JPH11302635A - Polishing composition and method for polishing using it - Google Patents
Polishing composition and method for polishing using itInfo
- Publication number
- JPH11302635A JPH11302635A JP10115291A JP11529198A JPH11302635A JP H11302635 A JPH11302635 A JP H11302635A JP 10115291 A JP10115291 A JP 10115291A JP 11529198 A JP11529198 A JP 11529198A JP H11302635 A JPH11302635 A JP H11302635A
- Authority
- JP
- Japan
- Prior art keywords
- polishing
- acid
- weak
- polishing composition
- silicon oxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000005498 polishing Methods 0.000 title claims abstract description 124
- 239000000203 mixture Substances 0.000 title claims abstract description 74
- 238000000034 method Methods 0.000 title claims abstract description 30
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 51
- 239000002253 acid Substances 0.000 claims abstract description 49
- 229910052814 silicon oxide Inorganic materials 0.000 claims abstract description 33
- 239000000243 solution Substances 0.000 claims abstract description 33
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 17
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 17
- 239000010703 silicon Substances 0.000 claims abstract description 17
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 12
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 12
- 239000007853 buffer solution Substances 0.000 claims abstract description 10
- 239000011164 primary particle Substances 0.000 claims abstract description 10
- 230000003139 buffering effect Effects 0.000 claims abstract description 9
- 239000002245 particle Substances 0.000 claims abstract description 9
- 238000010494 dissociation reaction Methods 0.000 claims abstract description 7
- 230000005593 dissociations Effects 0.000 claims abstract description 7
- 150000003839 salts Chemical class 0.000 claims description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- 239000006260 foam Substances 0.000 claims description 4
- 239000002649 leather substitute Substances 0.000 claims description 4
- 239000004745 nonwoven fabric Substances 0.000 claims description 4
- 239000003960 organic solvent Substances 0.000 claims description 4
- 229920003002 synthetic resin Polymers 0.000 claims description 4
- 239000000057 synthetic resin Substances 0.000 claims description 4
- 239000000758 substrate Substances 0.000 abstract description 6
- 239000004065 semiconductor Substances 0.000 abstract description 5
- 239000002585 base Substances 0.000 description 31
- 238000012545 processing Methods 0.000 description 25
- 235000012431 wafers Nutrition 0.000 description 20
- 238000002474 experimental method Methods 0.000 description 13
- 239000010419 fine particle Substances 0.000 description 13
- 239000008119 colloidal silica Substances 0.000 description 12
- 239000007788 liquid Substances 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 7
- NQRYJNQNLNOLGT-UHFFFAOYSA-N Piperidine Chemical compound C1CCNCC1 NQRYJNQNLNOLGT-UHFFFAOYSA-N 0.000 description 6
- 239000003513 alkali Substances 0.000 description 6
- 239000003795 chemical substances by application Substances 0.000 description 6
- 150000001412 amines Chemical class 0.000 description 5
- 230000003628 erosive effect Effects 0.000 description 5
- GLUUGHFHXGJENI-UHFFFAOYSA-N Piperazine Chemical compound C1CNCCN1 GLUUGHFHXGJENI-UHFFFAOYSA-N 0.000 description 4
- 239000000084 colloidal system Substances 0.000 description 4
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 4
- WGTYBPLFGIVFAS-UHFFFAOYSA-M tetramethylammonium hydroxide Chemical compound [OH-].C[N+](C)(C)C WGTYBPLFGIVFAS-UHFFFAOYSA-M 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- ZMANZCXQSJIPKH-UHFFFAOYSA-N Triethylamine Chemical compound CCN(CC)CC ZMANZCXQSJIPKH-UHFFFAOYSA-N 0.000 description 3
- 239000000654 additive Substances 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- QUSNBJAOOMFDIB-UHFFFAOYSA-N Ethylamine Chemical compound CCN QUSNBJAOOMFDIB-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 150000008044 alkali metal hydroxides Chemical class 0.000 description 2
- 239000000908 ammonium hydroxide Substances 0.000 description 2
- HQABUPZFAYXKJW-UHFFFAOYSA-N butan-1-amine Chemical compound CCCCN HQABUPZFAYXKJW-UHFFFAOYSA-N 0.000 description 2
- 239000002270 dispersing agent Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- IXCSERBJSXMMFS-UHFFFAOYSA-N hcl hcl Chemical compound Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 150000007524 organic acids Chemical class 0.000 description 2
- 235000005985 organic acids Nutrition 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 125000001453 quaternary ammonium group Chemical group 0.000 description 2
- 229910002027 silica gel Inorganic materials 0.000 description 2
- 239000000741 silica gel Substances 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 239000004094 surface-active agent Substances 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- HZAXFHJVJLSVMW-UHFFFAOYSA-N 2-Aminoethan-1-ol Chemical compound NCCO HZAXFHJVJLSVMW-UHFFFAOYSA-N 0.000 description 1
- WFCSWCVEJLETKA-UHFFFAOYSA-N 2-piperazin-1-ylethanol Chemical compound OCCN1CCNCC1 WFCSWCVEJLETKA-UHFFFAOYSA-N 0.000 description 1
- CJNRGSHEMCMUOE-UHFFFAOYSA-N 2-piperidin-1-ylethanamine Chemical compound NCCN1CCCCC1 CJNRGSHEMCMUOE-UHFFFAOYSA-N 0.000 description 1
- NUKYPUAOHBNCPY-UHFFFAOYSA-N 4-aminopyridine Chemical compound NC1=CC=NC=C1 NUKYPUAOHBNCPY-UHFFFAOYSA-N 0.000 description 1
- RPNUMPOLZDHAAY-UHFFFAOYSA-N Diethylenetriamine Chemical compound NCCNCCN RPNUMPOLZDHAAY-UHFFFAOYSA-N 0.000 description 1
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 239000003082 abrasive agent Substances 0.000 description 1
- 239000006061 abrasive grain Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical group [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- IMUDHTPIFIBORV-UHFFFAOYSA-N aminoethylpiperazine Chemical compound NCCN1CCNCC1 IMUDHTPIFIBORV-UHFFFAOYSA-N 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- 239000000872 buffer Substances 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- ZBCBWPMODOFKDW-UHFFFAOYSA-N diethanolamine Chemical compound OCCNCCO ZBCBWPMODOFKDW-UHFFFAOYSA-N 0.000 description 1
- HPNMFZURTQLUMO-UHFFFAOYSA-N diethylamine Chemical compound CCNCC HPNMFZURTQLUMO-UHFFFAOYSA-N 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 229960004979 fampridine Drugs 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 239000000499 gel Substances 0.000 description 1
- 238000001879 gelation Methods 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910013633 m-SiO Inorganic materials 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 239000012452 mother liquor Substances 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 238000010979 pH adjustment Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000007517 polishing process Methods 0.000 description 1
- 238000007781 pre-processing Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- AOHJOMMDDJHIJH-UHFFFAOYSA-N propylenediamine Chemical compound CC(N)CN AOHJOMMDDJHIJH-UHFFFAOYSA-N 0.000 description 1
- 239000008213 purified water Substances 0.000 description 1
- KIDHWZJUCRJVML-UHFFFAOYSA-N putrescine Chemical compound NCCCCN KIDHWZJUCRJVML-UHFFFAOYSA-N 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000012086 standard solution Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000011550 stock solution Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 229920003169 water-soluble polymer Polymers 0.000 description 1
- 239000012224 working solution Substances 0.000 description 1
Landscapes
- Mechanical Treatment Of Semiconductor (AREA)
Abstract
Description
【０００１】[0001]
【発明が属する技術分野】本発明は、シリコンウェーハ
あるいは化合物ウェーハ等よりなる半導体基板の表面の
研磨加工を行なう研磨用組成物および該研磨用組成物の
調整方法、および該研磨用組成物を用いた研磨加工方法
に関する。更に詳しくは、緩衝作用を持ち、かつ導電率
の大きい研磨用組成物溶液に係わる。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing composition for polishing a surface of a semiconductor substrate such as a silicon wafer or a compound wafer, a method for preparing the polishing composition, and a method for using the polishing composition. Polishing method. More specifically, the present invention relates to a polishing composition solution having a buffering action and a high electrical conductivity.
