JP2004188586A - Foam sheet for polishing - Google Patents
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- JP2004188586A JP2004188586A JP2003373168A JP2003373168A JP2004188586A JP 2004188586 A JP2004188586 A JP 2004188586A JP 2003373168 A JP2003373168 A JP 2003373168A JP 2003373168 A JP2003373168 A JP 2003373168A JP 2004188586 A JP2004188586 A JP 2004188586A
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Abstract
Description
本発明は、半導体、各種メモリーハードディスク用基板等の研磨に使用される研磨パッドに用いられる研磨用発泡シートに関するものである。 The present invention relates to a foamed polishing sheet used for a polishing pad used for polishing semiconductors, substrates for various memory hard disks, and the like.
半導体のデバイスウエハの表面平坦化加工に用いられる、代表的なプロセスである化学的機械的研磨法（ＣＭＰ）の一例を図１に示す。定盤（２）、試料ホルダー（５）を回転させ、砥粒を含有する研磨スラリー（４）をスラリー供給用配管（１０）を通して滴下しながら、半導体ウエハ（１）を研磨パッド（６）表面に押しあてることにより、デバイス表面を高精度に平坦化するというものである。なお研磨中、ドレッシングディスク（３）を回転させながら研磨パッド（６）表面に押しあてることにより、研磨パッド（６）の表面状態を整えている。研磨条件はもとより、研磨パッド（６）、ドレッシングディスク（３）、研磨スラリー（４）、ウエハ固定用治具（８）およびバッキング材（９）等、各構成部材の特性が、研磨速度、研磨後のデバイス表面の平坦性、ウエハ面内における均一性の指標となる平坦性のばらつき、およびそれらの経時変動等に代表される研磨性能に影響を及ぼすが、その中でも研磨パッド（６）と研磨スラリー（４）および研磨スラリー中に含まれる砥粒の及ぼす影響は極めて大きい。 FIG. 1 shows an example of a chemical mechanical polishing method (CMP), which is a typical process used for flattening a surface of a semiconductor device wafer. The semiconductor wafer (1) is placed on the surface of the polishing pad (6) while rotating the platen (2) and the sample holder (5) and dropping the polishing slurry (4) containing abrasive grains through the slurry supply pipe (10). To flatten the device surface with high precision. During polishing, the surface condition of the polishing pad (6) is adjusted by pressing the dressing disk (3) against the surface of the polishing pad (6) while rotating. In addition to the polishing conditions, the characteristics of each component such as a polishing pad (6), a dressing disk (3), a polishing slurry (4), a wafer fixing jig (8), and a backing material (9) are determined by the polishing rate and the polishing. Influence on the polishing performance typified by the flatness of the device surface later, the flatness variation as an index of uniformity in the wafer surface, and their variation over time, among which polishing pad (6) and polishing The effect of the abrasive grains contained in the slurry (4) and the polishing slurry is extremely large.
従来から、層間絶縁膜や金属配線等の研磨に用いられる研磨パッドの研磨層として、高分子マトリックス中に、空隙スペースを有する高分子微小エレメントを含浸した独立発泡体が標準的に使用されてきた（例えば、特許文献１参照。）。
従来の独立発泡体は、使用前、使用中におけるドレッシング、および研磨の進行に伴う研磨パッド表面の摩耗により、高分子微小エレメントのシェルが破れて空孔が開口し、研磨スラリーの保持能力を発現するというものであった。従来の独立発泡体においては、研磨性能に大きく影響を及ぼすと考えられる、研磨面において開口した空孔の開口部のサイズ、数および総面積等に言及している文献、報告書類等は非常に少なく、高分子微小エレメントのサイズ、数、空隙率等の記述に留まっているものが大部分であった。
Conventionally, as a polishing layer of a polishing pad used for polishing an interlayer insulating film, a metal wiring, and the like, a closed cell impregnated with a polymer microelement having a void space in a polymer matrix has been normally used. (For example, refer to Patent Document 1).
Conventional closed-cell foams exhibit the ability to hold the polishing slurry by dressing during and before use and by abrasion of the polishing pad surface due to the progress of polishing, which breaks the shell of polymer microelements and opens holes. It was to do. In conventional closed cell foams, there are very few documents and reports referring to the size, number, total area, etc. of the openings of the holes opened on the polishing surface, which are considered to greatly affect the polishing performance. In most cases, the description of the size, the number, the porosity, etc. of the polymer microelement was mostly limited.
