive component, and its thickness and capacitive component are determined by the electrode voltage, the density of the generated plasma, the electron temperature, and the like. Plasma processing such as etching, sputtering, chemical vapor deposition (CVD), or the like is performed using the plasma thus generated. A dielectric is filled to protect the first electrode 110, the supply electrode 112, and the second electrode 120. The supply electrode 112 and the first electrode 110 are protected by the first electrode holding dielectric 111, and the second electrode 120 is protected by the second electrode holding dielectric 121.

  Referring to FIG. 2, the voltage difference (V10 V1N) between the plasma 20 and the first electrode 110 is the sheath voltage (V1SH VNSH) between the plasma 20 and the target substrate 10 or each second electrode 120. , Determined by the sum of the voltage (V10S VN0S) between each of the second electrodes 120 and the first electrode 110. The voltage (V10S VN0S) between each of the second electrodes 120 and the first electrode 110 is the same as the voltage of the capacitor. In order to control the capacity (C1SH CNSH) of the plasma sheath 30, the capacity of each capacitor (C10S CN0S) is controlled. Therefore, the volume of the plasma sheath 30 formed on the target substrate 10 is uniformly guided. The plurality of capacitors 130 reduce the difference caused by the position of the high frequency waveform appearing on the second electrode 120. Therefore, even when the target substrate 10 is a very large panel, plasma processing can be performed while reducing plasma non-uniformity as a whole.

  Capacitor 130 includes a rated capacitor. If a rated capacitor having a capacity corresponding to a point where plasma is generated nonuniformly in the plasma processing apparatus is installed, the plasma in the plasma processing apparatus can be uniformly distributed. Further, in order to use a highly uniform plasma processing apparatus, the capacitor 130 may include a capacitor whose capacitance is adjustable. The capacitor 130 may include an anti-fixed capacitor or a variable capacitor. Preferably, the capacitor 130 includes a vacuum capacitor. A vacuum capacitor is a capacitor that can be easily obtained from the periphery. It is advantageous that the variable capacitor can be adjusted in capacity without disassembling the second electrode 120 after the plasma processing apparatus 1000 is assembled. In order to apply this, a separate motor is mounted on the variable capacitor so that the capacitance of the capacitor can be easily controlled externally. Further, in order to monitor the voltage generated on the second electrode 120, a separate monitor circuit may be installed. The reason why the already used high impedance electrode is connected for monitoring is to further improve the control effect of the plasma processing apparatus 1000.

The capacity of the capacitor 130 is shown as per unit area can ^range from ^{100pF / cm 2 ~0.01pF / cm 2} . Preferably, capacitor 130 ^is in the range of ^{3pF / cm 2 ~0.05pF / cm 2} . Assuming that the area of the second electrode 120 is 1 m ² , it is desirable to use 30000 pF to 100 pF as the capacitance range of the adjustment capacitor 130.

  FIG. 3 is a block diagram showing the flow of radio waves in a conventional plasma processing apparatus. 4 to 11 are graphs showing the distribution of radio waves at the electrodes of the plasma processing apparatus of FIGS. 1 and 3.

  Referring to FIG. 3, radio waves of a general plasma processing apparatus are generated by supplying a high frequency power source 200 to the supply electrode 212. Since the high-frequency power source 200 moves along the surfaces of the supply electrode 212 and the first electrode 210, the movement of the radio wave to the first electrode 210 is performed at both ends of the first electrode 210 where the supply electrode 212 and the first electrode 210 are in contact with each other. The waveform of the radio wave going to and the waveform of the radio wave returning to the center of the first electrode 210 at both ends of the first electrode 210 are formed differently. Further, the standing wave 201 of the radio wave flowing on the surface of the first electrode 210 is formed differently depending on the position of the first electrode 210. The graph shown in FIG. 3 shows the standing wave 201 of the radio wave generated at the corresponding position of the first electrode 210, and the standing wave 201 has the maximum amplitude 202 at the center of the first electrode 210. And has a minimum amplitude 203 at the end of the first electrode 210. Therefore, it has a waveform with different intensity depending on the position of the first electrode 210, which generates non-uniformity of the plasma to be generated soon. It is therefore necessary to adjust this. The capacitor unit 130 used in the embodiment of the present invention controls such a non-uniformity of the standing wave 201 uniformly.

