JP2016174060A

JP2016174060A - Plasma processing device

Info

Publication number: JP2016174060A
Application number: JP2015052813A
Authority: JP
Inventors: 洋輔酒井; Yosuke Sakai; 匡規角谷; Masanori Sumiya
Original assignee: Hitachi High Technologies Corp; Hitachi High Tech Corp
Current assignee: Hitachi High Tech Corp
Priority date: 2015-03-17
Filing date: 2015-03-17
Publication date: 2016-09-29

Abstract

【課題】処理の歩留まりを向上させたプラズマ処理装置を提供する。【解決手段】真空容器の内部に配置され内側が減圧される処理室と、この処理室内に配置されその上面に処理対象の試料が載せられて保持される試料台と、試料台の内部に配置され内側をその温度が所定の値に調節された熱交換媒体が通流する媒体流路とを備え、前記処理室内にプラズマを形成して前記試料を処理するプラズマ処理装置であって、前記媒体流路は、試料台の内部でその径方向について多重に配置された複数の円弧形状部分及びこれらの間を湾曲して接続する折り返し部と、この折り返し部内に配置され当該媒体流路を水平方向について前記湾曲の内側及び外側に分ける柱状の部材を供えた。【選択図】図２PROBLEM TO BE SOLVED: To provide a plasma processing apparatus having improved processing yield. SOLUTION: A processing chamber arranged inside a vacuum vessel and depressurized inside, a sample table arranged in the processing chamber and a sample to be processed is placed and held on an upper surface thereof, and an arrangement inside the sample table. A plasma processing apparatus that is provided with a medium flow path through which a heat exchange medium whose temperature is adjusted to a predetermined value flows, and that forms plasma in the processing chamber to process the sample. The flow path is a plurality of arc-shaped portions arranged multiple times in the radial direction inside the sample table, a folded portion that is curved and connected between these portions, and a folded portion that is arranged in the folded portion to provide the medium flow path in the horizontal direction. A columnar member was provided for dividing the inside and outside of the curve. [Selection diagram] Fig. 2

Description

本発明は、真空容器内部に配置された処理室内に形成したプラズマを用いて当該処理室内に配置された試料台上面に載せられ保持された半導体ウエハ等の基板状の試料を処理するプラズマ処理装置に係り、特に、試料台内部にその内側を冷媒を通流させて循環させ試料台の温度を所定の範囲に調節しつつ試料を処理するプラズマ処理装置に関する。
The present invention relates to a plasma processing apparatus for processing a substrate-like sample such as a semiconductor wafer placed on and held on an upper surface of a sample table disposed in a processing chamber using plasma formed in a processing chamber disposed in a vacuum vessel. In particular, the present invention relates to a plasma processing apparatus for processing a sample while adjusting the temperature of the sample stage to a predetermined range by circulating a coolant through the inside of the sample stage.

上記プラズマ処理装置、特にプラズマを用いて試料であるウエハの上面に予め形成されたレジスト等の樹脂製のマスク及び少なくとも１つの処理対象の膜層を含む膜構造をエッチングするドライエッチング装置は、ターボ分子ポンプ等の真空ポンプが連結され真空排気される真空容器内部の処理室内にウエハを配置して処理用ガスを導入し、当該ガスの原子または分子を処理室に供給した電界または磁界により励起させてプラズマ化し膜構造のマスク層の形状に応じて処理対象の膜層をエッチングすることで所望の膜構造の形状を得る半導体微細加工装置である。
The plasma processing apparatus, particularly a dry etching apparatus that etches a film structure including a resin mask such as a resist formed in advance on the upper surface of a wafer as a sample and at least one film layer to be processed using plasma is a turbo process. A wafer is placed in a processing chamber inside a vacuum vessel connected to a vacuum pump such as a molecular pump, and a processing gas is introduced, and the atoms or molecules of the gas are excited by an electric field or a magnetic field supplied to the processing chamber. This is a semiconductor microfabrication apparatus that obtains a desired film structure shape by plasmaizing and etching a film layer to be processed according to the shape of the mask layer of the film structure.

このようなエッチング処理において、ウエハの膜構造を処理した結果としての当該膜の形状の均一性は、処理に用いられるプラズマの密度や強度の分布、さらには処理中のウエハ表面の面内方向についての温度とその分布、供給されるガスの組成およびその量と分布といった要件が影響を与える。近年は、ウエハ表面に処理対象の膜として複数の膜層が形成された多層の構造を、より微細に、より高い精度で加工ことが求められている。このことから、試料台に載せられるウエハの温度とその分布とを、精度良く所望に近いものにすることが求められている。
In such an etching process, the uniformity of the film shape as a result of processing the film structure of the wafer is related to the density and intensity distribution of the plasma used in the process, as well as the in-plane direction of the wafer surface being processed. Requirements such as the temperature and distribution of the gas, the composition of the gas supplied and the amount and distribution of the gas are affected. In recent years, it has been required to process a multilayer structure in which a plurality of film layers are formed as films to be processed on the wafer surface with finer and higher accuracy. For this reason, it is demanded that the temperature of the wafer placed on the sample stage and its distribution be close to desired with high accuracy.

このような処理対象の試料としてのウエハの温度を調節する技術は、従来から検討されており、例えば特開２０１４−１５０１６０号公報（特許文献１）に示されるように、試料台の内部に複数のヒータを配置し是等の複数のヒータの発熱量を調節する制御部を備えたプラズマ処理装置が知られている。
Such a technique for adjusting the temperature of a wafer as a sample to be processed has been studied conventionally. For example, as disclosed in Japanese Unexamined Patent Application Publication No. 2014-150160 (Patent Document 1), a plurality of techniques are provided inside a sample stage. There is known a plasma processing apparatus provided with a control unit that arranges the heaters and adjusts the heat generation amount of a plurality of heaters such as the right heater.

特開２０１４−１５０１６０号公報JP 2014-150160 A

上記従来技術においては、次の点について考慮が不十分であったため問題が生じていた。
In the prior art described above, problems have arisen due to insufficient consideration of the following points.

すなわち、試料台を加熱あるいは冷却するために循環する冷媒が通流する試料台の内部に備えられた冷媒流路のパターンは、通常、被加工試料の全面にわたって温調効果を得るために、円板あるいは円筒形を有した試料台の中心軸周りに同心状または螺旋状に、半径方向について多重に配置される。この場合、試料台の内部には、試料台上に載せられるウエハを試料台上面に静電気により吸着させるための静電チャックの電極に給電するためのケーブルやコネクタ、或いはウエハを加熱するために試料台内部に配置されるヒータとこれに給電するためのケーブルやコネクタ、さらには、静電吸着されたウエハと試料台上面との間の隙間に供給されるＨｅ等の熱伝達性のガスが通る管路等が配置される。
That is, the pattern of the refrigerant flow path provided inside the sample stage through which the refrigerant circulating to heat or cool the sample stage normally has a circular shape in order to obtain a temperature control effect over the entire surface of the sample to be processed. Multiple plates are arranged in the radial direction concentrically or spirally around the central axis of the sample stage having a plate or cylinder. In this case, a cable or connector for supplying power to an electrode of an electrostatic chuck for adsorbing a wafer placed on the sample table to the upper surface of the sample table by static electricity, or a sample for heating the wafer is provided inside the sample table. Heat transfer gas such as He supplied to the gap between the electrostatically adsorbed wafer and the upper surface of the sample stage passes through the heater and the cable and connector for supplying power to the heater. Pipe lines and the like are arranged.