エレクトロニクス業界の最近の著しい発展により、トランジスター、ＩＣ、ＬＳＩ、超ＬＳＩと進化してきている。これら半導体素子における回路の集積度が急激に増大するにつれて、半導体デバイスのデザインルールは、年々微細化が進み、デバイス製造プロセスでの焦点深度は浅くなり、パターン形成面の平坦性はますます厳しくなってきている。それに伴い、ＣＭＰに求められる研磨精度、つまりは研磨パッドに要求される研磨性能レベルも著しく高まっており、従来パッドの性能を上回る、高精度な研磨を実現できる研磨パッドの出現が大望されている。 The recent remarkable development of the electronics industry has evolved into transistors, ICs, LSIs, and VLSIs. As the degree of integration of circuits in these semiconductor devices has rapidly increased, the design rules of semiconductor devices have been miniaturized year by year, the depth of focus in the device manufacturing process has become shallower, and the flatness of the pattern formation surface has become increasingly severe. Is coming. Along with this, the polishing accuracy required for CMP, that is, the polishing performance level required for the polishing pad has been significantly increased, and the emergence of a polishing pad capable of realizing high-precision polishing that exceeds the performance of the conventional pad has been greatly desired. .
本発明は、従来の独立発泡体を用いた研磨パッドの、例えば研磨速度を向上させ、研磨性能ばらつきの問題を解決することにより、研磨性能の向上をはかるためのもので、その目的とするところは、高精度の研磨性能を経時的にも安定に発現することのできる研磨用発泡シートを提供することにある。 The present invention is intended to improve the polishing performance of a conventional polishing pad using a closed-cell foam, for example, by improving the polishing rate and solving the problem of polishing performance variation, and aims at improving the polishing performance. An object of the present invention is to provide a polishing foam sheet capable of stably exhibiting high-precision polishing performance over time.
本発明者らは、本発明者らは鋭意検討の結果、研磨面の状態に着目し、研磨面において
、シートに含まれる空孔が開口した結果生じた開口部の円相当直径の平均値、円相当直径０．１〜１０μｍの開口部個数密度、さらには全開口部の総面積の研磨面全体に対する割合が研磨性能と密接に関係しており、研磨パッドの高性能化を図る上で非常に重要な役割を果たすことを見出した。
前記従来の問題点を鑑み、鋭意検討を重ねた結果、以下の手段により、本発明を完成するに至った。
The present inventors, as a result of intensive studies, focused on the state of the polished surface, on the polished surface, the average value of the circle equivalent diameter of the opening resulting from the opening of the holes included in the sheet, The number density of openings with a circle equivalent diameter of 0.1 to 10 μm and the ratio of the total area of all openings to the entire polishing surface are closely related to the polishing performance, and are extremely important in improving the performance of the polishing pad. I found it to play an important role.
In view of the conventional problems described above, as a result of intensive studies, the present invention has been completed by the following means.
すなわち本発明は、
（１） 研磨面において、シートに含まれる空孔が開口した結果生じた開口部の円相当直径の平均値が１〜５０μｍであり、かつ円相当直径０．１〜１０μｍの開口部が少なくとも１０００個／ｃｍ２以上含まれていることを特徴とする研磨用発泡シート、
（２） 研磨面において、全開口部の総面積の割合が研磨面全体の３０〜７０％である第（１）項記載の研磨用発泡シート、
（３） ２５℃における見掛けの圧縮率が５〜１５％である、第（１）又は（２）項のいずれかに記載の研磨用発泡シート。
（４） シートを構成する原料の主成分が、ＪＩＳＫ−７３１１に準じたＡ硬度で７０以上の熱可塑性エラストマーである第（１）〜（３）項のいずれかに記載の研磨用発泡シート、
（５） 熱可塑性エラストマーがポリウレタンである第（４）項記載の研磨用発泡シート、
である。
That is, the present invention
(1) On the polished surface, the average value of the circle-equivalent diameter of the opening formed as a result of the opening included in the sheet is 1 to 50 μm, and the opening having the circle-equivalent diameter of 0.1 to 10 μm is at least 1000 μm. abrasive foam sheet, characterized in that it contains pieces / cm 2 or more,
(2) The foamed polishing sheet according to (1), wherein the ratio of the total area of all the openings on the polished surface is 30 to 70% of the entire polished surface.
(3) The polishing foam sheet according to any one of (1) and (2), wherein the apparent compression ratio at 25 ° C is 5 to 15%.
