JPH08148455A - Surface flattening method for thin film - Google Patents
Surface flattening method for thin filmInfo
- Publication number
- JPH08148455A JPH08148455A JP19417794A JP19417794A JPH08148455A JP H08148455 A JPH08148455 A JP H08148455A JP 19417794 A JP19417794 A JP 19417794A JP 19417794 A JP19417794 A JP 19417794A JP H08148455 A JPH08148455 A JP H08148455A
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- Prior art keywords
- polishing
- abrasive
- abrasive grains
- sio
- ceo
- Prior art date
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- Weting (AREA)
- Mechanical Treatment Of Semiconductor (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は薄膜の表面平坦化方法に
関し、より詳細には、半導体装置を製造する過程におけ
る凹凸を有する薄膜の表面を、研磨により平坦化するた
めの薄膜の表面平坦化方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for flattening the surface of a thin film, and more particularly, to flattening the surface of a thin film having unevenness in the process of manufacturing a semiconductor device by polishing. Regarding the method.
【０００２】[0002]
【従来の技術】半導体集積回路の高集積化、高速化にと
もない配線の微細化、多層化が進んでいる。配線を微細
化するために、良好な寸法精度が得られる異方性エッチ
ングがパターン形成に多く用いられており、この場合、
基板上における第１層目の配線パターンに関する微細化
はある程度容易に図れるが、基板上における配線パター
ンの段差は急峻となる。次に該急峻な段差を有する第１
層目の配線パターン上に層間絶縁膜を形成した場合、こ
の層間絶縁膜の表面にも段差（凹凸）が生じ、さらに該
層間絶縁膜上に第２層目の配線パターンを形成して多層
化を図った場合、この第２層目の配線パターン自体も段
差を有するようになる。このように段差が生じたものに
フォトリソグラフィプロセスを施すと、焦点深度の限界
からパターン解像度が悪化し、第２層目以降の配線パタ
ーンにおける微細化・高精度化を図ることが難しいとい
う問題があった。また成膜プロセスの際、段部では膜厚
が薄くなり易いため、この部分で配線が断線するおそれ
があるという問題があった。また段差により実効的な配
線長が増加することとなり、その結果、配線抵抗や配線
容量が増大するという問題もあった。2. Description of the Related Art As semiconductor integrated circuits become highly integrated and operate at high speed, wirings are becoming finer and multilayered. In order to miniaturize the wiring, anisotropic etching is often used for pattern formation, which gives good dimensional accuracy.
Although the miniaturization of the first layer wiring pattern on the substrate can be easily achieved to some extent, the step of the wiring pattern on the substrate becomes steep. Next, the first having the steep step
When an interlayer insulating film is formed on the wiring pattern of the first layer, a step (unevenness) is also generated on the surface of the interlayer insulating film, and a wiring pattern of the second layer is further formed on the interlayer insulating film to form a multilayer structure. In this case, the wiring pattern itself of the second layer also has a step. When the photolithography process is applied to a step having such a step, the pattern resolution deteriorates due to the limit of the depth of focus, and it is difficult to achieve miniaturization and high accuracy in the wiring patterns of the second and subsequent layers. there were. Further, during the film forming process, the film thickness is likely to be thin in the step portion, so that there is a problem that the wiring may be broken in this portion. Further, there is a problem that the effective wiring length increases due to the step, and as a result, the wiring resistance and wiring capacitance increase.
【０００３】上記したように、半導体装置表面の段差、
とりわけ多層配線の層間絶縁膜における段差の平坦化は
非常に重要な技術であり、多くの方法が開発されてい
る。As described above, a step on the surface of the semiconductor device,
In particular, flattening the steps in the interlayer insulating film of the multi-layer wiring is a very important technique, and many methods have been developed.
【０００４】層間絶縁膜の平坦化方法として、自己平坦
性を有するＴＥＯＳ（Tetra EthoxyOrtho Silicate)−
ＣＶＤ（Chemical Vapor Deposition)によるＳｉＯ2 の
成膜方法が広く用いられているが、配線間隔が大きい等
の際には完全な平坦表面を得ることは困難であった。こ
のような場合、ＴＥＯＳを用いた方法により形成された
層間絶縁膜上にフォトレジストや有機樹脂膜等を塗布
し、これらの膜と前記層間絶縁膜とを同一速度でエッチ
ングするいわゆるエッチバック方法を併用することが多
い。しかし、２つの異なる物質を同一速度でエッチング
することは難しく、完全な平坦化を図ることは困難であ
った。TEOS (Tetra EthoxyOrtho Silicate) having self-flatness is used as a method of flattening an interlayer insulating film.
Although a SiO 2 film forming method by CVD (Chemical Vapor Deposition) is widely used, it is difficult to obtain a completely flat surface when the wiring interval is large. In such a case, there is a so-called etch-back method in which a photoresist, an organic resin film, or the like is applied on the interlayer insulating film formed by the method using TEOS, and these films and the interlayer insulating film are etched at the same rate. Often used together. However, it is difficult to etch two different substances at the same rate, and it is difficult to achieve complete planarization.
【０００５】これらの問題を解決するため、研磨による
平坦化方法が提案され始めている。図２は従来のこの種
研磨による平坦化方法を説明するために示した製造過程
中における半導体装置の模式的断面図であり、図中３１
は基板を示している。基板３１上には酸化膜３２が形成
され、酸化膜３２上にはポリシリコン膜３３が形成され
ており、基板３１、酸化膜３２、ポリシリコン膜３３を
覆うように、第１層目の層間絶縁膜としてのＳｉＯ2 膜
３４が形成されている。ＳｉＯ2 膜３４にはポリシリコ
ン膜３３と導通するコンタクトホール３５が形成されて
いる。コンタクトホール３５内及びその上方と、ＳｉＯ
2 膜３４上の所定箇所とには第１層目の配線としてのア
ルミニウム層３６が形成されており、アルミニウム層３
６及びＳｉＯ2 膜３４上には、これらを覆うようにして
第２層目の層間絶縁膜としてのＳｉＯ2 膜３７が形成さ
れている。段差３６ａ、３６ｂを有するアルミニウム層
３６の上方に位置するＳｉＯ2 膜３７の表面には比較的
広い凸部３７ａ、狭い凸部３７ｂや比較的狭い凹部３７
ｃが生じており、アルミニウム層３６が形成されていな
いＳｉＯ2 膜３４の上方に位置するＳｉＯ2 膜３７の表
面には比較的広い凹部３７ｄが発生している。これら基
板３１、アルミニウム層３６、ＳｉＯ2 膜３４、３７等
により、製造過程中の半導体装置３０が構成されてい
る。In order to solve these problems, a flattening method by polishing has been proposed. FIG. 2 is a schematic cross-sectional view of the semiconductor device during the manufacturing process shown for explaining the conventional flattening method by this type of polishing.
Indicates the substrate. An oxide film 32 is formed on the substrate 31, and a polysilicon film 33 is formed on the oxide film 32. The first layer interlayer is formed so as to cover the substrate 31, the oxide film 32, and the polysilicon film 33. A SiO 2 film 34 as an insulating film is formed. A contact hole 35 is formed in the SiO 2 film 34 so as to be electrically connected to the polysilicon film 33. In and above the contact hole 35, SiO
An aluminum layer 36 as a first-layer wiring is formed at a predetermined position on the 2 film 34.
6 and the SiO 2 film 34, a SiO 2 film 37 is formed as a second interlayer insulating film so as to cover them. On the surface of the SiO 2 film 37 located above the aluminum layer 36 having the steps 36a and 36b, a relatively wide convex portion 37a, a narrow convex portion 37b and a relatively narrow concave portion 37 are formed.
c is generated, and a relatively wide recess 37d is formed on the surface of the SiO 2 film 37 located above the SiO 2 film 34 where the aluminum layer 36 is not formed. The substrate 31, the aluminum layer 36, the SiO 2 films 34, 37 and the like constitute the semiconductor device 30 in the manufacturing process.
