JP2004356299A - Liquid processor, component used for wetted part and manufacturing method of the component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid processor in which occurrence of particles on a workpiece accompanying liquid processing of the workpiece is suppressed. <P>SOLUTION: A wafer cleaning device 10 is provided with a holding mechanism 50 holding a wafer W, a motor 33 rotating the wafer W, a cleaning liquid discharge nozzle 24 supplying cleaning liquid to the wafer W, and an outer cup 22 arranged to surround the wafer W. Surface roughness of an inner wall face of the outer cup 22 is adjusted to Ra of 0.5 to 10.0 so that it functions as a hydrophilic front surface. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００４２】
表１に示されるように、外カップＡは、サンドペーパーによって表面粗度Ｒａが９．０に調整されたものである。また、外カップＢでは、水と樹脂粉末を混合してなるスラリーの吹き付け処理によって、表面粗度Ｒａが０．９に調整されている。外カップＣ・Ｄは、ともに水とアルミナ粉末を混合してなるスラリーの吹き付け処理が施されており、カップＣでは表面粗度Ｒａは４．０に、カップＤでは表面粗度Ｒａは９．０にそれぞれ調整されている。なお、このような表面粗度は、非接触式の表面粗度計を用いて測定した値である。
【００４３】
リンス処理およびスピン乾燥処理は、ウエハＷの表面が下側を向くようにウエハＷを保持機構５０に保持させ、純水と窒素ガスを混合させてスプレー状とし、これをウエハＷに吹き付けることによって行った。ここで、純水と窒素ガスの混合比率は、Ｈ_２Ｏ：Ｎ_２＝２００ｍｌ：８０Ｎｌとした。また、スピン乾燥処理は、ウエハＷを３０００ｒｐｍで１５秒回転させることによって行った。なお、これらの処理中には、一定の圧力でドレイン２６からの排気を行っている。パーティクルの増加量は、ウエハＷの外周から３ｍｍの環状部分を除く領域内に存在するパーティクルの数を測定し、その平均値を求めることによって決定した。
【００４４】
図５に示されるように、内壁面の表面粗度の調整を行っていない外カップＥでは、パーティクルの増加量は５００以上であるのに対して、外カップＡ〜Ｄでは約４〜１７と極めて少なく、ウエハＷを清浄に維持することができることが確認された。また、リンス処理後の外カップＡ〜Ｅの内壁面を目視観察した結果、外カップＡ〜Ｄでは水滴の発生が殆ど認められなかったのに対し、カップＥでは多くの水滴が確認された。
【００４５】
上述したような、ポリプロピレン（ＰＰ）等の疎水性樹脂材料からなる外カップの内壁面の表面粗度を調整することによって実質的に親水性表面として機能させる方法に代えて、外カップの内壁面を純水等の接触角が小さくなるように表面改質することによって親水性を高める方法を用いることによっても、ウエハＷに発生するパーティクル量を低減させることができる。具体的には、外カップの内壁面を所定時間、所定の条件で発生させた大気圧プラズマ放電にさらす処理によって、外カップの内壁面での純水等の接触角を小さくすることができる。
【００４６】
表２は、ポリプロピレン（ＰＰ）の角材（以下「ＰＰ角材」という）をプラズマチャンバーに収容し、処理時間を変化させたときのプラズマ処理表面における純水の接触角の変化を示している。このＰＰ角材のプラズマ処理表面の接触角の測定は、ＰＰ角材のプラズマ処理表面の複数箇所にそれぞれ１滴の純水を垂らして、その接触角をＣＣＤカメラで観察して得られた値の平均値である。
【００４７】
【表２】

【００４８】
一般的なポリプロピレン（ＰＰ）での純水の接触角は８１度であるが、表２に示されるように、準備したＰＰ角材では、純水の接触角は未処理の場合に約９５度であった。プラズマ処理によって純水の接触角は小さくなる傾向にあり、５分間のプラズマ処理によって純水の接触角を約２０度にまで小さくすることができることが確認された。この結果は、ウエハ洗浄装置１０に、内壁面にプラズマ処理が施された外カップ２２と、外壁面にプラズマ処理が施された内カップ２３とを用いることにより、ウエハＷにおけるパーティクルの発生を抑制することができることを示している。
【００４９】
なお、試料の処理面全体で純水の接触角を約２０度にまで小さくすることが好ましいが、純水の接触角が４０度以下であれば、十分にスピン乾燥処理時等の気流によってミスト化するような水滴がリンス処理時等に発生することを抑制することができる。また、液体の接触角は液体の種類によって異なるために、その他の液体の接触角はこの範囲とは必ずしも一致しない。しかし、例えば、スクラブ洗浄処理等では、ほぼ純水と同粘度の洗浄液が用いられ、高粘度液体は用いられないために、純水の接触角が２０度以上４０度以下の範囲となる限りにおいて、外カップの内壁面や内カップの外壁面における液滴の付着を十分に抑制することができる。
【００５０】
また、原子間力顕微鏡（ＡＦＭ）を用いて試料におけるプラズマ処理面の凹凸観察を行ったが、プラズマ処理時間に依存した表面形態の変化は観察されず、平坦さが維持されていることが確認された。このことから、プラズマ処理による純水の接触角の変化は、試料表面の物理的な変化ではなく、化学的な変化によって生じているものと推測される。
【００５１】
以上、本発明の実施の形態について説明してきたが、本発明はこのような形態に限定されるものではない。例えば、外カップ２２と内カップ２３の材質としてポリプロピレン（ＰＰ）を取り上げたが、外カップ２２と内カップ２３には、ＰＶＣ（ポリ塩化ビニル）やＰＭＭＡ（ポリメチルメタクリレート）、ＰＡ（ポリアミド）、ＰＥ（ポリエチレン）、ＰＣＴＦＥ（ポリクロロトリフルオロエチレン）、ＰＰＳ（ポリフェニレンサルファイド）、ＰＴＦＥ（ポリテトラフルオロエチレン）等を用いることもできる。