(4) The polishing foam sheet according to any one of (1) to (3), wherein the main component of the raw material forming the sheet is a thermoplastic elastomer having an A hardness of 70 or more according to JIS K-7311,
(5) The polishing foam sheet according to (4), wherein the thermoplastic elastomer is polyurethane.
It is.
本発明の研磨用発泡シートを用いて、例えば半導体デバイスウエハを研磨すれば、従来パッドに比べて、研磨速度が速くなるだけでなく、研磨後のデバイス表面の平坦性およびそれらのウエハ面内の均一性が著しく向上し、高精度な研磨の実現が期待できる。 When the semiconductor device wafer is polished, for example, by using the polishing foam sheet of the present invention, the polishing rate is increased as compared with the conventional pad, and also the flatness of the device surface after polishing and the in-plane The uniformity is remarkably improved, and high-precision polishing can be expected.
本発明において、高精度のＣＭＰを実現するために、研磨パッド用基材として使用される研磨用発泡シートの研磨面における好適な発泡状態を規定する。
本発明においては、研磨性能の指標として、例えば研磨対象が半導体デバイスウエハの場合、研磨速度、研磨速度のウエハ面内におけるばらつき、研磨速度の経時変動の３項目に着目する。
なお本発明の研磨用発泡シートにおいては、研磨面において、シートに含まれる空孔が開口した結果生じた開口部の形状は真円である必要はなく、楕円形、もしくはいびつな多角形形状でも良い。このため本発明における開口部の直径は、開口部の円相当直径をもって規定する。以後、開口部の直径とは円相当直径を意味し、また簡単のため、開口部の円相当直径を開口部径と記述する。
In the present invention, in order to realize high-precision CMP, a suitable foaming state on a polishing surface of a polishing foam sheet used as a substrate for a polishing pad is defined.
In the present invention, as an index of the polishing performance, for example, when a polishing target is a semiconductor device wafer, three items of a polishing speed, a variation in the polishing speed in a wafer surface, and a temporal change in the polishing speed are focused.
In the polishing foam sheet of the present invention, on the polishing surface, the shape of the opening resulting from the opening of the holes contained in the sheet need not be a perfect circle, and may be an elliptical shape or an irregular polygonal shape. good. For this reason, the diameter of the opening in the present invention is defined by the equivalent circle diameter of the opening. Hereinafter, the diameter of an opening means a circle equivalent diameter, and for simplicity, the circle equivalent diameter of an opening is described as an opening diameter.
本発明の研磨用発泡シートにおいては、研磨面において、シートに含まれる空孔が開口した結果生じた開口部径の平均値は、好ましくは１〜５０μｍ、さらに好ましくは２〜４０μｍ、最も好ましくは３〜３０μｍであり、かつ直径０．１〜１０μｍの開口部は少なくとも１０００個／ｃｍ２以上、さらに好ましくは５０００個／ｃｍ２以上、最も好ましくは１００００個／ｃｍ２以上である。
開口部径の平均値が１μｍ未満であると、研磨スラリー中に含まれる砥粒の凝集物および研磨の進行に伴い発生する研磨屑等が空孔内から排出されにくく、空孔が目詰まりし易い。その結果、研磨速度のウエハ面内におけるばらつきを引き起こしやすく、さらには研磨速度の経時変動が大きくなるので好ましくない。逆に５０μｍを超えると、ウエハ面内においてスラリーの保持性能がばらつき安く、研磨速度のウエハ面内におけるばらつきが大きくなるため、高精度な研磨の実現が非常に困難となる。
In the foamed sheet for polishing of the present invention, the average value of the diameter of the opening portion resulting from the opening of the pores contained in the sheet is preferably 1 to 50 μm, more preferably 2 to 40 μm, and most preferably the polishing surface. The number of openings having a diameter of 3 to 30 μm and a diameter of 0.1 to 10 μm is at least 1000 / cm 2 , more preferably 5000 / cm 2 or more, and most preferably 10,000 / cm 2 or more.
When the average value of the diameter of the opening is less than 1 μm, it is difficult to discharge the agglomerates of the abrasive grains contained in the polishing slurry and the polishing debris generated with the progress of the polishing from the pores, and the pores are clogged. easy. As a result, variations in the polishing rate within the wafer surface are likely to occur, and furthermore, the polishing rate fluctuates with time, which is not preferable. Conversely, if it exceeds 50 μm, the slurry holding performance in the wafer surface tends to vary less, and the polishing rate in the wafer surface varies greatly, making it very difficult to achieve highly accurate polishing.
