JPH10223742A - Electrostatic chuck - Google Patents
Electrostatic chuckInfo
- Publication number
- JPH10223742A JPH10223742A JP1934497A JP1934497A JPH10223742A JP H10223742 A JPH10223742 A JP H10223742A JP 1934497 A JP1934497 A JP 1934497A JP 1934497 A JP1934497 A JP 1934497A JP H10223742 A JPH10223742 A JP H10223742A
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- electrodes
- wafer
- electrostatic chuck
- suction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Links
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- Container, Conveyance, Adherence, Positioning, Of Wafer (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、半導体製造装置や
液晶製造装置における半導体ウエハや液晶用ガラス基板
などの被固定物を静電的に吸着保持するために使用する
静電チャックに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic chuck used for electrostatically holding an object to be fixed such as a semiconductor wafer or a liquid crystal glass substrate in a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus. .
【０００２】[0002]
【従来の技術】従来、半導体製造工程において、半導体
ウエハに薄膜を形成するための成膜装置やウエハに微細
加工を施すためのドライエッチング装置などにおいて
は、ウエハを保持するために静電チャックが使用されて
いる。2. Description of the Related Art Conventionally, in a semiconductor manufacturing process, in a film forming apparatus for forming a thin film on a semiconductor wafer or a dry etching apparatus for performing fine processing on a wafer, an electrostatic chuck is used to hold the wafer. It is used.
【０００３】この静電チャックには、静電チャックに内
蔵する吸着用電極とウエハとの間に電圧を印加すること
で保持面にウエハを吸着保持する単極型のものと、静電
チャックに内蔵する対になった吸着用電極間に正負の電
圧を印加することでウエハを保持面に吸着保持する双極
型のものがあり、このうち双極型の静電チャックは、単
極型のようにウエハに直接通電する必要がないため、ウ
エハに悪影響を与えることが少ないといった利点があっ
た。[0003] The electrostatic chuck includes a monopolar type in which a voltage is applied between a chucking electrode and a wafer built in the electrostatic chuck to suck and hold the wafer on a holding surface; There is a bipolar type that holds a wafer on a holding surface by applying positive and negative voltages between a pair of built-in suction electrodes, and among these, a bipolar electrostatic chuck is a single-pole type electrostatic chuck. Since there is no need to directly energize the wafer, there is the advantage that the wafer is not adversely affected.
【０００４】図３に双極型静電チャックの一般的な構造
を示すように、絶縁基体３１の上面を保持面３４とする
とともに、内部に対になった第１の吸着用電極３２と第
２の吸着用電極３３とを具備してなり、例えば、第１の
吸着用電極３２に正電圧を印加し、第２の吸着用電極３
３に負電圧を印加することで保持面３４に載置したウエ
ハ２０を保持面３４の帯電状態と逆に誘電分極させて静
電吸着力を発現させ、ウエハ２０を保持面３４に保持す
るようになっていた。FIG. 3 shows a general structure of a bipolar electrostatic chuck, in which an upper surface of an insulating substrate 31 is used as a holding surface 34, and a pair of a first suction electrode 32 and a second For example, a positive voltage is applied to the first attraction electrode 32 and the second attraction electrode 3
By applying a negative voltage to the wafer 3, the wafer 20 placed on the holding surface 34 is dielectrically polarized in a direction opposite to the charged state of the holding surface 34, and an electrostatic attraction force is developed to hold the wafer 20 on the holding surface 34. Had become.
【０００５】また、上記対になった吸着用電極３２，３
３のパターン形状としては、図４（ａ）に示すような半
円状をした第１の吸着用電極３２と第２の吸着用電極３
３とを円を構成するように配置したものや、図４（ｂ）
に示すような帯状をした第１の吸着電極３２と第２の吸
着電極３３とを互いに入り組ませた、クシ型状に配置し
たものがあった。The pair of suction electrodes 32, 3
The pattern shape of the first and second suction electrodes 32 and 3 has a semicircular shape as shown in FIG.
And FIG. 4 (b).
The first suction electrode 32 and the second suction electrode 33 having a band shape as shown in FIG.
【０００６】[0006]
【発明が解決しようとする課題】ところが、上記双極型
の静電チャック３０をプラズマを発生させた状態で使用
すると、ウエハ２０を均一に吸着することができないと
いった課題があった。However, if the bipolar electrostatic chuck 30 is used in a state where plasma is generated, there is a problem that the wafer 20 cannot be uniformly attracted.
【０００７】これは、図５にその模式図を示すように、
プラズマを発生させた状態ではプラズマとウエハ２０と
の間にセルフバイアスと呼ばれる電位差が発生し、ウエ
ハ２０が負に帯電することから、正電圧を印加した第１
の吸着用電極３２側では吸着力が増大し、逆に負電圧を
印加した第２の吸着用電極３３側では吸着力が減少する
ことになるため、吸着力の不均一が発生していた。This is shown in FIG. 5 as a schematic diagram thereof.
In a state where the plasma is generated, a potential difference called self-bias is generated between the plasma and the wafer 20, and the wafer 20 is negatively charged.
The suction force increases on the suction electrode 32 side, and the suction force decreases on the second suction electrode 33 side to which a negative voltage is applied, so that the suction force becomes non-uniform.
【０００８】そして、図４（ａ）のような半円状の吸着
用電極３２，３３を有する双極型の静電チャック３０で
は、正電圧を印加する第１の吸着用電極３２と負電圧を
印加する第２の吸着用電極３３とが中央部を境に別々に
配置されていることから吸着力の不均一が顕著であっ
た。In the bipolar electrostatic chuck 30 having the semicircular chucking electrodes 32 and 33 as shown in FIG. 4A, the first chucking electrode 32 for applying a positive voltage and the negative voltage are connected to each other. Since the second suction electrode 33 to be applied and the second suction electrode 33 are separately arranged at the center, the non-uniformity of the suction force is remarkable.