【００５２】
外カップ２２の内壁面等の表面粗度を調整する方法は、上述したウエットブラスト法に限定されず、砥粒を空気圧を利用して噴射するサンドブラスト法や、先に示した表１に示したようなサンドペーパー等の研磨紙を用いる方法を用いてもよい。またバレル研磨処理やレーザー照射処理を用いることもできる。なお、上述した樹脂は一般的には耐薬品性に優れるが、所定の薬液によってこれらの表面を荒らすウエットエッチングを用いることができる場合もある。なお、外カップとしてウエットブラスト法によりその内壁面の表面粗度を調整したものを用い、内カップとして大気圧プラズマ処理によりその外壁面での純水等の接触角を小さくしたものを用いてもよいことはいうまでもない。
【００５３】
また、保持機構５０が具備する爪部材５７と支持ピン５９にはＰＥＥＫ（ポリエーテルエーテルケトン）等が用いられているが、これもまた疎水性樹脂材料の１つであるために、ウエハＷと爪部材５７の接触部で液滴が生じ、この液滴の乾燥速度が遅いためにウエハＷの外周部でパーティクルが多く発生しやすい。同様に、ウエハＷと支持ピン５９との接触部で処理液が乾燥し難いために、この部分でパーティクルが多く発生しやすい。そこで、爪部材５７と支持ピン５９に対しても、その表面が親水性を示すようにウエットブラスト法等による表面粗度の調整を行い、または、大気圧プラズマ放電処理を行うことによって、元来は疎水性であった表面を親水性に改質してもよい。これによって、ウエハＷと爪部材５７または支持ピン５９との接触部でのパーティクルの発生を抑えることができる。
【００５４】
スピンチャック２１としては、ウエハＷの端面を保持する構造のものを示したが、ウエハＷの裏面を減圧吸着するタイプのスピンチャックを用いてもよい。この減圧吸着タイプのスピンチャックでは、一般的にウエハＷの裏面中央部のみを吸着保持するために、ウエハＷの裏面の外周部が内カップ２３と直接に対面することとなる。このため、外カップ２２の内壁面および／または内カップ２３の外壁面を親水性とすることによってウエハＷの下側の面におけるパーティクルの発生を抑制する効果は、図１および図３に示したスピンチャック２１を用いる場合よりも、減圧吸着タイプのスピンチャックを用いた場合に顕著に抑えられる。
【００５５】
ウエハ洗浄装置１０においては、回転ステージ３１の下側から略放射状に不活性ガスを噴出させることによって、ミストがウエハＷに接近することを抑制し、これによって、ウエハＷの下側の面におけるパーティクルの発生を抑制することも好ましい。
【００５６】
図６はこのガス噴出機構６０の概略説明図である。ガス噴出機構６０は、枢軸３２をその軸方向に貫通しているガス供給路６１と、ガス供給路６１へ不活性ガスを供給するガス供給部６６と、ガス供給路６１の上部に設けられた座ぐり部６２と、不活性ガスを半径方向に導くために座ぐり部６２に対向するようにして回転ステージ３１側に配置された円錐部材６３と、を有している、回転ステージ３１と枢軸３２のフランジ部３２ａとの間には、複数の支持ピン６４が設けられており、これにより、回転ステージ３１の下側とフランジ部３２ａとの間に、不活性ガスの案内路６５が形成されている。
【００５７】
ガス噴出機構６０では、ガス供給部６６から送られてくる不活性ガス（例えば窒素ガス）が、枢軸３２の下側から不活性ガス供給路６１を通して回転ステージ３１の裏面に向けて供給され、座ぐり部６２および円錐部材６３により径方向外側に導かれ、案内路６５に沿って径方向に放射状に噴出される。こうして放射状に噴出された不活性ガスによって、ウエハＷへのミストの接近が抑制される。
【００５８】
上記説明においては、本発明をスクラブ洗浄処理装置に適用した場合について説明したが、特に純水を用いるその他の液処理装置、例えば、露光処理されたレジスト膜を現像する現像処理装置等にも適用することができる。また、被処理体は基板に限定されるものではない。被処理体が基板の場合においては、半導体ウエハのみならず、その他の用途の基板、例えば、ＬＣＤ用ガラス基板の液処理にも本発明を適用することができる。
【００５９】
【発明の効果】
上述したように、本発明によれば、外カップの内壁面や内カップの外壁面が実質的に親水性表面として機能するために、被処理体等から振り切られる洗浄液が外カップの内壁面等で跳ね返ってミスト化したり、または外カップの内壁面に液滴が付着することが抑制される。これにより被処理体にミストが付着することによるパーティクルの発生が抑制され、被処理体の品質を高く保持することができる。また、被処理体を保持する保持機構を構成する部品の表面を実質的に親水性とすることによって、これらの部品と被処理体との接触部分での液滴の発生が抑制される。これによって被処理体にパーティクルが発生することが抑制されて、被処理体の品質を高く保持することができる。
【図面の簡単な説明】
【図１】ウエハ洗浄装置の概略断面図。
【図２】ウエハ洗浄装置の概略平面図
【図３】保持機構がウエハを保持している状態およびウエハＷを開放している状態を示す説明図。
【図４】外カップの内壁面に設けられる凹凸を模式的に示す説明図。
【図５】ウエハにリンス処理およびスピン乾燥処理を施したその前後でのパーティクルの増加量を示すグラフ。
【図６】ガス噴出機構の概略説明図。
【符号の説明】
１０；ウエハ洗浄装置
２１；スピンチャック
２２；外カップ
２２ａ；凹凸
２３；内カップ
２４；洗浄液吐出ノズル
２５；回転ブラシ
３１；回転ステージ
３２；枢軸
３３；モータ
５０；保持機構
５５；リンク部材
５７；爪部材
６０；ガス噴出機構[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a liquid processing apparatus for performing a liquid processing by supplying a predetermined processing liquid to an object to be processed, a component used for a liquid contact part thereof, and a method of manufacturing the component.