直径０．１〜１０μｍの開口部は、研磨後のデバイス表面の平坦性向上に寄与し、さらには研磨速度のウエハ面内におけるばらつきおよび経時変動を低減する役割を担うが、１０００個／ｃｍ２未満では、全開口部に占める割合が小さく、つまりは均一性向上の効果が小さいので好ましくない。本発明の研磨用シートにおいては、少なくとも１０００個／ｃｍ２以上必要である。 The opening having a diameter of 0.1 to 10 μm contributes to improving the flatness of the device surface after polishing, and further has the role of reducing the variation in the polishing rate within the wafer surface and the variation with time, but 1000 / cm 2. If the ratio is less than 10%, the proportion of the entire opening is small, that is, the effect of improving the uniformity is small. In the polishing sheet of the present invention, at least 1,000 pieces / cm 2 or more are required.
本発明において、研磨面全体に占める全開口部の総面積の割合は、研磨速度と強い相関関係にあり、特に限定しないが好ましくは研磨面全体の３０〜７０％、さらに好ましくは３５〜６５％、最も好ましくは４０〜６０％である。
全開口部の総面積の割合が研磨面全体の３０％未満であると、研磨スラリーの保持性能が低くなり、研磨速度が小さくなるだけでなく、ウエハ面内におけるばらつきが生じやすく、さらには経時変動が大きくなるので好ましくない。
また、７０％を超えると、発泡シートの厚み方向における機械的強度が著しく低下するだけでなく、見掛けの表面硬度が低下し、研磨後のデバイス表面の平坦性低下を引き起こす要因となることから、好ましくない。
In the present invention, the ratio of the total area of all the openings to the entire polished surface has a strong correlation with the polishing rate and is not particularly limited, but is preferably 30 to 70%, more preferably 35 to 65% of the entire polished surface. , Most preferably 40 to 60%.
If the ratio of the total area of all the openings is less than 30% of the entire polished surface, the holding performance of the polishing slurry is lowered, not only the polishing rate is reduced, but also variation in the wafer surface is liable to occur. It is not preferable because the fluctuation becomes large.
On the other hand, if it exceeds 70%, not only the mechanical strength in the thickness direction of the foamed sheet is significantly reduced, but also the apparent surface hardness is reduced, which causes a reduction in flatness of the device surface after polishing. Not preferred.
本発明において圧縮率は特に限定しないが、高精度な研磨に好適な見掛けの圧縮率の範囲は、２５℃雰囲気下で５〜１５％である。
なお本発明の見掛けの圧縮率は、熱応力歪測定装置（ＴＭＡ）により測定したシート厚みの変化量より算出した値である。測定サンプルシートの厚みは１ｍｍとし、面圧の経時変化（プロファイル）を図２に示す。
具体的には、見掛けの圧縮率は、３００ｇ／ｃｍ２の面圧を６０秒間掛けたときの厚み（Ｔ１）から、引き続き１８００ｇ／ｃｍ２の面圧を同じく６０秒間掛けた時の厚み（Ｔ２）を引いた値をＴ１で除し、さらにその値を１００倍することによる得られる値である。
ＣＭＰの場合、圧縮率が５％未満であると、研磨用シートがウエハ全体のうねりに追従しきれず、研磨速度および研磨速度のウエハ面内におけるばらつきが大きくなり、さらには研磨速度の経時変動が大きくなるので好ましくない。逆に２５％以上では、見掛けの表面硬度が低下し、研磨後のデバイス表面の平坦性低下を引き起こす要因となるため好ましくない。
In the present invention, the compression ratio is not particularly limited, but the range of the apparent compression ratio suitable for high-precision polishing is 5 to 15% in a 25 ° C atmosphere.
The apparent compression ratio of the present invention is a value calculated from the amount of change in sheet thickness measured by a thermal stress strain measuring device (TMA). The thickness of the measurement sample sheet was 1 mm, and the change over time (profile) of the surface pressure is shown in FIG.
Specifically, the apparent compression ratio is calculated from the thickness (T1) when a surface pressure of 300 g / cm 2 is applied for 60 seconds, and the thickness (T2) when a surface pressure of 1800 g / cm 2 is continuously applied for 60 seconds. ) Is divided by T1, and the value is obtained by multiplying the value by 100.
In the case of CMP, if the compression ratio is less than 5%, the polishing sheet cannot completely follow the undulation of the entire wafer, and the polishing rate and the variation in the polishing rate within the wafer surface become large. It is not preferable because it becomes large. Conversely, if it is 25% or more, the apparent surface hardness decreases, which is a factor that causes a decrease in flatness of the device surface after polishing, which is not preferable.
