JPH0982667A - Abrasive and polishing and flattening - Google Patents
Abrasive and polishing and flatteningInfo
- Publication number
- JPH0982667A JPH0982667A JP24129995A JP24129995A JPH0982667A JP H0982667 A JPH0982667 A JP H0982667A JP 24129995 A JP24129995 A JP 24129995A JP 24129995 A JP24129995 A JP 24129995A JP H0982667 A JPH0982667 A JP H0982667A
- Authority
- JP
- Japan
- Prior art keywords
- polishing
- film
- abrasive
- cerium oxide
- polishing rate
- 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.)
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- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
- Mechanical Treatment Of Semiconductor (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、素子や配線パターン等
による段差が表面に形成され、段差が生じた基板の表面
を平坦化するための研磨剤、および研磨平坦化方法に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing agent for flattening the surface of a substrate on which a step due to an element, a wiring pattern or the like is formed on the surface, and a polishing flattening method.
【０００２】[0002]
【従来の技術】従来、広く用いられている段差付き基板
の研磨平坦化方法の代表例２種を図１および図２を用い
て説明する。2. Description of the Related Art Conventionally, two typical examples of a method of polishing and flattening a stepped substrate will be described with reference to FIGS.
【０００３】図１は、最もシンプルな方法である。ま
ず、同図（ａ）のように、段差付き基板１上に化学気相
成長法（以下、ＣＶＤ）により、酸化珪素膜等の絶縁膜
２を形成する。この際、下地基板の凹部上の絶縁膜が少
なくとも下地基板の凸部よりも高くなるようにする必要
がある。次いで、同図（ｂ）に示すように、基板表面を
化学機械研磨法（以下、ＣＭＰ）を用いて研磨平坦化す
る。この例のように酸化珪素膜等を研磨する場合は、研
磨剤として、フュームドシリカをアルカリ中に分散した
研磨剤が用いられることが多い。研磨の結果、同図
（ｃ）に示すような、研磨前よりも平坦化された表面を
得る。FIG. 1 is the simplest method. First, as shown in FIG. 3A, an insulating film 2 such as a silicon oxide film is formed on a substrate 1 with steps by a chemical vapor deposition method (hereinafter, CVD). At this time, the insulating film on the concave portion of the base substrate needs to be at least higher than the convex portion of the base substrate. Then, as shown in FIG. 3B, the surface of the substrate is polished and flattened by a chemical mechanical polishing method (hereinafter, CMP). When polishing a silicon oxide film or the like as in this example, a polishing agent in which fumed silica is dispersed in an alkali is often used as the polishing agent. As a result of polishing, a flattened surface as compared with that before polishing is obtained as shown in FIG.
【０００４】絶縁膜２を形成する際には、下地段差の間
隔が狭い場所で絶縁膜中２に空洞（ボイド）が生じない
ようにすることが望ましい。このため以下に示すよう
に、絶縁膜の形成法あるいは材料に工夫がされることが
多い。まず第一に、硼素，燐のいずれかあるいはその両
者を１原子％以上含む酸化珪素膜（以下、ＢＰＳＧ）を
用いることである。ＢＰＳＧは８００度から９００度の
温度で流動化（リフロー）するため、この温度で加熱す
れば空洞をなくすことができる。第二に、バイアスエレ
クトロンサイクロトロンレゾナンス方式によるＣＶＤ
（以下、バイアスＥＣＲ ＣＶＤ）法を用いることであ
る。この方法は、膜形成時に基板１にバイアス（負電
圧）を加えることによって堆積とエッチングを同時に行
うため、埋め込み性がよい。従って、ボイドを生じるこ
となく酸化珪素膜で段差を埋め込むことができる。ま
た、このバイアスＥＣＲ ＣＶＤ法を用いて、低誘電率
のフッ素を１原子％以上含む酸化珪素膜（以下、ＳｉＯ
Ｆ）で段差を埋め込むこともある。以下、ＢＰＳＧ，Ｓ
ｉＯＦ等をドープド酸化珪素膜と呼ぶ。When the insulating film 2 is formed, it is desirable that voids do not occur in the insulating film 2 in places where the gap between the underlying steps is narrow. Therefore, as shown below, a method or material for forming the insulating film is often devised. First of all, a silicon oxide film (hereinafter, BPSG) containing 1 atomic% or more of either or both of boron and phosphorus is used. Since BPSG fluidizes (reflows) at a temperature of 800 to 900 ° C., it is possible to eliminate voids by heating at this temperature. Second, CVD by bias electron cyclotron resonance method
(Hereinafter referred to as bias ECR CVD) method. In this method, since the deposition and the etching are performed at the same time by applying a bias (negative voltage) to the substrate 1 when forming the film, the embedding property is good. Therefore, the step can be filled with the silicon oxide film without generating voids. Further, by using this bias ECR CVD method, a silicon oxide film containing 1 atomic% or more of fluorine having a low dielectric constant (hereinafter referred to as SiO 2
The step may be embedded in F). Below, BPSG, S
iOF and the like are called a doped silicon oxide film.