【０００６】このように構成された半導体装置３０にお
いて、鎖線３８で示した箇所を平坦化する場合、ＳｉＯ
2 粒子と弱アルカリ溶液との混合物と、ポリウレタン系
の布とを用い、ＳｉＯ2 膜３７の凸部３７ａ、３７ｂ、
凹部３７ｃを研磨により除去する平坦化法が開示されて
いる（特開昭５９−１３６９３４号公報）。In the semiconductor device 30 having the above structure, when the portion shown by the chain line 38 is flattened, SiO 2 is used.
Using a mixture of 2 particles and a weak alkaline solution and a polyurethane cloth, the protrusions 37a, 37b of the SiO 2 film 37,
A flattening method is disclosed in which the recess 37c is removed by polishing (JP-A-59-136934).
【０００７】また、図３は従来の別の研磨による平坦化
方法（特開昭６２−１０２５４３号公報）を説明するた
めに示した製造過程中における半導体装置の模式的断面
図であり、図中４１は基板を示している。基板４１上の
所定箇所には配線としての導電性金属層４２がパターン
化して形成され、基板４１及び導電性金属層４２上には
層間絶縁膜としてのＳｉＯ2 膜４３が形成されている。
導電性金属層４２は急峻な段差４２ａ、４２ｂ、４２ｃ
を有しており、これら段差４２ａ、４２ｂ、４２ｃを有
する導電性金属層４２の上方におけるＳｉＯ2 膜４３の
表面には凸部４３ａ、４３ｂが生じている。これら基板
４１、導電性金属層４２、ＳｉＯ2 膜４３により、製造
過程中の半導体装置４０が構成されている。FIG. 3 is a schematic cross-sectional view of the semiconductor device during the manufacturing process shown for explaining another conventional flattening method by polishing (Japanese Patent Laid-Open No. 62-102543). Reference numeral 41 indicates a substrate. A conductive metal layer 42 as a wiring is patterned and formed at a predetermined position on the substrate 41, and a SiO 2 film 43 as an interlayer insulating film is formed on the substrate 41 and the conductive metal layer 42.
The conductive metal layer 42 has steep steps 42a, 42b, 42c.
And the convex portions 43a and 43b are formed on the surface of the SiO 2 film 43 above the conductive metal layer 42 having the steps 42a, 42b and 42c. The substrate 41, the conductive metal layer 42, and the SiO 2 film 43 form a semiconductor device 40 during the manufacturing process.
【０００８】このように構成された半導体装置４０にお
いて、鎖線４４で示した箇所を平坦化する場合、研磨材
料とポリエステル製の研磨パッドとを用い、ＳｉＯ2 膜
４３の凸部４３ａ、４３ｂ及び導電性金属層４２上部を
研磨により除去する。研磨材料にｐＨが約１１〜１１．
５の水酸化カリウム（以下、ＫＯＨと記す）溶液とＳｉ
Ｏ2 粒子との混合物を用いると、導電性金属層４２が保
護膜になるとともにＳｉＯ2 膜４３が選択的に研磨され
る。In the semiconductor device 40 having such a structure, when flattening the portion indicated by the chain line 44, a polishing material and a polishing pad made of polyester are used, and the projections 43a and 43b of the SiO 2 film 43 and the conductive material are formed. The upper part of the conductive metal layer 42 is removed by polishing. The polishing material has a pH of about 11-11.
5 potassium hydroxide (hereinafter referred to as KOH) solution and Si
When a mixture with O 2 particles is used, the conductive metal layer 42 serves as a protective film and the SiO 2 film 43 is selectively polished.
【０００９】また、図４は従来のさらに別の研磨による
平坦化方法（Y. Hayashi et al, Extended Abstracts o
f the 1992 International Conference on Solid State
Devices and Materials, pp.533-535) を説明するため
に示した製造過程中における半導体装置の模式的断面図
であり、図中５１は基板を示している。基板５１上の所
定箇所にはキャパシタ５２が形成され、基板５１及びキ
ャパシタ５２の上には層間絶縁膜としてのＢＰＳＧ（Bo
ro Phospho Silicate Glass)膜５３が形成されている。
急峻な段差５２ａを有するキャパシタ５２の上方に位置
するＢＰＳＧ膜５３の表面には凸部５３ａが生じてお
り、キャパシタ５２が形成されていない基板５１の上方
に位置するＢＰＳＧ膜５３の表面には凹部５３ｂが発生
している。さらにＢＰＳＧ膜５３の表面にはＳｉ3 Ｎ4
膜（凹部５３ｂ内のＳｉ3 Ｎ4 膜５４のみを図示し、凸
部５３ａ上のＳｉ3 Ｎ4 膜は図示せず）が形成されてい
る。これら基板５１、キャパシタ５２、ＢＰＳＧ膜５
３、前記Ｓｉ3 Ｎ4 膜により、半導体装置５０が構成さ
れている。Further, FIG. 4 shows another conventional flattening method by polishing (Y. Hayashi et al, Extended Abstracts o.
f the 1992 International Conference on Solid State
(Devices and Materials, pp.533-535), which is a schematic cross-sectional view of the semiconductor device during the manufacturing process shown for the purpose of explaining (Devices and Materials, pp.533-535). A capacitor 52 is formed at a predetermined position on the substrate 51, and BPSG (Bo as an interlayer insulating film is formed on the substrate 51 and the capacitor 52.
A ro Phospho Silicate Glass) film 53 is formed.
A convex portion 53a is formed on the surface of the BPSG film 53 located above the capacitor 52 having the steep step 52a, and a concave portion is formed on the surface of the BPSG film 53 located above the substrate 51 where the capacitor 52 is not formed. 53b has occurred. Furthermore, Si 3 N 4 is formed on the surface of the BPSG film 53.
A film (only the Si 3 N 4 film 54 in the concave portion 53b is shown, and the Si 3 N 4 film on the convex portion 53a is not shown) is formed. These substrate 51, capacitor 52, BPSG film 5
3. The semiconductor device 50 is composed of the Si 3 N 4 film.
【００１０】このように構成された半導体装置５０にお
いて、鎖線５５で示した箇所を平坦化する場合、まずフ
ォトリソグラフィーとエッチングにより、凸部５３ａ上
のＳｉ3 Ｎ4 膜を除去し、図４に示した状態にする。そ
の後、凹部５３ｂ内に残存しているＳｉ3 Ｎ4 膜５４を
保護膜として利用し、コロイダルシリカスラリを用いて
ＢＰＳＧ膜５３の凸部５３ａを研磨により除去する。In the semiconductor device 50 having such a structure, when the portion indicated by the chain line 55 is to be flattened, first, the Si 3 N 4 film on the convex portion 53a is removed by photolithography and etching. Put in the state shown. After that, the Si 3 N 4 film 54 remaining in the recesses 53b is used as a protective film, and the protrusions 53a of the BPSG film 53 are removed by polishing using colloidal silica slurry.
【００１１】また、ガラス材料を研磨する際、酸化セリ
ウム（以下、ＣｅＯ2 と記す）粒子を水等の溶液に分散
させた砥粒液を用いると、ＳｉＯ2 砥粒液に比べて研磨
速度が速くなることが従来から知られている（特開平３
−１４６５８５号公報）。Further, when polishing a glass material, if an abrasive grain liquid in which cerium oxide (hereinafter referred to as CeO 2 ) particles are dispersed in a solution such as water is used, the polishing rate is higher than that of the SiO 2 abrasive grain liquid. It has been conventionally known that the speed becomes faster (Japanese Patent Laid-Open No. Hei 3)
No. 146585).
【００１２】[0012]
【発明が解決しようとする課題】半導体装置の平坦化工
程に研磨を用いる場合、生産効率上スループットが大き
いことが必要であり、約１μｍの段差を有する薄膜を平
坦化するには約３分程度の時間内で研磨できることが望
ましく、すなわち３０００Å／ｍｉｎ以上の研磨速度が
要求されている。When polishing is used in the planarization process of a semiconductor device, it is necessary to have a high throughput in terms of production efficiency, and it takes about 3 minutes to planarize a thin film having a step of about 1 μm. It is desirable that polishing can be performed within the above time, that is, a polishing rate of 3000 Å / min or more is required.
【００１３】しかし、上記の図２に示した薄膜の表面平
坦化方法においては、直径が約０．０１μｍのＳｉＯ2
粒子を弱アルカリ溶液に懸濁させた砥粒液を用いると、
研磨速度は約１００Å／ｍｉｎであり、生産効率が極め
て悪いという課題があった。However, in the method of flattening the surface of the thin film shown in FIG. 2, the SiO 2 having a diameter of about 0.01 μm is used.
