JP4456666B2

JP4456666B2 - Cleaning sheet, conveying member with cleaning function, and method for cleaning substrate processing apparatus using them

Info

Publication number: JP4456666B2
Application number: JP2000168423A
Authority: JP
Inventors: 亮並河
Original assignee: Nitto Denko Corp
Current assignee: Nitto Denko Corp
Priority date: 2000-06-06
Filing date: 2000-06-06
Publication date: 2010-04-28
Anticipated expiration: 2020-06-06
Also published as: JP2001351960A

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning sheet of a substrate treating device vulnerable to a foreign matter, such as a manufacturing apparatus, an inspecting unit or the like of, for example, a semiconductor, a flat-panel display, a printed board. SOLUTION: The cleaning sheet comprises a layer which substantially does not have stickiness or substantially does not have conductivity as a cleaning layer on a support or a normal pressure sensitive adhesive layer, moreover provided on one side surface of a sheet-like material which substantially does not have stickiness or conductivity.

Description

【０００１】
【発明の属する技術分野】
本発明は、各種の基板処理装置をクリーニングするシート、及びこれを用いた基板処理装置のクリーニング方法に関し、例えば、半導体、フラットパネルディスプレイ、プリント基板などの製造装置や検査装置など、異物を嫌う基板処理装置のクリーニングシート及びクリーニング方法に関する。
【０００２】
【従来の技術】
各種基板処理装置は、各搬送系と基板とを物理的に接触させながら搬送する。その際、基板や搬送系に異物が付着していると、後続の基板を次々に汚染することになり、定期的に装置を停止させ、洗浄処理をする必要があった。このため、稼働率低下や多大な労力が必要になるという問題があった。これらの問題を解決するため、粘着性の物質を固着した基板を搬送することにより基板処理装置内の付着した異物をクリーニング除去する方法が提案されている（例えば特開平１０−１５４６８６号）。
【０００３】
【発明が解決しようとする課題】
粘着性の物質を固着した基板を搬送することにより基板処理装置内の付着した異物をクリーニング除去する方法は、前述の課題を克服する有効な方法である。しかしこの方法では粘着性物質と装置接触部とが強く接着しすぎて剥れない恐れがあり、基板を確実に搬送できなくなる恐れがあった。
本発明は、このような事情に照らし、基板処理装置内に基板を確実に搬送できると共に、装置内に付着している異物を簡便かつ確実に除去できるクリーニングシートを提供することを目的としている。
【０００４】
【課題を解決するための手段】
本発明者らは、上記の目的を達成するために、鋭意検討した結果、クリーニング層を固着したシートあるいはこのシートを固着した基板等の搬送部材を搬送することにより、基板処理装置内の付着した異物をクリーニング除去するにあたり、実質的に粘着性を有さずかつ実質的に導電性を有しないシートを、クリーニング層として使用することにより、前記問題を生じることなく、さらに異物を簡便かつ確実に剥離除去できることを見出し、本発明を完成するに至つた。
【０００５】