【０００５】図２は従来の段差付き基板の研磨平坦化方
法のもう一つの方法である。まず、同図（ａ）のよう
に、段差付き基板１上に化学気相成長法（以下、ＣＶ
Ｄ）により、酸化珪素膜等の絶縁膜２を形成する。この
際、絶縁膜２として用いられる材料及び形成方法は図１
に示した例と同様である。次いで、同図（ｂ）に示すよ
うに、下地段差の凹部に研磨速度の遅い膜（研磨ストッ
パ）３を形成する。次に、基板表面をＣＭＰ法を用いて
研磨平坦化する。研磨剤も図１に示した例と同様であ
る。研磨の結果、同図（ｃ）に示すような、研磨前より
も平坦化された表面を得る。FIG. 2 shows another conventional method for flattening a stepped substrate by polishing. First, as shown in FIG. 3A, a chemical vapor deposition method (hereinafter, CV
The insulating film 2 such as a silicon oxide film is formed by D). At this time, the material used for the insulating film 2 and the forming method are shown in FIG.
This is the same as the example shown in FIG. Next, as shown in FIG. 3B, a film (polishing stopper) 3 having a slow polishing rate is formed in the concave portion of the underlying step. Next, the surface of the substrate is polished and flattened by the CMP method. The abrasive is also similar to the example shown in FIG. As a result of polishing, a flattened surface as compared with that before polishing is obtained as shown in FIG.
【０００６】上記の例での研磨ストッパ３は、研磨速度
が絶縁膜２の１／５以下の材料を用いる。ここでの研磨
速度とは、図２（ｂ）（ｃ）のような段差付き基板上で
複数の膜を同時に研磨している場合の研磨速度ではな
く、平坦な基板上にこれらの材料を単独で形成し、それ
を図２（ｂ）（ｃ）と同じ条件で独立に研磨したときの
研磨速度のことである。以下、研磨速度とはこの意味で
用いる。例えば、フュームドシリカ研磨剤を用いる場
合、ＢＰＳＧ用の研磨ストッパとしては窒化珪素が用い
られる。窒化珪素の研磨速度はＢＰＳＧの約１／６であ
る。The polishing stopper 3 in the above example uses a material whose polishing rate is ⅕ or less of that of the insulating film 2. The polishing rate here does not mean the polishing rate in the case where a plurality of films are simultaneously polished on a stepped substrate as shown in FIGS. 2B and 2C, but these materials alone on a flat substrate. And the polishing rate when independently polished under the same conditions as in FIGS. 2 (b) and 2 (c). Hereinafter, the polishing rate is used in this sense. For example, when using a fumed silica polishing agent, silicon nitride is used as a polishing stopper for BPSG. The polishing rate of silicon nitride is about 1/6 that of BPSG.
【０００７】[0007]
【発明が解決しようとする課題】図１で示した方法で十
分な平坦性を得るには、絶縁膜２の膜厚を非常に厚く
し、研磨量を多くしなければならない。しかし、絶縁膜
２を形成するためのＣＶＤ法はコストが高いため、この
方法は実用的ではない。コストの問題は、膜形成速度の
遅いバイアスＥＣＲ ＣＶＤ法を用いた場合には特に深
刻である。従って、実用上のコストを考えた場合、絶縁
膜２の膜厚は最低限（下地基板の凹部上の絶縁膜が少な
くとも凸部よりも高くなるようにする）にせざるを得な
いため、図１（ｃ）に示したように表面に段差が残る。In order to obtain sufficient flatness by the method shown in FIG. 1, the insulating film 2 must be extremely thick and the polishing amount must be large. However, since the CVD method for forming the insulating film 2 is expensive, this method is not practical. The cost problem is particularly serious when the bias ECR CVD method having a low film formation rate is used. Therefore, in consideration of the practical cost, the film thickness of the insulating film 2 has to be minimized (the insulating film on the concave portion of the base substrate is at least higher than that on the convex portion). As shown in (c), a step remains on the surface.