With an abrasive solution in which particles are suspended in a weak alkaline solution,
The polishing rate was about 100Å / min, and there was a problem that the production efficiency was extremely poor.
【００１４】また上記の図３に示した薄膜の表面平坦化
方法においては、直径が約０．０６μｍのアルミナを弱
酸に懸濁させた砥粒液を用いると、研磨速度は８０〜４
２５Å／ｍｉｎであり、やはり生産効率が悪いという課
題があった。Further, in the method of flattening the surface of the thin film shown in FIG. 3 described above, the polishing rate is 80 to 4 when the abrasive grain liquid in which alumina having a diameter of about 0.06 μm is suspended in a weak acid is used.
It was 25 Å / min, and there was a problem that the production efficiency was still poor.
【００１５】また上記の図４に示した薄膜の表面平坦化
方法においては、研磨速度が約１５００Å／ｍｉｎに達
するものの３０００Å／ｍｉｎには程遠く、やはり生産
効率がまだ悪いという課題があった。Further, in the method of flattening the surface of the thin film shown in FIG. 4, although the polishing rate reaches about 1500 Å / min, it is far from 3000 Å / min, and the production efficiency is still poor.
【００１６】また上記したＣｅＯ2 粒子を分散させた砥
粒液を用いる研磨方法においては、研磨終了面にＣｅＯ
2 が凝着して洗浄することが難しく、パーティクルが残
存し易くなり、ガラス研磨技術をそのまま半導体装置の
製造工程に導入することは困難であるという課題があっ
た。Further, in the polishing method using the abrasive liquid in which CeO 2 particles are dispersed, in the polishing end surface, CeO
However, there is a problem that it is difficult to introduce the glass polishing technique as it is into the manufacturing process of the semiconductor device, because the particles of No. 2 adhere to each other and are difficult to wash.
【００１７】本発明はこのような課題に鑑みなされたも
のであり、研磨速度を速めることができるとともに、パ
ーティクルの残存を抑制することができる薄膜の表面平
坦化方法を提供することを目的としている。The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for flattening the surface of a thin film, which can increase the polishing rate and can suppress the particles from remaining. .
【００１８】[0018]
【課題を解決するための手段】上記目的を達成するため
に本発明に係る薄膜の表面平坦化方法は、ＳｉＯ2 、Ａ
ｌ2 Ｏ3 もしくはコロイダルシリカ砥粒の少なくとも１
種以上の砥粒とＣｅＯ2 砥粒とを含む砥粒液を用い、研
磨により平坦化することを特徴としている。In order to achieve the above-mentioned object, a method of flattening the surface of a thin film according to the present invention comprises SiO 2 , A
l 2 O 3 or at least one of colloidal silica abrasive grains
It is characterized by using an abrasive liquid containing at least one kind of abrasive grains and CeO 2 abrasive grains and flattening by polishing.
【００１９】また、前記したＳｉＯ2 、Ａｌ2 Ｏ3 もし
くはコロイダルシリカ砥粒の少なくとも１種以上の砥粒
の濃度は０．５％以上であり、かつ前記したＳｉＯ2 、
Ａｌ2 Ｏ3 もしくはコロイダルシリカ砥粒の少なくとも
１種以上の砥粒と前記ＣｅＯ2 砥粒との濃度は５０％以
下であることが好ましい。The concentration of at least one of the above-mentioned SiO 2 , Al 2 O 3 or colloidal silica abrasive grains is 0.5% or more, and the above-mentioned SiO 2 ,
The concentration of at least one kind of Al 2 O 3 or colloidal silica abrasive grains and the CeO 2 abrasive grains is preferably 50% or less.
【００２０】さらには、前記したＳｉＯ2 、Ａｌ2 Ｏ3
もしくはコロイダルシリカ砥粒の少なくとも１種以上の
砥粒の濃度及び前記ＣｅＯ2 砥粒の濃度は、下記の表６
〜表１０におけるパーティクル数が数十個以下となる範
囲が望ましい。Further, the above-mentioned SiO 2 , Al 2 O 3
Alternatively, the concentration of at least one kind of colloidal silica abrasive grains and the concentration of the CeO 2 abrasive grains are shown in Table 6 below.
~ The range in which the number of particles in Table 10 is several tens or less is desirable.
【００２１】なお、前記濃度は（前記砥粒の重量／砥粒
液重量）×１００、また該砥粒液重量は前記各砥粒の合
計重量に純水重量（化学成分を含有する場合は該化学成
分を含む液重量）を加えた重量として定義した。The above concentration is (weight of the abrasive grains / weight of the abrasive liquid) × 100, and the weight of the abrasive liquid is the weight of pure water in the total weight of each of the abrasive grains (if a chemical component is contained, It was defined as the weight including the liquid weight containing the chemical components).
【００２２】[0022]
【作用】本発明に係る薄膜の表面平坦化方法によれば、
ＣｅＯ2 砥粒を含む砥粒液を用い、研磨により平坦化す
るので、砥粒液中に存在する前記ＣｅＯ2 砥粒により研
磨速度を速め得ることとなる。一方、前記砥粒液中に存
在する前記ＳｉＯ2 、Ａｌ2 Ｏ3 もしくはコロイダルシ
リカ砥粒の少なくとも１種以上の砥粒により、研磨の際
に研磨面に凝着しようとする前記ＣｅＯ2 砥粒分を連続
的に除去し得ることとなり、研磨終了後における前記研
磨面には前記ＣｅＯ2 砥粒分がほとんど残存しないこと
となる。他方、研磨終了後の前記研磨面に残存する前記
ＳｉＯ2 、Ａｌ2 Ｏ3 もしくはコロイダルシリカ砥粒分
は、研磨終了後に行う洗浄工程によりそれぞれ容易に除
去される。したがってこれら砥粒の複合作用により清浄
な研磨面が得られ、この結果パーティクルの残存を抑制
し得るとともに、研磨速度を速め得ることとなる。According to the thin film surface flattening method of the present invention,
Since an abrasive liquid containing CeO 2 abrasive grains is used to flatten the surface by polishing, the polishing rate can be increased by the CeO 2 abrasive grains present in the abrasive liquid. On the other hand, the CeO 2 abrasive grains which are to be adhered to the polishing surface at the time of polishing by at least one kind of the abrasive grains of SiO 2 , Al 2 O 3 or colloidal silica abrasive grains present in the abrasive grain liquid. As a result, the CeO 2 abrasive grains are scarcely left on the polished surface after the polishing is completed. On the other hand, the SiO 2 , Al 2 O 3 or colloidal silica abrasive grains remaining on the polished surface after polishing is easily removed by a cleaning step performed after polishing. Therefore, a clean polishing surface can be obtained by the combined action of these abrasive grains, and as a result, the particles can be suppressed from remaining and the polishing rate can be increased.
【００２３】また、前記ＳｉＯ2 、Ａｌ2 Ｏ3 もしくは
コロイダルシリカ砥粒の少なくとも１種以上の砥粒の濃
度が０．５％以上であり、かつ前記ＳｉＯ2 、Ａｌ2 Ｏ
3 もしくはコロイダルシリカ砥粒の少なくとも１種以上
の砥粒と前記ＣｅＯ2 砥粒との濃度が５０％以下である
場合には、前記ＣｅＯ2 砥粒等が凝集して固まるのを阻
止して前記砥粒液の取り扱いを容易にし得ることとな
り、また砥粒材料費を削減し得ることとなる。Further, the concentration of at least one kind of the above-mentioned SiO 2 , Al 2 O 3 or colloidal silica abrasive grains is 0.5% or more, and the above-mentioned SiO 2 , Al 2 O grains are contained.
When the concentration of at least one kind of 3 or colloidal silica abrasive grains and the CeO 2 abrasive grains is 50% or less, the CeO 2 abrasive grains are prevented from coagulating and solidifying. The abrasive grain liquid can be easily handled, and the abrasive grain material cost can be reduced.