【０００２】[0002]
【従来の技術】従来、シリコンウェーハあるいは化合物
ウェーハ等よりなる半導体基板の工作物（以下ウェーハ
等と略記する）の表面の研磨加工を行なう研磨用組成物
としては酸化珪素またはその水和物をコロイド状に分散
した懸濁液、所謂コロイダルシリカが研磨剤として使用
され、加工に際しては合成樹脂発泡体あるいはスウェー
ド調合成皮革等よりなるポリッシャーを展張した定盤上
に工作物を載置し、押圧回転しつつ前記研磨用組成物溶
液を定量的に供給しながら加工を行なう方法が一般的で
ある。ここでいう研磨加工とは、ラッピング、エッチン
グ等の前加工を行なったウェーハ等を、最終的な鏡面に
仕上るためのプレポリッシングあるいはポリッシング工
程およびデバイス基板のＣＭＰ研磨工程を指すものであ
る。2. Description of the Related Art Conventionally, as a polishing composition for polishing a surface of a workpiece (hereinafter abbreviated as a wafer or the like) of a semiconductor substrate formed of a silicon wafer or a compound wafer, silicon oxide or a hydrate thereof is colloidally used. The workpiece is placed on a platen on which a polisher made of a synthetic resin foam or suede-like synthetic leather is spread, and is pressed and rotated. In general, a method of performing processing while quantitatively supplying the polishing composition solution while polishing is performed. Here, the term "polishing" refers to a pre-polishing or polishing step for finishing a wafer or the like which has been subjected to pre-processing such as lapping or etching into a final mirror surface, and a CMP polishing step for a device substrate.
【０００３】上述のプレポリッシング加工には上下に不
織布を貼付した定盤を配した両面加工機が一般的に使用
され、またポリッシング加工には不織布またはやや軟質
なスウェード調合成皮革等よりなるポリッシャーを片面
に配した片面加工機が使用される。ＣＭＰ加工には、や
や硬質の合成樹脂発泡体よりなるポリッシャーを片面に
配した片面加工機が使用される。加工においては上記の
加工機に酸化珪素の微粒子を含んだ研磨用組成物水分散
液を供給しつつ、工作物であるシリコンウェーハ等を押
圧回転して行なうものである。For the above-mentioned pre-polishing processing, a double-sided processing machine having a platen on which a non-woven fabric is attached on the upper and lower sides is generally used. For the polishing processing, a polisher made of a non-woven fabric or a somewhat soft suede-like synthetic leather is used. A single-sided processing machine arranged on one side is used. For the CMP processing, a single-side processing machine in which a polisher made of a somewhat hard synthetic resin foam is disposed on one side is used. In the processing, a silicon wafer or the like as a workpiece is pressed and rotated while an aqueous dispersion of a polishing composition containing fine particles of silicon oxide is supplied to the processing machine.
【０００４】研磨用組成物としては、例えば米国特許第
３３２８１４１号公報に示されているように、アルカリ
成分を含んだ溶液に微細なコロイド状酸化珪素微粒子を
分散した溶液が一般的に使用される。この加工は、その
前工程までに行なわれる、例えばダイヤモンド砥石を使
用したり、あるいは硬質なアルミナ系砥粒を用いた所謂
機械的な加工とは異なるものであって、その成分である
アルカリの化学的作用、具体的にはシリコンウェーハ等
工作物に対する浸蝕性を応用したものである。すなわ
ち、アルカリの腐食性により、ウェーハ等工作物表面に
薄い軟質の浸蝕層が形成される。その薄層を微細なコロ
イド状酸化珪素微粒子の機械的作用により除去してゆく
ことにより加工を行なうものであって、一般的にメカノ
ケミカル加工と称せられる方法である。研磨用組成物溶
液のｐＨは、溶液が持つアルカリ成分の化学的作用によ
り加工が進むのであるから、７以上のアルカリ性領域に
なければならない。すなわちｐＨ値が７の中性を示す数
値に近くなるにつれその化学作用の力は弱くなり、研磨
加工速度は遅くなるしまた、１４に近い強アルカリ領域
になるに従ってその力は強くなり研磨加工速度は速くな
る。As a polishing composition, for example, as disclosed in US Pat. No. 3,328,141, a solution in which fine colloidal silicon oxide fine particles are dispersed in a solution containing an alkali component is generally used. . This processing is different from the so-called mechanical processing using, for example, a diamond grindstone or using hard alumina-based abrasive grains, which is performed up to the previous step. This is an application of the mechanical action, specifically, the erosion of a workpiece such as a silicon wafer. That is, a thin soft erosion layer is formed on the surface of a workpiece such as a wafer due to the corrosiveness of the alkali. The processing is performed by removing the thin layer by the mechanical action of fine colloidal silicon oxide fine particles, and is a method generally called mechanochemical processing. The pH of the polishing composition solution must be in an alkaline range of 7 or more because the processing proceeds by the chemical action of the alkali component of the solution. That is, as the pH value becomes closer to the value indicating neutrality of 7, the power of the chemical action becomes weaker, and the polishing speed becomes slower. Is faster.
