JP2013115269A - Plasma processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove deposits on a gas ejection part, an edge part of a wafer, etc., by supplying an activated cleaning gas to a gas flow passage extending from a gas duct 118 to a wafer end.SOLUTION: A plasma processing apparatus includes: a vacuum vessel to which a vacuum exhaust device can be connected and the interior of which can be decompressed; gas supply means of supplying gas into the vacuum vessel; plasma generating means of making the gas supplied into the vacuum vessel into plasma; a sample table which is arranged in the vacuum vessel and holds a sample mounted on its upper surface; and a susceptor which covers an outer periphery of the sample table in a ring shape to protect the sample table against the plasma. In the plasma processing apparatus, the susceptor includes a gas filled part 113 in which the gas is introduced and stored, a gas ejection part 115 which ejects the gas filling the gas filled part to the side of a sample mount surface, and a transmission window 111 which introduces light emitted by the plasma in the filled part.

Description

  The present invention relates to a plasma etching technique, and more particularly to a plasma etching technique suitable for processing a workpiece such as a semiconductor substrate stably over a long period of time.

  In the semiconductor manufacturing process, dry etching using plasma is generally performed. Various types of plasma processing apparatuses for performing dry etching are used.

  In general, a plasma processing apparatus includes a vacuum processing chamber, a gas supply device connected to the vacuum processing chamber, an evacuation system for maintaining the pressure in the vacuum processing chamber at a desired value, an electrode on which a wafer as a processing object is placed, a vacuum processing It comprises plasma generating means for generating plasma in the room. The plasma generation means changes the processing gas supplied from the shower plate or the like into the vacuum processing chamber into a plasma state, whereby the wafer held by the wafer mounting electrode is etched.

  In recent years, along with the improvement in the degree of integration of semiconductor devices, fine processing, that is, improvement in processing accuracy is required, and in-plane uniformity of etching rate or uniformity of in-plane uniformity of CD value (Critical Dimension) in etching shape. Improvement is required.

  However, around the outer periphery of the wafer, the etching process becomes non-uniform due to electromagnetic, thermodynamic or hydrodynamic factors, and it may be difficult to ensure the etching uniformity within the wafer surface.

  Various studies have been made to improve the non-uniformity of the etching process at the outer periphery of the wafer in the plasma processing apparatus. For example, by arranging a structure for independently supplying gas to the outer periphery of the wafer, In this structure, a uniform etching result can be obtained.

  In Patent Document 1, a focus ring is provided on the lower electrode facing the outer periphery of the wafer placed on the lower electrode. The focus ring is in communication with the gas passage and the gas passage. A plurality of gas ejection holes opened toward the surface are formed, and an etching gas is ejected from the gas ejection holes to the peripheral region of the wafer. By changing the flow rate and composition of the ejected gas, it is possible to reduce the ratio of the etchant that is excessive in the wafer peripheral area and increase the deposition gas for correcting the effect of the biproduct that is insufficient in the wafer peripheral area. This enables uniform etching.

  Further, Patent Document 2 includes a chamber housing including a side wall portion and a ceiling portion, a workpiece support, and the workpiece support, and has an upper surface and a base portion, from the base portion to the upper surface. A cathode liner having a plurality of internal gas flow channels extending thereon, a gas supply plenum of the base connected to each of the internal gas flow channels, and lying on the top surface of the cathode liner; A treatment ring having an inner edge adjacent to the outer edge of the support surface; and a gas injection path that passes through the inner edge and faces the workpiece support surface, and further includes a plurality of internal gas flow channels. A gas injection unit in the processing ring and a gas supply system connected to the gas supply plenum are connected to each other in the plasma reactor chamber. It has been shown to the etch rate of the whole over in a uniform distribution.

JP 2002-217171 A JP 2009-65153 A

  However, the conventional plasma etching apparatus is not sufficiently considered with respect to maintaining the etching performance uniformly over a long period of time. That is, in a system that supplies gas to the outer periphery of the wafer, during etching, etching products, foreign matter, or organic substances contained in the processing gas adhere to the gas supply path, and the gas flow path cross-sectional area gradually increases. Change. For this reason, the gas supply pressure and the gas flow rate gradually change.

  For this reason, even if the in-plane distribution such as the etching gas concentration is initially uniform, the distribution near the outer periphery is disrupted by the change in the gas supply pressure and flow velocity, and the etching gas concentration and the like surface. The internal distribution gradually deteriorates, the uniformity of etching deteriorates, and consequently the yield of the semiconductor device decreases. This tendency becomes more prominent as the substrate diameter increases.