これはら試料台の上部に配置されるもの或いは上部において動作するものであるため、冷媒の流路は試料台内部でこれらを避けて、且つ上記同心または螺旋状に配置されることが必要になる。しかし、ケーブル、コネクタや配管を避けることが困難である場合には、冷媒流路は折り返した形状となってしまい、上方から見て３６０度に満たない円弧状に配置され当該円弧の端部においてその円弧の曲率を急激に大きくされて折り返されたものとなり、内部を流れる冷媒は上流側の流路に並行で逆向きに折り返されることになる。
Since these are arranged at the upper part of the sample stage or operate at the upper part, the flow path of the refrigerant must be arranged inside the sample stage so as to avoid them and be arranged concentrically or spirally. . However, when it is difficult to avoid cables, connectors, and pipes, the refrigerant flow path has a folded shape and is arranged in an arc shape of less than 360 degrees when viewed from above, and at the end of the arc. The curvature of the arc is suddenly increased and folded, and the refrigerant flowing in the arc is folded in the reverse direction in parallel with the upstream flow path.

このような折り返し部分は、試料台またはこれに載せられるウエハの周方向についての温度とその分布の不均一を低減するために、試料台の内部において周方向に（同じ半径位置で）距離を開けた位置に別の折り返し部分が配置されるものが一般的である。このような構成を有した冷媒流路では、冷媒による熱交換の効率を向上させて温度の調節の精度と速度とを向上させるため、内部を通流する熱交換媒体（冷媒）は、内部で乱流となるように比較的に大きな流量、速度で循環している。
In order to reduce unevenness of the temperature and its distribution in the circumferential direction of the sample stage or the wafer placed on the sample stage, such a folded portion is spaced apart in the circumferential direction (at the same radial position) inside the sample stage. In general, another folded portion is disposed at a certain position. In the refrigerant flow path having such a configuration, in order to improve the efficiency of heat exchange by the refrigerant and improve the accuracy and speed of temperature adjustment, the heat exchange medium (refrigerant) flowing through the inside It circulates at a relatively large flow rate and speed so as to be turbulent.

しかしながら、このような従来技術における冷媒流路の折り返し部おいては、ウエハまたは試料台の面内方向について冷媒の速度が低下してしまうことから、熱伝達率が低下してしまいその上方の試料台上面またはウエハの温度が局所的に周囲の部分からズレてしまう温度の不均一が生じる虞がある。発明者等はこの冷媒流路の折り返し部の近傍における冷媒の流れやウエハの温度を検出してその対策の要否について検討した。
However, in the folded portion of the refrigerant flow path in such a conventional technique, since the speed of the refrigerant decreases in the in-plane direction of the wafer or the sample stage, the heat transfer coefficient decreases, and the sample above it. There is a possibility that the temperature of the table top surface or the wafer may be locally deviated from the surrounding portion, resulting in non-uniform temperature. The inventors have examined the necessity of countermeasures by detecting the flow of the refrigerant and the temperature of the wafer in the vicinity of the folded portion of the refrigerant flow path.

図６は、従来技術における試料台の媒体流路の折り返し部の構成を模式的に示す横断面図である。本図において、外周側（図上上側）の媒体流路２５を左側から右側に向けて流れる冷媒は、折り返し部２６において向きを右側（図上下方）に変える小さな曲率の流路に沿って流れて凡そ１８０度向きを変えて中央側（図上下側）の媒体流路を外周側の流路とは逆向きに流れる。
FIG. 6 is a cross-sectional view schematically showing the configuration of the folded portion of the medium flow path of the sample stage in the prior art. In this figure, the refrigerant flowing from the left side to the right side in the medium flow path 25 on the outer peripheral side (upper side in the figure) flows along the flow path with a small curvature that changes the direction to the right side (lower side in the figure) at the folded portion 26. The direction is changed by about 180 degrees, and the medium flow path on the center side (upper and lower sides in the figure) flows in the direction opposite to the flow path on the outer peripheral side.

この折り返し部２６を流れる冷媒の流速はその媒体流路内で分布を生じており、１８０度に曲ったＵ字状の折り返し部２６内の上流側の部分で流速の増し、一方で折り返し部２６内の下流側部分では流速が相対的に低減する。この結果液体状態で抵抗の大きな冷媒は折り返し部２６の上流側部分では流路のセンタよりもイン側に寄って流れ、下流側の部分ではアウト側に寄って流れることが発明者らの検討により判った。
The flow velocity of the refrigerant flowing through the folded portion 26 is distributed in the medium flow path, and the flow velocity is increased at an upstream portion in the U-shaped folded portion 26 bent at 180 degrees, while the folded portion 26. The flow velocity is relatively reduced in the downstream portion. As a result, the inventors have studied that the refrigerant having a large resistance in the liquid state flows closer to the in-side than the center of the flow path in the upstream portion of the folded portion 26 and flows closer to the out-side in the downstream portion. understood.

さらに、アウト側に流れる下流側の部分おいては、媒体流路２５の内側表面の壁面の近傍に流速が増す箇所３２が生じて、当該箇所３２において熱伝達率は周辺よりも著しく大きなってしまうために、周囲と比較して過剰な熱交換が生じて温度が過度に大きいまたは小さいものとなってしまい、加熱または冷却いずれの場合においても折り返し部２６の近傍における試料台およびウエハの温度が所期のものからズレて少なくとも試料台またはウエハの周方向について均一性が損なわれることが判った。このため、ウエハの処理の結果の加工形状が許容範囲からはずれてしまい、製造される半導体デバイスの性能が損なわれたり処理の歩留まりが低下してしまったりする問題が生じていた。
Further, in the downstream portion that flows to the out side, there is a portion 32 where the flow velocity increases in the vicinity of the wall surface on the inner surface of the medium flow path 25, and the heat transfer coefficient at the portion 32 is significantly larger than the surroundings. Therefore, excessive heat exchange occurs compared with the surroundings, and the temperature becomes excessively large or small. In either case of heating or cooling, the temperature of the sample stage and the wafer in the vicinity of the folded portion 26 is low. It was found that the uniformity was impaired at least in the circumferential direction of the sample stage or wafer, deviating from the intended one. For this reason, the processing shape as a result of the processing of the wafer deviates from the allowable range, and there is a problem that the performance of the semiconductor device to be manufactured is impaired or the processing yield is lowered.

上記の従来技術では、このような問題について考慮されていなかった。本発明の目的は、処理の歩留まりを向上させたプラズマ処理装置を提供することにある。
In the above prior art, such a problem has not been considered. An object of the present invention is to provide a plasma processing apparatus with improved processing yield.

上記目的は、真空容器の内部に配置され内側が減圧される処理室と、この処理室内に配置されその上面に処理対象の試料が載せられて保持される試料台と、試料台の内部に配置され内側をその温度が所定の値に調節された熱交換媒体が通流する媒体流路とを備え、前記処理室内にプラズマを形成して前記試料を処理するプラズマ処理装置であって、前記媒体流路は、試料台の内部でその径方向について多重に配置された複数の円弧形状部分及びこれらの間を湾曲して接続する折り返し部と、この折り返し部内に配置され当該媒体流路を水平方向について前記湾曲の内側及び外側に分ける柱状の部材を供えたことにより達成される。
The purpose is to place the processing chamber in the vacuum vessel, the inside of which is depressurized, the sample table placed in the processing chamber and holding the sample to be processed on the upper surface, and the sample table. A medium flow path through which a heat exchange medium whose temperature is adjusted to a predetermined value flows, and forms a plasma in the processing chamber to process the sample, wherein the medium The flow path includes a plurality of arc-shaped portions arranged in multiple in the radial direction inside the sample stage, a folded portion that bends and connects them, and a medium flow path that is disposed in the folded portion in the horizontal direction. This is achieved by providing a columnar member that divides the inside and outside of the curve.