即ち、本発明は、基板処理装置内に搬送して上記装置内に付着している異物を除去するためのクリーニングシートであって、支持体に、ＪＩＳＫ７１２７に準じて測定される引張弾性率が０．１Ｎ／ｍｍ ² 以上に設定されて粘着性を有さず、かつ導電性を有しない層がクリーニング層として設けられてなり、上記の粘着性を有さず、かつ導電性を有しない層は、ポリエチレン、ポリエチレンテレフタレート、アセチルセルロース、ポリカーボネート、ポリプロピレン、ポリアミド、ポリイミド、ポリカルボジイミドの中から選ばれるプラスチックのフィルムであるか、または感圧接着性ポリマーに分子内に不飽和二重結合を１個以上有する化合物と重合開始剤を少なくとも含有させた硬化型粘着剤を、活性エネルギーにより重合硬化反応させて粘着性を消失させたものであることを特徴とするクリーニングシート（請求項１）、基板処理装置内に搬送して上記装置内に付着している異物を除去するためのクリーニングシートであって、ＪＩＳＫ７１２７に準じて測定される引張弾性率が０．１Ｎ／ｍｍ ² 以上に設定されて粘着性を有さず、かつ導電性を有しないシート状物の片面に、シリコンウエハのミラー面に対する１８０°引き剥がし粘着力が０．２０〜０．９８Ｎ／１０ｍｍである粘着剤層が設けられてなり、上記の粘着性を有さず、かつ導電性を有しないシート状物は、ポリエチレン、ポリエチレンテレフタレート、アセチルセルロース、ポリカーボネート、ポリプロピレン、ポリアミド、ポリイミド、ポリカルボジイミドの中から選ばれるプラスチックのフィルムであるか、または感圧接着性ポリマーに分子内に不飽和二重結合を１個以上有する化合物と重合開始剤を少なくとも含有させた硬化型粘着剤を、活性エネルギーにより重合硬化反応させて粘着性を消失させたものであることを特徴とするクリーニングシート（請求項２）、基板処理装置内に搬送して上記装置内に付着している異物を除去するためのクリーニングシートであって、支持体の片面に、ＪＩＳＫ７１２７に準じて測定される引張弾性率が０．１Ｎ／ｍｍ ² 以上に設定されて粘着性を有さず、かつ導電性を有しない層がクリーニング層として設けられ、他面にシリコンウエハのミラー面に対する１８０°引き剥がし粘着力が０．２０〜０．９８Ｎ／１０ｍｍである粘着剤層が設けられてなり、上記の粘着性を有さず、かつ導電性を有しない層は、ポリエチレン、ポリエチレンテレフタレート、アセチルセルロース、ポリカーボネート、ポリプロピレン、ポリアミド、ポリイミド、ポリカルボジイミドの中から選ばれるプラスチックのフィルムであるか、または感圧接着性ポリマーに分子内に不飽和二重結合を１個以上有する化合物と重合開始剤を少なくとも含有させた硬化型粘着剤を、活性エネルギーにより重合硬化反応させて粘着性を消失させたものであることを特徴とするクリーニングシート（請求項３）などに係るものである。
【０００６】
【発明の実施の形態】
本発明のクリーニングシートにおけるクリーニング層は、その粘着力は実質的になく、その導電性も実質的にない層からなる。本発明においては、クリーニング層の粘着力を実質的になくする設計にすることにより、搬送トラブルを発生することなく、またその導電性を実質的になくすることにより、静電吸着力で異物を除去することができる。
本発明において好ましいクリーニング層は、その引張弾性率（試験法ＪＩＳＫ７１２７に準ずる）が０．１Ｎ／ｍｍ²以上、好ましくは１〜３０００Ｎ／ｍｍ²である。かかる引張弾性率が０．１Ｎ／ｍｍ²未満の場合、クリーニング層が粘着性を発現するようになり、搬送時に装置内の被クリーニング部に接着して搬送トラブルとなる恐れがある。
【０００７】
また該クリーニング層は、その表面抵抗率が１×１０¹³Ω／□以上、好ましくは１×１０¹⁴Ω／□以上であることが望ましい。クリーニング層の表面抵抗率をかかる特定値以上に設計して、クリーニング層をできるだけ絶縁体にすることにより、静電気による異物の捕獲、吸着できるという効果が得られる。よって、表面抵抗率が１×１０¹³Ω／□未満の場合は、かかる静電気による異物の捕獲、吸着効果が低下するおそれがある。
【０００８】
かかるクリーニング層は、その粘着力と導電性とが実質的にない限り、その材質や構成などは特に限定されないが、例えばポリエチレン、ポリエチレンテレフタレート、アセチルセルロース、ポリカーボネート、ポリプロピレン、ポリアミド、ポリイミド、ポリカルボジイミドなどのプラスチックフィルム、硬化型粘着剤を硬化させて粘着性を実質的に消失させたものなどが挙げられる。またクリーニング層の厚さは特に限定されないが、通常５〜１００μｍ程度である。
【０００９】
上記硬化型粘着剤としては、感圧接着性ポリマーに分子内に不飽和二重結合を１個以上有する化合物と重合開始剤を少なくとも含有させたものを、活性エネルギーにより重合硬化反応させて粘着性が実質的に消失されてなるものが挙げられる。かかる感圧接着性ポリマーとしては、例えばアクリル酸、アクリル酸エステル、メタクリル酸、メタクリル酸エステルから選ばれる（メタ）アクリル酸及び／又は（メタ）アクリル酸エステルを主モノマーとしたアクリル系ポリマーが挙げられる。このアクリル系ポリマーの合成にあたり、共重合モノマーとして分子内に不飽和二重結合を２個以上有する化合物を用いるか、あるいは合成後のアクリル系ポリマーに分子内に不飽和二重結合を有する化合物を官能基間の反応で化学結合させるなどして、アクリル系ポリマーの分子内に不飽和二重結合を導入しておくことにより、このポリマー自体も活性エネルギーにより重合硬化反応に関与させるようにすることもできる。