本発明の研磨用発泡シート原料の主成分は特に限定しない。ポリウレタン、ポリスチレン、ポリエステル、ポリプロピレン、ポリエチレン、ナイロン、ポリ塩化ビニル、ポリ塩化ビニリデン、ポリブテン、ポリアセタール、ポリフェニレンオキシド、ポリビニルアルコール、ポリメチルメタクリレート、ポリカーボネート、ポリアリレート、芳香族系ポリサルホン、ポリアミド、ポリイミド、フッ素樹脂、エチレン−プロピレン樹脂、エチレン−エチルアクリレート樹脂、アクリル樹脂、ノルボルネン系樹脂、例えば、ビニルポリイソプレン−スチレン共重合体、ブタジエン−スチレン共重合体、アクリロニトリル−スチレン共重合体、アクリロニトリル−ブタジエン−スチレン共重合体等に代表されるスチレン共重合体、あるいは天然ゴム、合成ゴム等を用いることができる。これらは単独で用いても良いし、混合あるいは共重合させてもよいが、研磨後の被研磨面の平坦性と均一性のバランスが非常に取りやすく、特に研磨対象が比較的柔らかいＣｕのような金属の場合では、例えばウレタン系やオレフィン系の、ＪＩＳＫ−７３１１に準じたＡ硬度で７０以上の熱可塑性エラストマーが好適である。その中でも研磨用発泡シートの重要特性の一つである耐摩耗性を、比較的広い範囲でコントロールすることが可能であるという点で、熱可塑性ポリウレタンエラストマーが最も好ましい。 The main component of the raw material for the foamed sheet for polishing of the present invention is not particularly limited. Polyurethane, polystyrene, polyester, polypropylene, polyethylene, nylon, polyvinyl chloride, polyvinylidene chloride, polybutene, polyacetal, polyphenylene oxide, polyvinyl alcohol, polymethyl methacrylate, polycarbonate, polyarylate, aromatic polysulfone, polyamide, polyimide, fluorine resin , Ethylene-propylene resin, ethylene-ethyl acrylate resin, acrylic resin, norbornene-based resin, for example, vinyl polyisoprene-styrene copolymer, butadiene-styrene copolymer, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer A styrene copolymer represented by a polymer or the like, natural rubber, synthetic rubber, or the like can be used. These may be used alone or may be mixed or copolymerized, but it is very easy to balance the flatness and uniformity of the surface to be polished after polishing, and the polishing object is relatively soft, such as Cu. In the case of a suitable metal, for example, a urethane-based or olefin-based thermoplastic elastomer having an A hardness of 70 or more according to JIS K-7311 is suitable. Among them, thermoplastic polyurethane elastomers are most preferable because abrasion resistance, which is one of the important characteristics of the foamed abrasive sheet, can be controlled in a relatively wide range.
なお本発明の研磨用発泡シートを研磨パッドとして用いる場合、必要に応じてシート表面に溝加工を施すことができる。溝の形状は特に限定しないが、例えば平行、格子状、同
心円状、さらには渦巻き状等、随時選定することができる。シート表面に溝を施すことにより、研磨面全域に研磨スラリーがより行き渡り安くなり、本発明の研磨用発泡シートの性能がさらに引き出される。
When the foamed polishing sheet of the present invention is used as a polishing pad, a groove can be formed on the sheet surface as necessary. Although the shape of the groove is not particularly limited, for example, a parallel shape, a lattice shape, a concentric shape, and a spiral shape can be selected as needed. By providing grooves on the surface of the sheet, the polishing slurry can be more widely distributed over the entire polishing surface, and the performance of the foamed polishing sheet of the present invention can be further enhanced.