本発明によれば、試料を精度良くの加工でき歩留まりを向上させたプラズマ処理装置を提供できる。
According to the present invention, it is possible to provide a plasma processing apparatus capable of processing a sample with high accuracy and improving the yield.

本発明の第１の実施例に関わるプラズマ処理装置の基本構成図1 is a basic configuration diagram of a plasma processing apparatus according to a first embodiment of the present invention. 図１に示す実施例の試料台の構成を示す縦断面図1 is a longitudinal sectional view showing the configuration of the sample stage of the embodiment shown in FIG. 図１に示す実施例ならびに本発明の比較例における試料台内部の流路パターンを示す横断面図1 is a cross-sectional view showing a flow path pattern inside a sample stage in the embodiment shown in FIG. 1 and a comparative example of the present invention. 図１に示す実施例の試料台内部の流路パターンの折り返し部の詳細図Detailed view of the folded portion of the flow path pattern inside the sample stage of the embodiment shown in FIG. 本発明の第２の実施例に関わる試料台内部の流路パターンの折り返し部の詳細図Detailed view of the folded portion of the flow path pattern inside the sample stage according to the second embodiment of the present invention 本発明の比較例における試料台内部の流路パターンの折り返し部の詳細図Detailed view of the folded portion of the flow path pattern inside the sample stage in the comparative example of the present invention

以下、実施例により説明する。なお、実施例においてはプラズマ処理装置として平行平板型のドライエッチング装置を用いて説明するが、これに限定されない。
Hereinafter, an example explains. In the embodiment, a parallel plate type dry etching apparatus will be described as the plasma processing apparatus, but the present invention is not limited to this.

本発明の実施例について図１乃至４を用いて説明する。図１は、本発明の実施例に係るプラズマ処理装置の構成の概略を模式的に示すプラズマ処理装置の縦断面図である。
An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view of a plasma processing apparatus schematically showing an outline of a configuration of a plasma processing apparatus according to an embodiment of the present invention.

本実施例のプラズマ処理装置は、内部の処理室において処理対象の試料を処理室内で形成したプラズマを用いてエッチングするドライエッチング装置である。本例においてプラズマ処理装置は、その内部にプラズマが形成される空間である処理室を備えた金属製の真空容器１１と、その上方に配置され処理室内にプラズマを形成するために供給される電界及び磁界を生成するプラズマ生成装置と、真空容器１１下方に配置され処理室内部のガスやプラズマ等の粒子を外部に排気するためのターボ分子ポンプ等の真空ポンプを備えて構成された排気装置とを備えている。
The plasma processing apparatus according to this embodiment is a dry etching apparatus that etches a sample to be processed in a processing chamber using plasma formed in the processing chamber. In this example, the plasma processing apparatus includes a metal vacuum vessel 11 having a processing chamber that is a space in which plasma is formed therein, and an electric field that is disposed above and supplied to form plasma in the processing chamber. And a plasma generation device that generates a magnetic field, and an exhaust device that includes a vacuum pump such as a turbo molecular pump that is disposed below the vacuum vessel 11 and exhausts particles such as gas and plasma inside the processing chamber to the outside. It has.

真空容器１１内部の処理室内には、試料２がその上面に載置されて保持される試料台１と、この試料台１の上面上方にこれと対向して配置され処理室の天井面を構成して処理室内に処理用ガスや希ガスがこれを通って流入する複数の貫通孔を備え円板形状を有したシャワープレート１８が配置されている。試料台１とシャワープレート１８との間の処理室内の空間はシャワープレート１８から供給された処理用ガスの原子または分子が励起されてプラズマが形成される放電空間８となっている。
In the processing chamber inside the vacuum vessel 11, a sample table 1 on which the sample 2 is placed and held is held, and a ceiling surface of the processing chamber is arranged above the upper surface of the sample table 1 so as to be opposed thereto. Then, a shower plate 18 having a plurality of through holes through which a processing gas or a rare gas flows through the processing chamber and having a disk shape is disposed. A space in the processing chamber between the sample stage 1 and the shower plate 18 is a discharge space 8 in which plasma is formed by exciting the atoms or molecules of the processing gas supplied from the shower plate 18.

シャワープレート１８の試料台１から見て背面の上方には、真空容器１の上部を構成しアルミやステンレス等の導体で形成された円板形状を有した上部電極３が、その周囲を真空容器１１との間を絶縁する絶縁リングにより囲まれてこれを挟んで真空容器１１の放電空間８を囲む円筒形の側壁の上端部に接続されて配置されている。また、上部電極３は、その内部に供給た流体（ガス等）の冷媒が通流する通路を備え、この通路は真空容器１１の外側に配置された上部電極温度制御手段１７とガス流路１８を介して連結されている。上部電極温度制御手段１７において温度が調節されたガスがガス流路１８を通して上部電極３内の通路を通流して循環することで、電力が印加され高温にされる上部電極３の温度が所定の許容される範囲内の値に維持される。
Above the back surface of the shower plate 18 as viewed from the sample stage 1, an upper electrode 3 having a disk shape that is formed of a conductor such as aluminum or stainless steel and that constitutes the upper portion of the vacuum vessel 1 is surrounded by a vacuum vessel. 11 is surrounded by an insulating ring that insulates the electrode 11 and is connected to the upper end of a cylindrical side wall that surrounds the discharge space 8 of the vacuum vessel 11. The upper electrode 3 is provided with a passage through which a refrigerant of a fluid (gas or the like) supplied therein passes, and this passage is provided with an upper electrode temperature control means 17 and a gas passage 18 disposed outside the vacuum vessel 11. It is connected through. The gas whose temperature is adjusted in the upper electrode temperature control means 17 circulates through the gas flow path 18 through the passage in the upper electrode 3, so that the temperature of the upper electrode 3 to which high temperature is applied by applying electric power becomes a predetermined temperature. It is maintained at a value within the allowable range.

上部電極３とシャワープレート５との間には隙間が形成され、当該隙間には図示しない貯留部等のガス源からの処理用ガスあるいは希ガスが通流する図示しないガス供給経路と連結されて、当該処理用ガスあるいは希ガスが隙間内に導入された後、シャワープレート５を貫通して形成され下方の試料台１の上面上方に対応するその中心部を含んだ領域に配置された複数のガス導入孔７から処理室の放電空間８に導入される。なお、本実施例では、上記隙間には供給されたガスを分散させるために各々が複数の貫通孔を有した複数枚の円形の分散板６が、相互の間に隙間を開け且つ各々の貫通孔の位置をズラして配置されている。
A gap is formed between the upper electrode 3 and the shower plate 5, and the gap is connected to a gas supply path (not shown) through which a processing gas or a rare gas from a gas source such as a reservoir (not shown) flows. After the processing gas or the rare gas is introduced into the gap, a plurality of gas is formed through the shower plate 5 and disposed in a region including the central portion corresponding to the upper surface of the lower sample stage 1. The gas is introduced from the gas introduction hole 7 into the discharge space 8 of the processing chamber. In this embodiment, a plurality of circular dispersion plates 6 each having a plurality of through-holes in order to disperse the supplied gas in the gap are formed with a gap between each other and each through-hole. The positions of the holes are shifted.