【０００９】また、図４（ｂ）のようなクシ型状の吸着
用電極３２，３３を有する双極型の静電チャックにおい
ては、第１の吸着用電極３２と第２の吸着用電極３３と
の間の幅が狭すぎると漏れ電流が増大し、ウエハに悪影
響を与える恐れがあり、逆に第１の吸着用電極３２と第
２の吸着用電極３３との間の幅が広すぎたり、あるいは
各吸着用電極３２，３３の線幅が部分的に広すぎたりす
ると、吸着力の不均一を生じるというように各吸着用電
極３２，３３の線幅と吸着用電極３２，３３間の幅の管
理が十分になされていないとさまざまな不都合があっ
た。Further, in a bipolar electrostatic chuck having comb-shaped suction electrodes 32 and 33 as shown in FIG. 4B, the first suction electrode 32 and the second suction electrode 33 Is too narrow, the leakage current increases, which may adversely affect the wafer. Conversely, the width between the first suction electrode 32 and the second suction electrode 33 is too large, Alternatively, if the line width of each of the attraction electrodes 32, 33 is too large, the attraction force becomes non-uniform, so that the line width of each of the attraction electrodes 32, 33 and the width between the attraction electrodes 32, 33 are reduced. There were various inconveniences if the management of the system was not performed sufficiently.
【００１０】また、特公平１−５２８９９号公報には、
図４（ａ）の吸着用電極３２，３３をさらに２分割し、
点対象な位置に設けたものもあるが、このようなパター
ン形状としても吸着力の不均一を解消することは難しい
ものであった。[0010] Japanese Patent Publication No. 1-52899 discloses that
The suction electrodes 32 and 33 in FIG.
Some of them are provided at symmetrical points, but it is difficult to eliminate non-uniformity of the attraction force even with such a pattern shape.
【００１１】[0011]
【課題を解決するための手段】そこで、本発明は上記課
題に鑑み、被固定物に対する保持面を有する基体の内部
に対になった帯状電極を備えた双極型の静電チャックに
おいて、上記帯状電極の線幅及び帯状電極間の幅をそれ
ぞれ０．３〜３ｍｍとしたものである。SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a bipolar electrostatic chuck having a pair of strip electrodes inside a base having a holding surface for an object. The line width of the electrodes and the width between the strip electrodes are each set to 0.3 to 3 mm.
【００１２】また、本発明は上記誘電体層として、アル
ミナ、窒化珪素、炭化珪素、窒化アルミニウム、イット
リウム・アルミニウム・ガーネット（ＹＡＧ）等を主成
分とするセラミックスを用いたものである。In the present invention, the dielectric layer is made of a ceramic mainly composed of alumina, silicon nitride, silicon carbide, aluminum nitride, yttrium aluminum garnet (YAG) or the like.
【００１３】[0013]
【本発明の実施の形態】以下、本発明の実施形態につい
て説明する。Embodiments of the present invention will be described below.
【００１４】図１は本発明に係る静電チャック１０の一
例を示す縦断面図であり、セラミックス等の絶縁体から
なる円板状をした基体１１の上面を保持面１４とし、該
保持面１４の近傍内部に、対をなす第１の吸着用電極１
２と第２の吸着用電極１３を備えている。また、基体１
１の下面には各吸着用電極１２，１３に連通する固定孔
１５ａ，１６ａを穿設してあり、該固定孔１５ａ，１６
ａに接合した給電端子１５，１６を介して各吸着用電極
１２，１３にそれぞれ通電するようにしてある。FIG. 1 is a longitudinal sectional view showing an example of an electrostatic chuck 10 according to the present invention. The upper surface of a disk-shaped base 11 made of an insulator such as ceramic is used as a holding surface 14. Inside the vicinity of the first adsorption electrode 1 forming a pair
2 and a second adsorption electrode 13. Also, the base 1
Fixed holes 15a and 16a communicating with the respective suction electrodes 12 and 13 are formed in the lower surface of the fixing hole 15a.
A current is supplied to each of the attraction electrodes 12 and 13 via the power supply terminals 15 and 16 joined to a.
【００１５】その為、上記第１の吸着用電極１２に正電
圧を印加し、第２の吸着用電極１３に負電圧を印加する
と、第１の吸着用電極１２に対応するウエハ２０の裏面
が負電荷に帯電し、第２の吸着用電極１３に対応するウ
エハ２０の裏面が正電荷に帯電するため、ウエハ２０と
保持面１４との間には静電吸着力が発現し、ウエハ２０
を保持面１４に保持することができる。Therefore, when a positive voltage is applied to the first attraction electrode 12 and a negative voltage is applied to the second attraction electrode 13, the back surface of the wafer 20 corresponding to the first attraction electrode 12 is turned off. Since the wafer 20 is charged to a negative charge and the back surface of the wafer 20 corresponding to the second suction electrode 13 is charged to a positive charge, an electrostatic attraction force is developed between the wafer 20 and the holding surface 14, and the wafer 20
Can be held on the holding surface 14.
【００１６】また、図２（ａ）に第１の吸着用電極１２
と第２の吸着用電極１３のパターン形状を示すように、
第１の吸着用電極１２は、水平方向に配置した帯状電極
１２ａと該帯状電極１２ａに対して垂直方向に等間隔に
配置した複数の帯状電極１２ｂとからなり、第２の吸着
用電極１３は、環状をした帯状電極１３ａと上記第１の
吸着用電極１２の帯状電極１２ｂ間に位置するように配
置した複数の帯状電極１３ｂとから構成してあり、上記
吸着用電極１２の帯状電極１２ｂと吸着用電極１３の帯
状電極１３ｂとが互い違いに配列されたクシ型状のパタ
ーンを形成するようにしてある。FIG. 2A shows the first adsorption electrode 12.
And the pattern shape of the second adsorption electrode 13,
The first attraction electrode 12 is composed of a strip electrode 12a arranged in the horizontal direction and a plurality of strip electrodes 12b arranged at regular intervals in the vertical direction with respect to the strip electrode 12a. And a plurality of band-shaped electrodes 13b arranged so as to be located between the band-shaped electrodes 13a having an annular shape and the band-shaped electrodes 12b of the first suction electrode 12. The attraction electrode 13 and the strip electrode 13b form a comb-shaped pattern that is alternately arranged.
