JP2000303060A - Abrasive material for semiconductor containing fluorocompound abrasive grains - Google Patents
Abrasive material for semiconductor containing fluorocompound abrasive grainsInfo
- Publication number
- JP2000303060A JP2000303060A JP11043299A JP11043299A JP2000303060A JP 2000303060 A JP2000303060 A JP 2000303060A JP 11043299 A JP11043299 A JP 11043299A JP 11043299 A JP11043299 A JP 11043299A JP 2000303060 A JP2000303060 A JP 2000303060A
- Authority
- JP
- Japan
- Prior art keywords
- abrasive
- polishing
- abrasive grains
- oxide
- fluoride
- 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.)
- Withdrawn
Links
Landscapes
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
- Mechanical Treatment Of Semiconductor (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、半導体デバイス製
造工程における化学的機械研磨用研磨剤に関し、特に半
導体基板上に形成されたタンタル（Ｔａ）またはＴａ化
合物等の金属層や金属化合物層のＣＭＰに使用される研
磨剤に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing agent for chemical mechanical polishing in a semiconductor device manufacturing process, and more particularly to a CMP method for a metal layer or a metal compound layer such as tantalum (Ta) or a Ta compound formed on a semiconductor substrate. The present invention relates to an abrasive used for:
【０００２】[0002]
【従来の技術】現在、種々のデジタル家電製品、モバイ
ルコンピュータ、携帯情報通信機器等の更なる小型化、
高機能化、高速化、低消費電力化の要請に応じて、これ
ら機器のキーコンポーネントとして組み込まれて使用さ
れる半導体集積回路（以下、単に半導体装置、ＬＳＩ装
置又は半導体デバイスなどと云う。）においても微細化
・高密度化の検討が続けられており、基板上に形成した
絶縁層上に、サブミクロンのデザインルールの微細な線
幅の配線パターンを埋め込み、その微細な配線構造を絶
縁層を介してより多層積層化し高密度化した多層配線構
造が追求されている。2. Description of the Related Art At present, various digital home appliances, mobile computers, portable information communication devices and the like are further miniaturized.
In response to demands for higher functionality, higher speed, and lower power consumption, semiconductor integrated circuits (hereinafter, simply referred to as semiconductor devices, LSI devices, semiconductor devices, and the like) incorporated and used as key components of these devices. Investigations on miniaturization and high density are being continued, and a wiring pattern with a fine line width of submicron design rule is embedded on the insulating layer formed on the substrate, and the fine wiring structure is formed on the insulating layer. A multilayer wiring structure having a higher density and a higher density has been pursued.
【０００３】このように半導体装置の微細化・高密度化
が進むと、各層表面の凹凸が激しくなり、その凹凸段差
がリソグラフィ光学系の焦点深度を越えるようになり、
又、多層配線工程における断線やショートの原因となる
等種々の問題を惹起するので製造プロセスの然るべき段
階で、ウエハ表面を平坦化することが必須である。As the miniaturization and density increase of the semiconductor device progress as described above, the unevenness on the surface of each layer becomes severe, and the unevenness exceeds the depth of focus of the lithography optical system.
In addition, various problems such as disconnection and short circuit in the multi-layer wiring process are caused. Therefore, it is essential to flatten the wafer surface at an appropriate stage of the manufacturing process.
【０００４】従って、平坦化処理の重要なキーテクノロ
ジーとして、多層配線構造の半導体装置の製造工程にお
いて、その各々の層（半導体基板上）に形成された絶縁
膜及び／又は金属膜を超精密に平坦化しうるポリシング
技術である化学的機械研磨(Chemical Mechanical Polis
hing ; 以下、ＣＭＰと称することがある。）が、注目
されている。[0004] Therefore, as an important key technology of the flattening process, in a manufacturing process of a semiconductor device having a multilayer wiring structure, an insulating film and / or a metal film formed on each layer (on a semiconductor substrate) of the semiconductor device are super-precisely formed. Chemical Mechanical Polishing is a polishing technology that can be planarized.
hing; Hereinafter, it may be referred to as CMP. ) Has been noticed.