【００１０】
ここで、分子内に不飽和二重結合を１個以上有する化合物（以下、重合性不飽和化合物という）としては、不揮発性でかつ重量平均分子量が１００００以下の低分子量体であるのがよく、特に硬化時の接着剤層の三次元網状化が効率よくなされるように、５０００以下の分子量を有しているのが好ましい。
【００１１】
また、クリーニング層に添加される重合開始剤は、特に限定されず公知のものを使用でき、例えば活性エネルギー源に熱を用いる場合は、ベンゾイルパーオキサイド、アゾビスイソブチロニトリルなどの熱重合開始剤、また光を用いる場合は、ベンゾイル、ベンゾインエチルエーテル、シベンジル、イソプロピルベンゾインエーテル、ベンゾフェノン、ミヒラーズケトンクロロチオキサントン、ドデシルチオキサントン、ジメチルチオキサントン、アセトフェノンジエチルケタール、ベンジルジメチルケタール、α−ヒドルキシシクロヒキシルフェニルケトン、２−ヒドロキシジメチルフェニルプロパン、２，２−ジメトキシ−２−フェニルアセトフェノンなどの光重合開始剤が挙げられる。
【００１２】
本発明は、上記の実質的に粘着性を有さず、かつ導電性を有しないシート状物の片面に、通常の粘着剤層が設けられたクリーニングシート（請求項２）、また支持体の片面に、上記の特定のクリーニング層が設けられ、他面に通常の粘着剤層が設けられたクリーニングシート（請求項３）も提供する。
この通常の粘着剤層は、粘着機能を満たす限りその材質などは特に限定されず、通常の粘着剤（例えばアクリル系、ゴム系など）を用いることができる。
かかる構成とすることにより、クリーニングシートを通常の粘着剤層により各種基板や他のテープ・シートなどの搬送部材に貼り付けて、クリーニング機能付き搬送部材（請求項４）として装置内に搬送して、被洗浄部位に接触させてクリーニングすること（請求項５）ができる。
【００１３】
本発明において上記の基板などの搬送部材を再利用するために、クリーニング後に基板をかかる粘着剤層から剥がす場合は、かかる通常の粘着剤層の粘着力は、シリコンウエハ（ミラー面）に対する１８０°引き剥がし粘着力が０．２０〜０．９８Ｎ／１０ｍｍ、特に０．４０〜０．９８Ｎ／１０ｍｍ程度であれば、搬送中に剥離することなく、かつクリーニング後に容易に再剥離できるので好ましい。
【００１４】
またクリーニングシートの支持体としては特に限定されないが、例えばポリエチレン、ポリエチレンテレフタレート、アセチルセルロース、ポリカーボネート、ポリプロピレン、ポリアミド、ポリイミド、ポリカルボジイミドなどのプラスチックフィルムなどが挙げられる。その厚みは通常１０〜１００μｍ程度である。
クリーニングシートが貼り付けられる搬送部材としては特に限定されないが、例えば半導体ウエハ、ＬＣＤ、ＰＤＰなどのフラットパネルディスプレイ用基板、その他コンパクトディスク、ＭＲヘッドなどの基板などが挙げられる。
【００１５】
【実施例】
以下、本発明を実施例に基づいて説明するが、本発明はこれらに限定されるものではない。なお、以下、部とあるのは重量部を意味するものとする。
実施例１
アクリル酸−２−エチルヘキシル７５部、アクリル酸メチル２０部、及びアクリル酸５部からなるモノマ―混合液から得たアクリル系ポリマー（重量平均分子量７０万）１００部に対して、ポリエチレングリコ―ルジメタクリレ―ト５０部、ウレタンアクリレ―ト５０部、ベンジルジメチルケタール３部、及びジフエニルメタンジイソシアネ―ト３部を均一に混合し、紫外線硬化型の粘着剤溶液とした。
一方、上記粘着剤からベンジルジメチルケタールを除いた以外は、上記と同様にして得た粘着剤溶液を、幅２５０ｍｍ、厚み２５μｍのポリエステル製支持フィルムの片面に、乾燥後の厚みが１０μｍになるように塗布して通常の粘着剤層を設け、その表面に厚さ３８μｍのポリエステル系剥離フィルムを貼った。支持フィルムのもう一方の側に、前記の紫外線硬化型粘着剤溶液を乾燥後の厚みが４０μｍになるように塗布してクリーニング層を設け、その表面に同様の剥離フィルムを貼った。
このシートに中心波長３６５ｎｍの紫外線を積算光量３０００ｍＪ／ｃｍ²照射して、本発明のクリーニングシートを得た。かかるクリーニング層の表面は実質的に粘着性は有していなかった。また、このクリーニング層の紫外線硬化後の引張弾性率は０．５８Ｎ／ｍｍ²であった。ここで引張弾性率は、試験法ＪＩＳＫ７１２７に準じて測定した。また、クリーニング層をシリコンウエハのミラー面に幅１０ｍｍで貼り付け、ＪＩＳＺ０２３７に準じてシリコンウエハに対する１８０°引き剥がし粘着力を測定した結果、０．００４９Ｎ（０．５ｇ）／１０ｍｍで実質的に粘着性を有さないことが確認できた。
また、温度２３℃、湿度６０％ＲＨの条件下でクリーニング層上から表面抵抗率を表面抵抗測定計（三菱化学社製、型式MCP−UP450）にて測定したところ、９．９９×１０¹³Ω／□以上で測定不能であった。この結果から、クリーニング層は実質的に導電性を有さないことが確認できた。