【００１７】また、上記吸着用電極１２を構成する帯状
電極１２ａ，１２ｂと吸着用電極１３を構成する帯状電
極１３ａ，１３ｂとの間の幅Ｗはどの位置においてもほ
ぼ一定の３ｍｍ以下とし、かつ各帯状電極１２ａ，１２
ｂ，１３ａ，１３ｂの線幅Ｔを３ｍｍ以下としてある。The width W between the strip electrodes 12a and 12b forming the suction electrode 12 and the strip electrodes 13a and 13b forming the suction electrode 13 is substantially constant at 3 mm or less at any position. Each strip electrode 12a, 12
The line width T of b, 13a, 13b is 3 mm or less.
【００１８】その為、帯状電極１２ｂと帯状電極１３ｂ
との間、帯状電極１２ａと帯状電極１３ｂとの間、及び
帯状電極１２ｂと帯状電極１２ａとの間では吸着力の不
均一が発生しているものの、各帯状電極１２ａ，１２
ｂ，１３ａ，１３ｂの線幅Ｔ及び帯状電極１２ａ，１２
ｂと帯状電極１３ａ，１３ｂとの間の幅Ｗを細かくする
とともに、帯状電極１２ａ，１２ｂと帯状電極１３ａ，
１３ｂとを一定の間隔としてあることから、実質的に第
１の吸着用電極１２と第２の吸着用電極１３とを均一に
配置した構造とすることができ、全体としての吸着力の
不均一を解消することができる。Therefore, the strip electrode 12b and the strip electrode 13b
, Between the strip-shaped electrodes 12a and 13b and between the strip-shaped electrodes 12b and the strip-shaped electrodes 12a.
b, 13a, 13b and the band-shaped electrodes 12a, 12b
b and the band electrodes 13a and 13b, the width W between the band electrodes 12a and 12b and the band electrodes 13a and 13b are reduced.
Since the first and second suction electrodes 13b and 13b are arranged at a constant interval, the first and second suction electrodes 12 and 13 can be substantially uniformly arranged, and the suction power as a whole is not uniform. Can be eliminated.
【００１９】ただし、吸着用電極１２，１３を構成する
帯状電極１２ａ，１２ｂ，１３ａ，１３ｂの線幅Ｔが
０．３ｍｍより小さくなると内部抵抗（インピーダン
ス）が大きくなり、十分な吸着力が得られなくなる。ま
た、帯状電極１２ａ，１２ｂと帯状電極１３ａ，１３ｂ
との間の幅Ｗが０．３ｍｍより小さくなると絶縁性が低
下することになり、漏れ電流が増大することから、ウエ
ハ２０上の微小回路が破壊されるなどウエハ２０に悪影
響を与えることになる。However, if the line width T of the strip electrodes 12a, 12b, 13a, 13b constituting the attraction electrodes 12, 13 is smaller than 0.3 mm, the internal resistance (impedance) becomes large, and a sufficient attraction force is obtained. Disappears. Further, the strip electrodes 12a and 12b and the strip electrodes 13a and 13b
If the width W between them is smaller than 0.3 mm, the insulating property is reduced and the leakage current is increased, so that the fine circuit on the wafer 20 is destroyed and the wafer 20 is adversely affected. .
【００２０】その為、各帯状電極１２ａ，１２ｂ，１３
ａ，１３ｂの線幅Ｔは０．３〜３ｍｍとするとともに、
帯状電極１２ａ，１２ｂと帯状電極１３ａ，１３ｂとの
間の幅Ｗを０．３〜３ｍｍとすれば、ウエハ２０を均一
な吸着力でもって保持することができる。Therefore, each of the strip electrodes 12a, 12b, 13
a and 13b have a line width T of 0.3 to 3 mm,
If the width W between the strip electrodes 12a, 12b and the strip electrodes 13a, 13b is set to 0.3 to 3 mm, the wafer 20 can be held with a uniform suction force.
【００２１】また、静電チャック１０の外径がウエハ２
０径より大きい場合、プラズマを発生させた状態下では
保持面１４の周縁がプラズマエネルギーにより摩耗し、
この摩耗粉（パーティクル）が雰囲気を汚染する恐れが
あるが、このような場合、図２（ａ）に示すようなパタ
ーン形状を採用すれば、ウエハ２０に覆われていない保
持面１４周縁の下部には第２の吸着用電極１３の帯状電
極１３ａが形成されることになるため、上記第２の吸着
用電極１３に正電圧を印加するようにすることでウエハ
２０により覆われていない保持面１４の周縁にプラズマ
エネルギーと同じ電荷をもった正電荷を帯電させること
ができるため、その間に発生する反発作用によってプラ
ズマエネルギーによる摩耗を低減することもできる。The outer diameter of the electrostatic chuck 10 is
When the diameter is larger than 0, the periphery of the holding surface 14 is worn by the plasma energy under a state where the plasma is generated,
This wear powder (particles) may contaminate the atmosphere. In such a case, if a pattern shape as shown in FIG. 2A is employed, the lower portion of the periphery of the holding surface 14 not covered by the wafer 20 may be used. Since the strip-shaped electrode 13a of the second suction electrode 13 is formed on the holding surface, a positive voltage is applied to the second suction electrode 13 so that the holding surface not covered by the wafer 20 is formed. Since a positive charge having the same charge as that of the plasma energy can be charged to the periphery of 14, the abrasion due to the plasma energy can also be reduced by the repulsive action generated during that time.
【００２２】次に、本発明の他の実施形態を説明する。Next, another embodiment of the present invention will be described.