以下に、実施例により本発明を具体的に説明するが、本発明は、実施例の内容になんら限定されるものではない。
＜発泡シート化設備＞
本発明の実施例で使用した発泡シート化設備の概略図を図３に示す。バレル径５０ｍｍ、Ｌ／Ｄ＝３２の単軸押出機（１１）とバレル径６５ｍｍ、Ｌ／Ｄ＝３６の単軸押出機（１２）を中空の単管（１６）で連結したタンデム型押出機の先端に、リップ幅３００ｍｍの成形用金型（１３）を取り付けた。
発泡剤としては二酸化炭素を用い、ボンベ（１７）から取り出した後に、昇圧ポンプ（１８）により昇圧した二酸化炭素を、単軸押出機（１１）の中央前寄りに取り付けた注入口（１４）を通して押出機中に注入した。
＜シート物性評価＞
○発泡状態
研磨面をＨＩＴＡＣＨＩ製走査型電子顕微鏡（ＳＥＭ）Ｓ−２４００で観察し、開口部径、研磨面単位面積当たりの直径０．１〜１０μｍの開口部個数、および全開口部の総面積の割合を算出した。
○圧縮率
セイコーインスツルメンツ（株）社製ＴＭＡを使用して、研磨加工により厚み１ｍｍに調整したシートの、２５℃雰囲気下における厚み変化を測定した。
面圧のプロファイルは図２の通りである。負荷無しの状態から、３００ｇ／ｃｍ２の面圧を掛け、引き続き１８００ｇ／ｃｍ２の面圧を掛けた後に荷重を取り除くという一連の操作を１サイクルとして、連続的に５サイクル測定した。厚み変化から算出した各サイクルにおける圧縮率の５回の平均値を、見掛けの圧縮率として用いた。
Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to the contents of the examples.
<Foam sheeting equipment>
FIG. 3 is a schematic view of the equipment for forming a foam sheet used in the example of the present invention. A tandem type extruder in which a single screw extruder (11) having a barrel diameter of 50 mm and L / D = 32 and a single screw extruder (12) having a barrel diameter of 65 mm and L / D = 36 are connected by a hollow single tube (16). Was attached to a tip of a molding die (13) having a lip width of 300 mm.
Carbon dioxide was used as a foaming agent. After the carbon dioxide was taken out of the cylinder (17), the carbon dioxide pressurized by the pressurizing pump (18) was passed through an inlet (14) attached to the center of the single screw extruder (11). It was injected into the extruder.
<Sheet property evaluation>
○ Foaming state The polished surface is observed with a scanning electron microscope (SEM) S-2400 manufactured by HITACHI, and the diameter of the opening, the number of openings having a diameter of 0.1 to 10 μm per unit area of the polished surface, and the total area of all the openings are provided. Was calculated.
○ Compression rate Using a TMA manufactured by Seiko Instruments Inc., the change in thickness of the sheet adjusted to 1 mm in thickness by polishing was measured in a 25 ° C. atmosphere.
The profile of the surface pressure is as shown in FIG. From a state of no load, a series of operations of applying a surface pressure of 300 g / cm 2 , subsequently applying a surface pressure of 1800 g / cm 2 , and removing the load were defined as one cycle, and measurement was continuously performed for five cycles. The average of the five compression ratios in each cycle calculated from the thickness change was used as the apparent compression ratio.
（実施例１）
主原料であるＪＩＳＫ−７３１１に準じたＡ硬度で９９（カタログ収載値）の熱可塑性ポリウレタンエラストマー（商品名：レザミンＰ−４２５０大日精化工業（株）製）に、同社の架橋剤（商品名：クロスネートＥＭ−３０）をあらかじめ混合した原料を使用した。発泡シート化条件を表１に示す。
得られた発泡シート表面を、丸源鐵工所製ベルトサンダー（商品名：ＭＮＷ−６１０−Ｃ２）で研磨し、シート表面近傍の無発泡層であるスキン層を除去することにより気泡を開口させ、厚み１．３ｍｍの研磨用発泡シートを得た。発泡状態および圧縮率に関するデータを表１に示す。
該シート３枚を両面テープと貼り合わせた後に、円盤状に切り取り、直径６００ｍｍφの研磨パッドを作製した。
（実施例２）
発泡シート化条件を変更した以外は、（実施例１）と全く同様にして研磨パッドを作製した。発泡シート化条件、発泡状態および圧縮率に関するデータを表１に示す。
（実施例３）
ショーダテクトロン社製クロスワイズソー（商品名：ＣＷＳ−６５０Ａ）を用いて、（実施例１）で得た研磨パッド表面に溝幅２ｍｍ、隣り合う溝と溝との間隔１３ｍｍ、溝深さ０．６ｍｍの溝を格子状に施した。
（実施例４）
ＪＩＳＫ−７３１１に準じたＡ硬度で９０（カタログ収載値）の熱可塑性ポリウレタンエラストマー（商品名：レザミンＰ−４０７０ＥＸ大日精化工業（株）製）を原料として使用した。（実施例１）〜（実施例３）で用いた同社の架橋剤（商品名：クロスネートＥ
Ｍ−３０）は使用していない。発泡シート化条件、発泡状態および圧縮率に関するデータを表１に示す。
（比較例１）
発泡シート化条件を変更した以外は、（実施例１）と全く同様にして研磨パッドを作製した。発泡シート化条件、発泡状態および圧縮率に関するデータを表１に示す。
（比較例２）
研磨パッドとして、溝幅２ｍｍ、隣り合う溝と溝との間隔１３ｍｍ、溝深さ０．６ｍｍの格子溝が施されたロデール社製ＩＣ１０００を使用した。発泡状態および圧縮率に関するデータを表１に示す。
(Example 1)
A thermoplastic polyurethane elastomer (trade name: Rezamin P-4250, manufactured by Dainichi Seika Kogyo Co., Ltd.) having an A hardness of 99 (listed in the catalog) according to JIS K-7311, which is the main raw material, and a crosslinking agent (trade name) : Crosnate EM-30) was used in advance. Table 1 shows the conditions for forming a foam sheet.