【０００５】従って、このような加工においては、研磨
用組成物溶液の性質が極めて重要なファクターとなる。
即ち、工作物表面はアルカリによって浸蝕され薄層が形
成されるのであり、その性状、性質等、具体的にはその
厚さ硬度等は使用する研磨用組成物溶液の性質、特に電
気化学的性質に影響されること極めて大であるため、そ
の電気化学的性質、具体的にはｐＨが安定した範囲にあ
ることが大変重要である。もしこのｐＨが、熱、外気と
の接触、あるいは外部からの混入物等による外的条件に
よって容易に変化するようであれば、前述の浸蝕層の深
さ、浸蝕の速度、均一性、除去のし易さ等が微妙に変化
し精密かつ均質な加工を期待することはできない。ま
た、前記浸蝕層は、研磨用組成物中に研磨剤として含有
されるコロイド状酸化珪素粒子の機械的作用によって除
去されるのであるから、その粒子は適度なサイズを有
し、容易に破壊したり、あるいは高次に凝集してゲル化
したりするものであってはならない。すなわち、酸化珪
素粒子は、アルカリにより形成された浸蝕層を機械的作
用により効果的に除去してゆくものである。従って、除
去後の新しい鏡面に何らかの影響を与えるようなもので
あってはならない。[0005] Therefore, in such processing, the properties of the polishing composition solution are extremely important factors.
That is, the surface of the workpiece is eroded by alkali to form a thin layer, and its properties, properties, etc., specifically, its thickness, hardness, etc., depend on the properties of the polishing composition solution to be used, especially the electrochemical properties. It is extremely important that the electrochemical properties, specifically the pH, be in a stable range. If this pH easily changes due to external conditions such as heat, contact with the outside air, or contaminants from the outside, the depth of the eroded layer, the erosion speed, uniformity, Ease of processing changes delicately and precise and uniform processing cannot be expected. Further, since the erosion layer is removed by the mechanical action of colloidal silicon oxide particles contained as a polishing agent in the polishing composition, the particles have an appropriate size and are easily broken. Or agglomerate or gel in higher order. That is, the silicon oxide particles effectively remove the erosion layer formed by the alkali by mechanical action. Therefore, it should not have any effect on the new mirror surface after removal.
【０００６】従来より様々な研磨組成物がウェーハ等の
研磨剤として提案されている。たとえば、米国特許第３
１７０２７３号公報では、シリカゾル及びシリカゲルが
研磨剤として提案されている。さらに米国特許第３３２
８１４１号公報では、該懸濁液のｐＨを１０．５〜１
２．５の範囲内にすることにより、研磨速度が増大する
事が開示されている。米国特許第４１６９３３７号公報
では、アミン類を研磨用組成物に添加することが開示さ
れている。特開平２−１５８６８４号公報には、水、コ
ロイダルシリカ、分子量１０万以上の水溶性高分子、水
溶性塩類からなる研磨用組成物が開示されている。更に
特開平５−１５４７６０号公報では、水溶性アミンの一
種であるピペラジンを、シリカゾルまたはシリカゲルの
シリカ基準にて、１０〜８０重量％含む研磨組成物を使
用した研磨方法を開示している。これら開示されている
方法は、アルカリ性の母液にコロイダルシリカあるいは
シリカゾル等の微細粒子からなる研磨剤を分散させた基
本構造の溶液に、様々な添加剤を加えることにより研磨
剤の分散性を上げたり、加工力の安定性を図ったりする
ものであって、従来の研磨用組成物加工速度を画期的に
改善するようなものではない。Conventionally, various polishing compositions have been proposed as polishing agents for wafers and the like. For example, US Pat.
In Japanese Patent No. 170273, silica sol and silica gel are proposed as abrasives. See also US Pat.
No. 8141 discloses that the pH of the suspension is from 10.5 to 1
It is disclosed that the polishing rate is increased by setting the ratio within the range of 2.5. U.S. Pat. No. 4,169,337 discloses adding amines to the polishing composition. JP-A-2-158684 discloses a polishing composition comprising water, colloidal silica, a water-soluble polymer having a molecular weight of 100,000 or more, and water-soluble salts. Further, Japanese Patent Application Laid-Open No. 5-154760 discloses a polishing method using a polishing composition containing 10 to 80% by weight of piperazine which is a kind of water-soluble amine, based on silica of silica sol or silica gel. These disclosed methods increase the dispersibility of the abrasive by adding various additives to a solution having a basic structure in which an abrasive composed of fine particles such as colloidal silica or silica sol is dispersed in an alkaline mother liquor. It is intended to stabilize the processing power and does not remarkably improve the conventional polishing composition processing speed.
【０００７】基本的に、プレポリッシング、あるいはポ
リッシング工程は上述の研磨用組成物を用いる方法によ
るものであるから、一般的に加工速度が遅く生産効率に
劣る上、外的条件の変化によりｐＨが変化し易く加工の
安定性に欠くことが多く、時間がかかりまた難度の高い
加工方法であり、完全な方法とは言い難いものであっ
た。しかしながら、特に近年電子回路の高集積化および
ウェーハ自体の大型化に伴いシリコンウェーハ、半導体
デバイス基板表面の高度な平坦化が必須となっている。
さらに、生産効率を向上させるため、加工速度が速い研
磨用組成物及び研磨方法が望まれている。特開昭５２−
４７３６９においては、アルミニウム原子で被覆された
コロイド状シリカを用いて、ｐＨ約１１〜１２．５の間
で研磨加工を行なうことにより、研磨加工速度を向上改
善する方法が開示されている。この方法においては、水
酸化ナトリウムを用いてｐＨ値を調整することを行なっ
ているが、このようなｐＨ調整法を踏襲すると研磨加工
時におけるｐＨが著しく低下する現象が見られ、研磨加
工速度は安定しない。さらに、この液をリサイクルし再
使用すると、研磨加工速度が低下してゆく現象が見ら
れ、実際の使用には問題が多く完全なものとは言い難か
った。Basically, the pre-polishing or polishing step is based on the above-mentioned method using the polishing composition. Therefore, the processing speed is generally low, the production efficiency is poor, and the pH is changed due to a change in external conditions. It is a processing method that often changes and lacks processing stability, is time-consuming, and has a high degree of difficulty, and is hardly a perfect method. However, in particular, with the recent increase in the degree of integration of electronic circuits and the size of the wafer itself, it has become essential to highly planarize the surfaces of silicon wafers and semiconductor device substrates.
Furthermore, in order to improve production efficiency, a polishing composition and a polishing method with a high processing speed are desired. JP-A-52-
No. 47369 discloses a method for improving and improving the polishing rate by performing polishing at a pH of about 11 to 12.5 using colloidal silica coated with aluminum atoms. In this method, the pH value is adjusted using sodium hydroxide, but if such a pH adjustment method is followed, a phenomenon in which the pH during polishing is significantly reduced is observed, and the polishing speed is reduced. Not stable. Furthermore, when this solution is recycled and reused, a phenomenon in which the polishing speed is reduced is seen, and it is difficult to say that the solution is complete because it has many problems in actual use.