  The present invention has been made in view of these problems, and it is an object of the present invention to provide a plasma etching technique capable of maintaining the uniformity of etching in a surface to be processed uniformly over a long period of time.

  In order to solve the above problems, the present invention employs the following means.

A vacuum vessel to which an evacuation apparatus can be connected and whose inside can be depressurized, a gas supply means for supplying gas into the vacuum vessel, a plasma generating means for converting the gas supplied into the vacuum vessel into plasma, and the vacuum In a plasma processing apparatus provided with a susceptor that is arranged in a container and places and holds a sample on the upper surface thereof, and a susceptor that covers the outer periphery of the sample stage in a ring shape to protect the sample stage from plasma,
The susceptor includes a gas filling unit that introduces and accumulates a gas, a gas ejection unit that ejects a gas filled in the gas filling unit toward the sample mounting surface, and a light transmission that introduces light emission of the plasma into the filling unit. With windows.

  Since the present invention has the above-described configuration, it is possible to provide a plasma etching technique that can maintain the uniformity of etching in the surface to be processed uniformly over a long period of time.

It is sectional drawing which shows typically the internal structure of a microwave ECR etching apparatus. It is a figure explaining the structure of the susceptor arrange | positioned around the electrode for mounting. It is a figure explaining the other example of the ultraviolet transmissive window which comprises a susceptor. It is a figure explaining the other example of a susceptor. It is a figure explaining the structure of a susceptor. It is a figure explaining the example of the structure of a gas filter. It is sectional drawing which shows typically the internal structure of a microwave ECR etching apparatus. It is a figure explaining the process of the gas supply part which supplies gas to a gas filling part.

[Embodiment 1]
Hereinafter, a first embodiment of the present invention will be described with reference to FIG. 1, FIG. 2, FIG. 3, and FIG. FIG. 1 is a sectional view schematically showing an internal structure of a microwave ECR (Electron Cyclotron Resonance) etching apparatus.

  A dielectric window 103 (for example, made of quartz) for introducing a microwave into the vacuum vessel 101 is installed on the upper portion of the vacuum vessel 101 whose upper portion is opened to form a processing chamber 104. A vacuum exhaust device (not shown) is connected to the vacuum exhaust port 110 at the lower part of the vacuum vessel 101. A quartz shower plate 102 for supplying an etching gas is provided on the lower surface side of the dielectric window 103 disposed above the vacuum vessel 101.

  Above the dielectric window 103, a waveguide 105 (or an antenna) for transmitting electromagnetic waves is provided, and power for generating plasma is transmitted to the processing chamber 104. The electromagnetic wave transmitted through the waveguide 105 is oscillated by the electromagnetic wave generator 106.

  The frequency of the electromagnetic wave is not particularly limited, but in the present embodiment, a microwave of 2.45 GHz is used. A magnetic field generating coil 107 that forms a magnetic field is provided on the outer periphery of the processing chamber 104, and electromagnetic waves oscillated from the electromagnetic wave generator 106 have a high density in the processing chamber 104 due to interaction with the formed magnetic field. Generate plasma.

  Opposite to the dielectric window 103, a wafer mounting electrode 108 is provided below the vacuum vessel 101 as a sample stage on which a sample wafer 109 is mounted. A high frequency power source 121 is connected to the wafer mounting electrode 108 via a matching circuit 120.

  The wafer mounting electrode 108 is covered with a sprayed film (not shown) on the electrode surface, and a DC power source 123 is connected to the electrostatic adsorption film provided on the electrode surface via a high frequency blocking filter 122.

  The wafer 109 transferred into the processing chamber 104 is adsorbed onto the wafer mounting electrode 108 by electrostatic force generated by a DC voltage applied from the DC power source 123. The etching gas passes between the dielectric window 103 and the quartz shower plate 102 via a mass flow controller (not shown), and is introduced into the processing chamber 104 from the gas hole of the quartz shower plate 102.

  During processing, the inside of the vacuum vessel 101 is adjusted to a predetermined pressure, and plasma 116 is generated in the processing chamber 104. By applying high frequency power (RF bias) from the high frequency power supply 121 to the wafer mounting electrode 108, ions in the plasma 116 are attracted to the wafer 109 and the wafer 109 is etched. Etching gas and reaction products generated by the etching are exhausted from the lower part 110 of the vacuum vessel 101.