【０００８】図２に示した方法は、研磨ストッパ３を設
けて、少ない研磨量でも十分な平坦性が得られるように
工夫した方法である。しかしこの方法でも、図２（ｃ）
に示したように表面に段差が残ってしまう。これは、図
２（ｂ）のように研磨ストッパが露出した後にディッシ
ングが生じるからである。ディッシングとは、研磨速度
が極端に違う物質が同時に露出したときに、研磨速度の
速い方の物質が選択的に研磨されて表面が凹んでしまう
現象である。The method shown in FIG. 2 is a method in which a polishing stopper 3 is provided so that sufficient flatness can be obtained even with a small polishing amount. However, even with this method, FIG.
As shown in, the step remains on the surface. This is because dishing occurs after the polishing stopper is exposed as shown in FIG. Dishing is a phenomenon in which when a substance having an extremely different polishing rate is exposed at the same time, the substance having a higher polishing rate is selectively polished and the surface is dented.
【０００９】本発明の目的は、研磨後の基板表面の平坦
性が不足したり、平坦性は十分にできても著しくコスト
が増加してしまったりする問題を解決する研磨剤と研磨
平坦化方法を提供することにある。An object of the present invention is to provide a polishing agent and a polishing flattening method for solving the problems that the flatness of the substrate surface after polishing is insufficient, or the cost is remarkably increased even if the flatness is sufficiently achieved. To provide.
【００１０】[0010]
【課題を解決するための手段】本発明では、図３（ａ）
に示すように、絶縁膜２の上に低コストの有機塗布ガラ
ス膜４（以下、有機ＳＯＧ）を形成して研磨前の絶縁膜
の膜厚を厚くしておく。ここで、有機ＳＯＧとは、オル
ガノシロキサンオリゴマ液を塗布・焼成して得られるオ
ルガノシロキサン系皮膜である。In the present invention, as shown in FIG.
As shown in, the low-cost organic coating glass film 4 (hereinafter, organic SOG) is formed on the insulating film 2 to increase the thickness of the insulating film before polishing. Here, the organic SOG is an organosiloxane film obtained by applying and firing an organosiloxane oligomer solution.
【００１１】また、本発明では、研磨特性の異なる複数
の研磨剤を混合し、絶縁膜２と有機塗布ガラス膜４の研
磨速度が同程度になるように調製した研磨剤を用いて、
上記の絶縁膜２と有機塗布ガラス膜４の積層膜を、図３
（ｂ）（ｃ）に示すように研磨平坦化する。Further, in the present invention, a plurality of abrasives having different polishing characteristics are mixed, and the abrasives prepared so that the insulating film 2 and the organic coating glass film 4 have approximately the same polishing rate,
The laminated film of the insulating film 2 and the organic coating glass film 4 is shown in FIG.
(B) As shown in (c), the surface is polished and flattened.
【００１２】[0012]
【作用】絶縁膜２の上に形成する有機ＳＯＧ膜４は塗布
膜なので、絶縁膜２のようにＣＶＤ法により形成した膜
（以下、ＣＶＤ膜）に比べて成膜コストは低い。また、
一回の塗布で形成するのであれば、膜厚が厚くても成膜
コストは低いままである。したがって、ＣＶＤ膜を厚く
形成して研磨量を増やしたのと同等の平坦化効果を、低
成膜コストで得ることができる。さらに、有機ＳＯＧ膜
の表面形状は同じ膜厚のＣＶＤ膜に比べて最初から平坦
に近いので、研磨後の平坦性の点からも有利である。Since the organic SOG film 4 formed on the insulating film 2 is a coating film, the film forming cost is lower than that of a film formed by the CVD method like the insulating film 2 (hereinafter referred to as a CVD film). Also,
If the film is formed by one-time coating, the film formation cost remains low even if the film thickness is large. Therefore, it is possible to obtain the flattening effect equivalent to that when the CVD film is formed thick and the polishing amount is increased at a low film forming cost. Further, since the surface shape of the organic SOG film is closer to flat from the beginning as compared with the CVD film having the same film thickness, it is advantageous in terms of flatness after polishing.
【００１３】また、絶縁膜２と有機ＳＯＧ膜４の研磨速
度が同程度になるように調製した研磨剤を用いれば、こ
れらの膜を同時に研磨しても研磨速度差に起因する平坦
性の悪化を抑制することができる。理想的には同時に研
磨する膜の研磨速度は等しいのが望ましいが、実際には
研磨速度比（有機ＳＯＧ膜４／絶縁膜２）が０.５ 以上
２以下であれば、平坦性は殆ど悪化しない。この条件を
満たし、かつ研磨速度が高い実用的な研磨剤が必要であ
る。Further, if the polishing agent prepared so that the insulating film 2 and the organic SOG film 4 have the same polishing rate, even if these films are simultaneously polished, the flatness is deteriorated due to the difference in polishing rate. Can be suppressed. Ideally, it is desirable that the films to be simultaneously polished have the same polishing rate, but in reality, if the polishing rate ratio (organic SOG film 4 / insulating film 2) is 0.5 or more and 2 or less, the flatness is almost deteriorated. do not do. A practical abrasive that satisfies this condition and has a high polishing rate is required.