【００２４】また、前記ＳｉＯ2 、Ａｌ2 Ｏ3 もしくは
コロイダルシリカ砥粒の少なくとも１種以上の砥粒の濃
度及び前記ＣｅＯ2 砥粒の濃度が、下記の表６〜表１０
におけるパーティクル数が数十個以下となる範囲である
場合には、研磨速度を十分に高め得るとともに、研磨の
際に前記ＣｅＯ2 砥粒分が研磨面に凝着するのをより一
層防止し得ることとなり、研磨終了後における前記研磨
面をより一層清浄なものにしてパーティクルの発生をよ
り一層抑制し得ることとなる。The concentration of at least one of the above-mentioned SiO 2 , Al 2 O 3 or colloidal silica abrasive grains and the concentration of the above CeO 2 abrasive grains are shown in Tables 6 to 10 below.
When the number of particles in the above is in the range of several tens or less, it is possible to sufficiently increase the polishing rate, and it is possible to further prevent the CeO 2 abrasive grains from adhering to the polishing surface during polishing. As a result, it is possible to further clean the polished surface after completion of polishing and further suppress the generation of particles.
【００２５】[0025]
【実施例及び比較例】以下、本発明に係る薄膜の表面平
坦化方法の実施例を図面に基づいて説明する。EXAMPLES AND COMPARATIVE EXAMPLES Examples of the method for flattening the surface of a thin film according to the present invention will be described below with reference to the drawings.
【００２６】図１は本実施例に係る薄膜の表面平坦化方
法を施す前後の試料の状態を示した模式的断面図であ
り、（ａ）はシリコンウエハ上に配線パターンを形成
し、この配線の上面に絶縁膜を形成した状態、（ｂ）は
研磨により絶縁膜表面の段差を除去し、表面を平坦化し
た状態を示している。薄膜の平坦化方法により半導体装
置表面の凹凸を平坦化するには、まず例えばスパッタ法
等によりシリコンウエハ１１上にＡｌ配線材料としての
金属膜（図示せず）を形成し、次にフォトリソグラフィ
技術によりパターニング処理を施して配線１２を形成す
る。この後ＥＣＲ−ＣＶＤ法等により配線１２上にＳｉ
Ｏ2 膜等の絶縁膜１３を形成する（ａ）。この状態にお
ける絶縁膜１３上部には、配線１２パターンに対応して
凹部１２ａと凸部１２ｂとが生じている。次に絶縁膜１
３の凸部１３ｂを研磨により除去し、全体的に平坦１３
ｃにする。この研磨の際、ＳｉＯ2 、Ａｌ2 Ｏ3 もしく
はコロイダルシリカ砥粒の少なくとも１種以上の砥粒と
ＣｅＯ2 砥粒とを含む砥粒液を使用する（ｂ）。FIG. 1 is a schematic cross-sectional view showing the state of a sample before and after the method of flattening the surface of a thin film according to this embodiment. FIG. 1A shows a wiring pattern formed on a silicon wafer. 2B shows a state in which an insulating film is formed on the upper surface of FIG. 2B, and FIG. 6B shows a state in which the steps on the surface of the insulating film are removed by polishing to flatten the surface. In order to flatten the unevenness on the surface of the semiconductor device by the thin film flattening method, first, a metal film (not shown) as an Al wiring material is formed on the silicon wafer 11 by, for example, the sputtering method, and then the photolithography technique is used. A patterning process is performed to form the wiring 12. After that, Si is formed on the wiring 12 by ECR-CVD method or the like.
An insulating film 13 such as an O 2 film is formed (a). In this state, a concave portion 12a and a convex portion 12b are formed on the insulating film 13 corresponding to the wiring 12 pattern. Next, the insulating film 1
The convex portion 13b of No. 3 was removed by polishing, and the entire surface was flat.
Set to c. In this polishing, an abrasive liquid containing at least one kind of SiO 2 , Al 2 O 3 or colloidal silica abrasive and CeO 2 abrasive is used (b).
【００２７】以下に、通常用いられる研磨装置を使用
し、下記の表１に示した砥粒を純水中に所定量混合した
砥粒液を用いて研磨を行った場合における研磨速度と、
洗浄後のパーティクル数を測定した結果について説明す
る。ＣｅＯ2 、ＳｉＯ2 、Ａｌ2 Ｏ3 の各砥粒は平均粒
径がそれぞれ約０．２μｍのものを用いた。またサンプ
ルとしてはＥＣＲ−ＣＶＤ法により厚さが約１μｍのＳ
ｉＯ2 膜を形成した直径が約６インチのシリコンウエハ
１１を用いた。そして圧力が１００ｇ／ｃｍ2 、研磨定
盤の周速をシリコンウエハ１１に対する相対速度が６０
ｃｍ／ｓｅｃとなる周速にして約３分間研磨を行い、研
磨速度を計測した。この後、約１分間のスクラブ洗浄及
び約１分間のメガソニック洗浄処理を施し、６インチの
前記ウエハ上における約０．２μｍ以上のパーティクル
数をパーティクルカウンターにて測定した。なお比較例
１としてＣｅＯ2 砥粒のみを純水中に所定量混合した砥
粒液、比較例２としてＳｉＯ2 砥粒のみを純水中に混合
したもの、比較例３としてＡｌ2 Ｏ3 砥粒のみを純水中
に混合したもの、比較例４としてコロイダルシリカ砥粒
のみを純水中に混合したものを用い、それぞれ研磨した
場合について併せ説明する。The polishing rate in the case where polishing is carried out by using a polishing apparatus which is usually used, and polishing is carried out by using an abrasive liquid obtained by mixing a predetermined amount of the abrasive particles shown in Table 1 below in pure water,
The result of measuring the number of particles after cleaning will be described. The CeO 2 , SiO 2 , and Al 2 O 3 abrasive grains each had an average grain size of about 0.2 μm. As a sample, an SCR having a thickness of about 1 μm was formed by the ECR-CVD method.
A silicon wafer 11 having a diameter of about 6 inches on which an iO 2 film was formed was used. The pressure is 100 g / cm 2 , and the peripheral speed of the polishing platen is 60 relative to the silicon wafer 11.
Polishing was performed for about 3 minutes at a peripheral speed of cm / sec, and the polishing rate was measured. After that, scrub cleaning for about 1 minute and megasonic cleaning processing for about 1 minute were performed, and the number of particles of about 0.2 μm or more on the 6-inch wafer was measured with a particle counter. As Comparative Example 1, a CeO 2 abrasive grain mixed with a predetermined amount in pure water, as Comparative Example 2, only SiO 2 abrasive grain mixed in pure water, and as Comparative Example 3 Al 2 O 3 abrasive. A case in which only particles are mixed in pure water and a case in which only colloidal silica abrasive particles are mixed in pure water as Comparative Example 4 are used and polished respectively will be described together.
【００２８】[0028]
【表１】 [Table 1]
【００２９】比較例１のＣｅＯ2 砥粒のみを混合した砥
粒液を用いた場合、下記の表２に示したように研磨速度
は速いが、洗浄後のパーティクルの残存数が極めて多
く、薄膜の表面平坦化には不適当である。When the abrasive liquid containing only the CeO 2 abrasive grains of Comparative Example 1 was used, the polishing rate was high as shown in Table 2 below, but the number of remaining particles after cleaning was extremely large and the thin film was thin. Is not suitable for surface flattening.
【００３０】[0030]
【表２】 [Table 2]
【００３１】また比較例２のＳｉＯ2 砥粒のみを混合し
た砥粒液を用いた場合、下記の表３に示したようにパー
ティクル数は比較的少ないが、研磨速度が遅く、薄膜の
表面平坦化には不適当である。When the abrasive liquid containing only the SiO 2 abrasive grains of Comparative Example 2 was used, the number of particles was relatively small as shown in Table 3 below, but the polishing rate was slow and the surface of the thin film was flat. Is not suitable for conversion.
【００３２】[0032]
【表３】 [Table 3]
【００３３】また比較例３のＡｌ2 Ｏ3 砥粒のみを混合
した砥粒液を用いた場合、下記の表４に示したようにパ
ーティクル数は比較的少ないが、研磨速度が極めて遅
く、薄膜の表面平坦化には不適当である。When the abrasive liquid containing only the Al 2 O 3 abrasive grains of Comparative Example 3 was used, the number of particles was relatively small as shown in Table 4 below, but the polishing rate was extremely slow and the thin film was thin. Is not suitable for surface flattening.