また、他面側の通常の粘着剤層をシリコンウエハのミラー面に幅１０ｍｍで貼り付け、ＪＩＳＺ０２３７に準じてシリコンウエハに対する１８０°引き剥がし粘着力を測定した結果、０．２５Ｎ（２６ｇ）／１０ｍｍであった。
【００１６】
このクリーニングシートの通常の粘着剤層側の剥離フィルムを剥がし、８ｉｎｃｈのシリコンウエハの裏面（ミラー面）にハンドローラで貼り付け、クリーニング機能付き搬送用クリーニングウエハ（１）を作製した。
【００１７】
実施例２
幅２５０ｍｍ、厚み２５μｍのポリエステル製フィルムをクリーニング層としてその片面に、乾燥後の厚みが１０μｍになるように実施例１と同様の通常の粘着剤層を設け、その表面に３８μｍのポリエステル系剥離フィルムを貼ったクリーニングシートを作成した。
かかるクリーニング層としてのポリエステル系フィルムの、引張弾性率は２００Ｎ／ｍｍ²であった。また、シリコンウエハに対する１８０°引き剥がし粘着力を測定した結果、０Ｎ／１０ｍｍで粘着性を有さないことが確認できた。
また、表面抵抗率は、９．９９×１０¹³Ω／□以上で測定不能であった。この結果から、このクリーニング層は実質的に導電性を有さないことが確認できた。
【００１８】
このクリーニングシートの剥離フィルムを剥がし、実施例１と同様にして、クリーニング機能付き搬送用クリーニングウエハ（２）を作製した。
【００１９】
一方、レーザー式異物測定装置で、新品の８ｉｎｃｈシリコンウエハ３枚のミラー面の０．２μｍ以上の異物を測定したところ、１枚目は８個、２枚目は１２個、３枚目は１０個であった。これらのウエハを別々の基板処理装置にミラー面を下側に向けて搬送した後、レーザー式異物測定装置でミラー面を測定したところ、８ｉｎｃｈウエハサイズのエリア内で１枚目は２３７８８個、２枚目は２６００８個、３枚目は２８４０３個であった。
【００２０】
次いで前記で得た搬送用クリーニングウエハ（１）のクリーニング層側の剥離フィルムを剥がし、上記の２３７８８個の異物が付着していたウエハステージを持つ基板処理装置内に搬送したところ、支障なく搬送できた。その後に０．２μｍ以上の異物が７個のっていた新品の８ｉｎｃｈシリコンウエハをミラー面を下側に向けて搬送し、レーザー式異物測定装置で０．２μｍ以上の異物を測定したところ、８ｉｎｃｈウエハサイズのエリア内で６２０５個であり、クリーニング前に付着していた異物数の７４％を除去することができた。
【００２１】
次いで前記で得た搬送用クリーニングウエハ（２）を、前述の２６００８個の異物が付着していたウエハステージを持つ基板処理装置内に搬送したところ、支障なく搬送できた。その後に０．２μｍ以上の異物が１３個のっていた新品の８ｉｎｃｈシリコンウエハで上記と同様の測定をしたところ、８ｉｎｃｈウエハサイズのエリア内で７９８８個であり、クリーニング前に付着していた異物数の６９％を除去することができた。
【００２２】
比較例１
実施例１において、中心波長３６５ｎｍの紫外線積算光量を５Ｊ／ｃｍ²照射にした以外は、実施例１と同じ方法で作製したクリーニングシートのクリーニング層は粘着性を有し、その引張弾性率を測定したところ、０．０６７Ｎ／ｍｍ²であった。また、クリーニング層の対シリコンウエハ粘着力を測定したところ、０．３３Ｎ（３４ｇ）／１０ｍｍであった。
このクリーニングシートから実施例１と同じ方法で作製した搬送用クリーニングウエハ（３）を、前述の２８４０３個の異物が付着しているウエハステージを持つ基板処理装置内を搬送したところ、ウエハステージに固着し、搬送できなかった。
【００２３】
【発明の効果】
以上のように本発明のクリーニングシートによれば、基板処理装置内を確実に搬送できると共に、装置内に付着している異物を簡便かつ確実に除去できる。[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet for cleaning various substrate processing apparatuses and a substrate processing apparatus cleaning method using the same, and, for example, a substrate that dislikes foreign matters, such as a manufacturing apparatus or an inspection apparatus such as a semiconductor, a flat panel display, and a printed board. The present invention relates to a cleaning sheet and a cleaning method for a processing apparatus.