[0002]
[Prior art]
For example, in a photolithography process in a semiconductor device manufacturing process, a semiconductor wafer (hereinafter, referred to as a “wafer”) is subjected to a cleaning process, a hydrophobic process, a resist solution applied to the wafer, and a resist film formed. A predetermined resist pattern is formed on the surface of the wafer by exposing the resist film in a predetermined pattern in an exposure apparatus and developing the exposed resist film.
[0003]
The apparatus for cleaning the wafer includes a rotatable spin chuck that holds the wafer in a substantially horizontal posture, a nozzle that supplies a cleaning liquid or pure water to the surface of the wafer, a rotating brush that contacts the surface of the wafer, There is known a scrub cleaning apparatus which is disposed so as to surround a wafer held by a chuck, and has a cup for preventing the cleaning liquid shaken off from the spin chuck from scattering around the wafer.
[0004]
The cleaning processing of a wafer by such a scrub cleaning apparatus is generally performed as follows. That is, first, the wafer is held by the spin chuck. Next, while rotating the wafer at a predetermined number of revolutions, a scrubbing process is performed in which a cleaning liquid is discharged onto the surface of the wafer and a rotating brush or the like is applied to the surface of the wafer. Thereafter, a rinsing process is performed by supplying pure water to the surface of the wafer while rotating the wafer, and then a spin drying process is performed in which the wafer is rotated at a high speed to shake off the pure water attached to the wafer and the rotary table to dry the wafer. I do.
[0005]
In such scrub processing, rinsing processing, and spin drying processing, pure water and the like shaken off from the wafer and the spin chuck bounce off the inner wall surface of the cup to generate mist. In order to suppress the generation of such mist, the cup is made of a resin material having a relatively small contact angle such as pure water, for example, PVC (polyvinyl chloride), PMMA (polymethyl methacrylate), PA (polyamide), PP (Polypropylene), PE (polyethylene) and the like are used (for example, see Patent Document 1).
[0006]
[Patent Document 1]
JP-A-11-283949 (paragraphs 43 and 44, FIG. 2)
[0007]
[Problems to be solved by the invention]
However, the contact angle of these resin materials is 60 degrees or more. For this reason, in the conventional scrub processing and rinsing processing, generation of mist during such processing cannot be completely suppressed, and the generated mist adheres to the front and back surfaces of the wafer to generate particles. There is. Further, in the step of spin-drying the wafer, pure water spun off from the wafer bounces off the inner wall surface of the cup to generate mist, and the mist adheres to the front and back surfaces of the wafer to generate particles. .
[0008]
Further, when the cup is made of these resin materials, droplets of pure water adhere to the inner wall surface of the cup during the rinsing process. For this reason, there is a problem that the droplets are mist-formed by an air current caused by rotation of the wafer during the spin drying process, and the generated mist adheres to the front and back surfaces of the wafer to generate particles on the wafer.
[0009]
The present invention has been made in view of such circumstances, and it is considered that a mist is generated in a cleaning liquid or a droplet adhered to a cup which is shaken off from a processing target or the like during liquid processing or spin drying processing of the processing target. It is an object of the present invention to provide a liquid processing apparatus that suppresses, thereby suppressing generation of particles on an object to be processed. Another object of the present invention is to provide a part used in a liquid contact part of such a liquid processing apparatus, that is, a part in contact with a processing liquid, and a method of manufacturing the part.
[0010]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided an apparatus for performing a liquid processing by supplying a predetermined processing liquid to an object to be processed,
A holding mechanism for holding the object,
A liquid supply mechanism for supplying a predetermined processing liquid to the object to be processed held by the holding mechanism,
An outer cup arranged to surround the object to be processed held by the holding mechanism,
With
A liquid processing apparatus is provided, wherein the inner wall surface of the outer cup has a surface roughness functioning as a desired hydrophilic surface.
[0011]
In this liquid processing apparatus, an object whose outer wall surface has a predetermined surface roughness like the inner wall surface of the outer cup can be arranged below the object to be processed. Further, since the inner wall surface of the outer cup is made hydrophilic by making the inner wall surface have a predetermined surface roughness, a resin material which is originally hydrophobic can be used as the material of the outer cup. Adjustment of the surface roughness of the inner wall surface of the outer cup can be performed by spraying a slurry obtained by mixing abrasive particles (eg, ceramic powder, resin powder) with a liquid (eg, water) on the inner wall surface of the outer cup. it can.
[0012]
The fact that the inner wall surface of the outer cup has a predetermined surface roughness means that the inner wall surface of the outer cup is roughened and irregularities are formed. Therefore, the unevenness of the inner wall surface of the outer cup should have a directionality so that the processing liquid scattered toward the inner wall surface of the outer cup easily flows downward in the vertical direction after colliding with the inner wall surface of the outer cup. Is preferred. For example, when the slurry is sprayed on the inner wall surface of the outer cup, the direction of the unevenness on the inner wall surface of the outer cup can be changed by changing the spray angle. The surface roughness of the inner wall surface of the outer cup is preferably Ra 0.5 or more and 10 or less.
[0013]
According to a second aspect of the present invention, there is provided an apparatus for performing a liquid processing by supplying a predetermined processing liquid to an object to be processed,
A holding mechanism for holding the object,
A liquid supply mechanism for supplying a predetermined processing liquid to the processing target held by the holding mechanism, and an outer cup made of a hydrophobic resin material disposed so as to surround the processing target held by the holding mechanism,
With
A liquid processing apparatus is provided, wherein an inner wall surface of the outer cup is modified to a desired hydrophilic property by an atmospheric pressure plasma discharge treatment.
[0014]
In this liquid processing apparatus, an object whose outer wall surface has been modified to a desired hydrophilic property by atmospheric pressure plasma discharge treatment can be arranged below the object to be processed, similarly to the inner wall surface of the outer cup. The contact angle of pure water on the inner wall surface of the outer cup is preferably 20 degrees or more and 40 degrees or less. The contact angles of other liquids do not always coincide with this range.