  4 to 11 adopt a power frequency of 13.56 MHz and apply the radio wave 1 and radio wave 2 on the electrode when plasma is generated with an electrode of 7 m, the standing wave, and the capacitor used in the embodiment of the present invention. It is a graph which shows the sheath voltage (correction wave) of the plasma.

  Generally, 13.56 MHz is mainly used as a frequency that can be adopted for plasma generation. However, the plasma processing apparatus according to the embodiment of the present invention is applicable to high frequencies from 2 MHz to 60 MHz. 4 to 11 adopt 13.56 MHz. Moreover, the radio wave 1, the radio wave 2, and the standing wave on the electrode when the plasma is generated with the electrode having a side of 7 m in the conventional plasma processing apparatus are shown. When the radio wave 1 and the radio wave 2 supply power to the first electrode with a single high frequency power source, the radio wave 1 is the direction from the center to both ends, and the wave 2 is the waveform that returns from both ends to the center. A standing wave is formed as the sum of the waveforms of the radio waves 1 and 2.

  4 to 11, the sum of the radio wave 1 and the radio wave 2 forms a standing wave. 4 to 11 show both the half-cycle waveforms of the radio wave 1 and the radio wave 2 of the first electrode. 4 to 11 are processes in which the radio wave 1 and the radio wave 2 move while the time changes. When the radio wave 1 and the radio wave 2 are mixed, a standing wave is formed, and the intensity of the amplitude is formed approximately twice. As for the standing wave, even if the radio wave 1 and the radio wave 2 have any phase difference, a waveform of one standing wave is finally formed, and a part having a strong amplitude and a weak part are formed. Accordingly, the intensity of the plasma is determined in the standing wave distribution band, and the plasma is nonuniformly formed on the target substrate 10.

However, the correction wave according to the embodiment of the present invention shows a uniform distribution on the second electrode 120. The correction wave is a waveform formed on the second electrode 120 after performing correction through a variable capacitor formed on the first electrode 110. The plasma density is set to 10 ¹¹ cm ⁻³ , the electron temperature is set to 2 eV, a variable capacitor is formed between the second electrode 120 and the first electrode 110, and the second electrode 120 and the plasma 20 are formed. The generated potential difference is shown in the form of a correction wave.

  Referring to the graph shown in FIG. 4 again, the distribution of the standing wave on the first electrode 210 by the conventional plasma processing apparatus shows a potential difference that is relatively higher in the central portion than in the peripheral portion. However, it can be seen that the distribution of the correction wave in the embodiment of the present invention shows a constant distribution by being corrected by the capacitor. Similarly, in the graphs of FIGS. 5 to 11, it can be seen that even if the waveforms of the radio wave 1 and the radio wave 2 change with the passage of time, the distribution of the correction wave depending on the position of the second electrode 120 is formed uniformly. Therefore, the plasma processing of the target substrate 10 is uniformly generated by generating the plasma uniformly over the target substrate 10.

  12-13 is a block diagram which shows the electrode part of the plasma processing apparatus which concerns on other embodiment of this invention.

  The plasma processing apparatus according to another embodiment of the present invention has substantially the same configuration and operating principle as the plasma processing apparatus 1000 shown in FIG. 1 except for the first electrode 310, the capacitor unit 321 and the second electrode 320. It is. Therefore, the overlapping description is omitted.

  The electrode unit according to another embodiment of the present invention includes a supply electrode 312, a first electrode 310, a capacitor unit 321, and a second electrode 320. The capacitor unit 321 includes one dielectric. The capacitor unit 321 includes a single dielectric instead of a plurality of variable capacitors, and forms a capacitor between the second electrode 320 and the first electrode 310. In this case, the capacitance of the capacitor unit 321 due to the distribution of the second electrode 320 is controlled by changing the thickness of the dielectric. Referring to FIG. 12, the dielectric is formed thick at the center and thin at the periphery. As shown in FIG. 12, the capacity of the capacitor according to the embodiment of the present invention increases toward the periphery. The dielectric is formed thinner toward the periphery, and the capacitance of the capacitor is further increased. Therefore, in another embodiment of the present invention, a plurality of capacitors can be replaced by using a dielectric having a different thickness depending on the distance at the center.