【００３４】[0034]
【表４】 [Table 4]
【００３５】また比較例４のコロイダルシリカ砥粒のみ
を混合した砥粒液を用いた場合、下記の表５に示したよ
うにパーティクル数は比較的少ないが、研磨速度が比較
例２及び比較例３の場合の中間程度と遅く、薄膜の表面
平坦化には不適当である。Further, when the abrasive liquid containing only the colloidal silica abrasive grains of Comparative Example 4 was used, the number of particles was relatively small as shown in Table 5 below, but the polishing rate was Comparative Example 2 and Comparative Example. It is as slow as the middle of the case of 3, and is not suitable for flattening the surface of a thin film.
【００３６】[0036]
【表５】 [Table 5]
【００３７】一方、実施例１のＳｉＯ2 及びＣｅＯ2 砥
粒を純水中にそれぞれ０．５〜３０％及び５〜３０％濃
度に混合した砥粒液を用いた場合、下記の表６に示した
ように研磨速度が２５００Å／ｍｉｎ以上に速くなり、
パーティクル数は５００個以下に減少した。またＳｉＯ
2 砥粒濃度が約０．５％以上であり、かつＳｉＯ2 及び
ＣｅＯ2 砥粒のトータル濃度が約５０％以下の砥粒液で
は、上記の場合と同様に研磨速度が速く、パーティクル
数が少なくなるとともに、表示はしないが砥粒の凝集が
少なくなった。さらにＳｉＯ2 砥粒濃度が５〜３０％及
びＣｅＯ2 砥粒濃度が５〜３０％の砥粒液では、パーテ
ィクル数が約２０以下となった。On the other hand, in the case of using the abrasive liquid in which the SiO 2 and CeO 2 abrasive grains of Example 1 were mixed in pure water at the concentrations of 0.5 to 30% and 5 to 30%, respectively, the results are shown in Table 6 below. As shown, the polishing rate has increased to 2500 Å / min or more,
The number of particles was reduced to 500 or less. Also SiO
2 With an abrasive solution having a concentration of abrasives of about 0.5% or more and a total concentration of SiO 2 and CeO 2 abrasives of about 50% or less, the polishing rate is high and the number of particles is the same as in the above case. The number of particles decreased, but the aggregation of the abrasive grains decreased although not displayed. Further, the number of particles was about 20 or less in the abrasive liquid having the SiO 2 abrasive grain concentration of 5 to 30% and the CeO 2 abrasive grain concentration of 5 to 30%.
【００３８】[0038]
【表６】 [Table 6]
【００３９】上記結果から明らかなように、実施例１に
係る薄膜の表面平坦化方法では、砥粒液中に存在するＣ
ｅＯ2 砥粒により研磨速度を速めることができ、砥粒液
中に存在するＳｉＯ2 砥粒により、研磨の際に研磨面に
凝着しようとするＣｅＯ2 砥粒分を連続的に除去するこ
とができ、研磨終了後における研磨面１３ｃにはＣｅＯ
2 砥粒分の凝着はほとんどみられない。他方、研磨終了
後の研磨面１３ｃに残存するＳｉＯ2 砥粒分は、研磨終
了後に行う洗浄工程により容易に除去することができ
る。したがってこれら砥粒の複合作用により清浄な研磨
面１３ｃを得ることができ、この結果パーティクルの残
存を抑制することができるとともに、研磨速度を速める
ことができる。As is clear from the above results, in the method of flattening the surface of the thin film according to Example 1, C existing in the abrasive liquid was used.
eO 2 abrasive grains makes it possible to increase the polishing rate, the SiO 2 abrasive grains present in the abrasive fluid, the CeO 2 abrasive component to be adhesion to the polishing surface can be continuously removed during polishing Is formed, and CeO is formed on the polishing surface 13c after the polishing is completed.
Almost no adhesion of two abrasive grains was observed. On the other hand, the SiO 2 abrasive grains remaining on the polished surface 13c after the polishing can be easily removed by the cleaning step performed after the polishing. Therefore, a clean polishing surface 13c can be obtained by the combined action of these abrasive grains, and as a result, the remaining particles can be suppressed and the polishing rate can be increased.
【００４０】またＳｉＯ2 砥粒濃度が０．５％以上であ
り、かつＳｉＯ2 及びＣｅＯ2 砥粒濃度が５０％以下で
ある場合には、ＣｅＯ2 砥粒等が凝集して固まるのを阻
止して取り扱いを容易にすることができ、また砥粒材料
費を削減することができる。When the SiO 2 abrasive grain concentration is 0.5% or more and the SiO 2 and CeO 2 abrasive grain concentrations are 50% or less, it is possible to prevent the CeO 2 abrasive grains and the like from agglomerating and solidifying. Therefore, the handling can be facilitated and the abrasive grain material cost can be reduced.
【００４１】また、ＳｉＯ2 砥粒濃度が５〜３０％及
び、ＣｅＯ2 砥粒濃度が５〜３０％である場合には、研
磨速度を十分に高めることができるとともに、研磨の際
にＣｅＯ2 砥粒分が研磨面に凝着するのをより一層防止
することができ、研磨終了後における研磨面１３ｃをよ
り一層清浄なものにすることができ、この結果パーティ
クルの残存をより一層抑制することができる。When the SiO 2 abrasive grain concentration is 5 to 30% and the CeO 2 abrasive grain concentration is 5 to 30%, the polishing rate can be sufficiently increased and at the time of polishing, CeO 2 is used. It is possible to further prevent the abrasive grains from adhering to the polishing surface, and it is possible to further clean the polishing surface 13c after the polishing is completed, and as a result, it is possible to further suppress the residual particles. You can
【００４２】また実施例２のＡｌ2 Ｏ3 及びＣｅＯ2 砥
粒を純水中にそれぞれ０．５〜３０％及び５〜３０％濃
度に混合した砥粒液を用いた場合、下記の表７に示した
ように研磨速度が２５００Å／ｍｉｎ以上に速くなり、
パーティクル数は１０００個以下に減少した。またＡｌ
2 Ｏ3 砥粒濃度が約０．５％以上であり、かつＡｌ2Ｏ3
及びＣｅＯ2 砥粒のトータル濃度が約５０％以下の砥
粒液では、上記の場合と同様に研磨速度が速く、パーテ
ィクル数が少なくなるとともに、砥粒の凝集が少なくな
った。さらにＡｌ2 Ｏ3 砥粒濃度が５〜３０％及びＣｅ
Ｏ2 砥粒濃度が５〜３０％の砥粒液では、パーティクル
数が約２０以下となった。Further, in the case of using the abrasive liquid in which the Al 2 O 3 and CeO 2 abrasive grains of Example 2 were mixed in pure water at the concentrations of 0.5 to 30% and 5 to 30% respectively, the following Table 7 was used. As shown in, the polishing rate becomes more than 2500Å / min,
The number of particles was reduced to 1000 or less. Also Al
2 O 3 abrasive grain concentration is about 0.5% or more, and Al 2 O 3
With an abrasive liquid having a total concentration of CeO 2 abrasive particles of about 50% or less, the polishing rate was high, the number of particles was small, and the agglomeration of the abrasive particles was small, as in the above case. Further, the Al 2 O 3 abrasive grain concentration is 5 to 30% and Ce
With the abrasive liquid having an O 2 abrasive concentration of 5 to 30%, the number of particles was about 20 or less.