【００１４】しかし、従来、上記のような研磨剤は得ら
れていなかった。例えば、通常用いられるフュームドシ
リカ研磨剤では、研磨速度比（有機ＳＯＧ膜４／絶縁膜
２）が１／４程度である。However, hitherto, the above abrasives have not been obtained. For example, with a commonly used fumed silica polishing agent, the polishing rate ratio (organic SOG film 4 / insulating film 2) is about 1/4.
【００１５】発明者らは、研磨特性の異なる酸化セリウ
ム研磨剤を複数種類混ぜて調製したことで上記のような
研磨剤を得られることを見い出した。まず、酸化セリウ
ム研磨剤の研磨特性について、以下で説明する。特願平
6−236445 号明細書には酸化セリウム研磨剤の研磨特性
について記載されている。ここで酸化セリウム研磨剤と
は、酸化セリウムの研磨粉を水などの溶媒中に分散さ
せ、酸やアルカリを用いてｐＨを調整したものである。The inventors have found that the above-mentioned abrasive can be obtained by preparing a mixture of a plurality of cerium oxide abrasives having different polishing characteristics. First, the polishing characteristics of the cerium oxide abrasive will be described below. Japanese Patent Application
The specification of 6-236445 describes the polishing characteristics of cerium oxide abrasives. Here, the cerium oxide abrasive is one in which abrasive powder of cerium oxide is dispersed in a solvent such as water, and the pH is adjusted using acid or alkali.
【００１６】上記の酸やアルカリの他にも、必要に応じ
て界面活性剤を加えて、酸化セリウム粒子を分散させて
沈殿しないようにすることもある。酸化セリウム研磨剤
の研磨特性は、その固体成分（研磨粉）の平均結晶子径
および研磨剤のｐＨ（水素イオン濃度）によって大きく
変化する。In addition to the above acids and alkalis, a surfactant may be added as necessary to disperse the cerium oxide particles so that they do not precipitate. The polishing characteristics of the cerium oxide abrasive greatly vary depending on the average crystallite size of the solid component (abrasive powder) and the pH (hydrogen ion concentration) of the abrasive.
【００１７】図４は、結晶子の小さい（３０ｎｍ以下）
酸化セリウム研磨剤（以下、酸化セリウムＡ）の研磨特
性である。ｐＨが小さい（ｐＨ＜３）領域では、酸化珪
素膜，ドープド酸化珪素膜，有機ＳＯＧ膜の研磨速度は
同程度であるが、その値は低いので実用的ではない。ｐ
Ｈがこれより大きい領域(特に、中性からアルカリ性)で
は、有機ＳＯＧ膜の研磨速度は高いが、酸化珪素膜，ド
ープド酸化珪素膜は殆ど研磨されない。FIG. 4 shows small crystallites (30 nm or less).
It is a polishing characteristic of a cerium oxide polishing agent (hereinafter, cerium oxide A). In the low pH region (pH <3), the polishing rates of the silicon oxide film, the doped silicon oxide film, and the organic SOG film are about the same, but the values are low, which is not practical. p
In a region where H is larger than this range (particularly, neutral to alkaline), the polishing rate of the organic SOG film is high, but the silicon oxide film and the doped silicon oxide film are hardly polished.
【００１８】図５は、結晶子の大きい（６０ｎｍ以上）
酸化セリウム研磨剤（以下、酸化セリウムＢ）の研磨特
性である。ｐＨが小さい（ｐＨ＜３）領域では、３種の
膜とも研磨速度は同程度であるが、その値は低すぎて実
用的ではない。ｐＨがこれより大きい領域（特に、中性
からアルカリ性）では、酸化珪素膜とドープド酸化珪素
膜の研磨速度は高いが、有機ＳＯＧ膜の研磨速度はこれ
に比べて低い。FIG. 5 shows a large crystallite (60 nm or more).
It is a polishing characteristic of a cerium oxide abrasive (hereinafter, cerium oxide B). In the low pH region (pH <3), the polishing rates of the three types of films are about the same, but the values are too low to be practical. In a region where the pH is higher than this range (particularly from neutral to alkaline), the polishing rate of the silicon oxide film and the doped silicon oxide film is high, but the polishing rate of the organic SOG film is lower than this.