[0002]
[Prior art]
Various substrate processing apparatuses transport each transport system and the substrate in physical contact with each other. At this time, if foreign substances adhere to the substrate or the transport system, subsequent substrates are contaminated one after another, and it is necessary to periodically stop the apparatus and perform a cleaning process. For this reason, there existed a problem that an operation rate fall and a lot of labor were needed. In order to solve these problems, there has been proposed a method of cleaning and removing adhered foreign substances in the substrate processing apparatus by transporting a substrate to which an adhesive substance is fixed (for example, Japanese Patent Laid-Open No. 10-154686).
[0003]
[Problems to be solved by the invention]
The method of cleaning and removing the adhered foreign matter in the substrate processing apparatus by transporting the substrate to which the adhesive substance is fixed is an effective method for overcoming the above-described problems. However, in this method, the adhesive substance and the apparatus contact portion are too strongly bonded and may not be peeled off, and there is a possibility that the substrate cannot be reliably conveyed.
In view of such circumstances, an object of the present invention is to provide a cleaning sheet capable of reliably transporting a substrate into a substrate processing apparatus and easily and reliably removing foreign substances adhering to the apparatus.
[0004]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have adhered to the substrate processing apparatus by transporting a transport member such as a sheet to which the cleaning layer is fixed or a substrate to which the sheet is fixed. When cleaning and removing foreign matter, the use of a sheet that is substantially non-adhesive and substantially non-conductive as a cleaning layer allows the foreign matter to be more easily and reliably produced without causing the above problems. It has been found that it can be peeled and removed, and the present invention has been completed.
[0005]
That is, the present invention is a cleaning sheet for removing foreign matter adhering to the inside of the apparatus after being transported into the substrate processing apparatus, and the support has a tensile elastic modulus measured according to JIS K7127. 0.1 N / mm ² or more is in no tackiness is set to, and layers having no conductivity is provided as the cleaning layer, no the above adhesive, and layers having no conductive Is a plastic film selected from polyethylene, polyethylene terephthalate, acetylcellulose, polycarbonate, polypropylene, polyamide, polyimide, polycarbodiimide, or one unsaturated double bond in the molecule of the pressure-sensitive adhesive polymer. The curable pressure-sensitive adhesive containing at least the compound having the above and a polymerization initiator is polymerized and cured by active energy. A cleaning sheet that has lost its adhesiveness (Claim 1), and is a cleaning sheet that is transported into a substrate processing apparatus to remove foreign matter adhering to the apparatus. , on one side of the tensile elastic modulus is set to 0.1 N / mm ² or more has no adhesive, and the sheet-like material having no conductivity is measured according to JIS K7127, to the mirror surface of the silicon wafer A sheet-like material having a pressure-sensitive adhesive layer having a 180 ° peeling adhesive strength of 0.20 to 0.98 N / 10 mm and not having the above-mentioned adhesive property and having no electrical conductivity is polyethylene, polyethylene A plastic film selected from terephthalate, acetylcellulose, polycarbonate, polypropylene, polyamide, polyimide, and polycarbodiimide. Or a pressure-sensitive adhesive polymer containing at least a compound having at least one unsaturated double bond in the molecule and a polymerization initiator is allowed to undergo a polymerization and curing reaction with active energy to cause the adhesiveness to disappear. A cleaning sheet (Claim 2), which is a cleaning sheet for transporting into a substrate processing apparatus to remove foreign matter adhering to the apparatus, on one side of a support , JIS tensile modulus measured according to K7127 is no tackiness is set to 0.1 N / mm ² or more, and layers having no conductivity is provided as the cleaning layer, the silicon wafer on the other surface A layer that is provided with an adhesive layer having a peel adhesive strength of 0.20 to 0.98 N / 10 mm with respect to the mirror surface , and does not have the above-mentioned adhesive property and does not have conductivity. Is a plastic film selected from polyethylene, polyethylene terephthalate, acetylcellulose, polycarbonate, polypropylene, polyamide, polyimide, polycarbodiimide, or one unsaturated double bond in the molecule of the pressure-sensitive adhesive polymer. The present invention relates to a cleaning sheet (Claim 3) and the like, wherein the curable pressure-sensitive adhesive containing at least the compound having the above and a polymerization initiator is subjected to a polymerization and curing reaction by active energy to eliminate the adhesiveness. Is.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The cleaning layer in the cleaning sheet of the present invention consists of a layer that is substantially free of adhesive force and substantially free of electrical conductivity. In the present invention, the design that substantially eliminates the adhesive force of the cleaning layer eliminates the occurrence of transport troubles, and substantially eliminates the electrical conductivity, thereby eliminating foreign matters by electrostatic attraction. Can be removed.