【０００５】従来、ドライエッチング等で容易にパター
ンニングしうることから、アルミニウム（Ａｌ）系の配
線材料が多く使用されているが、Ａｌ系の配線の場合、
配線幅０．２５μｍ以下というデザインルールのもとで
は、素子間の配線抵抗が無視できなくなって大きな配線
遅延時間が生ずるようになる。また、これと共に、Ａｌ
系配線間の寄生容量に起因する充放電によるパワーロス
が、モバイル機器等の低消費電力化に対する大きな障害
となることが問題となっている。Conventionally, aluminum (Al) -based wiring materials are often used because they can be easily patterned by dry etching or the like. In the case of Al-based wiring,
Under the design rule of a wiring width of 0.25 μm or less, wiring resistance between elements cannot be ignored and a large wiring delay time occurs. Also, with this, Al
There is a problem that power loss due to charging and discharging due to parasitic capacitance between system wirings becomes a major obstacle to reducing power consumption of mobile devices and the like.
【０００６】このため、より低抵抗の材料である銅（Ｃ
ｕ）配線及びＣｕ合金配線( 以下、Ｃｕ等と略する。 )
を次世代ＬＳＩ装置の多層配線構造として使用しようと
する試みが行われている。Ｃｕ等についてはドライエッ
チング温度が高くなりＡｌのように容易にドライエッチ
ングによる薄膜のパターンニングを行うことができない
ので、通常、層間絶縁膜上の配線溝及び／又はビアホー
ル( コンタクト溝）へ電解メッキ等の手段でＣｕ等を埋
め込み、これをＣＭＰ研磨して余分なＣｕ等の平坦化が
行われる。For this reason, copper (C), which is a lower-resistance material, is used.
u) Wiring and Cu alloy wiring (hereinafter abbreviated as Cu etc.)
Attempts have been made to use this as a multilayer wiring structure for next-generation LSI devices. For Cu and the like, the dry etching temperature is high, and it is not possible to pattern a thin film by dry etching as easily as Al. Therefore, usually, electrolytic plating is performed on wiring grooves and / or via holes (contact grooves) on an interlayer insulating film. Cu or the like is buried by such means as above, and this is polished by CMP to planarize excess Cu or the like.
【０００７】[0007]
【発明が解決しようとする課題】ところが、Ａｌと異な
り、Ｃｕ等の場合は安定な不動態酸化膜を作らず、Ｓｉ
やＳｉＯ2 で形成された層間絶縁膜中に拡散しやすいの
で、当該絶縁膜とＣｕ配線の間にＣｕの拡散防止のため
に、ＴｉＮ、ＷＮ、Ｔａ、ＴａＮ等の高融点金属又はそ
の窒化物の膜等をバリア金属層として配線溝とビアホー
ルの内壁や底部に用いる。この厚さは平坦上で数十ｎ
ｍ、配線溝やビアホール内壁上で数ｎｍ程度である。However, unlike Al, when Cu or the like is used, a stable passive oxide film is not formed and Si is used.
Because and SiO 2 easily diffused into the interlayer insulating film formed by, for between the insulating film and the Cu wiring diffusion preventing Cu, TiN, WN, Ta, refractory metal or a nitride such as TaN Is used as a barrier metal layer on the inner walls and bottoms of the wiring trenches and via holes. This thickness is several tens n on a flat surface.
m, about several nm on the wiring groove or the inner wall of the via hole.