The surface of the obtained foamed sheet is polished with a belt sander (trade name: MNW-610-C2) manufactured by Marugen Iron Works, Ltd., and bubbles are opened by removing a skin layer which is a non-foamed layer near the sheet surface. And a foamed sheet for polishing having a thickness of 1.3 mm. Table 1 shows data on the foaming state and the compression ratio.
After laminating the three sheets with a double-sided tape, they were cut into a disk shape to produce a polishing pad having a diameter of 600 mmφ.
(Example 2)
A polishing pad was produced in exactly the same manner as in (Example 1) except that the conditions for forming a foam sheet were changed. Table 1 shows data on the conditions for forming the foamed sheet, the foamed state, and the compression ratio.
(Example 3)
Using a crosswise saw (trade name: CWS-650A) manufactured by Shoda Tectron Co., Ltd., a groove width of 2 mm, a space between adjacent grooves of 13 mm, and a groove depth of 0 were formed on the polishing pad surface obtained in (Example 1). A 0.6 mm groove was formed in a lattice pattern.
(Example 4)
A thermoplastic polyurethane elastomer (trade name: Resamine P-4070EX, manufactured by Dainichi Seika Kogyo Co., Ltd.) having an A hardness of 90 (listed in a catalog) according to JIS K-7311 was used as a raw material. The company's crosslinking agent (trade name: Closnate E) used in (Example 1) to (Example 3)
M-30) is not used. Table 1 shows data on the conditions for forming the foamed sheet, the foamed state, and the compression ratio.
(Comparative Example 1)
A polishing pad was produced in exactly the same manner as in (Example 1) except that the conditions for forming a foam sheet were changed. Table 1 shows data on the conditions for forming the foamed sheet, the foamed state, and the compression ratio.
(Comparative Example 2)
As the polishing pad, an IC1000 manufactured by Rodale having a lattice width of 2 mm, a groove width of 13 mm between adjacent grooves, and a groove depth of 0.6 mm was used. Table 1 shows data on the foaming state and the compression ratio.
＜研磨性能評価＞
被研磨物として、直径２００ｍｍのＣｕブランケットウエハを用いた。
（実施例）および（比較例）で得られた研磨パッドをＭＡＴ製片面研磨機ＡＲＷ−６８１ＭＳの定盤に貼り付け、ドレッシングを掛けた後に、キャボット社製研磨スラリー（商品名：ｉＣｕｅ５００３）を供給しながら研磨を実施した。ドレス条件および研磨条件を表２に示す。
<Polishing performance evaluation>
A Cu blanket wafer having a diameter of 200 mm was used as an object to be polished.
The polishing pad obtained in (Example) and (Comparative Example) was attached to a surface plate of a MAT single-side polishing machine ARW-681MS, dressed, and then supplied with a polishing slurry (trade name: iCue5003) manufactured by Cabot Corporation. Polishing was performed while performing. Table 2 shows the dressing conditions and polishing conditions.
研磨後のウエハを洗浄、乾燥後、シート抵抗測定機を用いてウエハ面内４９点のＣｕ膜厚を測定し、研磨速度の平均値および研磨速度のウエハ面内におけるばらつきを算出した。なお本評価はブランケットウエハを用いたため、研磨後のデバイス表面の平坦性は、研磨速度のウエハ面内におけるばらつきにより判定することができる。ばらつきが小さいほど、平坦性は良好であると判断した。
また適宜ドレスをかけながら、ウエハ５０枚を連続的に研磨し、研磨速度平均値のばらつきを算出し、研磨性能の経時変動の判断指標とした。
なお、研磨速度のウエハ面内におけるばらつきとして、４９点の研磨速度の最大値から最小値を引いた値を平均値の２倍で除した値を１００倍した値を用いた。その値が大きいほど均一性が低いことを意味する。
実施例の研磨性能の評価結果を表３に、比較例のそれを表４に示す。
After cleaning and drying the polished wafer, the Cu film thickness at 49 points in the wafer surface was measured using a sheet resistance measuring instrument, and the average polishing rate and the variation in the polishing rate in the wafer plane were calculated. Since a blanket wafer was used in this evaluation, the flatness of the device surface after polishing can be determined by a variation in the polishing rate within the wafer surface. The smaller the variation, the better the flatness.