【０００８】[0008]
【発明が解決しようとする課題】本発明者等は上述の従
来の研磨用組成物及び研磨方法が持つ問題点に鑑み、鋭
意研究を行ない、アルミニウムで被覆した微細な酸化珪
素微粒子を含むコロイド、すなわち特定のコロイダルシ
リカが、未被覆の酸化珪素微粒子を含む通常のコロイダ
ルシリカよりも高アルカリ領域で安定であることを見い
出し、本発明を完成するに至ったものである。即ち、研
磨用組成物溶液として前記アルミニウムで被覆した微細
な酸化珪素粒子を含むコロイドであって、ｐＨの緩衝作
用を有し、導電率の高い溶液を研磨用組成物溶液とする
ことで、安定した高速加工を達成したものであり、その
目的と為す所は高ｐＨ領域でｐＨの変化が少なく、かつ
研磨加工速度が高速で安定した研磨用組成物を提供する
こと及び該研磨用組成物を調整する方法を提供すること
にある。さらに本発明の他の目的は、その研磨用組成物
を用いた研磨方法を提供することにある。In view of the above-mentioned problems of the conventional polishing composition and polishing method, the present inventors have made intensive studies and have studied colloids containing fine silicon oxide fine particles coated with aluminum. That is, they have found that a specific colloidal silica is more stable in a high alkali region than ordinary colloidal silica containing uncoated silicon oxide fine particles, and have completed the present invention. That is, a colloid containing fine silicon oxide particles coated with aluminum as a polishing composition solution, having a pH buffering action, and having a high conductivity solution as a polishing composition solution, is stable. The purpose and the purpose of the present invention is to provide a stable polishing composition having a small change in pH in a high pH region and a high polishing rate, and to provide the polishing composition. It is to provide a method of adjusting. Still another object of the present invention is to provide a polishing method using the polishing composition.
【０００９】[0009]
【課題を解決するための手段】上述の目的は、アルミニ
ウムで表面を被覆した平均一次粒子径が８〜５００ｎｍ
の酸化珪素粒子を１〜１５重量％含むコロイドからな
り、該コロイド溶液が、２５℃における酸解離定数の逆
数の対数値が１０．０〜１２．５の弱酸及び／または、
弱塩基を使用して、弱酸と強塩基、強酸と弱塩基、弱酸
と弱塩基何れかの組み合わせのものを添加することによ
って、ｐＨ１０．７〜１２．５の間で緩衝作用を有する
緩衝溶液として調整されたものであることを特徴とする
研磨用組成物により達成することができる。更に、研磨
用組成物の導電率を酸化珪素１重量％あたり３０ｍＳ／
ｍ以下とすることにより、高品質の研磨面を保ちなが
ら、高速度研磨が可能な研磨用組成物を得ることができ
る。この研磨用組成物は、例えば１５〜６５重量％の濃
厚原液を使用の都度水、有機溶剤、塩類を含んだ溶液あ
るいはその混合物で希釈して調整することができる。An object of the present invention is to provide an aluminum-coated surface having an average primary particle diameter of 8 to 500 nm.
A colloidal solution containing 1 to 15% by weight of silicon oxide particles of the formula (I), wherein the colloidal solution has a logarithmic value of an inverse number of an acid dissociation constant at 25 ° C of 10.0 to 12.5 and / or
By using a weak base and adding a weak acid and a strong base, a strong acid and a weak base, or a combination of any of a weak acid and a weak base, a buffer solution having a buffering action between pH 10.7 to 12.5 is obtained. It can be achieved by a polishing composition characterized by being adjusted. Further, the conductivity of the polishing composition was adjusted to 30 mS / per 1% by weight of silicon oxide.
By setting m or less, a polishing composition capable of high-speed polishing while maintaining a high-quality polished surface can be obtained. The polishing composition can be prepared by diluting a concentrated stock solution of, for example, 15 to 65% by weight with a solution containing water, an organic solvent, salts or a mixture thereof each time it is used.
【００１０】更に、本発明の他の目的は、上下両面ある
いは片面に、合成樹脂発泡体、合成皮革あるいは不織布
等からなるポリッシャーを貼付した回転可能な定盤を有
する研磨加工機に、工作物であるシリコンウェーハ等を
載置押圧し、上述の研磨用組成物を供給しつつ、前記定
盤及び工作物の双方あるいはその一方を回転することに
より、前記工作物の研磨加工を行なう方法により達成さ
れる。Further, another object of the present invention is to provide a polishing machine having a rotatable platen on which a polisher made of synthetic resin foam, synthetic leather or non-woven fabric is stuck on both upper and lower surfaces or one surface. This is achieved by a method of performing a polishing process on the workpiece by rotating a surface plate and / or one of the workpieces while placing and pressing a certain silicon wafer or the like and supplying the polishing composition described above. You.
【００１１】[0011]
【発明の実施の形態】本発明に用いるコロイダルシリカ
に含まれるアルミニウムで表面を被覆した酸化珪素微粒
子は平均一次粒子径が８〜５００ｎｍのものであり、好
ましくは、８〜２００ｎｍのものである。これらの酸化
珪素微粒子は二次凝集していても良い。平均一次粒子径
が、８ｎｍより小さいとコロイド溶液が凝集し易く研磨
用組成物としての安定性が低下する。平均一次粒子径
が、２００〜５００ｎｍの場合、研磨用組成物としての
性能に影響はないが、安定した製品の製造が難しくま
た、価格的にも不利である。平均一次粒子径が、５００
ｎｍを越えると、粒子がコロイド次元を外れて好ましく
ない。アルミニウムで表面を被覆した酸化珪素微粒子の
濃度は、実際の研磨加工時において１〜１５重量％の範
囲にあることが肝要であり、更に、好ましい範囲は、１
〜１０重量％である。濃度が、１重量％以下であると研
磨加工速度は低くなり実用的ではない。研磨時の酸化珪
素濃度が高くなれば研磨加工速度自体は増大するが、約
１５重量％を越えるあたりでその値は飽和値に達し、そ
れ以上は濃度を高くした意味がなくなる。また、加工屑
として発生する珪素微粉はそのまま液中に残り、酸化さ
れて酸化珪素となり液中の酸化珪素濃度を高めて行く。
酸化珪素の濃度がはじめから高いと、前述の加工屑とし
て発生する珪素微粉が酸化したものも加わって、リサイ
クル液のゲル化をより早める傾向も見られ、コロイド溶
液としての安定性に欠き、研磨用組成物溶液のリサイク
ル性を著しく低下せしめ好ましくない。さらにコスト的
にも不利である。BEST MODE FOR CARRYING OUT THE INVENTION The fine particles of silicon oxide whose surface is coated with aluminum contained in the colloidal silica used in the present invention have an average primary particle diameter of 8 to 500 nm, preferably 8 to 200 nm. These silicon oxide fine particles may be secondary aggregated. If the average primary particle diameter is smaller than 8 nm, the colloid solution is likely to aggregate and the stability as a polishing composition is reduced. When the average primary particle size is from 200 to 500 nm, the performance as a polishing composition is not affected, but it is difficult to produce a stable product and the price is disadvantageous. The average primary particle diameter is 500
If it exceeds nm, the particles are out of the colloid dimension, which is not preferable. It is important that the concentration of the silicon oxide fine particles whose surface is coated with aluminum is in the range of 1 to 15% by weight during actual polishing, and a more preferable range is 1% by weight.