[0015]
In such a liquid processing apparatus, it is preferable that the surface of the portion where the processing liquid contacts the holding mechanism for holding the object to be processed also has a surface roughness that functions as a desired hydrophilic surface. When the holding mechanism includes a component made of a hydrophobic resin material, the surface of the component in contact with the processing liquid may be modified to a desired hydrophilic property by an atmospheric pressure plasma discharge treatment.
[0016]
In these liquid processing apparatuses according to the present invention, for example, since the inner wall surface of the outer cup functions substantially as a hydrophilic surface, the cleaning liquid shaken off from the object to be processed bounces off the inner wall surface of the outer cup to form mist. Is suppressed. In addition, since droplets are prevented from adhering to the inner wall surface of the outer cup, mist of the droplets is also suppressed. Accordingly, generation of particles due to mist adhering to the object to be processed is suppressed, and the quality of the object to be processed can be kept high. The same effect can be obtained by making the outer wall surface of the inner cup substantially hydrophilic. In addition, by making the surfaces of the components constituting the holding mechanism substantially hydrophilic, it is possible to suppress the generation of droplets at the contact portions between these components and the object to be processed, and thereby the Particles can be suppressed from being generated.
[0017]
According to the present invention, there are provided a component used in a liquid contact part of such a liquid processing apparatus and a method of manufacturing the same.
That is, according to the third aspect of the present invention, a component used in a liquid contacting part of the liquid processing apparatus that supplies a predetermined processing liquid to the object to be processed and liquid-treats the object to be processed, in contact with the processing liquid And
There is provided a component for a liquid processing apparatus, the surface of which is adjusted to a surface roughness functioning as a desired hydrophilic surface.
[0018]
According to a fourth aspect of the present invention, a hydrophobic material used in a liquid contacting part of the liquid processing apparatus that supplies a predetermined processing liquid to a processing target and performs liquid processing on the processing target, in which the processing liquid contacts the processing target Parts consisting of
A component for a liquid processing apparatus is provided, wherein the surface is modified from hydrophobic to a desired hydrophilic property by atmospheric pressure plasma treatment.
[0019]
According to a fifth aspect of the present invention, there is provided a method of manufacturing a component used in a liquid contacting part of a liquid processing apparatus that supplies a predetermined processing liquid to an object to be processed and liquid-treats the object to be processed, in contact with the processing liquid And
A method for manufacturing a component for a liquid processing apparatus, characterized by adjusting a surface thereof to a surface roughness functioning as a desired hydrophilic surface by spraying a slurry obtained by mixing predetermined abrasive grains with a predetermined liquid, Is provided.
[0020]
According to a sixth aspect of the present invention, in a liquid processing apparatus that supplies a predetermined processing liquid to an object to be processed and performs liquid processing on the object, a hydrophobic material used for a liquid contacting portion where the processing liquid contacts is used. A method of manufacturing a component comprising:
A method for producing a component for a liquid processing apparatus, characterized in that the surface is modified from hydrophobic to a desired hydrophilic property by atmospheric pressure plasma treatment.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Here, a wafer cleaning apparatus that picks up a wafer as an object to be processed and supplies various cleaning liquids to the surface of the wafer to clean the surface of the wafer will be described. FIG. 1 is a schematic sectional view of the wafer cleaning apparatus 10, and FIG. 2 is a schematic plan view of the wafer cleaning apparatus 10.
[0022]
The wafer cleaning apparatus 10 includes a rotatable spin chuck 21 that holds the wafer W in a substantially horizontal posture, an outer cup 22 that is arranged to surround the wafer W held by the spin chuck 21, The apparatus includes an inner cup 23 disposed therein, a cleaning liquid discharge nozzle 24 for supplying a cleaning liquid or the like to the surface of the wafer W, and a rotating brush 25 contacting the surface of the wafer W. The spin chuck 21 includes a rotating stage 31, a holding mechanism 50 attached to the rotating stage 31, for mechanically holding the wafer W near its end face, a pivot 32 for supporting the rotating stage 31, and a motor for rotating the pivot 32. 33.
[0023]
FIG. 3 is an explanatory diagram showing a state where the holding mechanism 50 is holding the wafer W (left side) and a state where the wafer W is opened (right side). As shown in FIGS. 2 and 3, the holding mechanism 50 includes a support member 51 disposed so as to surround a part of the pivot 32, and three cylindrical protrusion members 52 disposed on the support member 51. And an air cylinder 58 (not shown in FIG. 3; see FIG. 1) for raising and lowering the support member 51, and a disk-shaped flange portion 32 a provided on the upper portion of the pivot 32 and extending in a radial direction. Three arms 53, a pivot member 54 provided at the tip of each arm 53, a substantially L-shaped link member 55 pivotally supported by the pivot member 54, and a link attached to the arm 53; A spring 56 for urging the member 55 downward and a claw member 57 attached to the upper end of the link member 55 are provided. Note that a plurality of support pins 59 for supporting the wafer W are provided on the peripheral portion of the rotary stage 31.
[0024]
In the holding mechanism 50, as shown on the right side of FIG. 3, by extending the air cylinder 58 and raising the support member 51, the projecting member 52 contacts the lower end of the link member 55 and the link member 55 Arrow S ₁ In the direction of. Thereby, the claw member 57 is separated from the peripheral edge of the wafer W. In this state, the wafer W carried into the wafer cleaning apparatus 10 from the outside is supported by the support pins 59, and the wafer W after the scrub processing is carried out. On the other hand, as shown on the left side of FIG. 3, when the air cylinder 58 is contracted, the projecting member 52 separates from the link member 55, and the link member 55 ₂ In the direction of. As a result, the claw members 57 come into contact with the peripheral edge of the wafer W, and hold the wafer W by pressing the wafer W from the outside toward the center. In this state, the cleaning process and the drying process are performed on the wafer W.