真空容器１１の上方に配置されたプラズマ生成装置は、上部電極３を含み、上部電極３と同軸ケーブル等の電界伝達経路により電気的に接続され上部電極３に高周波電力を供給する高周波電源１０と、電界の伝達経路上に配置され上部電極３に高周波電力を供給する際にインピーダンスを整合させるため整合器とを有している。また、上部電極３の上方外側で同軸ケーブルを囲み、放電空間８の周囲の真空容器１１の円筒形状部の側方外側でこれを囲んで配置され、プラズマ生成のための磁界を形成するソレノイドコイル１２を備えている。
The plasma generator disposed above the vacuum vessel 11 includes an upper electrode 3, a high frequency power supply 10 that is electrically connected to the upper electrode 3 through an electric field transmission path such as a coaxial cable, and supplies high frequency power to the upper electrode 3. And a matching unit for matching impedance when high-frequency power is supplied to the upper electrode 3 disposed on the electric field transmission path. A solenoid coil that surrounds the coaxial cable on the upper outer side of the upper electrode 3 and surrounds the cylindrical part of the vacuum vessel 11 around the discharge space 8 to form a magnetic field for generating plasma. 12 is provided.

試料台１は円筒形を有し、内部に円板または円筒形を有した金属製の基材を備え、当該基材は試料２の処理中にバイアス電位を試料２上方に形成するために高周波電力を供給する高周波電源１４と整合器を挟んで給電経路により電気的に接続された電極となっている。円形を有した基材の上面には試料２がその上方に載せられる誘電体膜が配置され試料の載置面を構成する。
The sample stage 1 has a cylindrical shape and is provided with a metal base material having a disk or a cylindrical shape inside, and the base material has a high frequency to form a bias potential above the sample 2 during processing of the sample 2. It is an electrode that is electrically connected to the high-frequency power supply 14 that supplies power by a power supply path with the matching unit interposed therebetween. A dielectric film on which the sample 2 is placed is arranged on the upper surface of the substrate having a circular shape to constitute a sample placement surface.

基材上面上方の誘電体膜内には、金属製の膜状の電極であって誘電体膜上に試料２が載せられた状態で直流の電力が供給されて誘電体膜と試料２との間に電荷を蓄積して形成される静電気力により試料２を誘電体膜に対して吸着させる静電吸着用の電極が複数配置されている。これらの静電吸着用電極は、各々と接続された直流電源からの電力により異なる極性が付与され試料２をプラズマが放電空間８内に形成されていない状態で吸着力を形成できる双極型の静電チャックの電極を構成する。
In the dielectric film above the upper surface of the substrate, direct current power is supplied in the state where the sample 2 is placed on the dielectric film and is an electrode made of a metal film. A plurality of electrodes for electrostatic adsorption are provided for adsorbing the sample 2 to the dielectric film by electrostatic force formed by accumulating charges therebetween. These electrodes for electrostatic attraction are provided with different polarities depending on the electric power from a DC power source connected to each of the electrodes, and a bipolar type static electrode capable of forming an attraction force when the sample 2 is not formed in the discharge space 8. The electrode of the electric chuck is configured.

試料台１の上面下方の真空容器１１の底面には処理室内のガス、プラズマや反応生成物の粒子が排出される排気用の開口が、真空容器１の内外を連通して配置され、この排気用の開口は図示しないターボ分子ポンプ等の真空ポンプの入り口と排気用の管路で連結されている。排気装置は、真空ポンプと、この真空ポンプと排気用の開口との間を連結する排気用の管路と、真空ポンプ入り口と排気用の開口との間に配置され管路内をその軸方向を横切って配置された軸周りに回転して管路の流路断面積を増減させる複数枚の板状のフラップを供えた排気調整フラップとを含んで構成される。
On the bottom surface of the vacuum vessel 11 below the top surface of the sample stage 1, an exhaust opening through which gas, plasma and reaction product particles in the processing chamber are discharged is disposed in communication with the inside and outside of the vacuum vessel 1. The opening is connected to the inlet of a vacuum pump such as a turbo molecular pump (not shown) through an exhaust pipe. The exhaust device is disposed between a vacuum pump, an exhaust pipe connecting the vacuum pump and the exhaust opening, and between the vacuum pump inlet and the exhaust opening, and the inside of the pipe is axially disposed. And an exhaust adjustment flap provided with a plurality of plate-like flaps that rotate around an axis disposed across the pipe to increase or decrease the flow path cross-sectional area of the pipe.

このようなプラズマ処理装置において、真空容器１１内の処理室内が真空ポンプを含む排気装置の動作により減圧された状態で、真空容器１１の側壁と連結された図示しない別の真空容器であって内部の減圧された空間である搬送室内に配置された搬送用のロボットのアーム先端部上に試料２が載せられて搬送室内を搬送され、真空容器１１の側壁に配置された図示しないゲートを通りアームが伸長してその先端部及び試料２が処理室内に進入して試料台１に受け渡される。試料２が試料台１に受け渡された後、アームが収縮して処理室外の搬送室内に戻ると、真空容器外側に配置された図示しないゲートバルブが駆動されてゲートを気密に閉塞し内部を密封する。
In such a plasma processing apparatus, it is another vacuum container (not shown) connected to the side wall of the vacuum container 11 in a state where the processing chamber in the vacuum container 11 is decompressed by the operation of an exhaust device including a vacuum pump. The sample 2 is placed on the tip of the arm of the transfer robot arranged in the transfer chamber, which is a decompressed space, and is transferred through the transfer chamber and passes through a gate (not shown) arranged on the side wall of the vacuum vessel 11. Is extended, and the tip and the sample 2 enter the processing chamber and are transferred to the sample table 1. After the sample 2 is transferred to the sample stage 1, when the arm contracts and returns to the transfer chamber outside the processing chamber, a gate valve (not shown) disposed outside the vacuum vessel is driven to airtightly close the gate. Seal.

試料台１に受け渡された試料２は、試料台１の上面を構成する誘電体膜上面で構成される載置面上に載せられ、誘電体膜内の静電吸着用の電極に印加された直流の電圧により、当該誘電体膜上に吸着されて保持される。図示しない誘電体膜の載置面上に配置された開口から試料２の裏面と誘電体膜上面との間の隙間にＨｅ等の熱伝達性のガスが供給される。
The sample 2 delivered to the sample stage 1 is placed on a mounting surface constituted by the upper surface of the dielectric film that constitutes the upper surface of the sample stage 1, and is applied to the electrode for electrostatic adsorption in the dielectric film. It is attracted and held on the dielectric film by the direct current voltage. A heat transfer gas such as He is supplied to a gap between the back surface of the sample 2 and the top surface of the dielectric film from an opening arranged on the mounting surface of the dielectric film (not shown).