  FIG. 2 is a view for explaining the structure of the susceptor 100 arranged around the mounting electrode 108. As described above, the mounting electrode 108 incorporates a mechanism for attracting the wafer 109 by electrostatic attraction, and also incorporates a feeding electrode for supplying high frequency power for wafer bias (not shown). The mounting electrode 108 is provided with a flow path in the circumferential direction near the center and near the outer periphery, and the temperature-controlled refrigerant circulates at a desired flow rate in these flow paths to exchange heat. Is doing.

  On the surface of the sample mounting electrode 108 on the side in contact with the wafer, a step is provided at a position smaller in diameter than the wafer diameter, and the wafer 109 is overhanging. A cylindrical susceptor 100 is installed so as to fit into the step. The susceptor 100 introduces a gas filling unit 113 that introduces and accumulates gas, a gas ejection unit 115 that ejects the gas filled in the gas filling unit 113 to the sample mounting surface side, and introduces light emission of the plasma into the filling unit. A light transmission window 111 is provided. The light transmission window 111 is provided with a tapered guide wall portion up to a position higher than the height of the wafer 109.

  A gas supply hole 114 is provided at the lower part of the gas filling part 113, and a process gas or a cleaning gas is supplied to the gas filling part through the supply hole, and the filled gas is formed inside the cylindrical susceptor. It ejects toward the vicinity of the sample placement surface edge through the gas ejection part.

The ultraviolet transmitting window 111 is made of an insulator such as quartz, synthetic quartz, MgF2, CaF2, or sapphire, and surrounds the outer periphery of the mounting electrode 108 in order to protect the mounting electrode 108 from plasma. Moreover, the susceptor member 112 (the inner peripheral side member 112a and the outer peripheral side member 112b) is made of an insulator such as quartz, synthetic quartz, MgF2, CaF2, sapphire, alumina, and yttria.

  The inner peripheral side member 112 a of the susceptor member 112 is installed at a position where the upper surface is parallel to the lower surface of the wafer 109 or the lower surface of the wafer is slightly higher. At the time of the etching process, the wafer 109 is overhanging on the ultraviolet transmissive susceptor 112a by several millimeters with the wafer 109 having a minute gap in the mounting electrode 108.

  FIG. 3 is a diagram for explaining another example of the ultraviolet transmissive window constituting the susceptor. In the example of FIG. 2, the surface on the gas filling portion side of the ultraviolet light transmitting window 111 is a flat surface, but as shown in FIG. 3, a concave groove that is dug may be used. By adopting such a shape, the ultraviolet transmissive window 111 can be formed thin.

  That is, since the distance through which the ultraviolet light passes is reduced, the amount of the gas that reaches the gas filling portion 113 while the intensity of the ultraviolet light from the plasma is kept high and is activated in the susceptor increases. Moreover, the volume of the gas filling part 113 increases, and the amount of gas activated in the susceptor increases.

  In addition, by digging as shown in FIG. 3, other effects described below also occur. That is, the conductance in the circumferential direction of the gas filling portion 113 is larger than the conductance in the radial direction of the gas ejection portion 115, and the main flow of the gas flow in the gas filling portion 113 is in the circumferential direction along the groove. Therefore, the activated gas becomes uniform in the circumferential direction, and efficient ozone ejection is possible. The above effect can also be achieved by providing a projection between the gas ejection part 115 and the gas filling part 113 so as to guide the gas flow in the circumferential direction.

  FIG. 4 is a diagram illustrating another example of a susceptor. In the example of FIG. 2, the susceptor has a structure in which the ultraviolet transmitting window 111 and the hollow cylindrical susceptor member 112 are integrally formed by welding or the like, and further provided with a gas supply hole 114 and a gas ejection hole 115. It can be configured by fastening two or more members through an O-ring or the like.

  As shown in FIG. 4, the susceptor member 112 is formed by dividing it into an inner peripheral member 112a and an outer peripheral member 112b, and then these are connected by a bolt 114 via an O-ring 114a in order to maintain sealing performance. Form the susceptor body. As shown in FIG. 2, since the ultraviolet transmissive window 111, the outer peripheral side member 112b, and the inner peripheral side member 112a are integrated as a welded structure, they need to be replaced as consumable parts at the time of replacement. However, if the assembly structure is as shown in FIG. 4, only the outer peripheral side member 112b with the ultraviolet ray transmitting window is handled as a consumable, so that the cost for replacement can be reduced. In the integral formation, a welding, pressure bonding, or bonding structure can be employed.