【０００８】以上の如く、次世代半導体プロセスでにお
いては、Ｃｕ系配線技術及びこの平坦化技術としてのＣ
ＭＰが必須となる。現在、研磨剤としてはアルミナ等を
砥粒としＨ2 Ｏ2 等を酸化剤として含む研磨剤スラリー
が用いられ、研磨砥粒で被研磨表面を研削しながら酸化
された酸化生成物を研磨パッド( 研磨布 )と研磨剤スラ
リーで除去することが試みられている。しかしながら、
我々が検討したところによると、Ｃｕ等は比較的容易に
研磨できるものの、バリヤ金属層のうち、特にＴａやＴ
ａＮは、化学的反応性が乏しいためか、十分な研磨速度
が得られておらず、層間絶縁膜表面が露出するまでＣＭ
Ｐで平坦化研磨するのは困難であることがわかった。そ
のため、ＴａやＴａＮなどのバリア金属層をＣｕと共に
容易に研磨できる優れた研磨剤が必要とされている。As described above, in the next-generation semiconductor process, the Cu-based wiring technology and the C
MP is required. At present, as an abrasive, an abrasive slurry containing alumina or the like as abrasive grains and H 2 O 2 or the like as an oxidant is used, and an oxidized product oxidized while grinding the surface to be polished with the abrasive grains is used as a polishing pad ( Attempts have been made to remove them with a polishing cloth) and an abrasive slurry. However,
According to what we have studied, Cu and the like can be polished relatively easily, but among the barrier metal layers, in particular, Ta and T
aN is not sufficiently chemically polished due to poor chemical reactivity, and CM is used until the surface of the interlayer insulating film is exposed.
It was found that it was difficult to perform flattening polishing with P. Therefore, there is a need for an excellent polishing agent that can easily polish a barrier metal layer such as Ta or TaN together with Cu.
【０００９】本発明は、かくして、半導体デバイス製造
におけるＣＭＰ用として十分な研磨速度を有する研磨剤
の提供、特に、ＴａやＴａＮなどのバリア金属層を研磨
する際に、速い研磨速度を達成できる研磨剤の提供を目
的にする。Accordingly, the present invention provides a polishing agent having a sufficient polishing rate for CMP in the manufacture of semiconductor devices, and particularly, a polishing agent capable of achieving a high polishing rate when polishing a barrier metal layer such as Ta or TaN. The purpose is to provide an agent.
【００１０】[0010]
【課題を解決するための手段】(１) 本発明に従えば、
半導体デバイスの製造工程における化学的機械研磨用研
磨剤であって、水難溶性のフッ素化合物からなる砥粒が
含有され、半導体基板上に形成された金属層及び／又は
金属化合物層を研磨するための研磨剤、が提供される。Means for Solving the Problems (1) According to the present invention,
An abrasive for chemical mechanical polishing in a manufacturing process of a semiconductor device, which contains abrasive grains made of a poorly water-soluble fluorine compound, for polishing a metal layer and / or a metal compound layer formed on a semiconductor substrate. An abrasive is provided.
【００１１】(２) また本発明に従えば、上記の研磨剤
を化学的機械研磨装置の研磨布等の研磨手段に担持させ
て、すなわち具体的には上記の研磨剤のスラリーを化学
的機械研磨装置の研磨布に供給しながら、半導体基板上
に形成された金属層及び／又は金属化合物層の少なくと
も一部を研磨することを特徴とする半導体基板の研磨方
法、が提供される。本発明のさらに他の実施の形態は以
下の説明から明らかになるであろう。(2) Further, according to the present invention, the above-mentioned abrasive is carried on a polishing means such as a polishing cloth of a chemical mechanical polishing apparatus, that is, specifically, the slurry of the above-mentioned abrasive is subjected to chemical mechanical polishing. A method for polishing a semiconductor substrate, characterized in that at least a part of a metal layer and / or a metal compound layer formed on a semiconductor substrate is polished while being supplied to a polishing cloth of a polishing apparatus. Still other embodiments of the present invention will be apparent from the following description.
【００１２】[0012]
【発明の実施の形態】本発明は、水難溶性フッ素化合物
からなる砥粒を含有し、半導体基板上に形成された金属
層及び／又は金属化合物層の研磨に好適に適用しうる化
学的機械研磨( ＣＭＰ) 用研磨剤である。BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to chemical mechanical polishing which contains abrasive grains made of a poorly water-soluble fluorine compound and can be suitably applied to polishing of a metal layer and / or a metal compound layer formed on a semiconductor substrate. (CMP) abrasive.