[0025]
The wafer cleaning apparatus 10 includes an elevating pin (not shown) disposed so as to penetrate the rotating stage 31, and the tip of the elevating pin rises above the upper end of the outer cup 22. Can descend to below. The wafer W brought from above to the rotation stage 31 is transferred to the lift pins by raising the lift pins. In this state, the wafer W is transferred to the support pins 59 by lowering the lift pins. The wafer W supported by the support pins 59 can be carried out by the reverse procedure.
[0026]
The cleaning liquid discharge nozzle 24 and the rotary brush 25 can independently scan the surface of the wafer W held by the spin chuck 21 in the diameter direction by a slide mechanism (not shown), and can vertically scan the surface of the wafer W by a lifting mechanism (not shown). It is free to move. The cleaning liquid supply device 27 supplies a cleaning liquid or pure water to the cleaning liquid discharge nozzle 24.
[0027]
The outer cup 22 is made of, for example, polypropylene (PP), which is one type of hydrophobic resin, and the surface roughness of the inner wall surface is adjusted to, for example, Ra 0.5 to 10.0. By setting the inner wall surface of the outer cup 22 to such a surface roughness, the water retention of the inner wall surface of the outer cup 22 is enhanced, whereby a thin liquid film is formed on the inner wall surface of the outer cup 22. In other words, even when the outer cup 22 is made of hydrophobic polypropylene (PP), the inner wall surface can be made substantially hydrophilic by adjusting the surface roughness of the inner wall surface of the outer cup 22, As a result, it is possible to prevent the cleaning liquid or the like shaken off from the wafer W or the like from rebounding on the inner wall surface to generate mist or to prevent the cleaning liquid or the like from adhering to the inner wall surface as droplets.
[0028]
Such adjustment of the surface roughness of the inner wall surface of the outer cup 22 is performed by, for example, a method (wet blasting) in which a slurry obtained by mixing a predetermined liquid and a predetermined abrasive is sprayed onto the inner wall surface of the outer cup 22. be able to. In preparing a slurry used for such wet blasting, water is preferably used as the liquid. Examples of the abrasive include ceramic powder (eg, alumina powder, silica powder, silicon nitride powder, silicon carbide powder, calcium carbonate powder, cerium oxide powder, mica powder, glass powder, etc.) and resin powder (eg, engineering plastics, etc.). Hard resin powder) is used.
[0029]
In the wet blasting process on the inner wall surface of the outer cup 22, the cleaning liquid or the like scattered from the wafer W or the rotating stage 31 toward the outer cup 22 easily flows downward in the vertical direction after colliding with the inner wall surface of the outer cup 22. It is more preferable to adjust the angle at which the slurry is applied so that the irregularities on the inner wall surface of the outer cup 22 have a certain directionality. For example, FIG. 4 is an explanatory diagram schematically showing the unevenness provided on the inner wall surface of the outer cup 22. The cleaning liquid shaken off from the wafer W by providing the serrated unevenness 22a on the inner wall surface of the outer cup 22. Etc. can be made hard to bounce substantially perpendicular to the collision surface.
[0030]
The inner cup 23 is also made of, for example, polypropylene (PP). Like the inner wall surface of the outer cup 22, the outer wall surface of the inner cup 23 has a predetermined surface roughness (for example, Ra 0.5 to 10.0) so that the cleaning liquid or the like does not easily rebound and droplets do not easily adhere. Have. A drain 26 is provided on the bottom surface between the outer cup 22 and the inner cup 23 for exhausting the atmosphere inside the outer cup 22 and discharging the cleaning liquid and the like to the outside.
[0031]
The cleaning processing of the wafer W in such a wafer cleaning apparatus 10 is performed as follows. First, the wafer W is held by the holding mechanism 50. Next, the pivot 33 and the rotary stage 31 are rotated by driving the motor 33, whereby the wafer W held by the holding mechanism 50 is rotated. Subsequently, the cleaning liquid discharge nozzle 24 and the rotating brush 25 are arranged above the wafer W.
[0032]
After a predetermined cleaning liquid is discharged to the wafer W from the cleaning liquid discharge nozzle 24 to wet the surface of the wafer W with the cleaning liquid, the rotating brush 25 is rotated while discharging a predetermined amount of the cleaning liquid from the cleaning liquid discharge nozzle 24 to the surface of the wafer W. Then, the cleaning liquid discharge nozzle 24 and the rotating brush 25 are scanned on the surface of the wafer W in the radial direction of the wafer W. At this time, the wafer W can be uniformly cleaned by increasing the scanning speed at the center of the wafer W and decreasing the scanning speed at the outer periphery of the wafer W.
[0033]
During such a scrub cleaning process, a part of the cleaning liquid is shaken off from the wafer W and collides with the inner wall surface of the outer cup 22, but the inner wall surface of the outer cup 22 is adjusted in surface roughness, and is substantially hydrophilic. Since the cleaning liquid functions as a conductive surface, the cleaning liquid shaken off from the wafer W hardly rebounds and mist is hardly generated. Further, since the droplets of the cleaning liquid hardly adhere to the inner wall surface of the outer cup 22, the droplets are prevented from being mist-formed by the air current generated by the rotation of the wafer W.
[0034]
Since there is a gap between the wafer W and the rotary stage 31, if mist generated during the scrub cleaning process passes through this gap and adheres to the back surface of the wafer W, particles will be generated. However, in the wafer cleaning apparatus 10, generation of mist is suppressed, so that particles are hardly generated on the back surface of the wafer W.
[0035]
Similarly, during the scrub cleaning process, a part of the cleaning solution flows down from the wafer W and hits the outer wall surface of the inner cup 23. However, since the outer wall surface of the inner cup 23 is also processed to be hydrophilic, The treatment liquid does not easily rebound and droplets are unlikely to adhere. Thereby, generation of mist on the lower side of the wafer W is suppressed, and generation of particles on the back surface of the wafer W is suppressed.