  The gas ejection part 115 can be constituted by a slit formed between the ultraviolet ray transmitting window 111 and the inner peripheral side member 112a. By forming the gas ejection portion in a slit shape, variation in the ejection amount can be suppressed, and an etching process with less variation in the circumferential direction can be performed. The slit does not need to be provided in the entire circumference, and may be a plurality of holes.

  The height (slit width) of the gas ejection part 115 is preferably about 0.1 to 1 mm. This is set so as not to impair the flow smoothing ability in the gas filling unit 113. When the flow smoothing capability is insufficient, the amount of ejection from the gas ejection section 115 varies, and as a result, the uniformity of processing within the sample surface deteriorates.

  In FIG. 1, when performing the etching process, a process gas is introduced into the gas filling unit 113. A cleaning gas is introduced when performing the cleaning process. These gases are controlled by a mass flow controller or a pressure control valve (not shown) and then supplied to the gas filling unit via the process gas flow path 119. Switching to whether or not to supply gas to the gas flow path 119 is performed by the main gas switching valve 126.

  For example, when performing a cleaning process, cleaning gas (for example, oxygen gas) is introduce | transduced in the gas filling part 113, and the gas filling part 113 is filled with oxygen gas. Here, the filled oxygen gas can be activated (ozonized) by taking ultraviolet light generated by the plasma 116 into the gas filling unit 113 through the ultraviolet transmission window 111. The activated cleaning gas removes deposits (organic matter) deposited around the gas filling portion 113, the gas ejection portion 115, the side wall portion of the mounting electrode 108, and the side wall portion, back surface portion, and edge of the wafer 109. can do.

  According to the present embodiment, deposits deposited in the gas flow path including the gas filling portion in the susceptor can be suppressed by the activated cleaning gas. In addition, since it is possible to remove deposits (organic matter) around the wafer that mainly accumulate during etching, the state of the processing equipment for each etching can be stably maintained over a long period of time, and etching uniformity is maintained over a long period of time. It becomes possible to do.

  In addition, the gas emitted from the gas filling portion may be converted into plasma to remove the gas ejection portion 115, the side wall portion of the mounting electrode 108, the side wall portion of the wafer 109, the back surface portion, and deposits (organic matter) around the edge. Although it is conceivable, it is impossible to remove the deposit (organic matter) in the high-pressure side of the gas flow, that is, in the gas filling portion, so the removal range becomes narrow. Moreover, in order to turn into plasma, it is necessary to reduce the gas pressure. For this reason, the gas flow rate must be limited, and the effect of eliminating deposits is diminished.

[Embodiment 2]
5 and 6 are diagrams for explaining the second embodiment, FIG. 5 is a diagram for explaining the structure of the susceptor 100, and FIG. 6 is a diagram for explaining an example of the structure of the gas filter. 6A is a diagram illustrating a cross section of the gas ejection portion 115, FIG. 6B is a cross-sectional view taken along line AA of FIG. 6A, and FIG. BB cross-section of).

  As shown in FIGS. 5 and 6, in the plasma processing apparatus of this embodiment, a gas filter 127 is provided in the gas ejection portion 115. As the gas filter 127, a porous insulator (for example, an insulator made of quartz, synthetic quartz, MgF2, CaF2, sapphire, alumina, yttria), an uneven insulator (for example, quartz, synthetic quartz, MgF2, CaF2, sapphire). , Alumina, yttria insulator) or a plate-like insulator (for example, quartz, synthetic quartz, MgF2, CaF2, sapphire, alumina, yttria insulator) with a gap (slit). Can be formed by arranging a plurality of sheets.

  The filter material may be a composite material formed by coating a conductive material (for example, a metal such as aluminum, stainless steel, titanium, copper, tungsten, etc.) with an insulating material in addition to the insulator.

  In the case of arranging the gas filter 127 formed in this manner, even if the height of the opening of the gas ejection part is set to 1 mm or more, the resistance of the filter to the gas flow is large, so that the filling effect of the gas filling part 113 is achieved. (Smooth effect) can be maintained.

  Further, when using a composite material formed by coating a conductive material with an insulating material as a filter material, for example, by arranging the composite materials side by side and applying different potentials to each other, the inside of the susceptor ( It is possible to generate ultraviolet rays and radicals positively by generating a discharge in the gas filling portion).