-10% by weight. If the concentration is 1% by weight or less, the polishing speed becomes low, which is not practical. If the concentration of silicon oxide during polishing increases, the polishing rate itself increases, but the value reaches a saturation value when the concentration exceeds about 15% by weight, and there is no point in increasing the concentration beyond that. Further, silicon fine powder generated as processing waste remains in the liquid as it is and is oxidized to silicon oxide to increase the concentration of silicon oxide in the liquid.
If the concentration of silicon oxide is high from the beginning, the oxidized silicon fine powder generated as the above-mentioned processing waste is also added, and there is a tendency that the gelation of the recycled liquid tends to be accelerated. It is not preferable because the recyclability of the composition solution for use is significantly reduced. Further, it is disadvantageous in terms of cost.
【００１２】本発明においては研磨用組成物のｐＨは１
０．７〜１２．５の範囲にあることが肝要である。ｐＨ
が１０．７以下であると研磨速度は低く、実用の範囲か
ら外れる。また、ｐＨが１２．５より上になると、コロ
イダルシリカが凝集をはじめるため研磨用組成物の安定
性が低下しこれも実用の範囲から外れる。そしてまた、
このｐＨは摩擦、熱、外気との接触あるいは他の成分と
の混合等、考えられる外的条件の変化により容易に変化
するようなものであってはならないが、本発明において
は研磨用組成物溶液自体を、外的条件の変化に対してｐ
Ｈの変化の幅の少ない、所謂緩衝作用の強い液とするこ
とをその必要条件とするものである。緩衝溶液を形成す
る弱酸及び／または、弱塩基は、２５℃における酸解離
定数（ｋａ）の逆数の対数値（ｐＫａ）が１０．０〜１
２．５の範囲にあることが好ましい。２５℃における酸
解離定数の逆数の対数値が１０．０以下の場合、ｐＨを
上昇させるために、弱酸及び／または、弱塩基を大量に
添加することが必要となるため好ましくない。２５℃に
おける酸解離定数の逆数の対数値が１２．５より大きい
とｐＨの値を１０．７〜１２．５の範囲で安定させる大
きな緩衝能を持つ緩衝溶液を形成することができない。In the present invention, the pH of the polishing composition is 1
It is important that it is in the range of 0.7 to 12.5. pH
Is less than 10.7, the polishing rate is low, which is out of the practical range. Further, when the pH is higher than 12.5, the stability of the polishing composition is lowered because the colloidal silica starts to aggregate, which is also out of a practical range. and again,
This pH should not easily change due to possible changes in external conditions, such as friction, heat, contact with the outside air or mixing with other components, but in the present invention the polishing composition The solution itself is p
It is a necessary condition to use a liquid having a small change in H, that is, a so-called strong buffering action. The weak acid and / or weak base forming the buffer solution has a logarithmic value (pKa) of the inverse of the acid dissociation constant (ka) at 25 ° C. of 10.0 to 1
It is preferably in the range of 2.5. If the logarithm of the reciprocal of the acid dissociation constant at 25 ° C. is 10.0 or less, it is not preferable because a large amount of a weak acid and / or a weak base needs to be added to increase the pH. If the logarithm of the reciprocal of the acid dissociation constant at 25 ° C. is larger than 12.5, a buffer solution having a large buffering capacity for stabilizing the pH value in the range of 10.7-12.5 cannot be formed.
【００１３】本発明の緩衝作用を有する研磨用組成物溶
液の形成に使用する弱酸の一例をあげると、ホウ酸（ｐ
Ｋａ＝９．２４）、炭酸（ｐＫａ＝６．３５、１０．３
３）、燐酸（ｐＫａ＝２．１５、７．２０、１２．３
５）類及び水溶性の有機酸等があげられ、またその混合
物であってもかまわない。弱塩基としては、水溶性アミ
ンあるいはその混合物が使用できる。具体的には、例え
ばエチレンジアミン（ｐＫａ＝７．０８、９．８９）、
モノエタノールアミン（ｐＫａ＝９．５２）、ジエタノ
ールアミン（ｐＫａ＝８．９０）、トリエチルアミン、
エチルアミン、ジエチルアミン、４−アミノピリジン、
ピペラジン（ｐＫａ＝５．５９、９．７１）、ピペリジ
ン（ｐＫａ＝１１．１）、ブチレンジアミン、プロピレ
ンジアミン、ブチルアミン、ヒドロキシエチルピペラジ
ン、アミノエチルピペラジン（ｐＫａ＝４．０２、９．
１１、９．８０）およびその混合物をあげることができ
る。また、強塩基としては、アルカリ金属の水酸化物お
よび水溶性の四級アンモニウムの水酸化物が使用でき
る。更に強酸としては塩酸、硝酸、硫酸などが使用でき
る。ｐＫａの値が複数存在する場合はその内一つが該当
する範囲に入っていればよい。緩衝溶液を形成させるた
め、（１）弱酸と強塩基、（２）強酸と弱塩基、（３）
弱酸と弱塩基の組み合わせの塩類、または、塩類と塩
基、または、塩類と酸、で添加しても良い。本発明で述
べる緩衝溶液とは、上述の組み合わせで形成され、溶液
の中で弱酸及び／または、弱塩基がイオンとして解離し
ている状態及び、未解離の状態が共存している溶液を示
し、少量の酸または、塩基が混入してもｐＨの変化が少
ないことが特徴である。An example of the weak acid used for forming the polishing composition solution having a buffering action of the present invention is boric acid (p
Ka = 9.24), carbonic acid (pKa = 6.35, 10.3)
3), phosphoric acid (pKa = 2.15, 7.20, 12.3)
5) and water-soluble organic acids, and a mixture thereof. As the weak base, a water-soluble amine or a mixture thereof can be used. Specifically, for example, ethylenediamine (pKa = 7.08, 9.89),
Monoethanolamine (pKa = 9.52), diethanolamine (pKa = 8.90), triethylamine,
Ethylamine, diethylamine, 4-aminopyridine,
Piperazine (pKa = 5.59, 9.71), piperidine (pKa = 11.1), butylenediamine, propylenediamine, butylamine, hydroxyethylpiperazine, aminoethylpiperazine (pKa = 4.02, 9.
11, 9.80) and mixtures thereof. As the strong base, an alkali metal hydroxide and a water-soluble quaternary ammonium hydroxide can be used. Further, as the strong acid, hydrochloric acid, nitric acid, sulfuric acid and the like can be used. When there are a plurality of pKa values, one of them may be in the corresponding range. (1) weak acid and strong base, (2) strong acid and weak base, (3)
A salt of a combination of a weak acid and a weak base, or a salt and a base, or a salt and an acid may be added. The buffer solution described in the present invention is formed by the above-described combination, and indicates a solution in which a weak acid and / or a weak base are dissociated as ions in the solution, and an undissociated state is present, It is characterized by little change in pH even if a small amount of acid or base is mixed.