【００１９】上記のように、ｐＨ＞３の領域での有機Ｓ
ＯＧ膜の研磨速度は、酸化セリウムＡでは高く、逆に酸
化セリウムＢでは低い。従って、これらを混合すること
によって、有機ＳＯＧ膜の研磨速度を調節することがで
きる。As mentioned above, organic S in the region of pH> 3
The polishing rate of the OG film is high for cerium oxide A and conversely low for cerium oxide B. Therefore, by mixing these, the polishing rate of the organic SOG film can be adjusted.
【００２０】図６は、酸化セリウムＡ及び酸化セリウム
Ｂの混合の割合と研磨速度の関係の一例である。図中に
示したように、有機ＳＯＧ膜の研磨速度が高い酸化セリ
ウムＡと有機ＳＯＧ膜の研磨速度が低い酸化セリウムＢ
を混合することで、有機SOG膜とドープド酸化珪素膜の
研磨速度を等しくすることも、研磨速度比（有機SOG膜
／ドープド酸化珪素膜）を０.５ 以上２以下にすること
も可能である。しかも、有機ＳＯＧ膜とドープド酸化珪
素膜の研磨速度が等しくなる点では、図５の酸化セリウ
ムＢのみで低ｐＨの場合に比べて研磨速度が高く、実用
的な研磨が可能である。FIG. 6 shows an example of the relationship between the mixing ratio of cerium oxide A and cerium oxide B and the polishing rate. As shown in the figure, cerium oxide A having a high polishing rate for the organic SOG film and cerium oxide B having a low polishing rate for the organic SOG film
It is possible to make the polishing rates of the organic SOG film and the doped silicon oxide film equal to each other and to make the polishing rate ratio (organic SOG film / doped silicon oxide film) 0.5 to 2 by mixing . In addition, in that the polishing rate of the organic SOG film and that of the doped silicon oxide film are equal, the polishing rate is higher than that of cerium oxide B alone in FIG. 5 and the pH is low, and practical polishing is possible.
【００２１】上記では有機ＳＯＧ膜とドープド酸化珪素
膜の研磨速度の調節の例を示したが、有機ＳＯＧ膜とド
ープド酸化珪素膜の研磨速度も同様の方法で調節可能な
ことは明らかである。Although an example of adjusting the polishing rates of the organic SOG film and the doped silicon oxide film has been shown above, it is clear that the polishing rates of the organic SOG film and the doped silicon oxide film can be adjusted by the same method.
【００２２】上記の研磨剤の混合の際は、最初からｐＨ
の等しい酸化セリウムＡと酸化セリウムＢを調製してか
ら混合してもよいが、ｐＨを調整していない酸化セリウ
ムＡと酸化セリウムＢを混合した後に、酸やアルカリを
加えてｐＨを調整しても同様の効果が得られる。When mixing the above-mentioned abrasives, the pH is adjusted from the beginning.
The cerium oxide A and the cerium oxide B having the same pH may be mixed and then mixed, but after mixing the cerium oxide A and the cerium oxide B whose pH is not adjusted, the pH is adjusted by adding an acid or an alkali. Also has the same effect.
【００２３】上記のｐＨ調整に用いる酸やアルカリとし
ては、金属を構成要素として含まず、腐食性の弱いもの
が望ましい。これは、半導体用途に用いた場合に、汚染
や腐食の問題を起こさないためである。このような酸や
アルカリの例としては、シュウ酸，スルファミン酸，リ
ン酸，琥珀酸，クエン酸，硝酸，アンモニア，抱水ヒド
ラジン，アミン，過酸化水素等がある。As the acid or alkali used for the above-mentioned pH adjustment, those which do not contain a metal as a constituent and have weak corrosiveness are desirable. This is because when used for semiconductor applications, problems such as contamination and corrosion do not occur. Examples of such acids and alkalis include oxalic acid, sulfamic acid, phosphoric acid, succinic acid, citric acid, nitric acid, ammonia, hydrazine hydrate, amine, hydrogen peroxide and the like.