この状態で、処理用ガスがガス供給手段から分散板６及びシャワープレート５のガス導入孔７を通して放電空間８に導入される。排気装置は継続して駆動されており、処理用ガスの処理室への供給及び排気装置による処理室内のガス等の粒子の排気の流量、速度のバランスにより、処理室内の圧力が処理に適した範囲の値に調節される。この状態で、プラズマ生成装置の高周波電源からＵＨＦまたはＶＨＦ帯の電力が整合器９を介して給電経路を通り上部電極３に供給され、当該高周波電力の電界が放電空間８の上方からシャワープレート５を通して導入される。さらに、ソレノイドコイル１２に電力が供給されて形成された磁界が放電空間８内に導入され、これら電界と磁界との相互作用により電子サイクロトロン共鳴（ＥｌｅｃｔｒｏｎＣｙｃｌｏｔｒｏｎＲｅｓｏｎａｎｃｅ：ＥＣＲ）が生起され、処理用ガスの原子または分子が励起されてプラズマ１６が放電空間８内に形成される。
In this state, the processing gas is introduced into the discharge space 8 from the gas supply means through the dispersion plate 6 and the gas introduction hole 7 of the shower plate 5. The exhaust device is continuously driven, and the pressure in the processing chamber is suitable for processing due to the balance between the supply of the processing gas to the processing chamber and the flow rate and speed of exhaust of particles such as gas in the processing chamber by the exhaust device. Adjusted to range value. In this state, UHF or VHF band power is supplied from the high frequency power source of the plasma generating apparatus to the upper electrode 3 through the power supply path via the matching unit 9, and the electric field of the high frequency power is supplied from above the discharge space 8 to the shower plate 5. Introduced through. Further, a magnetic field formed by supplying electric power to the solenoid coil 12 is introduced into the discharge space 8, and electron cyclotron resonance (ECR) is generated by the interaction between the electric field and the magnetic field, thereby processing gas. As a result, the plasma 16 is formed in the discharge space 8.

バイアス電位形成用の高周波電源１４から整合器を介してプラズマ生成装置のものより低い所定の周波数（本例では８００ｋＨｚ）の高周波電力が試料台１内の基材に供給されて、プラズマ１６の電位との間の電位差に応じて試料２の上面上方にバイアス電位が形成される。プラズマ１６中のイオン等の荷電粒子は、電位差に応じて試料２の表面に誘引されこれと衝突し試料２上面に予め形成された膜構造の処理対象の膜層のエッチング処理が開始される。
A high-frequency power having a predetermined frequency (800 kHz in this example) lower than that of the plasma generation device is supplied from the high-frequency power supply 14 for forming the bias potential to the substrate in the sample stage 1 through the matching unit, and the potential of the plasma 16 is supplied. A bias potential is formed above the upper surface of the sample 2 in accordance with the potential difference between them. Charged particles such as ions in the plasma 16 are attracted to and collide with the surface of the sample 2 according to the potential difference, and the etching process of the film layer to be processed of the film structure formed in advance on the upper surface of the sample 2 is started.

エッチングが進行して終点が検出されると、バイアス用の高周波電力の供給が停止されプラズマ生成装置によるプラズマの生成が停止されてプラズマ１６が消火しエッチング処理が終了する。この後、ゲートバルブが駆動されてゲートが開放され搬送室からロボットのアームが処理室内に進入して処理済みの試料２がアーム先端部に試料台１から受け渡されて処理室外に搬出される。未処理の試料２が存在する場合には処理室内に搬入されて上記と同様の動作が実行され試料２のエッチング処理が実施される。
When the etching progresses and the end point is detected, the supply of the high frequency bias power is stopped, the plasma generation by the plasma generator is stopped, the plasma 16 is extinguished, and the etching process is completed. Thereafter, the gate valve is driven to open the gate, the arm of the robot enters the processing chamber from the transfer chamber, and the processed sample 2 is transferred from the sample stage 1 to the tip of the arm and carried out of the processing chamber. . When the unprocessed sample 2 exists, the sample 2 is carried into the processing chamber and the same operation as described above is executed, and the etching process of the sample 2 is performed.

図２を用いて試料台１の構成をさらに詳細に説明する。図２は、図１に示す実施例の試料台の構成を拡大して模式的に示す縦断面図である。
The configuration of the sample stage 1 will be described in more detail with reference to FIG. FIG. 2 is a longitudinal sectional view schematically showing an enlarged configuration of the sample stage of the embodiment shown in FIG.

本図に示す試料台１は上部に誘電体膜と静電吸着用の電極とを含む静電チャック２０を備えている。静電チャック２０は、基材２１の上面に誘電体材料を溶射して膜状に形成、或いは焼結して作成した厚さの小さな膜状の板部材を接着剤を介して接合して形成される第１の誘電体膜２２と、当該誘電体膜２２上に配置された膜状の静電吸着電極２３と、第１の誘電体膜２２及び静電吸着膜２３の上方を覆って配置された誘電体材料から構成された第２の誘電体膜２４とを備えている。
The sample stage 1 shown in the figure includes an electrostatic chuck 20 including a dielectric film and an electrode for electrostatic adsorption on the upper part. The electrostatic chuck 20 is formed by spraying a dielectric material on the upper surface of the base material 21 to form a film, or by bonding a thin film-shaped plate member formed by sintering through an adhesive. The first dielectric film 22 to be formed, the film-like electrostatic adsorption electrode 23 arranged on the dielectric film 22, and the first dielectric film 22 and the electrostatic adsorption film 23 are disposed so as to cover the upper side. And a second dielectric film 24 made of the dielectric material formed.

静電吸着電極２３は複数個、本例では２つの各々が上方から見て同じ面積またはこれと見做せる程度に近似した値の面積を有した形状で第１の誘電体膜上に配置されている。本例では、円形を有した試料２に合わせてリング状の形状を有した外側電極２３ａとその中央側に配置された円形を有した内側電極２３ｂとを備えた双極（ダイポール）型の電極を構成している。これらの電極それぞれが、図示しない異なる静電吸着用の直流電源に電気的に接続され、直流電圧の印加により各々異なる極性が付与される。
A plurality of electrostatic chucking electrodes 23, two in this example, are arranged on the first dielectric film in a shape having the same area as viewed from above or an area having a value approximated to be considered as this. ing. In this example, a bipolar (dipole) type electrode having an outer electrode 23a having a ring shape and a circular inner electrode 23b arranged on the center side of the sample 2 having a circular shape is used. It is composed. Each of these electrodes is electrically connected to a different DC power source for electrostatic attraction (not shown), and is given a different polarity by applying a DC voltage.

本例の静電吸着電極２３及び第２の誘電体膜は、各々の材料が溶射されて膜状に形成されるが、別の箇所においてタングステン等の金属製の電極を内部に形成したセラミクス等の誘電体材料を整形したのち焼成して形成した焼結体として構成も良い。この場合、第１の誘電体膜２２との間は接着剤を介して接合されて静電チャック２０が構成される。また、第１の誘電体膜２２を溶射により形成するとともにその内部に膜状のヒータを溶射によって形成しても良い。
The electrostatic adsorption electrode 23 and the second dielectric film of the present example are formed into a film shape by spraying each material, but ceramics or the like in which a metal electrode such as tungsten is formed inside in another place Alternatively, the dielectric material may be shaped and then fired to form a sintered body. In this case, the electrostatic chuck 20 is configured by being bonded to the first dielectric film 22 via an adhesive. Alternatively, the first dielectric film 22 may be formed by thermal spraying, and a film heater may be formed therein by thermal spraying.