  Referring to FIG. 13, the supply electrode 312 and the first electrode are formed to be movable. When the supply electrode 312 and the first electrode move individually, a separate space 322 is formed between the first electrode 310 and the dielectric. Since the distance between the first electrode 310 and the second electrode 320 is longer in the formed space 322, the capacity formed in the capacitor portion 321 becomes smaller as the space 322 becomes larger. Therefore, it is possible to control the capacitance of the capacitor unit 321 while adjusting the distance of the space 322.

  14-17 is a top view which shows the 2nd electrode of the plasma processing apparatus which concerns on other embodiment of this invention.

  The plasma processing apparatus according to another embodiment of the present invention has substantially the same configuration and operating principle as the plasma processing apparatus 1000 shown in FIG. 1 except for the second electrodes 125, 126, 127, and 128. Therefore, the overlapping description is omitted.

  14 to 17, the second electrodes 125, 126, 127, and 128 may be divided in various forms. Since each of the second electrodes 125, 126, 127, and 128 is connected to one capacitor, the magnitude of the corrected capacitance is the same. Therefore, the shape of the second electrodes 125, 126, 127, and 128 is a very important part in eliminating plasma non-uniformity in the plasma processing apparatus. The method of dividing the second electrodes 125, 126, 127, and 128 may be a quadrangular shape formed at equal intervals from the center as shown in FIG. However, generally, the potential difference between the standing waves formed on the second electrode is not generated at regular intervals, and varies depending on the distance from the center. Therefore, as shown in FIG. 15, the difference of the standing wave is a large part, and it can be divided so as to have other intervals depending on the position. Moreover, as shown in FIG. 16, the 2nd electrode 127 can be divided | segmented by the shape of a positive direction. Further, as shown in FIG. 17, the second electrode 128 can be divided in a form close to a circle. In the case of dividing into a circle like the second electrode 128 shown in FIG. 17, the distance from the center can be made more uniform. Further, the second electrodes 125, 126, 127, and 128 can be formed so as to be partially overlapped with each other by several mm to several tens mm. The overlapping portion of the second electrode can reduce the potential discontinuity between the electrodes.

  FIG. 18 is a configuration diagram showing an electrode portion of a plasma processing apparatus according to another embodiment of the present invention. FIG. 19 is a plan view showing a second electrode of the electrode portion of FIG.

  A plasma processing apparatus according to another embodiment of the present invention has substantially the same configuration and operating principle as the plasma processing apparatus 1000 shown in FIG. Therefore, the overlapping description is omitted.

  The electrode unit according to another embodiment of the present invention is used in chemical vapor deposition (CVD). When used in chemical vapor deposition (CVD), it is necessary to supply a deposition gas on the plasma generating electrode side. The electrode unit according to another embodiment of the present invention uses a porous ceramic dielectric 421 to supply a film forming gas through the porous formed in the dielectric 421. The dielectric 421 functions as a capacitor and a gas supply unit at the same time. The deposition gas is supplied to the dielectric 421 through the supply pipe 450 formed on the first electrode 410, diffused by the dielectric 421, and supplied onto the second electrode 420. When the deposition gas is diffused and transmitted through the porous material of the dielectric 421, the gas can be supplied uniformly by supplying the gas through a separate tube. A gas hole 425 for ejecting the supplied deposition gas is formed on the second electrode 420. The second electrode 420 is manufactured in the shape of a honeycomb structure. A gas hole 425 is formed at the center of the second electrode 420. The second electrode 420 can be manufactured in various forms as mentioned in the embodiments of FIGS.

  FIG. 20 is a block diagram showing a plasma processing apparatus according to another embodiment of the present invention.