[0036]
When the scrub cleaning process is completed, the rotating brush 25 is retracted to the outside of the outer cup 22, and pure water is discharged from the cleaning liquid discharge nozzle 24 to the wafer W while rotating the wafer W, so that the wafer W is rinsed. After the rinsing process is completed, the cleaning liquid discharge nozzle 24 is retracted to the outside of the outer cup 22, and the wafer W is rotated at a high speed to perform a spin drying process of shaking off the pure water attached to the wafer W. The wafer W for which the spin drying process has been completed is carried out of the wafer cleaning apparatus 10.
[0037]
At the time of such a rinsing process, the pure water is shaken off from the wafer W and the pure water flows down from the wafer W. However, similarly to the scrub cleaning process, the generation of the mist of the pure water is suppressed in the wafer cleaning apparatus 10, Generation of particles is suppressed.
[0038]
In the scrub cleaning process or the rinsing process, even if mist adheres to the surface of the wafer W, the mist is absorbed by the cleaning liquid or pure water and does not generate particles. When the pure water mist adheres to the surface of the wafer W because the film disappears, particles are generated.
[0039]
Here, compared with the rinsing process, in the spin drying process, since the wafer W is rotated at a high speed, the pure water shaken off from the wafer W collides more strongly with the inner wall surface of the outer cup 22. Mist is easily generated. Further, even after the pure water is shaken off from the wafer W, since the strong air current is generated by rotating the wafer W at a high speed, the pure water droplets are formed on the inner wall surface of the outer cup 22 and the outer wall surface of the inner cup 23. When the droplets are attached, the droplets are mist affected by the air flow. However, in the wafer cleaning apparatus 10, since the inner wall surface of the outer cup 22 and the outer wall surface of the inner cup 23 substantially function as hydrophilic surfaces, rebound and adhesion of water droplets are suppressed. Thereby, generation of mist of pure water is suppressed, and generation of particles on the front surface as well as the back surface of the wafer W is also suppressed.
[0040]
Table 1 shows the surface roughness of four types of outer cups A to D made of polypropylene (PP) manufactured as the outer cup 22 and having different inner wall surface roughness, and a method of adjusting the surface roughness. It is shown. The outer cup E shown in Table 1 is a conventional outer cup in which the surface roughness is not adjusted. FIG. 5 is a graph showing an increase amount of particles on the back surface of the wafer W before and after a rinsing process and a spin drying process are performed on the wafer W having a diameter of 300 mm using these outer cups A to E. . The inner cup 23 is not used for adjusting the surface roughness of the outer wall surface.
[0041]
[Table 1]

[0042]
As shown in Table 1, the outer cup A had a surface roughness Ra adjusted to 9.0 by sandpaper. In the outer cup B, the surface roughness Ra is adjusted to 0.9 by spraying a slurry formed by mixing water and resin powder. The outer cups C and D are both subjected to a spraying treatment of a slurry obtained by mixing water and alumina powder. The cup C has a surface roughness Ra of 4.0, and the cup D has a surface roughness Ra of 9. Each is adjusted to zero. In addition, such a surface roughness is a value measured using a non-contact type surface roughness meter.
[0043]
The rinsing process and the spin drying process are performed by holding the wafer W on the holding mechanism 50 so that the surface of the wafer W faces downward, mixing pure water and nitrogen gas to form a spray, and spraying the spray on the wafer W. went. Here, the mixing ratio of pure water and nitrogen gas is H ₂ O: N ₂ = 200 ml: 80 Nl. The spin drying was performed by rotating the wafer W at 3000 rpm for 15 seconds. During these processes, exhaust from the drain 26 is performed at a constant pressure. The amount of increase in particles was determined by measuring the number of particles existing in a region excluding the annular portion of 3 mm from the outer periphery of the wafer W, and determining the average value.
[0044]
As shown in FIG. 5, in the outer cup E in which the surface roughness of the inner wall surface is not adjusted, the increase amount of the particles is 500 or more, while in the outer cups A to D, it is about 4 to 17. It was confirmed that the number of the wafers W was extremely small and the wafer W could be kept clean. Further, as a result of visually observing the inner wall surfaces of the outer cups A to E after the rinsing treatment, almost no water droplets were generated in the outer cups A to D, whereas many water droplets were confirmed in the cup E.
[0045]
Instead of the above-described method of adjusting the surface roughness of the inner wall surface of the outer cup made of a hydrophobic resin material such as polypropylene (PP) to function as a substantially hydrophilic surface, the inner wall surface of the outer cup The amount of particles generated on the wafer W can also be reduced by using a method of improving the hydrophilicity by modifying the surface of the wafer W such that the contact angle of pure water or the like becomes small. Specifically, the contact angle of pure water or the like on the inner wall surface of the outer cup can be reduced by exposing the inner wall surface of the outer cup to atmospheric pressure plasma discharge generated under predetermined conditions for a predetermined time.
[0046]
Table 2 shows a change in the contact angle of pure water on the plasma-treated surface when a polypropylene (PP) bar (hereinafter referred to as “PP bar”) is housed in a plasma chamber and the processing time is changed. The measurement of the contact angle of the plasma-treated surface of the PP square was performed by dropping one drop of pure water on each of a plurality of locations on the plasma-treated surface of the PP square, and averaging the values obtained by observing the contact angle with a CCD camera. Value.
[0047]
[Table 2]

[0048]
The contact angle of pure water with general polypropylene (PP) is 81 degrees. However, as shown in Table 2, in the prepared PP timber, the contact angle of pure water is about 95 degrees when untreated. there were. The contact angle of pure water tends to be reduced by the plasma treatment, and it has been confirmed that the contact angle of pure water can be reduced to about 20 degrees by the plasma treatment for 5 minutes. The result is that generation of particles on the wafer W is suppressed by using the outer cup 22 having the inner wall surface subjected to the plasma treatment and the inner cup 23 having the outer wall surface subjected to the plasma treatment in the wafer cleaning apparatus 10. Shows that you can do it.