【００１４】本発明においては、研磨用組成物溶液の導
電率を高くすることにより、研磨加工速度を著しく向上
することができる。導電率とは液中の電気の通り易さを
示す数値であり、単位長さあたりの電気抵抗値の逆数の
数値である。本発明においては単位長あたりの導電率の
数値（ｍｉｃｒｏ・Ｓｉｅｍｅｎｓ）を酸化珪素１重量
％当りに換算した数値で示す。本発明においては導電率
が２３ｍＳ／ｍ／１％−ＳｉＯ2以上であれば良好な研
磨加工速度が得られ、３０ｍＳ／ｍ−ＳｉＯ2以上であ
れば更に好ましい。導電率を上昇させる方法としては、
次の二方法がある。一つは緩衝溶液の濃度を濃くする方
法、もう一つは塩類を添加する方法である。緩衝溶液の
濃度を濃くするには、（１）弱酸と強塩基、（２）強酸
と弱塩基、（３）弱酸と弱塩基、の何れかの組み合わせ
で、酸と塩基のモル比を変えずに濃度のみを濃くすれば
よい。塩類を添加する方法に用いる塩類は、酸と塩基の
組み合わせにより構成されるが、酸としては、強酸、弱
酸いずれであってもかまわず、鉱酸および、有機酸が使
用でき、またその混合物であっても良い。塩基として
は、強塩基、弱塩基いずれであっても良く、アルカリ金
属の水酸化物、水溶性の四級アンモニウムの水酸化物、
一価または二価の水溶性アミンが使用できその混合物で
あってもかまわない。弱酸と強塩基、強酸と弱塩基、弱
酸と弱塩基の組み合わせで添加する場合は、緩衝溶液の
ｐＨを変化させることがあるため、大量に添加すること
は望ましくない。前述の二方法を併用してもかまわな
い。In the present invention, the polishing rate can be significantly improved by increasing the conductivity of the polishing composition solution. The electrical conductivity is a numerical value indicating the ease of passing electricity in the liquid, and is a reciprocal of the electric resistance per unit length. In the present invention, the numerical value of the conductivity per unit length (micro-Siemens) is represented by a numerical value converted to 1% by weight of silicon oxide. In the present invention, if the conductivity is 23 mS / m / 1% -SiO 2 or more, a favorable polishing rate can be obtained, and more preferably 30 mS / m-SiO 2 or more. As a method of increasing the conductivity,
There are the following two methods. One is to increase the concentration of the buffer solution, and the other is to add salts. To increase the concentration of the buffer solution, use any combination of (1) a weak acid and a strong base, (2) a strong acid and a weak base, and (3) a weak acid and a weak base, without changing the molar ratio of the acid and the base. Only the density needs to be increased. Salts used in the method for adding salts are composed of a combination of an acid and a base.The acid may be a strong acid or a weak acid, and mineral acids and organic acids can be used. There may be. The base may be a strong base or a weak base, and may be an alkali metal hydroxide, a water-soluble quaternary ammonium hydroxide,
A monovalent or divalent water-soluble amine can be used, and a mixture thereof may be used. When adding a combination of a weak acid and a strong base, a strong acid and a weak base, or a combination of a weak acid and a weak base, the pH of the buffer solution may be changed. The above two methods may be used in combination.
【００１５】本発明の研磨組成物の物性を改良するた
め、研磨物の研磨表面の品質を向上させるため、界面活
性剤、分散剤、沈降防止剤などを併用することができ
る。界面活性剤、分散剤、沈降防止剤としては、水溶性
の有機物、無機層状化合物などがあげられる。また、本
発明の研磨組成物は水溶液としているが、有機溶媒を添
加してもかまわない。本発明の研磨組成物は、研磨時に
コロイダルシリカ及び、塩基と添加剤と水を混合して調
製してもよい。また、一般的にはコロイダルシリカとし
て、１５〜６５％の高濃度の組成物を調製しておき、水
あるいは、水と有機溶媒の混合物で希釈して使用するこ
とが多い。In order to improve the physical properties of the polishing composition of the present invention and to improve the quality of the polished surface of the polished material, a surfactant, a dispersant, an anti-settling agent and the like can be used in combination. Examples of the surfactant, dispersant, and antisettling agent include water-soluble organic substances and inorganic layered compounds. Although the polishing composition of the present invention is in the form of an aqueous solution, an organic solvent may be added. The polishing composition of the present invention may be prepared by mixing colloidal silica, a base, an additive and water during polishing. In general, a composition having a high concentration of 15 to 65% is prepared as colloidal silica, and is often used after being diluted with water or a mixture of water and an organic solvent.
【００１６】[0016]
【実施例】次に実施例及び比較例をあげて本発明の研磨
用組成物、およびそれを用いた研磨加工方法を具体的に
説明するが、特にこれにより限定を行なうものではな
い。実施例及び比較例において使用する研磨組成物は以
下の方法にて調製した。使用したアルミニウムで表面を
被覆した酸化珪素微粒子を含むコロイダルシリカは、平
均一次粒子径１５ｎｍ、濃度３０重量％の市販の製品で
ある。このコロイダルシリカ５００ｇを分取し、純水１
５００ｇを添加の後、撹拌しながら、酸及び塩基、塩類
を添加し純水で３０００ｇとして使用液とした。使用液
の状態で、液中の酸化珪素の濃度は５重量％である。研
磨条件は以下の方法で鏡面研磨加工を実施した。 研磨装置：スピードファム株式会社製、ＳＨ−２４型片面加工機 定盤回転数：７０ＲＰＭ プレッシャープレート回転数：５０ＲＰＭ 研磨布：ＳＵＢＡ４００（ロデールニッタ社製） 面圧力：４００ｇ／ｃｍ2 研磨組成物流量：８０ｍｌ／分 研磨時間：１０分 工作物：４インチシリコンウェーハ（エッチング後） 研磨速度は、研磨前後のシリコンウエハーの重量差より
求めた。研磨組成物のｐＨはｐＨメーターを用いて測定
した。測定にあたっては、ｐＨ６．８６と９．１８のｐ
Ｈ標準溶液であらかじめｐＨ電極の校正を行った後測定
した。導電率は導電率計にて測定した。研磨面の評価
は、集光灯下で肉眼にてヘイズ及びピットの状態を観察
した。EXAMPLES Next, the polishing composition of the present invention and the polishing method using the polishing composition of the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not particularly limited thereto. Polishing compositions used in Examples and Comparative Examples were prepared by the following methods. The used colloidal silica containing silicon oxide fine particles whose surface is coated with aluminum is a commercially available product having an average primary particle diameter of 15 nm and a concentration of 30% by weight. 500 g of this colloidal silica was fractionated, and purified water 1
After the addition of 500 g, an acid, a base and salts were added with stirring to make 3000 g with pure water to obtain a working solution. In the state of the used liquid, the concentration of silicon oxide in the liquid is 5% by weight. The polishing conditions were such that mirror polishing was performed by the following method. Polishing apparatus: Speed Fam Co., Ltd., SH-24 type single-side processing machine Surface plate rotation speed: 70 RPM Pressure plate rotation speed: 50 RPM Polishing cloth: SUBA400 (manufactured by Rodel Nitta) Surface pressure: 400 g / cm 2 Polishing composition flow rate: 80 ml / Min Polishing time: 10 minutes Workpiece: 4 inch silicon wafer (after etching) The polishing rate was determined from the difference in weight of the silicon wafer before and after polishing. The pH of the polishing composition was measured using a pH meter. In the measurement, pH 6.86 and 9.18 p
The measurement was performed after the pH electrode was previously calibrated with the H standard solution. The conductivity was measured with a conductivity meter. For evaluation of the polished surface, haze and pit states were observed with the naked eye under a condensing lamp.