  Referring to FIG. 20, the plasma processing apparatus 5000 according to another embodiment of the present invention includes a chamber 540, a gas supply unit 550, a first electrode 510, a baffle plate 581, and an adjustment unit 580. The interior of the chamber 540 is a space where plasma for plasma processing is formed. The gas supply unit 550 supplies necessary gas into the chamber 540. A gas supply port 541 and a gas discharge port 542 are formed in the chamber 540 and connected to the gas supply unit 550 through the gas supply port 541. The pressure is adjusted by gas supply from the gas supply unit 550. A radio frequency (RF) power supply unit 560 and an adjustment circuit 561 for adjusting the same are installed outside the chamber 540. In the case of the adjustment circuit 561, it may be installed inside the chamber 540 depending on the design. The high frequency power supply unit 560 supplies high frequency power (RF Power) inside the chamber 540. The adjustment circuit 561 controls the high frequency power supplied to the chamber interior 540. The adjustment circuit 561 is electrically connected to the supply electrode 512, and the supply electrode 512 is electrically connected to the first electrode 510. Accordingly, high frequency power is supplied to the first electrode 510. A second electrode 520 that is electrically connected and divided into a plurality of parts is disposed on the first electrode 510. Further, a grounded case 515 including a supply electrode 512 and a first electrode 510 is separately installed in the chamber 540. The case 515 protects the supply electrode 512 and the first electrode 510 from generated static electricity or the like.

  In another embodiment of the present invention, a baffle plate 581 formed around the first electrode 510 and the second electrode 520 is formed apart from the side wall of the chamber 540. The adjusting unit 580 improves plasma non-uniformity by having a high impedance value between the chamber 540 and the baffle plate 581. As a method of forming the adjustment unit 580, there are a method of inserting a dielectric having a low dielectric constant and a method of inserting a circuit for cutting off the plasma excitation frequency. Since the plasma 20 is formed between the first electrode 510 or the second electrode 520 and the grounded chamber 540, it is formed up to the side wall portion. However, since the conditions such as the distance from the first electrode 510 or the second electrode 520 are different in the side wall portion of the chamber 540, plasmas having different densities are easily formed. Accordingly, plasma having a density different from that of the central portion is formed at the end of the first electrode 510 or the second electrode 520. However, in the plasma processing apparatus 5000 according to another embodiment of the present invention, the adjustment unit 580 can prevent the impedance of the side wall of the chamber 540 from being lowered, so that uniform plasma can be generated. In addition, a dielectric is filled to protect the first electrode 510 and the second electrode 520. The first electrode 510 and the second electrode 520 are protected by an electrode holding dielectric 521.

  21 to 22 are enlarged partial configuration diagrams showing a portion B of FIG.

  Referring to FIG. 21, the adjusting unit 680 according to another embodiment of the present invention is thick and includes a dielectric having a low dielectric constant. The adjustment unit 680 is formed between the side wall of the chamber 540 and the baffle plate 681. As shown in FIG. 21, a side wall opposite to the side wall of the chamber 540 is formed on the baffle plate 681, and an adjustment unit 680 is formed between the side wall of the baffle plate 681 and the side wall of the chamber 540. The dielectric 680 includes a dielectric having a relatively low dielectric constant, and specifically includes high-purity polytetrafluoroethylene or quartz. The thickness of the dielectric 680 is 5 mm or more, desirably 1 cm or more. Accordingly, the dielectric 680 has a high impedance value and has a small influence on the formation of the plasma 20, so that the plasma is formed uniformly.

  Referring to FIG. 22, the adjusting unit 780 according to another embodiment of the present invention includes a low pass filter 710. The low-pass filter 710 is formed between the side wall of the chamber 540 and the baffle plate 781 to block the plasma excitation frequency. The low-pass filter 710 sets the cutoff frequency to a high frequency that is used for plasma generation, and sets the passing frequency to a frequency that is used for bias. The frequency that can be actually used for plasma generation is effective from 1 MHz to 60 MHz. The low-pass filter 710 is formed from a conductor 711, a resistor 712, and a dielectric 713. The low-pass filter 710 is composed of a parallel resonance circuit. A separate dielectric wall 720 is formed around the low-pass filter 710 so that plasma does not enter. The low-pass filter 710 generates a high impedance with respect to the ground potential. The low-pass filter 710 suppresses an increase in plasma density in the peripheral portion of a large plasma processing apparatus having an electrode length of 1 m or more, or a plasma processing apparatus having a structure in which the ratio of the maximum electrode length to the distance between the electrodes is 3 or more. . Therefore, uniform plasma processing can be performed.