【００２３】図２（ｂ）に示すものは、第１の吸着用電
極１２と第２の吸着用電極１２とをそれぞれ環状の帯状
電極１２ａ〜１２ｃ，１３ａ〜１３ｃとし、これらを同
心円状に互い違いに配置するとともに、帯状電極１２ａ
〜１２ｃと帯状電極１３ａ〜１３ｃとの間の幅Ｗをほぼ
一定の０．３〜３ｍｍとし、かつ各帯状電極１２ａ〜１
２ｃ，１３ａ〜１３ｃの線幅Ｔを０．３〜３ｍｍとした
ものである。In FIG. 2B, the first suction electrode 12 and the second suction electrode 12 are formed as annular strip electrodes 12a to 12c and 13a to 13c, respectively, and these electrodes are concentrically staggered. And the strip electrode 12a
-12c and the strip electrodes 13a-13c are set to a substantially constant width of 0.3-3 mm, and each of the strip electrodes 12a-1
The line width T of each of 2c and 13a to 13c is set to 0.3 to 3 mm.
【００２４】また、図２（ｃ）に示すものは、第１の吸
着用電極１２を構成する複数の帯状電極１２ａと、第２
の吸着用電極１２を構成する複数の帯状電極１３ａとを
交互に配置するとともに、帯状電極１２ａと帯状電極１
３ａとの間の幅Ｗをほぼ一定の０．３〜３ｍｍとし、か
つ各帯状電極１２ａ，１３ａの線幅Ｔを０．３〜３ｍｍ
としたものである。FIG. 2C shows a plurality of strip-shaped electrodes 12a constituting the first suction electrode 12 and a second electrode 12a.
The plurality of strip electrodes 13a constituting the suction electrode 12 are alternately arranged, and the strip electrodes 12a and the strip electrodes 1 are arranged alternately.
3a is set to a substantially constant width of 0.3 to 3 mm, and the line width T of each of the strip electrodes 12a and 13a is set to 0.3 to 3 mm.
It is what it was.
【００２５】また、図２（ｄ）に示すものは、第１の吸
着用電極１２を構成する複数の先細り状の帯状電極１２
ａと、第２の吸着用電極１２を構成する複数の先細り状
の帯状電極１３ａとを交互にかつ放射状に配置してあ
り、帯状電極１２ａと帯状電極１３ａとの間の幅Ｗをほ
ぼ一定の０．３〜３ｍｍとし、かつ各帯状電極１２ａ，
１３ａの線幅Ｔを０．３〜３ｍｍとしたものである。FIG. 2D shows a plurality of tapered strip electrodes 12 constituting the first suction electrode 12.
a and a plurality of tapered strip electrodes 13a constituting the second suction electrode 12 are alternately and radially arranged, and the width W between the strip electrodes 12a and the strip electrodes 13a is substantially constant. 0.3 to 3 mm, and each of the strip electrodes 12a,
13a has a line width T of 0.3 to 3 mm.
【００２６】さらに、図２（ｅ）に示すものは、第１の
吸着用電極１２と第２の吸着用電極１２とをクシ型状に
配置した従来より知られているものであるが、帯状電極
１１２ａ，１２ｂと帯状電極１３ａ，１３ｂとの間の幅
Ｗをほぼ一定の０．３〜３ｍｍとするとともに、各帯状
電極１２ａ，１２ｂ，１３ａ，１３ｂの線幅Ｔを０．３
〜３ｍｍとしたものである。FIG. 2E shows a conventional arrangement in which the first and second adsorption electrodes 12 and 12 are arranged in a comb shape. The width W between the electrodes 112a, 12b and the strip electrodes 13a, 13b is set to a substantially constant value of 0.3 to 3 mm, and the line width T of each of the strip electrodes 12a, 12b, 13a, 13b is set to 0.3.
３3 mm.
【００２７】これら図２（ｂ）〜（ｅ）のパターン形状
を有するものにおいても、第１の吸着用電極１２を構成
する帯状電極１２ａ〜１２ｄと第２の吸着用電極１３を
構成する帯状電極１３ａ〜１３ｄとの間の幅Ｗ及び各帯
状電極１２ａ〜１２ｄ，１３ａ〜１３ｄの線幅Ｔを上記
範囲とすることで、実質的に第１の吸着用電極１２と第
２の吸着用電極１３とを均一に配置した構造とすること
ができるため、全体としての吸着力の不均一を解消する
ことができる。2B to 2E, the strip electrodes 12a to 12d forming the first suction electrode 12 and the strip electrodes forming the second suction electrode 13 are also used. By setting the width W between the electrodes 13a to 13d and the line width T of each of the strip electrodes 12a to 12d and 13a to 13d within the above ranges, the first and second adsorption electrodes 12 and 13 are substantially formed. Can be arranged uniformly, so that non-uniformity of the suction force as a whole can be eliminated.
【００２８】なお、図２（ｂ）〜（ｄ）において、各吸
着用電極１２，１３を構成する複数の帯状電極への通電
は、基体１１内にビアホールを形成して導通をとるよう
にすれば良い。In FIGS. 2 (b) to 2 (d), current is supplied to a plurality of strip electrodes constituting each of the attraction electrodes 12 and 13 so that via holes are formed in the base 11 so as to conduct electricity. Good.
【００２９】また、本発明の第１の吸着用電極１２と第
２の吸着用電極１３のパターン形状としては、図２
（ａ）〜図２（ｄ）のものだけに限定されるものではな
く、第１の吸着用電極１２と第２の吸着用電極１３とが
帯状をしたもので、その電極の線幅Ｔが０．３〜３ｍｍ
で、かつ電極間の幅Ｗがほぼ一定の０．３〜３ｍｍであ
れば良い。The pattern of the first and second electrodes 12 and 13 of the present invention is shown in FIG.
2A to 2D, the first electrode 12 for adsorption and the second electrode 13 for adsorption are band-shaped, and the line width T of the electrodes is not limited to that shown in FIG. 0.3-3mm
It is sufficient if the width W between the electrodes is substantially constant at 0.3 to 3 mm.