【００２４】[0024]
（実施例１）固体濃度が１０重量％で平均結晶子径が２
０ｎｍの酸化セリウム研磨剤（以下、酸化セリウムＡ）
と固体濃度が１０重量％で平均結晶子径が８０ｎｍの酸
化セリウム研磨剤（以下、酸化セリウムＢ）のｐＨを
８.６ に調整した。このｐＨ調整には、シュウ酸あるい
はアンモニア水を用いた。これらを単独で、あるいは混
合して、ＢＰＳＧ膜，有機ＳＯＧ膜を研磨した。これら
の膜は、平坦な基板上にそれぞれ単独で形成したもので
ある。Example 1 A solid concentration of 10% by weight and an average crystallite size of 2
0 nm cerium oxide abrasive (hereinafter cerium oxide A)
Then, the pH of the cerium oxide abrasive (hereinafter, cerium oxide B) having a solid concentration of 10% by weight and an average crystallite diameter of 80 nm was adjusted to 8.6. Oxalic acid or aqueous ammonia was used for this pH adjustment. These were used alone or as a mixture to polish the BPSG film and the organic SOG film. These films are independently formed on a flat substrate.
【００２５】研磨加重は０.１５kg／cm2、研磨定盤の基
板に対する移動速度は３０ｍ／minである。ＢＰＳＧ膜
は、Ｂを１０原子％、Ｐを４原子％含むものであり、形
成後に窒素中で８５０度の熱処理を加えた。有機ＳＯＧ
膜は（株）日立化成工業製HSG2209S−R7であり、塗布後
の最終熱処理は窒素中で４５０℃で行った。The polishing load is 0.15 kg / cm 2 , and the moving speed of the polishing platen with respect to the substrate is 30 m / min. The BPSG film contains 10 atomic% of B and 4 atomic% of P, and was subjected to heat treatment at 850 ° C. in nitrogen after formation. Organic SOG
The film was HSG2209S-R7 manufactured by Hitachi Chemical Co., Ltd., and the final heat treatment after coating was performed in nitrogen at 450 ° C.
【００２６】研磨速度を図６に示す。酸化セリウムＡの
割合を０.４から０.８にすることで、ＢＰＳＧ膜と有機
ＳＯＧ膜の研磨速度が同程度（研磨速度比が０.５ 以上
２以下）になった。また、ｐＨ２の酸化セリウムＢのみ
を用いて研磨したときも両者の膜の研磨速度は同程度に
なったが、このときの研磨速度に比べて、上記のように
混合した酸化セリウム研磨剤を用いた場合の研磨速度は
２倍から３倍と速くなった。The polishing rate is shown in FIG. By changing the ratio of cerium oxide A from 0.4 to 0.8, the polishing rates of the BPSG film and the organic SOG film were about the same (the polishing rate ratio was 0.5 or more and 2 or less). Further, even when polishing was performed using only cerium oxide B having a pH of 2, the polishing rates of both films were about the same, but compared with the polishing rate at this time, the cerium oxide abrasive mixed as described above was used. The polishing rate was 2 to 3 times faster.
【００２７】上記の研磨剤を用いて、素子や配線で表面
に高さ５００ｎｍの段差のついた半導体基板を平坦化し
た。まず、図３（ａ）に示すように、絶縁膜２として厚
さ６００ｎｍのＢＰＳＧ膜を形成し、この上に厚さ５０
０ｎｍの有機ＳＯＧ膜４を形成した。これを上記の研磨
剤を用いて研磨平坦化した。最初は有機ＳＯＧ膜４のみ
を研磨していたが、途中で、図３（ｂ）に示すように絶
縁膜２が露出した。しかし、図３（ｃ）に示すように平
坦性が悪化することは殆どなかった。研磨後の段差の高
さは２０ｎｍ以下になっており、十分な平坦性が達成で
きた。これは、図１の従来の方法で、ＢＰＳＧ膜を１２
００ｎｍ以上堆積した場合と同等であり、膜の堆積コス
トが低減できた。Using the above-mentioned polishing agent, a semiconductor substrate having a height difference of 500 nm on the surface of the element or wiring was flattened. First, as shown in FIG. 3A, a BPSG film having a thickness of 600 nm is formed as the insulating film 2, and a thickness of 50 is formed thereon.
The 0 nm organic SOG film 4 was formed. This was polished and flattened using the above polishing agent. Initially, only the organic SOG film 4 was polished, but in the middle, the insulating film 2 was exposed as shown in FIG. 3B. However, as shown in FIG. 3C, the flatness hardly deteriorated. The height of the step after polishing was 20 nm or less, and sufficient flatness could be achieved. This is the conventional method of FIG.
This is equivalent to the case of depositing more than 00 nm, and the deposition cost of the film could be reduced.
【００２８】（実施例２）実施例１のＢＰＳＧ膜の代わ
りに、バイアスＥＣＲ ＣＶＤ法を用いて酸化珪素膜と
ＳｉＯＦ膜を形成して実施例１と同様の実験を行った。
これらの膜の場合は埋め込み状態は良好であり、形成後
に窒素中で高温（５００度以上）の熱処理を加える必要
はなかった。また、ＳｉＯＦ膜のフッ素含有量は６原子
％であった。これらの膜を実施例１と同様の酸化セリウ
ム研磨剤で研磨し、有機ＳＯＧ膜と研磨速度が同程度
（研磨速度比が０.５ 以上２以下）になる条件を求め
た。酸化珪素膜の場合は、酸化セリウムＡの割合が０.