【００１７】実施例１および比較例１ 本実施例中の実験番号１及び２においては、上述の調製
方法に準拠してアルミニウムで表面を被覆した酸化珪素
微粒子を含むコロイド状研磨用組成物の溶液を調整し、
それにピペリジンおよび塩酸（ＨＣｌ）を表１に示す処
方に従って添加し、本発明の研磨用組成物とした。比較
のために実験番号３においては水酸化テトラメチルアン
モニウム（ＴＭＡＯＨ）のみを加えたものを使用し、実
験番号４においては、別途、アミンとシリカゾルを含有
している市販のシリコンウエハー用研磨剤の酸化珪素濃
度を５重量％にまで純水で希釈したものを研磨用組成物
として用いた。上述の方法にて、液を１０回循環使用し
て研磨実験を行い各々の循環回数における研磨速度、ｐ
Ｈの変化、研磨面の表面状態を測定した。その結果を表
１に集約して示す。結果から明らかな通り、本発明の実
施例である実験番号１及び２においては、液の循環使用
を行ってもｐＨの変化は比較的緩やかであり研磨速度も
安定している。それに対し本発明の比較例である実験番
号３および４においては、循環使用における液のｐＨの
低下が顕著でありまたそれに従い、研磨速度の低下が顕
著に認められる。表面状態はいずれも良好であった。Example 1 and Comparative Example 1 In Experiment Nos. 1 and 2 in this example, a solution of a colloidal polishing composition containing silicon oxide fine particles whose surface was coated with aluminum according to the above-described preparation method was used. Adjust
Then, piperidine and hydrochloric acid (HCl) were added according to the formulation shown in Table 1 to obtain a polishing composition of the present invention. For comparison, in Experiment No. 3, the one to which only tetramethylammonium hydroxide (TMAOH) was added was used, and in Experiment No. 4, a polishing agent for a commercially available silicon wafer containing amine and silica sol was separately used. What was diluted with pure water to a silicon oxide concentration of 5% by weight was used as a polishing composition. In the above-described manner, a polishing experiment was performed using the liquid by circulating 10 times, and the polishing rate at each circulation number, p
The change in H and the surface condition of the polished surface were measured. The results are summarized in Table 1. As is evident from the results, in Experiment Nos. 1 and 2, which are examples of the present invention, the change in pH is relatively slow and the polishing rate is stable even when the liquid is circulated. On the other hand, in Experiment Nos. 3 and 4, which are comparative examples of the present invention, the pH of the liquid during recirculation is significantly reduced, and accordingly, the polishing rate is significantly reduced. The surface conditions were all good.
【００１８】[0018]
【表１】 [Table 1]
【００１９】実施例２ ピペリジン、アミノエチル−ピペリジン、ジエチレン−
トリアミンおよび塩酸（ＨＣｌ）を表２に示す組み合わ
せと量に基づいて、前記のアルミニウムで表面を被覆し
た酸化珪素微粒子を含むコロイド状研磨用組成物の溶液
に添加し、本発明の研磨用組成物とした。上述の方法に
て各々シリコンウェーハの研磨実験を行なった。本実施
例においては液の循環使用実験は行なわなかった。実験
結果を表２に集約して示す。Example 2 Piperidine, aminoethyl-piperidine, diethylene-
Triamine and hydrochloric acid (HCl) were added to a solution of a colloidal polishing composition containing fine particles of silicon oxide whose surface was coated with aluminum based on the combinations and amounts shown in Table 2, and the polishing composition of the present invention was added. And A polishing experiment was performed on each silicon wafer by the above-described method. In this example, no experiment was conducted to use the liquid in circulation. Table 2 summarizes the experimental results.
【００２０】[0020]
【表２】 [Table 2]
【００２１】比較例２ 実施例２と同様にして、添加剤の内容を表３に示す内容
として研磨用組成物溶液を調整した。実験番号９のもの
は緩衝作用を持たせずまた、導電率も低いもの、実験番
号１０〜１１ものは弱酸と強塩基、強酸と弱塩基あるい
は弱酸と弱塩基という組合わせをせずに、どちらか一方
の成分のみを加えた例である。実験番号１２においては
比較例１の実験番号４と同様、市販のシリコンウェーハ
用研磨剤の酸化珪素濃度を５重量％にまで純水で希釈し
たものを研磨用組成物として用いた。実施例２と同様に
シリコンウェーハの研磨実験を行なった。実験結果を表
３に集約して示す。Comparative Example 2 A polishing composition solution was prepared in the same manner as in Example 2 with the contents of the additives shown in Table 3. Experiment No. 9 has no buffering action and also has low conductivity, while Experiment Nos. 10 to 11 have no combination of weak acid and strong base, strong acid and weak base or weak acid and weak base. This is an example in which only one component is added. In Experiment No. 12, as in Experiment No. 4 of Comparative Example 1, a commercially available polishing agent for silicon wafers having a silicon oxide concentration diluted to 5% by weight with pure water was used as a polishing composition. A polishing experiment on a silicon wafer was performed in the same manner as in Example 2. The experimental results are summarized in Table 3.
【００２２】[0022]
【表３】 [Table 3]
【００２３】表２および表３の結果から明らかなよう
に、本発明の範囲内にあるものは良好な研磨速度を示す
が、比較例２に示すように単にｐＨのみを調整し緩衝作
用が不十分なものや、酸化珪素１重量％あたりの導電率
が２３ｍＳ／ｍ以下のものは研磨速度が十分でない。ま
た、実験例１３に見られるように塩を加えることにより
単に導電率を高くしたものも効果は認められない。As is clear from the results in Tables 2 and 3, those within the scope of the present invention show a good polishing rate, but as shown in Comparative Example 2, only the pH was adjusted and the buffer action was not effected. If the polishing rate is sufficient or the conductivity per 1% by weight of silicon oxide is 23 mS / m or less, the polishing rate is not sufficient. Further, as shown in Experimental Example 13, the effect of simply increasing the conductivity by adding a salt is not recognized.