【００１３】本発明においては研磨剤の砥粒としてフッ
素化合物からなる砥粒を使用する。この砥粒として使用
するフッ素化合物は、好ましくは研磨剤スラリーとして
使用するものであるから、水に分散させた場合、実質的
に水に溶解または水中で分解しない水難溶性のフッ素化
合物が好ましい。In the present invention, abrasive grains of a fluorine compound are used as abrasive grains of the abrasive. Since the fluorine compound used as the abrasive grains is preferably used as an abrasive slurry, a hardly water-soluble fluorine compound which does not substantially dissolve in water or decompose in water when dispersed in water is preferable.
【００１４】ここで水難溶性とは室温における水に対す
る溶解度が、少なくとも０．５ｇ／水１００ｇ以下のも
の、好ましくは０．１ｇ／水１００ｇ以下、更に好まし
くは０．０１ｇ／水１００ｇ以下、いっそう好ましくは
０．００１ｇ／水１００ｇ以下のものである。Here, the term "poorly water-soluble" means that the solubility in water at room temperature is at least 0.5 g / water 100 g or less, preferably 0.1 g / water 100 g or less, more preferably 0.01 g / water 100 g or less, and still more preferably. Is 0.001 g / 100 g or less of water.
【００１５】このような水難溶性のフッ素化合物として
は、例えば、フッ化リチウム( ＬｉＦ )；フッ化マグネ
シウム( ＭｇＦ2 ) 、フッ化カルシウム( ＣａＦ2 ) 、
フッ化ストロンチウム( ＳｒＦ2 ) 、フッ化バリウム(
ＢａＦ2 ) 等のアルカリ土類金属のフッ化物；フッ化セ
リウム( ＣｅＦ3 ，ＣｅＦ4 )、フッ化ランタン( Ｌａ
Ｆ3 )、フッ化プラセオジム( ＰｒＦ3 )、フッ化ネオ
ジム( ＮｄＦ3 )、フッ化ユーロピウム( ＥｕＦ2 ，Ｅ
ｕＦ3 )、フッ化ガドリニウム( ＧｄＦ3 )、フッ化サ
マリウム( ＳｍＦ3 )等のランタニド金属元素のフッ化
物；フッ化アクチニド( ＡｃＦ3 )、三フッ化ウラン(
ＵＦ3 )、フッ化ニプチニウム( ＮｐＦ 3 )、フッ化プ
ルトニウム( ＰｕＦ3 )、三フッ化アメリシウム( Ａｍ
Ｆ3 )、フッ化キュリウム( ＣｍＦ3 )等のアクチニド
金属元素のフッ化物；またはこれらの金属元素のオキシ
フッ素酸塩等が好ましいものとして挙げられる。これら
は単独で使用してもよいし混合して使用してもよい。As such a poorly water-soluble fluorine compound,
Is, for example, lithium fluoride (LiF);
Cium (MgFTwo ), Calcium fluoride (CaFTwo ),
Strontium fluoride (SrFTwo ), Barium fluoride (
BaFTwo ) And other alkaline earth metal fluorides;
Li (CeF)Three , CeFFour ), Lanthanum fluoride (La
FThree ), Praseodymium fluoride (PrFThree ), Neofluoride
Jim (NdFThree ), Europium fluoride (EuFTwo , E
uFThree ), Gadolinium fluoride (GdFThree ), Fluoride
Marium (SmFThree ) And other lanthanide metal elements
Substance; actinide fluoride (AcFThree ), Uranium trifluoride (
UFThree ), Nippinium fluoride (NpF Three ), Fluoride
Ruthenium (PuFThree ), Americium trifluoride (Am
FThree ), Curium fluoride (CmFThree ) And other actinides
Fluorides of metal elements; or oxy of these metal elements
Fluorate and the like are preferred. these
May be used alone or as a mixture.