５５から０.９５、ＳｉＯＦ膜の場合は、酸化セリウム
Ａの割合が０.４５から０.８５で研磨速度が同程度にな
った。Example 2 Instead of the BPSG film of Example 1, a silicon oxide film and a SiOF film were formed by using the bias ECR CVD method, and the same experiment as in Example 1 was conducted.
In the case of these films, the embedding state was good, and it was not necessary to apply heat treatment at high temperature (500 degrees or more) in nitrogen after formation. The fluorine content of the SiOF film was 6 atom%. These films were polished with the same cerium oxide abrasive as in Example 1, and conditions under which the polishing rate was about the same as the organic SOG film (polishing rate ratio was 0.5 or more and 2 or less) were obtained. In the case of a silicon oxide film, the proportion of cerium oxide A is 0.
In the case of the SiOF film of 55 to 0.95, the polishing rate was similar when the ratio of cerium oxide A was 0.45 to 0.85.
【００２９】上記の研磨剤を用いて、実施例１と同様に
段差付きの半導体基板を平坦化した。絶縁膜２として、
上記の酸化珪素膜を用いた場合と、ＳｉＯＦ膜を用いた
場合を検討した。研磨前の段差高さは５００ｎｍであっ
たが、絶縁膜２の上に有機ＳＯＧ膜４を形成して研磨し
た結果、段差の高さは２０ｎｍ以下になっており、十分
な平坦性が低コストで達成できた。The stepped semiconductor substrate was flattened using the above-mentioned polishing agent in the same manner as in Example 1. As the insulating film 2,
The case of using the silicon oxide film and the case of using the SiOF film were examined. The height of the step before polishing was 500 nm, but as a result of forming the organic SOG film 4 on the insulating film 2 and polishing, the height of the step was 20 nm or less, and sufficient flatness was obtained at low cost. Was achieved in.
【００３０】[0030]
【発明の効果】本発明によれば、著しくコストを増加さ
せることなく段差付き基板の表面を十分に平坦化するこ
とができる、研磨剤と研磨平坦化方法が提供される。According to the present invention, there are provided an abrasive and a polishing flattening method capable of sufficiently flattening the surface of a stepped substrate without significantly increasing the cost.
【図１】従来の平坦化方法の一例の説明図。FIG. 1 is an explanatory diagram of an example of a conventional planarization method.
【図２】従来の平坦化方法の一例の説明図。FIG. 2 is a diagram illustrating an example of a conventional flattening method.
【図３】本発明の平坦化方法の一例の説明図。FIG. 3 is an explanatory diagram of an example of a flattening method of the present invention.
【図４】酸化セリウムＡの水素イオン濃度と研磨速度の
関係の説明図。FIG. 4 is an explanatory diagram of a relationship between a hydrogen ion concentration of cerium oxide A and a polishing rate.
【図５】酸化セリウムＢの水素イオン濃度と研磨速度の
関係の説明図。FIG. 5 is an explanatory diagram of a relationship between a hydrogen ion concentration of cerium oxide B and a polishing rate.
【図６】酸化セリウムＡ及びＢの混合比と研磨速度の関
係の一例の説明図。FIG. 6 is an explanatory diagram showing an example of the relationship between the mixing ratio of cerium oxides A and B and the polishing rate.
１…段差付き半導体基板、２…絶縁膜、３…研磨ストッ
パ、４…有機塗布ガラス膜。1 ... Stepped semiconductor substrate, 2 ... Insulating film, 3 ... Polishing stopper, 4 ... Organic coated glass film.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 本間 喜夫 東京都国分寺市東恋ケ窪１丁目280番地 株式会社日立製作所中央研究所内 (72)発明者 長澤 正幸 東京都国分寺市東恋ケ窪１丁目280番地 株式会社日立製作所中央研究所内 (72)発明者 森山 茂夫 東京都国分寺市東恋ケ窪１丁目280番地 株式会社日立製作所中央研究所内 (72)発明者 五嶋 秀和 東京都小平市上水本町５丁目20番１号 株 式会社日立製作所半導体事業部内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Honma 1-280, Higashi Koikeku, Kokubunji, Tokyo Inside Central Research Laboratory, Hitachi, Ltd. (72) Masayuki Nagasawa 1-280, Higashi Koikeku, Kokubunji, Tokyo Hitachi, Ltd. Central Research Laboratory (72) Inventor Shigeo Moriyama 1-280 Higashi Koigokubo, Kokubunji City, Tokyo Hitachi Ltd. Central Research Laboratory (72) Inventor Hidekazu Goshima 5-20 1-1, Kamimizuhonmachi, Kodaira-shi, Tokyo Hitachi Within the Semiconductor Division of the manufacturing plant
Claims (7)
研磨剤を複数種類混合して得られることを特徴とする研
磨剤。1. A polishing agent obtained by mixing a plurality of types of polishing agents having different polishing rates for a material to be polished containing silicon.