[0049]
Note that it is preferable to reduce the contact angle of pure water to about 20 degrees on the entire processing surface of the sample. However, if the contact angle of pure water is 40 degrees or less, the mist can be sufficiently generated by airflow during spin drying or the like. It is possible to suppress the generation of water droplets that are formed during the rinsing process or the like. Further, since the contact angle of the liquid differs depending on the type of the liquid, the contact angles of other liquids do not always coincide with this range. However, for example, in a scrub cleaning process or the like, a cleaning liquid having substantially the same viscosity as pure water is used, and a high-viscosity liquid is not used, so long as the contact angle of pure water is in a range of 20 degrees or more and 40 degrees or less. In addition, it is possible to sufficiently suppress the adhesion of droplets on the inner wall surface of the outer cup and the outer wall surface of the inner cup.
[0050]
In addition, the surface of the sample was observed for irregularities using an atomic force microscope (AFM), but no change in surface morphology depending on the plasma processing time was observed, and it was confirmed that flatness was maintained. Was done. This suggests that the change in the contact angle of pure water due to the plasma treatment is caused not by a physical change of the sample surface but by a chemical change.
[0051]
The embodiments of the present invention have been described above, but the present invention is not limited to such embodiments. For example, polypropylene (PP) is taken as the material of the outer cup 22 and the inner cup 23, but the outer cup 22 and the inner cup 23 are made of PVC (polyvinyl chloride), PMMA (polymethyl methacrylate), PA (polyamide), PE (polyethylene), PCTFE (polychlorotrifluoroethylene), PPS (polyphenylene sulfide), PTFE (polytetrafluoroethylene) and the like can also be used.
[0052]
The method of adjusting the surface roughness of the inner wall surface and the like of the outer cup 22 is not limited to the above-described wet blast method, and the sand blast method in which abrasive grains are sprayed using air pressure, and the method shown in Table 1 described above. A method using abrasive paper such as sandpaper may be used. Barrel polishing or laser irradiation can also be used. Note that the above-described resins generally have excellent chemical resistance, but in some cases, wet etching in which these surfaces are roughened by a predetermined chemical solution can be used. In addition, it is also possible to use an outer cup whose surface roughness is adjusted by an inner wall surface by a wet blast method, and an inner cup whose contact angle of pure water or the like on its outer wall surface is reduced by atmospheric pressure plasma treatment. It goes without saying that it is good.
[0053]
Further, PEEK (polyetheretherketone) or the like is used for the claw members 57 and the support pins 59 provided in the holding mechanism 50. Since this is also one of hydrophobic resin materials, the wafer W Droplets are generated at the contact portions of the claw members 57, and since the drying speed of the droplets is low, many particles are likely to be generated at the outer peripheral portion of the wafer W. Similarly, since the processing liquid is not easily dried at the contact portion between the wafer W and the support pins 59, a large amount of particles are likely to be generated at this portion. Therefore, the surface roughness of the claw member 57 and the support pin 59 is adjusted by a wet blast method or the like so that the surfaces show hydrophilicity, or the atmospheric pressure plasma discharge treatment is performed. May modify the hydrophobic surface to hydrophilic. Thereby, generation of particles at the contact portion between the wafer W and the claw members 57 or the support pins 59 can be suppressed.
[0054]
Although the spin chuck 21 has a structure for holding the end surface of the wafer W, a spin chuck of a type that suctions the back surface of the wafer W under reduced pressure may be used. In this decompression type spin chuck, the outer peripheral portion of the back surface of the wafer W directly faces the inner cup 23 in order to generally hold only the central portion of the back surface of the wafer W by suction. For this reason, the effect of suppressing the generation of particles on the lower surface of the wafer W by making the inner wall surface of the outer cup 22 and / or the outer wall surface of the inner cup 23 hydrophilic is shown in FIGS. 1 and 3. Compared to the case where the spin chuck 21 is used, the use of a spin chuck of a reduced pressure adsorption type is significantly suppressed.
[0055]
In the wafer cleaning device 10, the mist is suppressed from approaching the wafer W by ejecting an inert gas substantially radially from the lower side of the rotary stage 31, whereby particles on the lower surface of the wafer W are reduced. It is also preferable to suppress the occurrence of.
[0056]
FIG. 6 is a schematic explanatory view of the gas ejection mechanism 60. The gas ejection mechanism 60 is provided on a gas supply path 61 penetrating the pivot 32 in the axial direction, a gas supply unit 66 for supplying an inert gas to the gas supply path 61, and an upper part of the gas supply path 61. The rotary stage 31 and a pivot having a counterbore portion 62 and a conical member 63 disposed on the rotary stage 31 side to face the counterbore portion 62 for guiding the inert gas in the radial direction. A plurality of support pins 64 are provided between the flange 32a and the flange 32a, thereby forming an inert gas guide path 65 between the lower side of the rotary stage 31 and the flange 32a. ing.
[0057]
In the gas ejection mechanism 60, an inert gas (for example, nitrogen gas) sent from the gas supply unit 66 is supplied from below the pivot 32 through the inert gas supply path 61 toward the rear surface of the rotary stage 31, It is guided radially outward by the boring portion 62 and the conical member 63 and is radially ejected along the guide path 65 in the radial direction. The approach of the mist to the wafer W is suppressed by the inert gas ejected radially in this manner.
[0058]
In the above description, the case where the present invention is applied to a scrub cleaning apparatus has been described, but it is particularly applicable to other liquid processing apparatuses using pure water, for example, a developing apparatus for developing an exposed resist film. can do. The object to be processed is not limited to the substrate. When the object to be processed is a substrate, the present invention can be applied not only to semiconductor wafers but also to liquid processing of substrates for other uses, for example, glass substrates for LCDs.