  According to the present embodiment, the blockage of the gas channel located downstream from the gas filling part in the susceptor can be suppressed. Thus, since the deposit (organic matter) around the wafer generated and deposited during etching can be removed, the uniformity of etching can be maintained over a long period of time.

[Embodiment 3]
FIGS. 7 and 8 are diagrams for explaining the third embodiment. FIG. 7 is a cross-sectional view schematically showing an internal structure of a microwave ECR (Electron Cyclotron Resonance) etching apparatus, and FIG. It is a figure explaining the process of the gas supply part which supplies gas.

  In the present embodiment, it is possible to prevent the gas flow path on the high pressure side from the gas filling part in the susceptor from being blocked by the deposit due to etching. Further, deposits (organic matter) deposited around the wafer during etching can be removed.

  In FIG. 7, reference numeral 117 denotes an activation device that activates (ozonization, ionization, or radicalization) a cleaning gas (for example, oxygen gas). Here, an ozone generator is used. The generated ozone is supplied to the gas filling unit 113 via the cleaning gas pipe 118 and the switching valve 124. Supplying and shutting off the gas generated by the ozone generator to the gas filling unit is performed by opening and closing the switching valve 124 by the controller 128.

  A deposit monitor 129 monitors the presence or absence of deposits in the flow path from the gas pipe 119 to the wafer end based on the flow rate or gas pressure of the gas flowing in the gas flow path 119.

  The gas (ozone) supplied to the gas filling unit 113 fills the gas filling unit 113 and cleans the gas filling unit 113. Thereafter, the gas ejection portion 115, the side wall portion of the mounting electrode 108, the side wall portion, the back surface portion, and the periphery of the edge of the wafer 109 are passed, and deposits (organic matter) deposited on these portions are removed to remove the gas flow path. The blockage of the flow path is suppressed.

  According to the present embodiment, it is possible to clean the gas flow path from the gas pipe 118 to the wafer end. However, the activity of the cleaning gas decreases as it goes downstream. Therefore, it is effective to use in combination with the first embodiment.

The gas flow path 118 can be formed of a normal stainless steel pipe or the like, but a quartz pipe, a lining (formed by attaching Teflon (trade name) or quartz or the like to the inner surface) pipe, a high corrosion resistance steel pipe, A pipe capable of holding activated ozone such as pure aluminum pipe or aluminum alloy pipe as close to the wafer as possible is preferable.
FIG. 8 is a diagram for explaining the processing of the gas supply unit that supplies process gas or cleaning gas to the gas filling unit.

  First, the inside of the vacuum vessel 101 is adjusted to a predetermined pressure, and plasma 116 is generated in the processing chamber 104. By applying high frequency power (RF bias) from the high frequency power supply 121 to the wafer mounting electrode 108, ions in the plasma 116 are drawn into the wafer 109, and the wafer 109 is etched (step S401). When the wafer processing is completed, cleaning (for each wafer) is performed to maintain the state in the chamber. At this time, ozone is generated in the filling portion 113 by the ultraviolet rays generated from the plasma (step S402).

  The amount of deposit deposited in the passage is monitored by a deposit monitor. The monitor. For example, the presence or absence of deposits is determined based on the pressure in the gas flow path or the gas flow rate. In the case of constant control of the flow rate of the cleaning gas, if deposits adhere, the pressure loss of the pipe increases, so the value of the pressure gauge on the inflow side increases. In addition, in the case of constant control of the cleaning gas pressure, if deposits adhere, the pressure loss of the piping increases, so the value of the flow meter on the inflow side decreases. Note that the pressure gauge and the flow meter are examples of determining the presence or absence of deposits, and any monitor that can determine the presence or absence of deposits may be used. If there is no deposit, it is determined that etching (step S401) is possible, and the process proceeds to the next wafer process. If there is a deposit, cleaning is performed by supplying the ozone generated by the ozone generator to the cleaning gas pipe 118 (step S404).

  According to the present embodiment, the blockage of the gas flow path on the downstream side of the gas filling portion can be suppressed, and the deposit (organic matter) around the wafer deposited during etching can be removed. The state of the etching process for each wafer can be maintained uniformly, and the uniformity of etching can be maintained over a long period of time. In addition, since the blockage of the flow path due to deposits accumulated in the gas supply path can be suppressed during etching or during other periods, the state of the entire system can be stably maintained for a long period of time. It is possible to maintain the etching uniformity for a long period of time.