【００２４】[0024]
【発明の効果】以上の説明で示される通り、本発明の研
磨組成物は、平均一次粒子径が８〜５００ｎｍであるア
ルミニウムで被覆された酸化珪素微粒子を含むコロイダ
ルシリカと、ｐＨが１０．７〜１２．５の間で緩衝溶液
を形成する酸及び塩基が含まれ、研磨時のシリカ濃度を
１〜１５重量％に調製した組成物で、研磨組成物を緩衝
溶液とすること、導電率を大きくすることで、ｐＨ変化
が少なく研磨速度が速い研磨組成物を形成している。本
発明の研磨組成物を使いシリコンウエハー、半導体デバ
イス基板を研磨表面の品質を落とさず、安定に高速研磨
する事が出来る。As described above, the polishing composition of the present invention comprises a colloidal silica containing silicon oxide fine particles coated with aluminum having an average primary particle diameter of 8 to 500 nm, a pH of 10.7. An acid and a base forming a buffer solution between 12.5 and 12.5 are included, and a silica concentration at the time of polishing is adjusted to 1-15% by weight. By increasing the value, a polishing composition having a small pH change and a high polishing rate is formed. Using the polishing composition of the present invention, silicon wafers and semiconductor device substrates can be stably polished at high speed without deteriorating the quality of the polished surface.
Claims (5)
子径が８〜５００ｎｍの酸化珪素粒子を１〜１５重量％
含むコロイドからなり、該コロイド溶液が、２５℃にお
ける酸解離定数の逆数の対数値が１０．０〜１２．５の
弱酸及び／または、弱塩基を使用して、弱酸と強塩基、
強酸と弱塩基、弱酸と弱塩基何れかの組み合わせのもの
を添加することによって、ｐＨ１０．７〜１２．５の間
で緩衝作用を有する緩衝溶液として調整されたものであ
ることを特徴とする研磨用組成物。1 to 15% by weight of silicon oxide particles having an average primary particle diameter of 8 to 500 nm, the surface of which is coated with aluminum.
A weak acid and / or a strong base using a weak acid and / or a weak base having a logarithm of the reciprocal of the acid dissociation constant at 25 ° C. of 10.0 to 12.5.
Polishing characterized by being prepared as a buffer solution having a buffering action between pH 10.7-12.5 by adding a combination of a strong acid and a weak base, or a combination of a weak acid and a weak base. Composition.
％あたり２３ｍＳ／ｍ以上であることを特徴とする請求
項第１項記載の研磨用組成物。2. The polishing composition according to claim 1, wherein the conductivity at 25 ° C. is at least 23 mS / m per 1% by weight of silicon oxide.
加することにより、２５℃における導電率が、酸化珪素
１重量％あたり２３ｍＳ／ｍ以上である請求項第３項記
載の研磨用組成物を調整する方法。3. The polishing composition according to claim 3, wherein the conductivity at 25 ° C. is at least 23 mS / m per 1% by weight of silicon oxide by increasing the concentration of the solution or adding salts. How to adjust.
子径が８〜５００ｎｍの酸化珪素粒子を１５〜６５重量
％含むコロイド溶液からなり、該コロイド溶液が、２５
℃における酸解離定数の逆数の対数値が１０．０〜１
２．５の弱酸及び／または、弱塩基を使用して、弱酸と
強塩基、強酸と弱塩基、弱酸と弱塩基何れかの組み合わ
せのものを添加することによりｐＨの緩衝作用を有する
緩衝溶液としたものを、水、有機溶剤、塩類等を含んだ
溶液あるいはその混合物によって希釈することにより請
求項第１項に記載の研磨用組成物を調整する方法。4. A colloidal solution containing 15 to 65% by weight of silicon oxide particles whose surface is coated with aluminum and having an average primary particle diameter of 8 to 500 nm.
The logarithmic value of the reciprocal of the acid dissociation constant at ℃ is 10.0 to 1
Using a weak acid and / or a weak base of 2.5 and adding a weak acid and a strong base, a strong acid and a weak base, or a combination of a weak acid and a weak base; The method for preparing the polishing composition according to claim 1, wherein the composition is diluted with a solution containing water, an organic solvent, salts, or the like or a mixture thereof.
体、合成皮革あるいは不織布等からなるポリッシャーを
貼付した回転可能な定盤を有する研磨加工機に、工作物
であるシリコンウェーハ等を載置押圧し、請求項第１項
ないし請求項第３項に記載の研磨用組成物を供給しつ
つ、前記定盤及び工作物の双方あるいはその一方を回転
することにより、前記工作物の研磨加工を行なう方法。5. A silicon wafer or the like, which is a workpiece, is placed and pressed on a polishing machine having a rotatable platen having a polisher made of synthetic resin foam, synthetic leather or non-woven fabric adhered to both upper and lower surfaces or one surface. The workpiece is polished by rotating the platen and / or one of the workpieces while supplying the polishing composition according to any one of claims 1 to 3. Method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10115291A JPH11302635A (en) | 1998-04-24 | 1998-04-24 | Polishing composition and method for polishing using it |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10115291A JPH11302635A (en) | 1998-04-24 | 1998-04-24 | Polishing composition and method for polishing using it |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11302635A true JPH11302635A (en) | 1999-11-02 |
Family
ID=14659029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10115291A Pending JPH11302635A (en) | 1998-04-24 | 1998-04-24 | Polishing composition and method for polishing using it |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH11302635A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6827639B2 (en) | 2002-03-27 | 2004-12-07 | Catalysts & Chemicals Industries Co., Ltd. | Polishing particles and a polishing agent |
| JP2006093655A (en) * | 2004-08-24 | 2006-04-06 | Disco Abrasive Syst Ltd | Polishing solution and polishing equipment |
| WO2006059537A1 (en) | 2004-12-01 | 2006-06-08 | Shin-Etsu Handotai Co., Ltd. | Process for producing abrasive material, abrasive material produced by the same, and process for producing silicon wafer |
| CN1322087C (en) * | 2002-03-29 | 2007-06-20 | 日本化学工业株式会社 | Composition for grinding agent and making-up method thereof |
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1998
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6827639B2 (en) | 2002-03-27 | 2004-12-07 | Catalysts & Chemicals Industries Co., Ltd. | Polishing particles and a polishing agent |
| CN1322087C (en) * | 2002-03-29 | 2007-06-20 | 日本化学工业株式会社 | Composition for grinding agent and making-up method thereof |
| JP2006093655A (en) * | 2004-08-24 | 2006-04-06 | Disco Abrasive Syst Ltd | Polishing solution and polishing equipment |
| WO2006059537A1 (en) | 2004-12-01 | 2006-06-08 | Shin-Etsu Handotai Co., Ltd. | Process for producing abrasive material, abrasive material produced by the same, and process for producing silicon wafer |
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