[0059]
【The invention's effect】
As described above, according to the present invention, since the inner wall surface of the outer cup or the outer wall surface of the inner cup substantially functions as a hydrophilic surface, the cleaning liquid shaken off from the object to be processed or the like is removed from the inner wall surface of the outer cup or the like. And the droplets are prevented from being repelled to form a mist or to adhere to the inner wall surface of the outer cup. Accordingly, generation of particles due to mist adhering to the object to be processed is suppressed, and the quality of the object to be processed can be kept high. In addition, by making the surfaces of the components constituting the holding mechanism for holding the object to be processed substantially hydrophilic, generation of droplets at the contact portions between these components and the object to be processed is suppressed. Thus, generation of particles on the object to be processed is suppressed, and the quality of the object to be processed can be kept high.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a wafer cleaning apparatus.
FIG. 2 is a schematic plan view of a wafer cleaning apparatus.
FIG. 3 is an explanatory view showing a state where the holding mechanism is holding the wafer and a state where the wafer W is opened.
FIG. 4 is an explanatory view schematically showing irregularities provided on the inner wall surface of the outer cup.
FIG. 5 is a graph showing an increase amount of particles before and after subjecting a wafer to a rinsing process and a spin drying process.
FIG. 6 is a schematic explanatory view of a gas ejection mechanism.
[Explanation of symbols]
10; Wafer cleaning device
21; spin chuck
22; outer cup
22a; unevenness
23; Inner cup
24; cleaning liquid discharge nozzle
25; rotating brush
31; rotary stage
32; Axis
33; motor
50; holding mechanism
55; link member
57; claw member
60; gas ejection mechanism

Claims (16)

An apparatus for performing a liquid processing by supplying a predetermined processing liquid to the object to be processed,
A holding mechanism for holding the object,
A liquid supply mechanism for supplying a predetermined processing liquid to the object to be processed held by the holding mechanism,
An outer cup arranged to surround the object to be processed held by the holding mechanism,
With
A liquid processing apparatus, wherein an inner wall surface of the outer cup has a surface roughness functioning as a desired hydrophilic surface. Further comprising an inner cup disposed below the object to be processed held by the holding mechanism,
The liquid processing apparatus according to claim 1, wherein an outer wall surface of the inner cup has a surface roughness functioning as a desired hydrophilic surface. 3. The liquid processing apparatus according to claim 1, wherein the outer cup is made of a hydrophobic resin material. The surface roughness of the inner wall surface of the outer cup is adjusted by spraying a slurry obtained by mixing a predetermined liquid with a predetermined abrasive grain on the inner wall surface of the outer cup. The liquid processing apparatus according to claim 3. The liquid processing apparatus according to claim 4, wherein the predetermined liquid constituting the slurry is water, and the abrasive grains are ceramic-based abrasive grains or resin-based abrasive grains. The processing liquid scattered toward the outer cup after being supplied from the liquid supply mechanism to the object to be processed, so that the processing liquid is likely to flow downward in the vertical direction after colliding with the inner wall surface of the outer cup, The liquid processing apparatus according to any one of claims 1 to 5, wherein the unevenness on the inner wall surface has directionality. The liquid processing apparatus according to any one of claims 1 to 6, wherein a surface roughness of an inner wall surface of the outer cup is not less than Ra0.5 and not more than Ra10. An apparatus for performing a liquid processing by supplying a predetermined processing liquid to the object to be processed,
A holding mechanism for holding the object,
A liquid supply mechanism for supplying a predetermined processing liquid to the processing target held by the holding mechanism, and an outer cup made of a hydrophobic resin material disposed so as to surround the processing target held by the holding mechanism,
With
The inner wall surface of the outer cup is modified to have a desired hydrophilic property by an atmospheric pressure plasma discharge treatment. It further comprises an inner cup made of a hydrophobic resin material disposed below the object to be processed held by the holding mechanism,
The liquid processing apparatus according to claim 8, wherein an outer wall surface of the inner cup is modified to a desired hydrophilic property by an atmospheric pressure plasma discharge treatment. The liquid processing apparatus according to claim 8, wherein a contact angle of pure water on an inner wall surface of the outer cup is not less than 20 degrees and not more than 40 degrees. The liquid processing apparatus according to any one of claims 1 to 10, wherein a surface of a portion of the holding mechanism that contacts the processing liquid has a surface roughness functioning as a desired hydrophilic surface. . The holding mechanism includes a part made of a hydrophobic resin material,
The liquid processing apparatus according to claim 1, wherein a surface of the component in contact with the processing liquid is modified to be hydrophilic by an atmospheric pressure plasma discharge processing. A liquid processing apparatus that supplies a predetermined processing liquid to the object to be processed and performs liquid processing on the object to be processed, and is a component used for a liquid contacting part where the processing liquid contacts.
A component for a liquid treatment apparatus, the surface of which is adjusted to a surface roughness functioning as a desired hydrophilic surface. A part of a liquid processing apparatus that supplies a predetermined processing liquid to the object to be processed and liquid-treats the object, wherein the part is made of a hydrophobic material used for a liquid contacting part where the processing liquid contacts.
A component for a liquid treatment apparatus, wherein the surface is modified from hydrophobic to a desired hydrophilic property by atmospheric pressure plasma treatment. A method for manufacturing a component used in a liquid contacting part where the processing liquid is in contact with a liquid processing apparatus that supplies a predetermined processing liquid to the processing target and performs liquid processing on the processing target,
A method for manufacturing a component for a liquid processing apparatus, comprising: spraying a slurry obtained by mixing a predetermined liquid with predetermined abrasive grains to adjust the surface to a surface roughness functioning as a desired hydrophilic surface. A method for manufacturing a part made of a hydrophobic material used in a liquid contacting part where the processing liquid contacts a liquid processing apparatus that supplies a predetermined processing liquid to the processing target and performs liquid processing on the processing target,
A method for manufacturing a component for a liquid treatment apparatus, wherein the surface is modified from hydrophobic to a desired hydrophilic property by atmospheric pressure plasma treatment.

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