【００３０】ところで、上記静電チャック１０を構成す
る基体１１は絶縁体であれば良いが、好ましくはアルミ
ナ、ジルコニア、炭化珪素、窒化珪素、窒化アルミニウ
ム、イットリウム・アルミニウム・ガーネット（ＹＡ
Ｇ）等を主成分とするセラミックスを用いることが良
い。これらのセラミックスは耐摩耗性、耐熱性、耐蝕性
の点で優れていることから静電チャック１０の基体１１
を構成するのに適している。The substrate 11 constituting the electrostatic chuck 10 may be an insulator, but is preferably alumina, zirconia, silicon carbide, silicon nitride, aluminum nitride, yttrium aluminum garnet (YA).
It is preferable to use a ceramic mainly composed of G) or the like. Since these ceramics are excellent in wear resistance, heat resistance and corrosion resistance, the substrate 11 of the electrostatic chuck 10
Suitable for constructing.
【００３１】また、これらの中でも耐プラズマ性の点で
は、９９重量％以上のＡｌ2 Ｏ3 を主成分とし、ＳｉＯ
2 、ＣａＯ、ＭｇＯ、ＴｉＯ等の焼結助剤を含有するア
ルミナ質セラミックスやＡｌＮを主成分とし、周期律表
２ａ族元素の酸化物や３ａ族元素の酸化物を０．５〜２
０重量％の範囲で含有する窒化アルミニウム質セラミッ
クス、あるいは９９重量％以上のＡｌＮを主成分とする
窒化アルミニウム質セラミックスのいずれかが良い。さ
らに、上記窒化アルミニウム質セラミックスは、半導体
ウエハ２０と熱膨張係数が近似していることからウエハ
２０の変形を抑えることができるとともに、熱伝導率が
他のセラミックスに比べて優れている（例えば、８０Ｗ
／ｍｋ以上を有する）ことから、保持面１４に載置した
半導体ウエハ２０を均一に加熱することができ、好適で
ある。Among them, from the viewpoint of plasma resistance, 99% by weight or more of Al 2 O 3 is the main component,
2. Alumina ceramic or AlN containing a sintering aid such as CaO, MgO, TiO or the like as a main component, and an oxide of a Group 2a element or an oxide of a Group 3a element in a periodic table of 0.5 to 2%.
Either aluminum nitride ceramics containing 0% by weight or aluminum nitride ceramics containing 99% by weight or more of AlN as a main component is preferable. Further, the aluminum nitride ceramics can suppress deformation of the wafer 20 because the thermal expansion coefficient is similar to that of the semiconductor wafer 20 and have a higher thermal conductivity than other ceramics (for example, 80W
/ Mk or more), so that the semiconductor wafer 20 placed on the holding surface 14 can be uniformly heated, which is preferable.
【００３２】さらに、第１の吸着用電極と第２の吸着用
電極の材質としては、基体１１を構成する絶縁体と熱膨
張係数が近似したものが良く、特に基体１１をセラミッ
クスで形成する場合、タングステン、モリブンデン、コ
バール、白金、あるいはこれらの合金等により形成する
ことが好ましい。Further, the material of the first adsorption electrode and the second adsorption electrode is preferably a material whose thermal expansion coefficient is close to that of the insulator constituting the base 11, especially when the base 11 is formed of ceramics. , Tungsten, molybdenum, kovar, platinum, or alloys thereof.
【００３３】また、上記静電チャック１０の残留吸着力
対策として、保持面１４の吸着用電極１２，１３の無い
部分に溝を設け、ウエハ２０との接触面積を小さくする
ことで、保持面１４に帯電する電荷を少なくし、ウエハ
２０の離脱応答性を高めることができる。ただし、保持
面１４に溝を形成すると、ウエハ２０の均熱性が低下す
ることから、上記溝にＨｅ等のガスを供給することで熱
伝達特性を高め、ウエハ２０の均熱性を向上させること
もできる。As a measure against the residual chucking force of the electrostatic chuck 10, a groove is provided in a portion of the holding surface 14 where the chucking electrodes 12, 13 are not provided to reduce the contact area with the wafer 20, thereby reducing the holding surface 14. , And the detachment response of the wafer 20 can be improved. However, if a groove is formed in the holding surface 14, the heat uniformity of the wafer 20 is reduced. Therefore, by supplying a gas such as He to the groove, the heat transfer characteristics can be improved, and the heat uniformity of the wafer 20 can be improved. it can.
【００３４】さらに、図１に示す静電チャック１０で
は、基体１１の内部に対になった吸着用電極１２，１３
だけを内蔵した例を示したが、ヒータ電極を埋設して静
電チャック１０を発熱させることによりウエハ２０を直
接加熱したり、プラズマ発生用電極を埋設し、保持面１
４の上方に配置する他方のプラズマ発生用電極との間で
プラズマを発生させるようにすることもできる。Further, in the electrostatic chuck 10 shown in FIG. 1, a pair of suction electrodes 12 and 13
Although the example in which only the heater electrode is built in is shown, the wafer 20 is directly heated by burying the heater electrode and causing the electrostatic chuck 10 to generate heat, or the plasma generation electrode is buried and the holding surface 1 is embedded.
The plasma may be generated between the other electrode for plasma generation and the plasma generation electrode disposed above the electrode 4.
【００３５】なお、本発明の静電チャック１０の製造方
法としては、セラミック原料をグリーンシートとし、こ
れらのシートのうち一つのシートに所定のパターン形状
を有する対になった吸着用電極１２，１３を形成して積
層し、一体焼成することにより得ることができる。As a method of manufacturing the electrostatic chuck 10 of the present invention, a ceramic material is used as a green sheet, and one of these sheets has a pair of suction electrodes 12 and 13 having a predetermined pattern shape. Are formed, laminated, and integrally fired.
【００３６】あるいは、保持面１４部分のみを薄膜法に
よって形成することもできる。この場合、セラミック基
板を形成し、その上面に対になった吸着用電極１２，１
３を形成する。これは金属箔のロウ付け、ＣＶＤ法等に
よる金属膜、導電ペーストを印刷し、焼き付けなどの方
法で形成する。その後、吸着用電極１２，１３を覆うよ
うにＣＶＤ法等でセラミック薄膜を被覆して保持面１４
を形成すれば良い。Alternatively, only the holding surface 14 can be formed by a thin film method. In this case, a ceramic substrate is formed, and a pair of adsorption electrodes 12, 1 is formed on the upper surface of the ceramic substrate.