Preferred cleaning layer in the present invention, the tensile modulus (according to test method JIS K7127) is 0.1 N / mm ² or more, preferably 1~3000N / mm ^2. When the tensile elastic modulus is less than 0.1 N / mm ² , the cleaning layer becomes sticky and may adhere to a portion to be cleaned in the apparatus during transportation, resulting in a transportation trouble.
[0007]
The cleaning layer has a surface resistivity of 1 × 10 ¹³ Ω / □ or more, preferably 1 × 10 ¹⁴ Ω / □ or more. By designing the surface resistivity of the cleaning layer to be higher than the specific value and making the cleaning layer an insulator as much as possible, the effect of capturing and adsorbing foreign matters due to static electricity can be obtained. Therefore, when the surface resistivity is less than 1 × 10 ¹³ Ω / □, the trapping and adsorbing effects of foreign matters due to such static electricity may be reduced.
[0008]
Such a cleaning layer is not particularly limited in material and configuration as long as its adhesive strength and conductivity are not substantially limited. For example, polyethylene, polyethylene terephthalate, acetylcellulose, polycarbonate, polypropylene, polyamide, polyimide, polycarbodiimide, etc. And a plastic film obtained by curing a curable pressure-sensitive adhesive to substantially eliminate the adhesiveness. The thickness of the cleaning layer is not particularly limited, but is usually about 5 to 100 μm.
[0009]
As the curable pressure-sensitive adhesive, a pressure-sensitive adhesive polymer containing at least a compound having at least one unsaturated double bond in the molecule and a polymerization initiator is subjected to a polymerization and curing reaction with active energy to be adhesive. In which is substantially eliminated. Examples of the pressure-sensitive adhesive polymer include acrylic polymers having (meth) acrylic acid and / or (meth) acrylic acid ester selected from acrylic acid, acrylic acid ester, methacrylic acid, and methacrylic acid ester as main monomers. It is done. In synthesizing this acrylic polymer, a compound having two or more unsaturated double bonds in the molecule is used as a copolymerization monomer, or a compound having an unsaturated double bond in the molecule is used in the synthesized acrylic polymer. By introducing an unsaturated double bond into the molecule of the acrylic polymer, for example, by chemically bonding it with a reaction between functional groups, this polymer itself is also involved in the polymerization curing reaction by active energy. You can also.
[0010]
Here, the compound having one or more unsaturated double bonds in the molecule (hereinafter referred to as a polymerizable unsaturated compound) is preferably a low molecular weight substance that is nonvolatile and has a weight average molecular weight of 10,000 or less. In particular, it is preferable to have a molecular weight of 5000 or less so that the three-dimensional network of the adhesive layer at the time of curing can be made efficiently.
[0011]
The polymerization initiator added to the cleaning layer is not particularly limited, and known ones can be used. For example, when heat is used as an active energy source, thermal polymerization initiation of benzoyl peroxide, azobisisobutyronitrile, etc. Benzoyl, benzoin ethyl ether, cibenzyl, isopropyl benzoin ether, benzophenone, Michler's ketone chlorothioxanthone, dodecyl thioxanthone, dimethylthioxanthone, acetophenone diethyl ketal, benzyl dimethyl ketal, α-hydroxycyclohexyl Examples include photopolymerization initiators such as silphenyl ketone, 2-hydroxydimethylphenylpropane, and 2,2-dimethoxy-2-phenylacetophenone.
[0012]
The present invention provides a cleaning sheet (Claim 2) in which a normal pressure-sensitive adhesive layer is provided on one side of the sheet-like material that is substantially non-adhesive and non-conductive, and a support. There is also provided a cleaning sheet (Claim 3) in which the specific cleaning layer is provided on one side and a normal pressure-sensitive adhesive layer is provided on the other side.
The material of the normal pressure-sensitive adhesive layer is not particularly limited as long as it satisfies the pressure-sensitive adhesive function, and a normal pressure-sensitive adhesive (for example, acrylic or rubber) can be used.
With this configuration, the cleaning sheet is attached to a transport member such as various substrates or other tapes / sheets with a normal adhesive layer, and transported into the apparatus as a transport member with a cleaning function (Claim 4 ). Then, cleaning can be performed by contacting the portion to be cleaned (Claim 5 ).
[0013]
In the present invention, when the substrate is peeled off from the pressure-sensitive adhesive layer after cleaning in order to reuse the transport member such as the substrate, the adhesive force of the normal pressure-sensitive adhesive layer is 180 ° with respect to the silicon wafer (mirror surface). A peel adhesive strength of about 0.20 to 0.98 N / 10 mm , particularly about 0.40 to 0.98 N / 10 mm , is preferable because it can be easily re-peeled after cleaning without peeling during transport.
[0014]
The support for the cleaning sheet is not particularly limited, and examples thereof include plastic films such as polyethylene, polyethylene terephthalate, acetylcellulose, polycarbonate, polypropylene, polyamide, polyimide, and polycarbodiimide. The thickness is usually about 10 to 100 μm.