In addition, while appropriately dressing, 50 wafers were continuously polished, and the variation in the average polishing rate was calculated, which was used as a judgment index of the change over time in the polishing performance.
As a variation in the polishing rate in the wafer surface, a value obtained by dividing a value obtained by subtracting the minimum value from the maximum value of the polishing rate at 49 points by twice the average value and multiplying the value by 100 was used. The higher the value, the lower the uniformity.
Table 3 shows the evaluation results of the polishing performance of the examples, and Table 4 shows the evaluation results of the comparative examples.
実施例は、比較例に比べ、いずれも研磨速度が大きくなり、かつ研磨速度のウエハ面内ばらつきおよび研磨速度の経時変動ともに小さい値を示した。本結果により、研磨後のＣｕ表面の平坦性も向上したものと判断できる。 In each of the examples, the polishing rate was higher than that of the comparative example, and both the in-plane variation of the polishing rate and the variation over time of the polishing rate were small. From this result, it can be determined that the flatness of the Cu surface after polishing was also improved.
本発明は、半導体、各種メモリーハードディスク用基板等の研磨に使用される研磨パッドに応用されるものであり、その中でも特に層間絶縁膜や金属配線等の、半導体デバイスウエハの表面平坦化加工に好適に用いられる。 INDUSTRIAL APPLICABILITY The present invention is applied to a polishing pad used for polishing semiconductors, various memory hard disk substrates, and the like, and is particularly suitable for flattening the surface of a semiconductor device wafer such as an interlayer insulating film or metal wiring. Used for
１ 半導体デバイスウエハ
２ 定盤
３ ドレッシングディスク
４ 研磨スラリー
５ 試料ホルダー
６ 研磨パッド
７ 回転軸
８ ウエハ固定用治具
９ バッキング材
１０ スラリー供給用配管
１１ 単軸押出機（第一）
１２ 単軸押出機（第二）
１３ 成形用金型
１４ 発泡剤注入口
１５ 原料ホッパ−
１６ 中空単管
１７ ボンベ
１８ 昇圧ポンプ
１９ 流量制御弁
DESCRIPTION OF
12 Single screw extruder (second)
13 Mold for molding 14
16 Hollow
Claims (5)
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003373168A JP2004188586A (en) | 2002-11-25 | 2003-10-31 | Foam sheet for polishing |
| AU2003284655A AU2003284655A1 (en) | 2002-11-25 | 2003-11-25 | Method for producing closed cell cellular material for use in polishing, cellular sheet for polishing, laminate for polishing and polishing method, method for producing laminate for polishing, and grooved polishing pad |
| PCT/JP2003/014964 WO2004054779A1 (en) | 2002-11-25 | 2003-11-25 | Method for producing closed cell cellular material for use in polishing, cellular sheet for polishing, laminate for polishing and polishing method, method for producing laminate for polishing, and grooved polishing pad |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002341240 | 2002-11-25 | ||
| JP2003373168A JP2004188586A (en) | 2002-11-25 | 2003-10-31 | Foam sheet for polishing |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2004188586A true JP2004188586A (en) | 2004-07-08 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2003373168A Pending JP2004188586A (en) | 2002-11-25 | 2003-10-31 | Foam sheet for polishing |
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| Country | Link |
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| JP (1) | JP2004188586A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008101155A (en) * | 2006-10-20 | 2008-05-01 | Futamura Chemical Co Ltd | Water-repellent porous structure and its manufacturing method |
| JP2018108612A (en) * | 2016-12-28 | 2018-07-12 | 花王株式会社 | Polishing pad |
-
2003
- 2003-10-31 JP JP2003373168A patent/JP2004188586A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008101155A (en) * | 2006-10-20 | 2008-05-01 | Futamura Chemical Co Ltd | Water-repellent porous structure and its manufacturing method |
| JP2018108612A (en) * | 2016-12-28 | 2018-07-12 | 花王株式会社 | Polishing pad |
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