【００４３】[0043]
【表７】 [Table 7]
【００４４】上記結果から明らかなように、実施例２に
係る薄膜の表面平坦化方法では、砥粒液中に存在するＣ
ｅＯ2 砥粒により研磨速度を速めることができ、砥粒液
中に存在するＡｌ2 Ｏ3 砥粒により、研磨の際に研磨面
に凝着しようとするＣｅＯ2砥粒分を連続的に除去する
ことができ、研磨終了後の前記研磨面に残存するＡｌ2
Ｏ3 砥粒分は洗浄工程により容易に除去することができ
るため、実施例１の場合と略同様の効果を得ることがで
きる。またＡｌ2 Ｏ3 砥粒濃度が０．５％以上であり、
かつＡｌ2 Ｏ3 及びＣｅＯ2 砥粒濃度が５０％以下であ
る場合には、実施例１の場合と略同様の効果を得ること
ができる。また、Ａｌ2 Ｏ3 砥粒濃度が５〜３０％及
び、ＣｅＯ2 砥粒濃度が５〜３０％である場合には、研
磨の際にＣｅＯ2 砥粒分が研磨面に凝着するのをより一
層防止することができるため、実施例１の場合と略同様
の効果を得ることができる。As is clear from the above results, in the method of flattening the surface of the thin film according to Example 2, C existing in the abrasive liquid was
eO 2 can increase the polishing rate by abrasive, by Al 2 O 3 abrasive grains present in the abrasive fluid, continuous removal of CeO 2 abrasive component to be adhesion to the polishing surface during polishing Al 2 remaining on the polished surface after completion of polishing
Since the O 3 abrasive grains can be easily removed by the cleaning process, it is possible to obtain substantially the same effect as that of the first embodiment. Further, the Al 2 O 3 abrasive grain concentration is 0.5% or more,
In addition, when the Al 2 O 3 and CeO 2 abrasive grain concentration is 50% or less, substantially the same effect as in the case of Example 1 can be obtained. Further, when the Al 2 O 3 abrasive grain concentration is 5 to 30% and the CeO 2 abrasive grain concentration is 5 to 30%, the CeO 2 abrasive grain component is prevented from adhering to the polished surface during polishing. Since it can be further prevented, it is possible to obtain substantially the same effect as that of the first embodiment.
【００４５】また実施例３のコロイダルシリカ及びＣｅ
Ｏ2 砥粒を純水中にそれぞれ０．５〜３０％及び５〜３
０％濃度に混合した砥粒液を用いた場合、下記の表８に
示したように研磨速度が２５００Å／ｍｉｎ以上に速く
なり、パーティクル数は８００個以下に減少した。また
コロイダルシリカ砥粒濃度が約０．５％以上であり、か
つコロイダルシリカ及びＣｅＯ2 砥粒のトータル濃度が
約５０％以下の砥粒液では、上記の場合と略同様に研磨
速度が速く、パーティクル数が少なくなるとともに、砥
粒の凝集が少なくなった。さらにコロイダルシリカ砥粒
濃度が５〜３０％及びＣｅＯ2 砥粒濃度が５〜３０％の
砥粒液では、パーティクル数が約２０以下となった。The colloidal silica and Ce of Example 3 are also used.
O 2 abrasive grains in pure water are 0.5 to 30% and 5 to 3 respectively.
When using the abrasive liquid mixed to a concentration of 0%, the polishing rate increased to 2500 Å / min or more and the number of particles decreased to 800 or less, as shown in Table 8 below. Further, with an abrasive liquid having a colloidal silica abrasive grain concentration of about 0.5% or more, and a total concentration of colloidal silica and CeO 2 abrasive grains of about 50% or less, the polishing rate is almost the same as in the above case, As the number of particles decreased, the agglomeration of abrasive particles decreased. Further, in the abrasive liquid having colloidal silica abrasive grain concentration of 5 to 30% and CeO 2 abrasive grain concentration of 5 to 30%, the number of particles was about 20 or less.
【００４６】[0046]
【表８】 [Table 8]
【００４７】上記結果から明らかなように、実施例３に
係る薄膜の表面平坦化方法では、砥粒液中に存在するＣ
ｅＯ2 砥粒により研磨速度を速めることができ、砥粒液
中に存在するコロイダルシリカ砥粒により、研磨の際に
研磨面に凝着しようとするＣｅＯ2 砥粒分を連続的に除
去することができ、研磨終了後の前記研磨面に残存する
コロイダルシリカ砥粒分は洗浄工程により容易に除去す
ることができるため、実施例１の場合と略同様の効果を
得ることができる。またコロイダルシリカ砥粒濃度が
０．５％以上であり、かつコロイダルシリカ及びＣｅＯ
2 砥粒濃度が５０％以下である場合には、実施例１の場
合と略同様の効果を得ることができる。また、コロイダ
ルシリカ砥粒濃度が５〜３０％及び、ＣｅＯ2 砥粒濃度
が５〜３０％である場合には、研磨の際にＣｅＯ2 砥粒
分が研磨面に凝着するのをより一層防止することができ
るため、実施例１の場合と略同様の効果を得ることがで
きる。As is clear from the above results, in the method of flattening the surface of the thin film according to Example 3, C existing in the abrasive grain liquid was used.
eO 2 abrasive grains makes it possible to increase the polishing rate, the colloidal silica abrasive present in the abrasive fluid, the CeO 2 abrasive component to be adhesion to the polishing surface can be continuously removed during polishing Since the colloidal silica abrasive grains remaining on the polished surface after polishing can be easily removed by the cleaning step, substantially the same effect as in the case of Example 1 can be obtained. Further, the colloidal silica abrasive grain concentration is 0.5% or more, and the colloidal silica and CeO
2 When the abrasive grain concentration is 50% or less, substantially the same effect as in the case of Example 1 can be obtained. Further, when the colloidal silica abrasive grain concentration is 5 to 30% and the CeO 2 abrasive grain concentration is 5 to 30%, the CeO 2 abrasive grain content is further prevented from adhering to the polishing surface during polishing. Since it can be prevented, it is possible to obtain substantially the same effect as in the case of the first embodiment.
【００４８】また実施例４のＳｉＯ2 とＡｌ2 Ｏ3 とを
１：１の重量比で混ぜ合わせた砥粒及びＣｅＯ2 砥粒を
純水中にそれぞれ０．５〜３０％及び５〜３０％濃度に
混合した砥粒液を用いた場合、下記の表９に示したよう
に研磨速度が２５００Å／ｍｉｎ以上に速くなり、パー
ティクル数は１０００個以下に減少した。またＳｉＯ2
とＡｌ2 Ｏ3 砥粒濃度が約０．５％以上であり、かつＳ
ｉＯ2 、Ａｌ2 Ｏ3 及びＣｅＯ2 砥粒のトータル濃度が
約５０％以下の砥粒液では、上記の場合と略同様に研磨
速度が速く、パーティクル数が少なくなるとともに、砥
粒の凝集が少なくなった。さらにＳｉＯ2 とＡｌ2 Ｏ3
砥粒濃度が５〜３０％及びＣｅＯ2 砥粒濃度が５〜３０
％の砥粒液では、パーティクル数が約２０以下となっ
た。Further, the abrasive grains obtained by mixing SiO 2 and Al 2 O 3 of Example 4 in a weight ratio of 1: 1 and CeO 2 abrasive grains in pure water are 0.5 to 30% and 5 to 30%, respectively. When using the abrasive liquid mixed at a concentration of 0.1%, the polishing rate was increased to 2500 Å / min or more and the number of particles was reduced to 1000 or less, as shown in Table 9 below. Also SiO 2
And Al 2 O 3 abrasive grain concentration is about 0.5% or more, and S
With an abrasive liquid having a total concentration of iO 2 , Al 2 O 3 and CeO 2 abrasives of about 50% or less, the polishing rate is high, the number of particles is small, and the agglomeration of the abrasive grains is almost the same as in the above case. I've run out. Furthermore, SiO 2 and Al 2 O 3
Abrasive grain concentration is 5-30% and CeO 2 abrasive grain concentration is 5-30
%, The number of particles was about 20 or less.