金属製の円板または円筒形を有した基材２１の内部には、熱交換媒体用の媒体流路２５が中心軸の周りに同心状または螺旋状に、半径方向に流路が多重となるように配置されている。媒体流路２５は温調器を含む温調手段１６と管路によって連結され、温調器１６によってその温度が所定の範囲内の値に調節された熱交換媒体が管路を通して循環して通流する。
Inside the base material 21 having a metal disk or cylinder, a medium flow path 25 for the heat exchange medium is concentrically or spirally around the central axis, and the flow paths are multiplexed in the radial direction. Are arranged as follows. The medium flow path 25 is connected to a temperature control means 16 including a temperature controller by a pipe line, and a heat exchange medium whose temperature is adjusted to a value within a predetermined range by the temperature controller 16 is circulated through the pipe line. Shed.

なお、基材２１の材質としては、適度な強度があればどのような金属でも使用でき、たとえばステンレス、アルミニウム、アルミニウム合金、チタンなどが好適に使用できる。または金属でなくとも構わない。また、第１の誘電体膜２２および第２の誘電体膜２４の材料は、電荷を蓄積できるとともに直流電流を絶縁でき、且つプラズマに対して耐性を有したものであればどのような材料であっても構わないが、例えばアルミナ（酸化アルミニウム、Ａｌ２Ｏ３）やイットリア（酸化イットリウム、Ｙ２Ｏ３）が好適に使用される。また、静電吸着電極２３の材質としては、例えばタングステンやニッケルなどが好適に使用できる。
In addition, as a material of the base material 21, any metal having an appropriate strength can be used. For example, stainless steel, aluminum, an aluminum alloy, titanium, or the like can be preferably used. Or it may not be a metal. In addition, the material of the first dielectric film 22 and the second dielectric film 24 may be any material as long as it can accumulate charges, insulate DC current, and has resistance to plasma. For example, alumina (aluminum oxide, Al2O3) or yttria (yttrium oxide, Y2O3) is preferably used. Moreover, as a material of the electrostatic adsorption electrode 23, for example, tungsten, nickel, or the like can be preferably used.

なお、本実施例において静電吸着電極２３は外電極２３ａと内電極２３ｂの２枚を備えたダイポール型としたが、必ずしもダイポール型である必要はなく、モノポール型であっても構わない。また、静電吸着以外による吸着方法であってもよい。
In this embodiment, the electrostatic chucking electrode 23 is a dipole type having two outer electrodes 23a and inner electrodes 23b. However, it is not necessarily a dipole type, and may be a monopole type. Further, an adsorption method other than electrostatic adsorption may be used.

図３を用いて本実施例の媒体流路の構成について説明する。図３は、図１に示す実施例に係る試料台の基材内部の媒体流路の形状を示す横断面図である。
The configuration of the medium flow path of the present embodiment will be described with reference to FIG. FIG. 3 is a cross-sectional view showing the shape of the medium flow path inside the substrate of the sample stage according to the embodiment shown in FIG.

本図において、内部を温調器１６からの冷媒が通流する媒体流路２５は、その折り返し部２６が８箇所に配置され、円板あるいは円筒形の試料台の中心の周りに同心状で５重の円弧を有して配置されている。媒体流路２５が、基材２１の内部において複数の円弧状の流路が同心状に多重に配置されたことにより、試料２または試料載置面の全面にわたり熱交換媒体の熱交換が実施され、その量の不均一が半径方向または周方向について抑制される。本例においては、試料２の温調効果をより高めるために媒体流路２５の内部で乱流となるように熱交換媒体は流量を大きくされている。
In this figure, the medium flow path 25 through which the refrigerant from the temperature controller 16 flows is provided with eight folded portions 26 and is concentrically around the center of a disk or cylindrical sample stage. Arranged with five arcs. Since the medium flow path 25 includes a plurality of arc-shaped flow paths arranged concentrically inside the base material 21, heat exchange of the heat exchange medium is performed over the entire surface of the sample 2 or the sample placement surface. The non-uniformity of the amount is suppressed in the radial direction or the circumferential direction. In this example, the flow rate of the heat exchange medium is increased so that the turbulent flow is generated inside the medium flow path 25 in order to further enhance the temperature control effect of the sample 2.

本実施例での媒体流路２５の断面は、１０×１０ｍｍの矩形状にされる。この場合、処理中におけるプラズマ１６から試料２に流入する熱を基材２１内部に伝達し媒体流路２５内を通流するフロリナート等の液体の熱交換媒体に伝達して取り除く場合には、熱交換媒体の流量を１０Ｌ／ｍｉｎ以上にすることで、試料２の全面に対して温度の変化と温度の分布とをそれぞれの許容の範囲内の値にできる。図２において、２７は媒体流路２５の熱交換媒体の導入口を、２８は熱交換媒体の導出口を示している。
The cross section of the medium flow path 25 in this embodiment is a 10 × 10 mm rectangular shape. In this case, when the heat flowing into the sample 2 from the plasma 16 during the process is transferred to the inside of the base material 21 and transferred to a liquid heat exchange medium such as florinate passing through the medium flow path 25, the heat is removed. By setting the flow rate of the exchange medium to 10 L / min or more, the change in temperature and the distribution of temperature can be set to values within the respective allowable ranges with respect to the entire surface of the sample 2. In FIG. 2, 27 indicates a heat exchange medium inlet of the medium flow path 25, and 28 indicates a heat exchange medium outlet.

円弧状の経路が５重に同心状に配置された媒体流路２５では、各々の周を構成する円弧は円板または円筒形を有した基材２１の中心の軸から同じ半径距離に流路の水平方向（図上は図面の面内方向）についての幅の中心位置が配置されている。このことで、冷媒は媒体流路２５の各周を同じ半径位置で通流することになり、周方向の試料台１または基材２１延いては試料２の温度の不均一が抑制される。
In the medium flow path 25 in which the arc-shaped paths are arranged concentrically in a 5-fold manner, the arcs constituting each circumference are flow paths at the same radial distance from the central axis of the base material 21 having a disk or a cylindrical shape. The center position of the width in the horizontal direction (in the drawing, the in-plane direction of the drawing) is arranged. As a result, the refrigerant flows through each circumference of the medium flow path 25 at the same radial position, and the temperature unevenness of the sample stage 1 or the base material 21 and the sample 2 in the circumferential direction is suppressed.

さらに、８箇所の折り返し部２６は、２つが基材２１の部材を挟んで所定の距離だけ離れて配置され各々の媒体流路２５の形状は基材２１の中心軸を含みから半径方向に延在する図面に垂直な面について対称に配置された４つの対を成している。即ち、折り返し部２６は外周側の周の円弧を構成する媒体流路２５とこれと隣接する内周側の周の円弧を構成する媒体流路２５とを連通して接続する媒体流路の部分であり、内外周の２つの円弧の曲率より小さな曲率でおよそ１８０度にわたり曲げられた流路となっている。
Further, two folding portions 26 are arranged at a predetermined distance with the member of the base material 21 interposed therebetween, and the shape of each medium flow path 25 extends in the radial direction from the central axis of the base material 21. Four pairs are arranged symmetrically about a plane perpendicular to the existing drawing. That is, the folded portion 26 is a portion of the medium flow path that connects and connects the medium flow path 25 that forms a circular arc on the outer peripheral side and the medium flow path 25 that forms an adjacent circular arc on the inner peripheral side. The flow path is bent over approximately 180 degrees with a curvature smaller than the curvature of the two arcs on the inner and outer circumferences.