  FIG. 23 is a block diagram showing a plasma processing apparatus according to another embodiment of the present invention. 24 to 27 are graphs showing the distribution of radio waves by electrodes in the conventional plasma processing apparatus and the plasma processing apparatus of FIG.

  Referring to FIG. 23, a plasma processing apparatus 8000 according to another embodiment of the present invention includes a chamber 840, a gas supply unit 850, a first electrode 810, and a resistance unit 890. The interior of the chamber 840 is a space where plasma for plasma processing is formed. The gas supply unit 850 supplies necessary gas into the chamber 840. A gas supply port 841 and a gas discharge port 842 are formed in the chamber 840 and connected to the gas supply unit 850 through the gas supply port 841. The pressure is adjusted by gas supply from the gas supply unit 850. A radio frequency (RF) power source unit 860 and an adjustment circuit 861 for adjusting the radio frequency power source unit 860 are installed outside the chamber 840. The high frequency power supply unit 860 supplies a high frequency power (RF Power) to the chamber 840. The adjustment circuit 861 controls the high frequency power supplied to the chamber interior 840. The adjustment circuit 861 is electrically connected to the supply electrode 812, and the supply electrode 812 is electrically connected to the first electrode 810. Accordingly, high frequency power is supplied to the first electrode 510. In addition, a dielectric is filled to protect the supply electrode 812 and the first electrode 810. The supply electrode 812 and the first electrode 810 are protected by the electrode holding dielectric 811.

  In another embodiment of the present invention, a resistor 890 is included on the first electrode 810. The resistor part 890 is made of a resistor sheet and is attached to the first electrode 810. The resistance unit 890 enables uniform plasma processing without generating a standing wave. Resistor 890 includes a material having a resistivity of 2.0 μ / cm or more, such as iron, nickel, cobalt, or platinum, or an alloy thereof. The resistor 890 includes silicon mixed with phosphorus, boron, or the like, a semiconductor whose resistivity can be adjusted, a ceramic having electrical resistance, or the like. The uniformity of the plasma density is achieved by adjusting the resistivity of the resistance portion 890.

  Referring to FIGS. 24 and 25, a radio wave moving in a conventional plasma processing apparatus travels with a uniform amplitude. Therefore, when the waveform shown in FIG. 24 and the waveform shown in FIG. 25 are added together, a standing wave is formed. It has been described with reference to the graphs shown in FIGS. 4 to 11 that the standing wave has a high point and a low point as a single independent wave, and causes plasma non-uniformity.

  Referring to FIG. 26 and FIG. 27, the amplitude of a radio wave moving in the resistance unit 890 according to another embodiment of the present invention is reduced due to the movement of the radio wave. As shown in FIGS. 26 and 27, the radio wave attenuated by movement does not form a standing wave, and NODE does not occur. Accordingly, the resistance portion 890 has a uniform energy distribution, and the plasma processing of the target substrate 10 can be made uniform. The uniformity of the plasma is induced by a method in which the resistor 890 absorbs energy and blocks the standing wave itself.

  As described above, according to the embodiment of the present invention, the capacitance can be set by setting a separate capacitor according to the position of the plasma generation electrode, and the sheath capacitance generated between the plasma generation electrode and the plasma surface. Can be maintained uniformly. Therefore, plasma can be generated uniformly, and non-uniform generation can be suppressed in plasma processing of a large substrate. The capacitor may be a variable capacitor or a ceramic having different thickness depending on the position. In addition, by forming a gas hole for the film forming gas in the second electrode, chemical vapor deposition (CVD) can proceed more uniformly.

  Note that a high-impedance adjusting unit is inserted between the chamber and the baffle plate to suppress a non-uniform phenomenon that occurs on the side surface of the target substrate. The regulator can use a low dielectric constant dielectric or a low pass filter, which prevents the plasma density near the sidewalls of the chamber from being distorted. When a low-pass filter is applied, radio waves passing through the chamber side wall can be sorted by frequency, and plasma uniformity can be more effectively ensured.