【００１６】なかでも製造の容易さの点から、フッ化セ
リウム( ＣｅＦ3 ，ＣｅＦ4 )、オキシフッ化セリウム
( ＣｅＯＦ，ＣｅＯ2 Ｆ，Ｃｅ3 Ｏ3 Ｆ4 )、フッ化マ
グネシウム( ＭｇＦ2 ) 、フッ化カルシウム( ＣａＦ
2 ) が挙げられ、特にＣｅＦ3、ＭｇＦ2 、ＣａＦ2 、
ＣｅＯＦが好ましい。Cerium fluoride (CeF 3 , CeF 4 ), cerium oxyfluoride, etc.
(CeOF, CeO 2 F, Ce 3 O 3 F 4 ), magnesium fluoride (MgF 2 ), calcium fluoride (CaF
2 ), especially CeF 3 , MgF 2 , CaF 2 ,
CeOF is preferred.
【００１７】本発明で使用するフッ素化合物は、アルカ
リ土類金属等の適当な塩にフッ化水素酸を作用する等の
手段により容易に得ることができる。又、市販品も容易
に入手することが可能でありこれを使用してもよい。The fluorine compound used in the present invention can be easily obtained by a method such as the action of hydrofluoric acid on a suitable salt such as an alkaline earth metal. Also, commercially available products can be easily obtained, and these may be used.
【００１８】これらのフッ素化合物からなる砥粒は、研
磨剤スラリーとして水に分散させたときに実質的に水に
溶解せずに砥粒として作用する。The abrasive grains made of these fluorine compounds, when dispersed in water as an abrasive slurry, act as abrasive grains without being substantially dissolved in water.
【００１９】本発明のフッ素化合物からなる砥粒の重量
平均粒径は、ＣＭＰ法に用いるためには、０．００５〜
２．０μｍが好ましく、研磨速度や、スクラッチの発生
量などを考慮すると０．０１〜０．５μｍが特に好まし
い。これより粒径があまり大であるとスクラッチが増加
し、あまり小であると研削力が低下する。The weight average particle diameter of the abrasive grains comprising the fluorine compound of the present invention is 0.005 to 0.005.
2.0 μm is preferable, and 0.01 to 0.5 μm is particularly preferable in consideration of the polishing rate, the amount of generation of scratches, and the like. If the particle size is too large, scratches will increase, and if it is too small, the grinding power will decrease.
【００２０】なお、本発明において、重量平均粒径は、
質量基準で粒度分布を求め、全質量を１００％とした累
積カーブにおいて、その累積カーブが５０％となる点の
粒径である。これを質量基準累積５０％径ともいう（例
えば、化学工学便覧「改定５版」（化学工学会編）ｐ２
２０〜２２１の記載参照）。粒径の測定は、水等の媒体
に超音波処理等で充分分散させて粒度分布測定すること
により行う。In the present invention, the weight average particle size is
The particle size distribution is determined based on the mass, and in the cumulative curve with the total mass being 100%, the particle size at the point where the cumulative curve becomes 50%. This is also referred to as a 50% diameter based on mass (for example, Chemical Engineering Handbook “Revision 5th Edition” (edited by the Society of Chemical Engineers), p2
20-221). The particle size is measured by sufficiently dispersing in a medium such as water by ultrasonic treatment or the like and measuring the particle size distribution.