流路の軸が上方から見て１８０度湾曲した２つの折り返し部２６の対は、外向きに湾曲した部分を対向させて上記面を挟んで対称な位置に配置される。基材２１の媒体流路２５の折り返し部２６の対同士の間の箇所は、その内外周を構成する媒体流路２５の円弧状の部分との間の箇所とともに、静電チャック２０を駆動するためのケーブルやコネクタ或いは基材２０に供給される高周波電力用のケーブルやコネクタを収納する箇所として利用可能である。これらコネクタやケーブルはその径や絶縁性能の確保するための距離等の仕様によって、これを迂回させて媒体流路２５の１つの周をを配置することが困難となる場合が有る。この場合、上記のように媒体流路２５を折り返して多重の流路を構成できる。
The pair of the two folded portions 26 whose channel axes are curved by 180 degrees when viewed from above are arranged at symmetrical positions with the above curved surfaces facing each other with the curved portions facing outward. The location between the pair of folded portions 26 of the medium flow path 25 of the substrate 21 drives the electrostatic chuck 20 together with the position between the arc-shaped portion of the medium flow path 25 constituting the inner and outer circumferences. Therefore, it can be used as a location for storing a cable or connector for high frequency power supplied to the substrate 20 or a cable or connector. Depending on the specifications such as the diameter and the distance for ensuring insulation performance of these connectors and cables, it may be difficult to circumvent this and arrange one circumference of the medium flow path 25. In this case, a plurality of flow paths can be formed by folding the medium flow path 25 as described above.

図４を用いて媒体流路２５の折り返し部の構成について詳細に説明する。図４は、図３に示す試料台内部の媒体流路の折り返し部の構成を拡大して模式的に示す横断面図である。
The configuration of the folded portion of the medium flow path 25 will be described in detail with reference to FIG. FIG. 4 is a cross-sectional view schematically showing an enlarged configuration of the folded portion of the medium flow path inside the sample table shown in FIG.

本図において、折り返し部２６の媒体流路２５の内部には、湾曲した媒体流路２５をその底面及び天井面の間を連接して当該湾曲の円弧の内側と外側との流路に分けて横断面が円弧状の柱部材である中州２９を備えている。この構成により、媒体流路２５を流れる熱交換媒体は折り返し部２６において内側流路３０及び外側流路３１に分かれて流れる。
In this figure, inside the medium flow path 25 of the folded portion 26, the curved medium flow path 25 is divided into a flow path inside and outside the curved arc by connecting the bottom surface and the ceiling surface. The middle state 29 which is a column member with a circular cross section is provided. With this configuration, the heat exchange medium flowing through the medium flow path 25 flows into the inner flow path 30 and the outer flow path 31 in the folded portion 26.

中州２９によって熱交換媒体が湾曲の円弧の中心側と外周側との内外の流路に分岐されて流れることによって、折り返し部２６では各々の流路の熱交換媒体の流路断面積は折り返し部２６より上流側及び下流側の箇所におけるものより、媒体流路２５全体でのの水平方向（図上図面の面内方向）についての幅が変化していない場合には、減少することになる。このため、折り返し部２６での熱交換媒体の圧力損失が増すことになり、必要な冷却または熱交換の量を維持するためにはポンプ能力が増大することになる。
When the heat exchange medium is branched and flowed into the inner and outer flow paths between the center side and the outer peripheral side of the curved arc by the middle state 29, the flow cross-sectional area of the heat exchange medium of each flow path is the turn-back portion. If the width in the horizontal direction (in-plane direction of the drawing in the drawing) of the entire medium flow path 25 is not changed from that at the upstream side and downstream side of H.26, it will decrease. For this reason, the pressure loss of the heat exchange medium at the turn-back portion 26 increases, and the pump capacity increases in order to maintain the necessary amount of cooling or heat exchange.

この増大の量を最小限に抑制するには中州２９の湾曲した円弧の半径方向についての幅を極力薄くすることが好ましい。また、折り返し部２６における熱交換媒体の流れの方向について中州２９の先端および終端の形状を端に向かって上記幅を狭めるようにすることが好ましい。この結果、中州２９の横断面は図に示されるように異なる半径の円弧が接合した三日月状の形状となる。
In order to minimize this amount of increase, it is preferable to make the width of the curved arc of the Nakashu 29 in the radial direction as thin as possible. Moreover, it is preferable to make the said width | variety narrow toward the end in the shape of the front-end | tip of a middle state 29, and a termination | terminus about the direction of the flow of the heat exchange medium in the folding | turning part 26. As a result, the cross-section of the Nakashu 29 has a crescent-like shape in which arcs of different radii are joined as shown in the figure.

さらに、本実施例においては、折り返し部２６を構成する媒体流路２５の湾曲の内周側と外周側の内側壁面の曲率半径は一定かこれと見做せる程度に近似した複数の値で、且つ可能な限り大きな値が選択される。また、内側流路３０及び外側流路３１の各々の幅は流路の入り口から出口までの間で一定かこれと見做せる程度に近似した複数の値となるように構成され、折り返し部２６での熱交換媒体の流れの圧力損失の低減を抑制している。また、中州２９は基材２１と一体に形成され、試料台１の基材２１は複数の金属板をブレージングによって接合して一体に構成されるようにしても良い。
Further, in the present embodiment, the curvature radius of the inner wall surface on the inner circumferential side and the outer wall surface on the outer circumferential side of the medium flow path 25 that constitutes the folded portion 26 is a plurality of values approximated to the extent that they are constant or can be regarded as this, The largest possible value is selected. In addition, the width of each of the inner flow path 30 and the outer flow path 31 is configured to be a plurality of values that are constant or approximate to the extent that they can be considered from the entrance to the exit of the flow path. The reduction of the pressure loss of the flow of the heat exchange medium is suppressed. The middle state 29 may be formed integrally with the base material 21, and the base material 21 of the sample stage 1 may be configured integrally by joining a plurality of metal plates by brazing.

中州２９によって分割された折り返し部２６では、外側流路３１の水平方向の幅は内側流路３０よりも小さくされ、折り返し部２６を流れる熱交換媒体が内側流路３０に多く流れるように構成されている。内側流路３０はその下流側の外周側の領域に熱交換媒体の流速が増して熱伝達率が過大となる箇所３２が生じるものの、中州２９の円弧の半径方向についての厚さは中州２９の他の部分と比較して小さくされており、熱伝達係数が低くされ基材２１側への熱の伝達量は抑制され、試料２の温度とその分布への影響が低減されている。
In the folded portion 26 divided by the middle state 29, the horizontal width of the outer flow path 31 is made smaller than that of the inner flow path 30, and the heat exchange medium flowing through the folded portion 26 flows through the inner flow path 30 more. ing. The inner flow path 30 has a portion 32 in which the heat transfer rate is increased due to an increase in the flow rate of the heat exchange medium in the region on the outer peripheral side downstream of the inner flow path 30. The heat transfer coefficient is reduced, the amount of heat transferred to the base material 21 is suppressed, and the influence on the temperature of the sample 2 and its distribution is reduced.

この点でも、中州２９は、その内部の上下方向（図上図面に垂直な方向）についての伝熱の抵抗を大きくする上で、水平方向の幅（三日月の厚さ）が出来るだけ小さくされることが望ましい。一方で、外側流路３１を流れる熱交換媒体は流速が相対的に低くされており、外側流路３１においては熱伝達率が過大となる箇所は生じない。
In this respect as well, in order to increase the heat transfer resistance in the vertical direction (the direction perpendicular to the drawing in the drawing) of the inner state 29, the horizontal width (the thickness of the crescent moon) is made as small as possible. It is desirable. On the other hand, the heat exchange medium flowing in the outer flow path 31 has a relatively low flow rate, and no location where the heat transfer coefficient is excessive in the outer flow path 31 is generated.