【００４９】[0049]
【表９】 [Table 9]
【００５０】上記結果から明らかなように、実施例４に
係る薄膜の表面平坦化方法では、砥粒液中に存在するＣ
ｅＯ2 砥粒により研磨速度を速めることができ、砥粒液
中に存在するＳｉＯ2 とＡｌ2 Ｏ3 砥粒により、研磨の
際に研磨面に凝着しようとするＣｅＯ2 砥粒分を連続的
に除去することができ、研磨終了後の前記研磨面に残存
するＳｉＯ2 とＡｌ2 Ｏ3 砥粒分は洗浄工程により容易
に除去することができるため、実施例１の場合と略同様
の効果を得ることができる。またＳｉＯ2 とＡｌ2 Ｏ3
砥粒濃度が０．５％以上であり、かつＳｉＯ2 、Ａｌ2
Ｏ3 及びＣｅＯ2 砥粒の濃度が５０％以下である場合に
は、実施例１の場合と略同様の効果を得ることができ
る。また、ＳｉＯ2 とＡｌ2 Ｏ3 砥粒濃度が５〜３０％
及び、ＣｅＯ2 砥粒濃度が５〜３０％である場合には、
研磨の際にＣｅＯ2 砥粒分が研磨面に凝着するのをより
一層防止することができるため、実施例１の場合と略同
様の効果を得ることができる。As is clear from the above results, in the method of flattening the surface of the thin film according to Example 4, C existing in the abrasive grain liquid was used.
eO 2 can increase the polishing rate by abrasive grains by SiO 2 and Al 2 O 3 abrasive grains present in the abrasive fluid, continuous CeO 2 abrasive component to be adhesion to the polishing surface during polishing The SiO 2 and Al 2 O 3 abrasive grains remaining on the polished surface after the polishing can be easily removed by the cleaning step. The effect can be obtained. In addition, SiO 2 and Al 2 O 3
Abrasive grain concentration is 0.5% or more, and SiO 2 , Al 2
When the concentration of the O 3 and CeO 2 abrasive grains is 50% or less, substantially the same effect as in the case of Example 1 can be obtained. Also, the SiO 2 and Al 2 O 3 abrasive grain concentration is 5 to 30%.
And, when the CeO 2 abrasive grain concentration is 5 to 30%,
Since it is possible to further prevent the CeO 2 abrasive grains from adhering to the polishing surface during polishing, it is possible to obtain substantially the same effect as in the case of Example 1.
【００５１】なお、実施例４ではＣｅＯ2 砥粒の外にＳ
ｉＯ2 とＡｌ2 Ｏ3 砥粒を用いた場合について説明した
が、別の実施例ではＣｅＯ2 砥粒の外に、ＳｉＯ2 とコ
ロイダルシリカ砥粒、Ａｌ2 Ｏ3 とコロイダルシリカ砥
粒をそれぞれ用いてもよい。Incidentally, in Example 4, S was added to the outside of the CeO 2 abrasive grains.
The case of using iO 2 and Al 2 O 3 abrasive grains has been described, but in another embodiment, in addition to CeO 2 abrasive grains, SiO 2 and colloidal silica abrasive grains, and Al 2 O 3 and colloidal silica abrasive grains, respectively. You may use.
【００５２】また実施例５のＳｉＯ2 とＡｌ2 Ｏ3 とコ
ロイダルシリカとを１：１：１の重量比で混ぜ合せた砥
粒及びＣｅＯ2 砥粒を純水中にそれぞれ０．５〜３０％
及び５〜３０％濃度に混合した砥粒液を用いた場合、下
記の表１０に示したように研磨速度が２５００Å／ｍｉ
ｎ以上に速くなり、パーティクル数は１０００個以下に
減少した。またＳｉＯ2 とＡｌ2 Ｏ3 とコロイダルシリ
カ砥粒濃度が約０．５％以上であり、かつＳｉＯ2 、Ａ
ｌ2 Ｏ3 、コロイダルシリカ及びＣｅＯ2 砥粒のトータ
ル濃度が約５０％以下の砥粒液では、上記の場合と略同
様に研磨速度が速く、パーティクル数が少なくなるとと
もに、砥粒の凝集が少なくなった。さらにＳｉＯ2 とＡ
ｌ2 Ｏ3 とコロイダルシリカ砥粒濃度が５〜３０％及び
ＣｅＯ2砥粒濃度が５〜３０％の砥粒液では、パーティ
クル数が約２０以下となった。Further, the abrasive grains and the CeO 2 abrasive grains obtained by mixing SiO 2 , Al 2 O 3 and colloidal silica in Example 5 in a weight ratio of 1: 1: 1 were added to pure water in an amount of 0.5 to 30 respectively. %
And when using an abrasive solution mixed to a concentration of 5 to 30%, the polishing rate was 2500 Å / mi as shown in Table 10 below.
It became faster than n and the number of particles decreased to 1000 or less. Further, the concentration of SiO 2 , Al 2 O 3 and colloidal silica abrasive grains is about 0.5% or more, and SiO 2 , A
With an abrasive liquid having a total concentration of l 2 O 3 , colloidal silica, and CeO 2 abrasive particles of about 50% or less, the polishing rate is high, the number of particles is small, and the agglomeration of the abrasive particles is almost the same as in the above case. I've run out. Furthermore, SiO 2 and A
The number of particles was about 20 or less in the abrasive grain liquid containing 12 O 3 and the colloidal silica abrasive grain concentration of 5 to 30% and the CeO 2 abrasive grain concentration of 5 to 30%.
【００５３】[0053]
【表１０】 [Table 10]
【００５４】上記結果から明らかなように、実施例５に
係る薄膜の表面平坦化方法では、砥粒液中に存在するＣ
ｅＯ2 砥粒により研磨速度を速めることができ、砥粒液
中に存在するＳｉＯ2 とＡｌ2 Ｏ3 とコロイダルシリカ
砥粒により、研磨の際に研磨面に凝着しようとするＣｅ
Ｏ2 砥粒分を連続的に除去することができ、研磨終了後
の前記研磨面に残存するＳｉＯ2 とＡｌ2 Ｏ3 とコロイ
ダルシリカ砥粒分は洗浄工程により容易に除去すること
ができるため、実施例１の場合と略同様の効果を得るこ
とができる。またＳｉＯ2 とＡｌ2 Ｏ3 とコロイダルシ
リカ砥粒濃度が０．５％以上であり、かつＳｉＯ2 、Ａ
ｌ2 Ｏ3 、コロイダルシリカ及びＣｅＯ2 砥粒の濃度が
５０％以下である場合には、実施例１の場合と略同様の
効果を得ることができる。また、ＳｉＯ2 とＡｌ2 Ｏ3
とコロイダルシリカ砥粒濃度が５〜３０％及び、ＣｅＯ
2 砥粒濃度が５〜３０％である場合には、研磨の際にＣ
ｅＯ2 砥粒分が研磨面に凝着するのをより一層防止する
ことができるため、実施例１の場合と略同様の効果を得
ることができる。As is clear from the above results, in the method of flattening the surface of the thin film according to Example 5, C existing in the abrasive grain liquid was used.
The polishing rate can be increased by the eO 2 abrasive grains, and the SiO 2 and Al 2 O 3 and colloidal silica abrasive grains present in the abrasive grain liquid tend to adhere to the polishing surface during polishing.
O 2 abrasive grains can be continuously removed, and SiO 2 , Al 2 O 3, and colloidal silica abrasive grains remaining on the polished surface after polishing can be easily removed by a cleaning process. It is possible to obtain substantially the same effect as that of the first embodiment. Further, the concentration of SiO 2 , Al 2 O 3 and colloidal silica abrasive grains is 0.5% or more, and SiO 2 , A
When the concentrations of l 2 O 3 , colloidal silica and CeO 2 abrasive grains are 50% or less, substantially the same effect as in the case of Example 1 can be obtained. In addition, SiO 2 and Al 2 O 3
And colloidal silica abrasive grain concentration of 5-30% and CeO
2 When the abrasive grain concentration is 5 to 30%, C
Since it is possible to further prevent the eO 2 abrasive grains from adhering to the polishing surface, it is possible to obtain substantially the same effect as in the case of Example 1.
【００５５】なお上記した実施例では、いずれもＳｉＯ
2 膜等の絶縁膜１３はＥＣＲ−ＣＶＤ法により形成した
場合について説明したが、ＴＥＯＳ−ＣＶＤ、ｐ−ＣＶ
Ｄ、熱ＣＶＤ、熱酸化等他の方法により形成してもよ
い。In each of the above embodiments, SiO is used.
The case where the insulating film 13 such as the two films is formed by the ECR-CVD method has been described, but the TEOS-CVD, p-CV
It may be formed by another method such as D, thermal CVD, or thermal oxidation.