Form 3 This is formed by a method such as brazing of a metal foil, printing of a metal film or a conductive paste by a CVD method or the like, and baking. Thereafter, a ceramic thin film is coated by a CVD method or the like so as to cover the adsorption electrodes 12 and 13, and the holding surface 14 is
May be formed.
【００３７】[0037]
【実施例】ここで、図２（ａ）に示すクシ型状のパター
ン形状を有する対になった吸着用電極１２，１３を備え
た双極型の静電チャック１０を試作し、上記吸着用電極
１２，１３をなす帯状電極１２ａ，１２ｂ，１３ａ，１
３ｂの線幅Ｔ及び帯状電極１２ａ，１２ｂと帯状電極１
３ａ，１３ｂとの間の幅Ｗをそれぞれ変化させた時の吸
着特性について実験を行った。Here, a bipolar electrostatic chuck 10 having a pair of chucking electrodes 12 and 13 having a comb-shaped pattern shown in FIG. Strip-shaped electrodes 12a, 12b, 13a, 1 forming 12, 13
3b and the band electrodes 12a and 12b and the band electrode 1
An experiment was conducted on the adsorption characteristics when the width W between the gaps 3a and 13b was changed.
【００３８】本実験では静電チャック１０を構成する基
体１１を、９９．８重量％のＡｌＮを主成分とする窒化
アルミニウム質セラミックスで形成するとともに、吸着
用電極１２，１３を構成する材質としてタングステン
（Ｗ）を使用した。In this experiment, the substrate 11 forming the electrostatic chuck 10 was formed of aluminum nitride ceramics containing 99.8% by weight of AlN as a main component, and tungsten was used as a material forming the electrodes 12 and 13 for adsorption. (W) was used.
【００３９】次に、各静電チャック１０をスパッタリン
グ装置に配置し、静電チャック１０の吸着用電極１２，
１３間に１ｋｖの直流電圧を印加してシリコンウエハ２
０を吸着保持させ、スパッタリング装置に備えるプラズ
マ発生用電極間に１ｋｗの電力を印加することによりプ
ラズマを発生させて１分間の成膜処理を施し、シリコン
ウエハ２０上に膜厚みが４０００ÅのＳｉＯ2 膜を被覆
した。Next, each of the electrostatic chucks 10 is arranged in a sputtering device, and the chucking electrodes 12 and
13 to apply a 1 kV DC voltage to the silicon wafer 2
0 was absorbed retained, to generate plasma by applying a power of 1kw between the plasma generating electrode provided in the sputtering apparatus performs a film forming process of 1 minute, the silicon wafer 20 SiO 2 membrane thickness of 4000Å on The membrane was coated.
【００４０】そして、吸着特性とウエハ２０に成膜した
ＳｉＯ2 膜の膜厚みとの間には相関関係があることか
ら、ウエハ２０に被覆したＳｉＯ2 膜の膜厚みをレーサ
ーフォーカス膜厚計で測定して画像解析し、その膜厚分
布を測定することにより吸着力の不均一が発生している
かどうかについて測定を行った。Since there is a correlation between the adsorption characteristics and the thickness of the SiO 2 film formed on the wafer 20, the thickness of the SiO 2 film coated on the wafer 20 is measured by a laser focus film thickness meter. The measurement and image analysis were performed, and the film thickness distribution was measured to determine whether or not the adsorption force was nonuniform.
【００４１】また、保持面１４に吸着保持したウエハ２
０への影響を確認するために、基体１１の抵抗値を各吸
着用電極１２，１３に通電するための給電端子１５，１
６間に絶縁抵抗計を設けて測定した。The wafer 2 sucked and held on the holding surface 14
In order to confirm the influence on the power supply terminals 15, 1, the resistance value of the base 11 is supplied to each of the suction electrodes 12, 13 in order to confirm the influence on the suction electrodes 12, 13.
The measurement was performed by providing an insulation resistance meter between 6.
【００４２】それぞれの結果は表１に示す通りである。The results are as shown in Table 1.
【００４３】[0043]
【表１】 [Table 1]
【００４４】この結果、試料Ｎｏ．５，６では、各帯状
電極１２ａ，１２ｂ，１３ａ，１３ｂの線幅Ｔが３ｍｍ
より大きいために吸着力に不均一が発生し、ウエハ２０
に被覆したＳｉＯ2 膜の膜厚みが所定の値に対して１５
％以上のバラツキを生じていた。As a result, the sample No. 5 and 6, the line width T of each strip electrode 12a, 12b, 13a, 13b is 3 mm.
Because of the larger size, the suction force becomes non-uniform, and the wafer 20
The thickness of the SiO 2 film coated on
% Or more.
【００４５】また、試料Ｎｏ．７では、帯状電極１２
ａ，１２ｂと帯状電極１３ａ，１３ｂとの間の幅Ｗが３
ｍｍより大きいために吸着力に不均一が発生し、ウエハ
２０に被覆したＳｉＯ2 膜の膜厚みが所定の値に対し１
５％〜２５％のバラツキを生じていた。The sample No. 7, the strip electrode 12
a, 12b and the strip electrodes 13a, 13b have a width W of 3
mm, the attraction force becomes non-uniform, and the thickness of the SiO 2 film coated on the wafer 20 is 1 to a predetermined value.
A variation of 5% to 25% occurred.