以上より、図６に示す従来の技術に対して本実施例のプラズマ処理装置においては、熱伝達率が過大となる箇所の試料２の処理への影響が抑制され、試料２の周方向の温度分布の均一性が向上し、試料２の面内方向についての温度とその分布を所望のものに近付けて処理の歩留まりを向上することができる。
As described above, in the plasma processing apparatus of the present embodiment compared to the conventional technique shown in FIG. 6, the influence on the processing of the sample 2 at the location where the heat transfer coefficient is excessive is suppressed, and the circumferential temperature of the sample 2 is suppressed. The uniformity of the distribution can be improved, and the temperature in the in-plane direction of the sample 2 and its distribution can be brought close to a desired one to improve the processing yield.

（変形例）
本発明の実施例の変形例について図５を用いて説明する。図５は、図１に示す実施例の変形例に係るプラズマ処理装置の試料台内部の媒体流路の折り返し部の構成を拡大して模式的に示す断面図である。
(Modification)
A modification of the embodiment of the present invention will be described with reference to FIG. FIG. 5 is a cross-sectional view schematically showing an enlarged configuration of the folded portion of the medium flow path inside the sample stage of the plasma processing apparatus according to a modification of the embodiment shown in FIG.

図５（ａ）は、媒体流路２５の折り返し部２６の構成を拡大して模式的に示す横断面図であり、図５（ｂ）は、図５（ａ）におけるＡ−Ａ線として示される図に垂直な面に沿った縦断面図を示している。なお、本例のプラズマ処理装置の試料台１内の媒体流路２５の折り返し部２６の構成以外の部分は、実施例と同等であり、必要の無い限り説明を省略する。
FIG. 5A is a cross-sectional view schematically showing an enlarged configuration of the folded portion 26 of the medium flow path 25, and FIG. 5B is shown as an AA line in FIG. 5A. 1 shows a longitudinal sectional view along a plane perpendicular to the figure. The portions other than the configuration of the folded portion 26 of the medium flow path 25 in the sample stage 1 of the plasma processing apparatus of the present example are the same as those in the example, and the description is omitted unless necessary.

本例では、図５（ｂ）に示すように、基材２１を上側基材２１ａと下側基材２１ｂとによって構成し、これらが接続されて一体にされた状態で、中州２９を試料２から遠い下側基材２１ｂとのみ一体化し、試料２に近い上側基材２１ａで構成される媒体流路２５の上側内壁面（天井面）と中州２９の上端面との間には隙間３３を備えた点が、実施例と異なる。この隙間は、例えば０．５ｍｍ程度が好ましい。
In this example, as shown in FIG. 5 (b), the base material 21 is constituted by an upper base material 21a and a lower base material 21b, and these are connected and integrated with each other, and the state 29 is sample 2 A gap 33 is formed between the upper inner wall surface (ceiling surface) of the medium flow path 25 that is integrated only with the lower base material 21 b far from the sample 2 and is composed of the upper base material 21 a close to the sample 2 and the upper end surface of the middle state 29. The point provided is different from the embodiment. The gap is preferably about 0.5 mm, for example.

本例においても、熱伝達率が過大となる箇所３２が中州表面に生じる点で図１の実施例と同様であるが、柱状の部材である中州２９の上端面と上側基材２１ａとの間には隙間が存在し、例えこれが熱交換媒体により充たされていても、試料２への熱伝達の量は下側基材２１ｂを介したものが主となるため、熱伝達が過大となる箇所３２からの試料２の温度とその分布とに及ぼされる影響は小さくされる。
This example is also similar to the embodiment of FIG. 1 in that the portion 32 where the heat transfer coefficient is excessive is generated on the surface of the Nakasu, but between the upper end surface of the Nakasu 29 that is a columnar member and the upper base material 21a. Even if this is filled with a heat exchange medium, the amount of heat transfer to the sample 2 is mainly via the lower substrate 21b, so that heat transfer is excessive. The effect on the temperature of sample 2 from location 32 and its distribution is reduced.

なお、本発明は上記した実施例に限定されるものではなく、様々な変形例が含まれる。例えば、上記した実施例は本発明を分かりやすく説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。また、ある構成の一部を他の構成に置き換えることも可能であり、また、ある構成に他の構成を加えることも可能である。
In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of a certain configuration can be replaced with another configuration, and another configuration can be added to a certain configuration.

１…試料台、
２…試料、
３…上部電極、
４…試料台支持部、
５…シャワープレート、
６…分散板、
７…ガス導入孔、
８…放電空間、
９…整合器、
１０…高周波電源、
１１…真空容器、
１２…ソレノイドコイル、
１３…プラズマ、
１４…高周波電源、
１５…整合器、
１６…温調手段、
１７…上部電極温度制御手段、
１８…ガス流路、
２０…静電チャック、
２１…基材、
２２…第１の誘電体膜、
２３…静電吸着電極、
２４…第２の誘電体膜、
２５…媒体流路、
２６…折り返し部、
２７…導入口、
２８…導出口、
２９…中州、
３０…内側流路、
３１…外側流路。 1 ... Sample stage,
2 ... Sample,
3 ... Upper electrode,
4 ... Sample stage support,
5 ... shower plate,
6 ... dispersion plate,
7: Gas introduction hole,
8 ... discharge space,
9: Matching device,
10 ... High frequency power supply,
11 ... Vacuum container,
12 ... Solenoid coil,
13 ... Plasma,
14 ... High frequency power supply,
15 ... matching device,
16 ... temperature control means,
17 ... Upper electrode temperature control means,
18 ... gas flow path,
20: Electrostatic chuck,
21 ... base material,
22 ... first dielectric film,
23 ... Electrostatic adsorption electrode,
24 ... second dielectric film,
25 ... medium flow path,
26 ... the folded part,
27 ... Introduction port,
28. Outlet,
29 ... Nakashu,
30 ... Inner channel,
31 ... Outer channel.

Claims

A processing chamber disposed inside the vacuum vessel and depressurized on the inside, a sample stage disposed in the processing chamber on which the sample to be treated is placed and held, and a sample stage disposed inside the sample stage and disposed on the inside A plasma processing apparatus for processing the sample by forming a plasma in the processing chamber, and a medium flow path through which a heat exchange medium whose temperature is adjusted to a predetermined value flows.
The medium flow path includes a plurality of arc-shaped portions arranged in a multiplex manner in the radial direction inside the sample stage, a folded portion connecting the curved portions, and a medium flow path disposed in the folded portion. A plasma processing apparatus provided with a columnar member that divides the inside and outside of the curve in the horizontal direction.

The plasma processing apparatus according to claim 1,
The plasma processing apparatus, wherein a radial width of a curve of the inner medium flow path divided by the columnar member in the folded portion is larger than a width of the outer medium flow path.

The plasma processing apparatus according to claim 1 or 2,
A plasma processing apparatus in which a gap is disposed between an upper surface of the columnar member and a top surface of a medium flow path of the folded portion.

A plasma processing apparatus according to any one of claims 1 to 3,
A plasma processing apparatus comprising a pair of the folded portions of the two medium flow paths facing the curved portions in the sample stage.