【００５６】また、ＳｉＯ2 膜以外にＳｉＮ、ＳｉＯ
Ｎ、ＳｉＯＦ、ＰＳＧ、ＢＰＳＧ、ＳＯＧ膜等に適用し
てもよい。In addition to the SiO 2 film, SiN, SiO
It may be applied to N, SiOF, PSG, BPSG, SOG films and the like.
【００５７】また、砥粒は何ら平均粒径が約０．２μｍ
に限定されるものではなく、これ以外の平均粒径を有す
る砥粒を用いてもよい。The average grain size of the abrasive grains is about 0.2 μm.
However, the abrasive grains having an average particle diameter other than this may be used.
【００５８】また、砥粒液に化学成分を混合してもよ
い。Further, chemical components may be mixed with the abrasive liquid.
【００５９】[0059]
【発明の効果】以上詳述したように本発明に係る薄膜の
表面平坦化方法にあっては、ＳｉＯ2、Ａｌ2 Ｏ3 もし
くはコロイダルシリカ砥粒の少なくとも１種以上の砥粒
とＣｅＯ2 砥粒とを含む砥粒液を用い、研磨により平坦
化するので、前記砥粒液中に存在する前記ＣｅＯ2 砥粒
により研磨速度を速めることができる。一方、前記砥粒
液中に存在する前記したＳｉＯ2 、Ａｌ2 Ｏ3 もしくは
コロイダルシリカ砥粒の少なくとも１種以上の砥粒によ
り、研磨の際に研磨面に凝着しようとする前記ＣｅＯ2
砥粒分を連続的に除去することができ、研磨終了後にお
ける前記研磨面に前記ＣｅＯ2 砥粒分はほとんど残存し
ない。他方、研磨終了後の前記研磨面に残存する前記Ｓ
ｉＯ2 、Ａｌ2 Ｏ3 もしくはコロイダルシリカ砥粒分は
研磨終了後に行う洗浄工程によりそれぞれ容易に除去す
ることができる。したがってこれら砥粒の複合作用によ
り清浄な研磨面を得ることができ、この結果パーティク
ルの残存を抑制することができるとともに、研磨速度を
速めることができる。As described above in detail, in the method of flattening the surface of a thin film according to the present invention, at least one kind of SiO 2 , Al 2 O 3 or colloidal silica abrasive grains and CeO 2 abrasive grains are used. Since the abrasive grain liquid containing the grains is used to flatten the surface by polishing, the polishing rate can be increased by the CeO 2 abrasive grains present in the abrasive grain liquid. On the other hand, the CeO 2 that tends to adhere to the polishing surface during polishing by at least one kind of the above-mentioned SiO 2 , Al 2 O 3 or colloidal silica abrasive grains present in the above-mentioned abrasive grain liquid.
The abrasive grains can be continuously removed, and the CeO 2 abrasive grains hardly remain on the polished surface after the polishing is completed. On the other hand, the S remaining on the polished surface after polishing is completed.
The iO 2 , Al 2 O 3 or colloidal silica abrasive grains can be easily removed by a cleaning step performed after the polishing is completed. Therefore, a clean polishing surface can be obtained by the combined action of these abrasive grains, and as a result, it is possible to suppress the particles from remaining and to increase the polishing rate.
【図１】本発明に係る薄膜の表面平坦化方法の実施例を
説明するために示した摸式的断面図であり、（ａ）はシ
リコンウエハ上に配線パターンを形成し、この配線の上
面に絶縁膜を形成した研磨前の状態、（ｂ）は研磨によ
り絶縁膜表面の段差を除去し、表面を平坦化した状態を
示している。FIG. 1 is a schematic cross-sectional view shown for explaining an embodiment of a surface flattening method for a thin film according to the present invention, in which (a) is a wiring pattern formed on a silicon wafer and the upper surface of this wiring is shown. The state before polishing, in which the insulating film is formed, is shown, and (b) shows the state in which the steps on the surface of the insulating film are removed by polishing and the surface is flattened.
【図２】従来の研磨による平坦化方法を説明するために
示した製造過程中における半導体装置の模式的断面図で
ある。FIG. 2 is a schematic cross-sectional view of a semiconductor device during a manufacturing process shown for explaining a conventional flattening method by polishing.
【図３】従来の別の研磨による平坦化方法を説明するた
めに示した製造過程中における半導体装置の模式的断面
図である。FIG. 3 is a schematic cross-sectional view of a semiconductor device during a manufacturing process shown for explaining another conventional planarization method by polishing.
【図４】従来のさらに別の研磨による平坦化方法を説明
するために示した製造過程中における半導体装置の模式
的断面図である。FIG. 4 is a schematic cross-sectional view of a semiconductor device during a manufacturing process shown for explaining another conventional planarization method by polishing.
１１ シリコンウエハ １２ 配線 １３ 絶縁膜 １３ａ 凹部 １３ｂ 凸部 １３ｃ 研磨後の表面 11 Silicon Wafer 12 Wiring 13 Insulating Film 13a Recess 13b Convex 13c Surface After Polishing
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｈ０１Ｌ 21/3205 (72)発明者 別府 敏保 大阪府大阪市中央区北浜４丁目５番33号 住友金属工業株式会社内 (72)発明者 渡辺 純二 大阪府大阪市中央区北浜４丁目５番33号 住友金属工業株式会社内─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification number Reference number within the agency FI Technical indication location H01L 21/3205 (72) Inventor Toshibo Beppu 4-53-3 Kitahama, Chuo-ku, Osaka-shi, Osaka Sumitomo Metal Industries, Ltd. (72) Inventor Junji Watanabe 4-53, Kitahama, Chuo-ku, Osaka City, Osaka Prefecture Sumitomo Metal Industries, Ltd.
Claims (1)
ルシリカ砥粒の少なくとも１種以上の砥粒とＣｅＯ2 砥
粒とを含む砥粒液を用い、研磨により平坦化することを
特徴とする薄膜の表面平坦化方法。1. A thin film characterized by being planarized by polishing using an abrasive liquid containing at least one kind of abrasive grains of SiO 2 , Al 2 O 3 or colloidal silica abrasive grains and CeO 2 abrasive grains. Surface flattening method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19417794A JPH08148455A (en) | 1994-08-18 | 1994-08-18 | Surface flattening method for thin film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19417794A JPH08148455A (en) | 1994-08-18 | 1994-08-18 | Surface flattening method for thin film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08148455A true JPH08148455A (en) | 1996-06-07 |
Family
ID=16320218
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19417794A Pending JPH08148455A (en) | 1994-08-18 | 1994-08-18 | Surface flattening method for thin film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08148455A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0826756A1 (en) * | 1996-09-03 | 1998-03-04 | Sumitomo Chemical Company, Limited | Abrasive composition for polishing a metal layer on a semiconductor substrate, and use of the same |
| EP0874036A1 (en) * | 1997-04-25 | 1998-10-28 | Mitsui Mining & Smelting Co., Ltd. | Fine particulate polishing agent, method for producing the same and method for producing semiconductor devices. |
| WO2005022621A1 (en) * | 2003-08-27 | 2005-03-10 | Fujimi Incorporated | Polishing composition and polishing method using same |
| KR100578231B1 (en) * | 2000-06-30 | 2006-05-12 | 주식회사 하이닉스반도체 | Method for manufacturing semiconductor for planarization in damascene gate process |
-
1994
- 1994-08-18 JP JP19417794A patent/JPH08148455A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0826756A1 (en) * | 1996-09-03 | 1998-03-04 | Sumitomo Chemical Company, Limited | Abrasive composition for polishing a metal layer on a semiconductor substrate, and use of the same |
| EP0874036A1 (en) * | 1997-04-25 | 1998-10-28 | Mitsui Mining & Smelting Co., Ltd. | Fine particulate polishing agent, method for producing the same and method for producing semiconductor devices. |
| US5951724A (en) * | 1997-04-25 | 1999-09-14 | Mitsui Mining And Smelting Co., Ltd. | Fine particulate polishing agent, method for producing the same and method for producing semiconductor devices |
| KR100578231B1 (en) * | 2000-06-30 | 2006-05-12 | 주식회사 하이닉스반도체 | Method for manufacturing semiconductor for planarization in damascene gate process |
| WO2005022621A1 (en) * | 2003-08-27 | 2005-03-10 | Fujimi Incorporated | Polishing composition and polishing method using same |
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