The transport member to which the cleaning sheet is attached is not particularly limited, and examples thereof include semiconductor wafers, substrates for flat panel displays such as LCDs and PDPs, and other substrates such as compact disks and MR heads.
[0015]
【Example】
Hereinafter, although the present invention is explained based on an example, the present invention is not limited to these. Hereinafter, “parts” means parts by weight.
Example 1
Polyethylene glycol dimethacrylate for 100 parts of an acrylic polymer (weight average molecular weight 700,000) obtained from a monomer mixture consisting of 75 parts of 2-ethylhexyl acrylate, 20 parts of methyl acrylate and 5 parts of acrylic acid. 50 parts of urethane, 50 parts of urethane acrylate, 3 parts of benzyldimethyl ketal, and 3 parts of diphenylmethane diisocyanate were uniformly mixed to obtain an ultraviolet curable adhesive solution.
On the other hand, the pressure-sensitive adhesive solution obtained in the same manner as above except that benzyldimethyl ketal was removed from the pressure-sensitive adhesive was applied to one side of a polyester support film having a width of 250 mm and a thickness of 25 μm so that the thickness after drying would be 10 μm. And a normal pressure-sensitive adhesive layer was provided, and a polyester release film having a thickness of 38 μm was stuck on the surface. On the other side of the support film, the UV curable pressure-sensitive adhesive solution was applied so that the thickness after drying was 40 μm, a cleaning layer was provided, and a similar release film was stuck on the surface.
The cleaning sheet of the present invention was obtained by irradiating this sheet with ultraviolet light having a central wavelength of 365 nm and an integrated light quantity of 3000 mJ / cm ² . The surface of the cleaning layer was not substantially sticky. The tensile modulus of the cleaning layer after curing with ultraviolet rays was 0.58 N / mm ² . Here, the tensile elastic modulus was measured according to the test method JIS K7127. Further, the cleaning layer was attached to the mirror surface of the silicon wafer with a width of 10 mm, and the 180 ° peel adhesion to the silicon wafer was measured according to JIS Z0237. As a result, the cleaning layer was substantially 0.0049 N (0.5 g) / 10 mm. It was confirmed that there was no tackiness.
Further, when the surface resistivity was measured from above the cleaning layer with a surface resistance meter (Model MCP-UP450, manufactured by Mitsubishi Chemical Corporation) under the conditions of a temperature of 23 ° C. and a humidity of 60% RH, it was 9.99 × 10 ¹³ Ω. It was impossible to measure above / □. From this result, it was confirmed that the cleaning layer has substantially no conductivity.
Further, a normal pressure-sensitive adhesive layer on the other surface side was attached to the mirror surface of the silicon wafer with a width of 10 mm, and the 180 ° peel-off adhesive strength to the silicon wafer was measured in accordance with JIS Z0237. It was 10 mm.
[0016]
The release film on the normal pressure-sensitive adhesive layer side of the cleaning sheet was peeled off and attached to the back surface (mirror surface) of an 8-inch silicon wafer with a hand roller to prepare a cleaning cleaning wafer (1) with a cleaning function.
[0017]
Example 2
A polyester film having a width of 250 mm and a thickness of 25 μm was used as a cleaning layer, and a normal pressure-sensitive adhesive layer similar to that of Example 1 was provided on one side so that the thickness after drying was 10 μm, and a 38 μm polyester release film was formed on the surface. A cleaning sheet with a mark was made.
The polyester film as the cleaning layer had a tensile elastic modulus of 200 N / mm ² . Moreover, as a result of measuring 180 degree peeling adhesive force with respect to a silicon wafer, it has confirmed that it has no adhesiveness at 0N / 10mm.
Further, the surface resistivity was not less than 9.99 × 10 ¹³ Ω / □ and could not be measured. From this result, it was confirmed that this cleaning layer has substantially no conductivity.
[0018]
The release film of this cleaning sheet was peeled off, and a cleaning wafer for conveyance (2) with a cleaning function was produced in the same manner as in Example 1.
[0019]
On the other hand, when measuring foreign matter of 0.2 μm or more on the mirror surface of three new 8-inch silicon wafers with a laser type foreign matter measuring device, the first piece has 8 pieces, the second piece has 12 pieces, and the third piece has 10 pieces. It was a piece. After these wafers were transferred to different substrate processing apparatuses with the mirror surface facing downward, the mirror surface was measured with a laser type foreign matter measuring apparatus. As a result, the first sheet was 23788 in an area of 8 inch wafer size. The number of sheets was 26008 and the number of sheets was 28403.