【００４６】さらに、試料Ｎｏ．８では、各帯状電極１
２ａ，１２ｂ，１３ａ，１３ｂの線幅Ｔが０．１ｍｍと
０．３ｍｍ以下であることから、ウエハ２０に被覆した
ＳｉＯ2 膜の膜厚みが所定の値に対し３０〜４０％もの
バラツキを生じていた。そこで、帯状電極１２ａ，１２
ｂ，１３ａ，１３ｂの内部抵抗について測定したとこ
ろ、線幅Ｔが狭すぎたためにその内部抵抗が大きくなり
すぎ、十分な吸着力が得られていなかったためであっ
た。Further, the sample No. 8, each strip electrode 1
Since the line widths T of 2a, 12b, 13a, and 13b are 0.1 mm and 0.3 mm or less, the thickness of the SiO 2 film coated on the wafer 20 varies as much as 30 to 40% with respect to a predetermined value. I was Therefore, the strip electrodes 12a, 12a
When the internal resistances of b, 13a and 13b were measured, the line width T was too small, the internal resistance was too large, and a sufficient attraction force was not obtained.
【００４７】また、試料Ｎｏ．９，10では、各帯状電極
１２ａ，１２ｂ，１３ａ，１３ｂの線幅Ｔが０．３〜３
ｍｍの範囲にあるために均一な吸着力が得られ、膜厚み
のバラツキを４〜１０％以下に抑えることができたもの
の、帯状電極１２ａ，１２ｂ，１３ａ，１３ｂ間の幅Ｗ
が０．３ｍｍより狭いことから、基体１１の絶縁抵抗が
１ＭΩと小さく、実用上ウエハ２０に悪影響を与える恐
れがあった。The sample No. 9 and 10, the line width T of each of the strip electrodes 12a, 12b, 13a and 13b is 0.3 to 3;
mm, a uniform attraction force was obtained, and the variation in film thickness could be suppressed to 4 to 10% or less, but the width W between the strip electrodes 12a, 12b, 13a, 13b was reduced.
Is smaller than 0.3 mm, the insulation resistance of the base 11 is as small as 1 MΩ, and there is a possibility that the wafer 20 may be adversely affected in practical use.
【００４８】これに対し、試料Ｎｏ．１〜４の本発明の
ものでは、各帯状電極１２ａ，１２ｂ，１３ａ，１３ｂ
の線幅Ｔが０．３〜３ｍｍで、かつ帯状電極１２ａ，１
２ｂと帯状電極１３ａ，１３ｂとの間の幅Ｗが０．３〜
３ｍｍの範囲にあるため、基体１１の絶縁抵抗が１００
ＭΩ以上と十分な絶縁性を有しており、また、全体的に
見て均一な吸着力が得られていたため、ウエハ２０に被
覆したＳｉＯ2 膜の膜厚みのバラツキを５〜１０％とす
ることができた。On the other hand, the sample No. In the present invention of Nos. 1 to 4, each of the strip electrodes 12a, 12b, 13a, 13b
Has a line width T of 0.3 to 3 mm and the band-shaped electrodes 12a, 1
2b and the width W between the strip electrodes 13a and 13b is 0.3 to
Since it is within the range of 3 mm, the insulation resistance of the base 11 is 100
Since it has a sufficient insulating property of MΩ or more and a uniform adsorption force is obtained as a whole, the variation in the thickness of the SiO 2 film coated on the wafer 20 is set to 5 to 10%. I was able to.
【００４９】なお、本実施例では、図２（ａ）のパター
ン形状を有する静電チャック１０の例を示したが、図２
（ｂ）〜（ｅ）のパターン形状を有する静電チャック１
０においても同様の傾向が見られた。In this embodiment, an example of the electrostatic chuck 10 having the pattern shape shown in FIG.
(B) Electrostatic chuck 1 having a pattern shape of (e)
At 0, the same tendency was observed.
【００５０】[0050]
【発明の効果】以上のように、本発明によれば、被固定
物に対する保持面を有する基体の内部に対になった帯状
電極を備えた双極型の静電チャックにおいて、上記帯状
電極の線幅及び帯状電極間の幅をそれぞれ０．３〜３ｍ
ｍとしたことから、プラズマを発生させた状態において
も被固定物を均一な吸着力でもって保持することができ
る。As described above, according to the present invention, in a bipolar electrostatic chuck provided with a pair of band-shaped electrodes inside a base having a holding surface for an object to be fixed, a wire of the band-shaped electrode is provided. The width and the width between the strip electrodes are each 0.3 to 3 m.
Because of m, the object can be held with a uniform suction force even in a state where plasma is generated.
【００５１】その為、この静電チャックを半導体装置や
液晶表示装置の製造工程における成膜工程やエッチング
工程等に使用すれば、被固定物である半導体ウエハやガ
ラス基板を均一に吸着し、その温度分布を小さくするこ
とができるため、成膜精度やエッチング加工精度を高め
ることができ、半導体装置や液晶表示装置の製造歩留り
を改善することができる。Therefore, if this electrostatic chuck is used in a film forming step, an etching step, and the like in a manufacturing process of a semiconductor device or a liquid crystal display device, a semiconductor wafer or a glass substrate as an object to be fixed is uniformly adsorbed. Since the temperature distribution can be reduced, the accuracy of film formation and etching can be improved, and the manufacturing yield of semiconductor devices and liquid crystal display devices can be improved.
【図１】本発明に係る静電チャックの一例を示す縦断面
図である。FIG. 1 is a longitudinal sectional view showing an example of an electrostatic chuck according to the present invention.
【図２】（ａ）〜（ｄ）は本発明の静電チャックに内蔵
する吸着用電極のさまざまなパターン形状を示す平面図
である。FIGS. 2A to 2D are plan views showing various pattern shapes of a suction electrode incorporated in the electrostatic chuck of the present invention.
【図３】従来の静電チャックを示す縦断面図である。FIG. 3 is a longitudinal sectional view showing a conventional electrostatic chuck.
【図４】（ａ），（ｂ）は従来の静電チャックに内蔵す
る吸着用電極のパターン形状を示す平面図である。FIGS. 4A and 4B are plan views showing pattern shapes of suction electrodes incorporated in a conventional electrostatic chuck.
【図５】プラズマ雰囲気下での静電チャックの状態を示
す模式図である。FIG. 5 is a schematic diagram showing a state of an electrostatic chuck in a plasma atmosphere.