ありかつその平均結晶子径が異なる研磨剤を複数種類混
合して得られることを特徴とする研磨剤。2. A polishing agent obtained by mixing a plurality of types of polishing agents having substantially the same composition of solid components of the polishing agent and having different average crystallite diameters.
求項１または２に記載の研磨剤。3. The abrasive according to claim 1, wherein the solid component of the abrasive is cerium oxide.
ウムであり平均結晶子径が３０ｎｍ以下の第一の研磨剤
と、研磨剤の固体成分が酸化セリウムであり平均結晶子
径が６０ｎｍ以上の第二の研磨剤を含む請求項１，２ま
たは３に記載の研磨剤。4. A first abrasive having a solid component of cerium oxide having an average crystallite diameter of 30 nm or less, and a solid component of abrasive having cerium oxide having an average crystallite diameter of 60 nm or more. The polishing agent according to claim 1, wherein the polishing agent contains a second polishing agent.
ぞれの膜を独立に研磨した場合の研磨速度の最大値が最
小値の２倍以下になるような研磨剤を用いて研磨する請
求項１，２，３または４に記載の研磨剤を用いた研磨平
坦化方法。5. When polishing a plurality of types of films at the same time, polishing is performed using a polishing agent such that the maximum value of the polishing rate when polishing each film independently is less than twice the minimum value. Item 5. A method of polishing and flattening using the abrasive according to Item 1, 2, 3 or 4.
るいはフッ素を含む酸化珪素膜、のいずれかからなる第
一の膜を独立に研磨した場合の研磨速度が、有機珪素化
合物からなる第二の膜を独立に研磨した場合の研磨速度
の０.５ 倍以上２倍以下になる請求項１，２，３、また
は４に記載の研磨剤。6. A second film made of an organosilicon compound having a polishing rate when the first film made of a silicon oxide film, or a silicon oxide film containing at least boron, phosphorus or fluorine, is independently polished. The polishing agent according to claim 1, 2, 3, or 4, which has a polishing rate of not less than 0.5 times and not more than 2 times when independently polished.
素膜、少なくとも硼素あるいは燐をあるいはフッ素を含
む酸化珪素膜、のいずれかからなる第一の膜と、有機珪
素化合物からなる第二の膜を同時に研磨する研磨平坦化
方法。7. The polishing agent according to claim 6 is used to form a silicon oxide film, a first film of at least one of a silicon oxide film containing boron, phosphorus, or fluorine, and an organic silicon compound. A polishing flattening method for simultaneously polishing the second film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24129995A JPH0982667A (en) | 1995-09-20 | 1995-09-20 | Abrasive and polishing and flattening |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24129995A JPH0982667A (en) | 1995-09-20 | 1995-09-20 | Abrasive and polishing and flattening |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0982667A true JPH0982667A (en) | 1997-03-28 |
Family
ID=17072221
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24129995A Pending JPH0982667A (en) | 1995-09-20 | 1995-09-20 | Abrasive and polishing and flattening |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0982667A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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. |
| JP2007129247A (en) * | 1997-12-18 | 2007-05-24 | Hitachi Chem Co Ltd | Abrasive and slurry |
| JP2007129249A (en) * | 1997-12-18 | 2007-05-24 | Hitachi Chem Co Ltd | Abrasive and slurry |
| US8673749B2 (en) | 2011-12-26 | 2014-03-18 | Denso Corporation | Semiconductor device manufacturing method |
-
1995
- 1995-09-20 JP JP24129995A patent/JPH0982667A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| JP2007129247A (en) * | 1997-12-18 | 2007-05-24 | Hitachi Chem Co Ltd | Abrasive and slurry |
| JP2007129249A (en) * | 1997-12-18 | 2007-05-24 | Hitachi Chem Co Ltd | Abrasive and slurry |
| US8673749B2 (en) | 2011-12-26 | 2014-03-18 | Denso Corporation | Semiconductor device manufacturing method |
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