[0020]
Next, the release film on the cleaning layer side of the transport cleaning wafer (1) obtained above was peeled off and transported into the substrate processing apparatus having the wafer stage on which the 23788 foreign substances had adhered, and it could be transported without any trouble. It was. After that, a new 8 inch silicon wafer having 7 foreign matters of 0.2 μm or more was transported with the mirror surface facing downward, and the foreign material of 0.2 μm or more was measured with a laser type foreign matter measuring device. It was 6205 in the area of the wafer size, and 74% of the number of foreign matters adhered before cleaning could be removed.
[0021]
Next, the transport cleaning wafer (2) obtained above was transported into the substrate processing apparatus having the wafer stage on which the above-mentioned 26008 foreign substances were adhered, and was successfully transported. Thereafter, the same measurement as described above was performed on a new 8 inch silicon wafer having 13 foreign matters having a size of 0.2 μm or more. As a result, there were 7988 foreign matters adhered within the area of the 8 inch wafer size, which were adhered before cleaning. 69% of the numbers could be removed.
[0022]
Comparative Example 1
In Example 1, the cleaning layer of the cleaning sheet produced by the same method as in Example 1 has adhesiveness except that the UV integrated light quantity with a center wavelength of 365 nm is irradiated to 5 J / cm ² , and its tensile elastic modulus is measured. As a result, it was 0.067 N / mm ² . Further, when the adhesive strength of the cleaning layer to the silicon wafer was measured, it was 0.33 N (34 g) / 10 mm.
When the cleaning wafer (3) for conveyance produced from this cleaning sheet in the same manner as in Example 1 is conveyed through the substrate processing apparatus having the wafer stage on which 28403 foreign substances are adhered, the wafer is fixed to the wafer stage. And could not be transported.
[0023]
【The invention's effect】
As described above, according to the cleaning sheet of the present invention, the inside of the substrate processing apparatus can be reliably conveyed, and foreign substances adhering to the inside of the apparatus can be easily and reliably removed.

Claims

A cleaning sheet for removing foreign substances adhering to the inside of the apparatus after being transferred into the substrate processing apparatus, and having a tensile elastic modulus measured according to JIS K7127 of 0.1 N / mm ^{2 on the} support. without a set tackiness or more and becomes layer having no electrical conductivity is provided as the cleaning layer, no the adhesive, and electrically conductive having no layer include polyethylene, polyethylene terephthalate Polymerization starts with a plastic film selected from acetylcellulose, polycarbonate, polypropylene, polyamide, polyimide, polycarbodiimide, or a compound having at least one unsaturated double bond in the molecule in a pressure-sensitive adhesive polymer Curable adhesives containing at least an agent are polymerized and cured by active energy to eliminate adhesiveness A cleaning sheet characterized by the above .

A cleaning sheet that is transported into a substrate processing apparatus to remove foreign substances adhering to the apparatus, and has a tensile elastic modulus measured according to JIS K7127 of 0.1 N / mm ² or more. no tackiness, and on one side of the sheet having no conductive adhesive layer 180 ° peel adhesion to the mirror surface of the silicon wafer is 0.20~0.98N / 10mm is provided Te The sheet-like material having no adhesiveness and having no electrical conductivity is a plastic film selected from polyethylene, polyethylene terephthalate, acetylcellulose, polycarbonate, polypropylene, polyamide, polyimide, and polycarbodiimide. Or a compound having at least one unsaturated double bond in the molecule and a pressure-sensitive adhesive polymer. Cleaning sheet characterized in that at least a curable adhesive which contains an initiator, in which abolished the adhesion by polymerization curing reaction by active energy.

A cleaning sheet for removing foreign substances adhering to the inside of the apparatus after being transported into the substrate processing apparatus, and having a tensile elastic modulus measured according to JIS K7127 of 0.1 N / mm ² or more is in no tackiness is set to, and layers having no conductivity is provided as the cleaning layer, 180 ° peel adhesion to the mirror surface of the silicon wafer on the other surface is 0.20 to 0. A pressure-sensitive adhesive layer of 98 N / 10 mm is provided, and the above-mentioned non-adhesive and non-conductive layers are polyethylene, polyethylene terephthalate, acetyl cellulose, polycarbonate, polypropylene, polyamide, polyimide, polycarbodiimide. A plastic film selected from the group consisting of Cleaning sheet, characterized in that the one or more compounds having a polymerization initiator curable adhesive which contains at least one in which abolished the adhesion by polymerization curing reaction by active energy.

A cleaning function in which the cleaning sheet according to claim 2 or 3 is provided on the conveying member via an adhesive layer having a 180 ° peel-off adhesive force with respect to the mirror surface of the silicon wafer of 0.20 to 0.98 N / 10 mm. Conveying member.

A cleaning sheet according to claim 1 or a transport member with a cleaning function according to claim 4 is transported into a substrate processing apparatus to remove foreign matter adhering to the apparatus. Cleaning method.