  In the above embodiment, the etching apparatus using microwave ECR discharge has been described as an example. However, other discharges (magnetic field UHF discharge, capacitively coupled discharge, inductively coupled discharge, magnetron discharge, surface wave excited discharge, transfer The same effect can be obtained in a dry etching apparatus using a coupled discharge). In each of the above embodiments, the etching apparatus has been described. However, other plasma processing apparatuses that perform plasma processing, such as a plasma CVD apparatus, an ashing apparatus, and a surface modification apparatus, have similar operational effects.

  As described above, according to the embodiment of the present invention, the activated cleaning gas is supplied to the gas flow path from the gas pipe line 118 to the wafer end, and is deposited on the gas ejection part, the edge part of the wafer, and the like. Remove deposits. For this reason, etching uniformity can be maintained for a long time.

DESCRIPTION OF SYMBOLS 101 Vacuum container 102 Shower plate 103 Dielectric window 104 Processing chamber 105 Waveguide 106 Electromagnetic wave generator 107 Magnetic field generation coil 108 Wafer mounting electrode 109 Wafer 110 Vacuum exhaust port 111 Susceptor which can transmit ultraviolet rays 112 Susceptor 113 Gas filling part 114 Gas Inlet 115 Gas ejection portion 116 Plasma 117 Ozone generator 118 Cleaning gas flow path 119 Process gas / cleaning gas flow path 120 Matching circuit 121 High frequency power supply 122 High frequency filter 123 DC power supply 124 Cleaning gas switching valve 125 Processing chamber exhaust path 126 Main gas Switching valve 127 Gas filter 128 Controller 129 Deposit monitor

Claims (5)

A vacuum vessel to which an evacuation apparatus can be connected and whose inside can be depressurized, a gas supply means for supplying gas into the vacuum vessel, a plasma generating means for converting the gas supplied into the vacuum vessel into plasma, and the vacuum In a plasma processing apparatus provided with a susceptor that is arranged in a container and places and holds a sample on the upper surface thereof, and a susceptor that covers the outer periphery of the sample stage in a ring shape to protect the sample stage from plasma,
The susceptor includes a gas filling unit that introduces and accumulates a gas, a gas ejection unit that ejects a gas filled in the gas filling unit toward the sample mounting surface, and a light transmission that introduces light emission of the plasma into the filling unit. A plasma processing apparatus comprising a window. The plasma processing apparatus according to claim 1,
The light transmission window is a transmission window that transmits ultraviolet light during plasma emission, the gas filling the gas filling part is a cleaning gas, and the cleaning gas activated by the ultraviolet light is used as a sample mounting surface side of the gas filling part A plasma processing apparatus, wherein the deposit is removed by jetting. The plasma processing apparatus according to claim 1,
The gas filling unit includes a flow path for supplying a process gas and a flow path for supplying an activated cleaning gas, and deposits in the gas flow path based on the pressure or flow rate of the gas in the flow path for supplying the process gas. A plasma processing apparatus, wherein the presence or absence of an object is determined, and when it is determined that there is accumulation, an activated cleaning gas is supplied to the gas filling unit. The plasma processing apparatus according to claim 1,
The light transmission window is disposed on a surface facing the plasma of a ring-shaped gas filling portion forming a ring-shaped susceptor, and has a ring-shaped groove on the gas filling portion side. . A vacuum vessel to which a vacuum exhaust device is connected and the inside of which can be depressurized, a gas supply means for supplying a processing gas into the vacuum vessel, a plasma generating means, and a sample placed on the upper surface of the vacuum vessel. A sample stage that is placed and held, and a susceptor that coats the outer periphery of the sample stage in a ring shape to protect the sample stage from plasma, and the gas supplied into the vacuum vessel by the plasma generating means is converted into plasma, In a plasma processing method for performing plasma processing on a sample,
The susceptor includes a gas filling unit that introduces and accumulates gas, a gas ejection unit that ejects a gas filled in the gas filling unit toward a sample placement surface edge of the sample stage, and the light emission of the plasma that is filled A light transmission window to be introduced into the part is provided, and the cleaning gas filled in the gas filling part is irradiated with ultraviolet light during plasma emission through the light transmission window, and the activated cleaning gas is directed to the edge of the sample placement surface. A plasma processing method characterized by removing deposits by jetting out.

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