  In addition, by forming a resistor on the surface of the plasma generation electrode, it is possible to prevent the generation of a standing wave that is formed by mixing two different waveforms that move in both directions when the high-frequency power supply is attenuated by the resistor Can do. Therefore, the nonuniformity of the voltage generated according to the position of the electrode is suppressed, whereby a uniform plasma can be formed.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention belongs can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Target board | substrate, 20 ... Plasma, 1000 ... Plasma processing apparatus, 110 ... 1st electrode, 120 ... 2nd electrode, 130 ... Capacitor part, 140 ... Chamber, 160 ... High frequency power supply, 5000 ... Plasma processing apparatus, 510 ... 1st 1 electrode, 520 ... 2nd electrode, 540 ... chamber, 580 ... adjustment part, 581 ... baffle plate, 560 ... high frequency power supply, 8000 ... plasma processing apparatus, 810 ... 1st electrode, 840 ... chamber, 890 ... resistance part, 860 ... high frequency power supply.

Claims (18)

A chamber;
A gas supply unit for supplying a necessary gas into the chamber;
A first electrode disposed in the chamber and to which a high frequency power is applied;
A capacitor portion formed on the first electrode and electrically connected to the first electrode;
A plurality of second electrodes formed on the capacitor unit and electrically connected to the capacitor unit;
A plasma processing apparatus comprising:   The plasma processing apparatus according to claim 1, wherein the capacitor unit includes a plurality of rated capacitors.   The plasma processing apparatus according to claim 1, wherein the capacitor unit includes a plurality of variable capacitors that can be adjusted outside the chamber.   The plasma processing apparatus according to claim 3, wherein each of the variable capacitors includes a vacuum capacitor.   The plasma processing apparatus according to claim 1, wherein the capacitor unit includes a ceramic, and the ceramic has different thicknesses according to positions in order to correct a plasma density.   6. The plasma processing apparatus according to claim 5, wherein the ceramic includes a porous ceramic in which a large number of holes through which an inflowing gas can move are formed. A gas introduction part penetrating the first electrode;
The plasma processing apparatus according to claim 6, wherein the gas supplied by the gas introduction unit is diffused through the porous ceramic, and a plasma chemical vapor deposition method is used for a target substrate.   The plasma processing apparatus of claim 7, wherein the second electrode further includes a gas hole and is formed of a honeycomb structure. A chamber;
A gas supply unit for supplying a necessary gas into the chamber;
A first electrode disposed in the chamber and to which a high frequency power is applied;
A baffle plate spaced from the chamber and formed around the first electrode;
An adjusting unit for adjusting a density of plasma generated in a peripheral portion of the first electrode;
A plasma processing apparatus comprising:   The baffle plate according to claim 9, wherein the baffle plate is spaced apart from a side wall of the chamber and disposed inside the chamber, and the adjustment unit is disposed between the side wall of the chamber and the baffle plate. Plasma processing equipment.   The plasma processing apparatus according to claim 9, wherein the adjustment unit includes a dielectric.   The plasma processing apparatus according to claim 9, wherein the adjustment unit includes a low-pass filter.   The plasma processing apparatus according to claim 12, wherein the low-pass filter blocks a plasma generation frequency and allows a frequency used for bias to pass. A chamber;
A gas supply unit for supplying a necessary gas into the chamber;
A first electrode disposed in the chamber to which high frequency power is applied;
A resistance portion that attenuates the high-frequency power that is located on the first electrode and moves on the first electrode;
A plasma processing apparatus comprising:   The plasma processing apparatus according to claim 14, wherein the resistance part includes a metal having a resistivity of 2.0 μ / cm or more.   The plasma processing apparatus according to claim 14, wherein the resistance part includes one of iron, nickel, cobalt, and platinum.   The plasma processing apparatus according to claim 14, wherein the resistance unit includes a semiconductor whose resistivity can be adjusted.   The plasma processing apparatus of claim 14, wherein the resistance part includes a boron nitride ceramic.

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