１０・・・静電チャック、 １１・・・基体、 １２・
・・第１の吸着用電極、１２ａ，１２ｂ・・・帯状電
極、 １３・・・第２の吸着用電極、１３ａ，１３ｂ・
・・帯状電極、 １４・・・保持面、１５，１６・・・
給電端子、 ２０・・・ウエハ10 ... electrostatic chuck 11 ... substrate 12 ...
..First adsorption electrodes, 12a, 12b ... strip electrodes, 13 ... second adsorption electrodes, 13a, 13b.
..Strip electrodes, 14 ... holding surfaces, 15, 16 ...
Power supply terminal, 20 ... wafer
Claims (2)
部に対になった帯状電極を備えた双極型の静電チャック
において、上記帯状電極の線幅及び帯状電極間の幅をそ
れぞれ０．３〜３ｍｍとしたことを特徴とする静電チャ
ック。In a bipolar electrostatic chuck provided with a pair of strip electrodes inside a base having a holding surface for an object to be fixed, the line width of the strip electrodes and the width between the strip electrodes are each set to 0. An electrostatic chuck having a thickness of 3 to 3 mm.
とする請求項１に記載の静電チャック。2. The electrostatic chuck according to claim 1, wherein said substrate is a ceramic.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1934497A JP3527823B2 (en) | 1997-01-31 | 1997-01-31 | Electrostatic chuck |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1934497A JP3527823B2 (en) | 1997-01-31 | 1997-01-31 | Electrostatic chuck |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10223742A true JPH10223742A (en) | 1998-08-21 |
| JP3527823B2 JP3527823B2 (en) | 2004-05-17 |
Family
ID=11996790
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1934497A Expired - Fee Related JP3527823B2 (en) | 1997-01-31 | 1997-01-31 | Electrostatic chuck |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3527823B2 (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000072376A1 (en) * | 1999-05-25 | 2000-11-30 | Toto Ltd. | Electrostatic chuck and treating device |
| JP2002345273A (en) * | 2001-05-18 | 2002-11-29 | Toto Ltd | Electrostatic chuck |
| JP2005051217A (en) * | 2003-07-08 | 2005-02-24 | Future Vision:Kk | Electrostatic chuck for substrate stage, electrode used for same, and processing system having the chuck and electrode |
| JP2006253703A (en) * | 2006-04-07 | 2006-09-21 | Toto Ltd | Electrostatic chuck and insulating substrate electrostatic attraction treatment method |
| WO2007007674A1 (en) | 2005-07-08 | 2007-01-18 | Creative Technology Corporation | Electrostatic chuck and electrode sheet for electrostatic chuck |
| US7468880B2 (en) | 2005-05-24 | 2008-12-23 | Toto Ltd. | Electrostatic chuck |
| US7672111B2 (en) | 2006-09-22 | 2010-03-02 | Toto Ltd. | Electrostatic chuck and method for manufacturing same |
| US9287806B2 (en) | 2012-10-16 | 2016-03-15 | Samsung Display Co., Ltd. | Electrostatic chuck |
| DE112005000621B4 (en) | 2004-03-19 | 2019-01-31 | Creative Technology Corporation | Bipolar electrostatic holding device |
| JPWO2019188496A1 (en) * | 2018-03-26 | 2020-04-30 | 日本碍子株式会社 | Wafer support |
-
1997
- 1997-01-31 JP JP1934497A patent/JP3527823B2/en not_active Expired - Fee Related
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6768627B1 (en) | 1999-05-25 | 2004-07-27 | Toto Ltd. | Electrostatic chuck and processing apparatus for insulative substrate |
| WO2000072376A1 (en) * | 1999-05-25 | 2000-11-30 | Toto Ltd. | Electrostatic chuck and treating device |
| US7209339B2 (en) | 1999-05-25 | 2007-04-24 | Ulvac, Inc. | Electrostatic chuck for an electrically insulative substrate, and a method of using same |
| JP2002345273A (en) * | 2001-05-18 | 2002-11-29 | Toto Ltd | Electrostatic chuck |
| JP2005051217A (en) * | 2003-07-08 | 2005-02-24 | Future Vision:Kk | Electrostatic chuck for substrate stage, electrode used for same, and processing system having the chuck and electrode |
| JP2009004806A (en) * | 2003-07-08 | 2009-01-08 | Future Vision:Kk | Substrate stage electrostatic chuck, electrode used therefor, and processing system having them |
| DE112005000621B4 (en) | 2004-03-19 | 2019-01-31 | Creative Technology Corporation | Bipolar electrostatic holding device |
| US7468880B2 (en) | 2005-05-24 | 2008-12-23 | Toto Ltd. | Electrostatic chuck |
| US7760484B2 (en) | 2005-05-24 | 2010-07-20 | Toto Ltd. | Electrostatic chuck |
| US8158238B2 (en) | 2005-07-08 | 2012-04-17 | Creative Technology Corporation | Electrostatic chuck and electrode sheet for electrostatic chuck |
| WO2007007674A1 (en) | 2005-07-08 | 2007-01-18 | Creative Technology Corporation | Electrostatic chuck and electrode sheet for electrostatic chuck |
| JP2006253703A (en) * | 2006-04-07 | 2006-09-21 | Toto Ltd | Electrostatic chuck and insulating substrate electrostatic attraction treatment method |
| US7672111B2 (en) | 2006-09-22 | 2010-03-02 | Toto Ltd. | Electrostatic chuck and method for manufacturing same |
| US9287806B2 (en) | 2012-10-16 | 2016-03-15 | Samsung Display Co., Ltd. | Electrostatic chuck |
| JPWO2019188496A1 (en) * | 2018-03-26 | 2020-04-30 | 日本碍子株式会社 | Wafer support |
| US11574822B2 (en) | 2018-03-26 | 2023-02-07 | Ngk Insulators, Ltd. | Wafer support table with ceramic substrate including core and surface layer |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3527823B2 (en) | 2004-05-17 |
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