【００２１】本発明のフッ素化合物からなる砥粒は単独
で使用してもよいが他の一種又は二種以上の研磨砥粒と
混合して用いてもよい。他の研磨砥粒の種類は研磨対象
により適宜選択されるが、コスト、研削力から、酸化セ
リウム( セリア，ＣｅＯ2 )、酸化アルミニウム（アル
ミナ，Ａｌ2 Ｏ3 ) 、二酸化ケイ素( シリカ，ＳｉＯ
2 ) 、酸化ジルコニウム( ジルコニア, ＺｒＯ2 ) 、酸
化チタン( チタニア, ＴｉＯ2 ) 、酸化ゲルマニウム(
ゲルマニア，ＧｅＯ，ＧｅＯ2 ) 、窒化ケイ素(Ｓｉ3
Ｎ4 ）、酸化マンガン( ＭｎＯ2 ，Ｍｎ2 Ｏ3 ，Ｍｎ3
Ｏ4 等）から選択されることが好ましく、なかでもセリ
ア、アルミナ、ジルコニア、チタニア、ゲルマニア、シ
リカが特に好ましく、製造の容易さの点でセリアまたは
アルミナが最も好ましい。これら砥粒の重量平均粒子径
も、上記と同様な理由により０．００５〜２．０μｍが
好ましく、研磨速度や、スクラッチの発生量などを考慮
すると０．０１〜０．５μｍがさらに好ましい。The abrasive grains comprising the fluorine compound of the present invention are used alone
May be used with other one or more abrasive grains
You may mix and use. Other types of abrasive grains are subject to polishing
Depending on cost and grinding power.
Li (Ceria, CeO)Two ), Aluminum oxide (Al
Mina, AlTwo OThree ), Silicon dioxide (silica, SiO
Two ), Zirconium oxide (zirconia,ZrOTwo ), Acid
Titanium (Titania,TiOTwo ), Germanium oxide (
Germania, GeO, GeOTwo ), Silicon nitride (SiThree
NFour ), Manganese oxide (MnO)Two , MnTwo OThree , MnThree
OFour Etc.) are preferred, and
A, alumina, zirconia, titania, germania,
Lica is particularly preferred, because of its ease of manufacture ceria or
Alumina is most preferred. Weight average particle size of these abrasive grains
Is 0.005 to 2.0 μm for the same reason as above.
Preferably, considering the polishing rate and the amount of scratches generated
Then, 0.01 to 0.5 μm is more preferable.
【００２２】ここで使用するセリア等は炭酸希土等の原
料を電気炉中で焼成することにより容易に得られ、ま
た、原料の粒径を粉砕等により調整することで砥粒粒子
の粒径を所望の範囲にすることが可能である。また、焼
成後、分級等により好ましい粒径を有する粒子を選択的
に得ることも可能である。The ceria and the like used here can be easily obtained by firing a material such as rare earth carbonate in an electric furnace, and the particle size of the abrasive particles can be adjusted by adjusting the particle size of the material by grinding or the like. Can be in a desired range. After firing, it is also possible to selectively obtain particles having a preferred particle size by classification or the like.
【００２３】本発明のフッ素化合物からなる砥粒と他の
研磨剤砥粒との重量比は、任意に選択できるものである
が、通常研削力の点からは、０．００１：１〜１：１が
好ましく、０．１：１〜１：１が特に好ましい。The weight ratio between the abrasive grains comprising the fluorine compound of the present invention and the other abrasive grains can be arbitrarily selected, but usually from the viewpoint of grinding power, 0.001: 1-1: 1: 1 is preferred, and 0.1: 1 to 1: 1 is particularly preferred.
【００２４】本発明の研磨剤の使用方法については特に
限定されないが、水に撹拌混合機やホモジナイザーで十
分分散させ、固形分が０．１〜３０重量％、好ましくは
１〜１５重量％のスラリー( 以下、研磨剤スラリーとも
云う。 )として用いることが望ましい。また、このスラ
リー中には、用途に応じて、分散剤、増粘剤、酸化剤ま
たはｐＨ調節剤等を適宜添加して使用してもよい。The method of using the abrasive of the present invention is not particularly limited. However, a slurry having a solid content of 0.1 to 30% by weight, preferably 1 to 15% by weight, is sufficiently dispersed in water with a stirring mixer or a homogenizer. (Hereinafter also referred to as an abrasive slurry). In addition, a dispersant, a thickener, an oxidizing agent, a pH adjuster, or the like may be appropriately added to the slurry depending on the use.
【００２５】この研磨剤スラリーを使用する研磨は、常
法に従って行うことができる。例えば上部に半導体基板
等の被研磨材を保持しながら回転を与える駆動装置を備
えたポリシングヘッドと、これに対向する下部のポリシ
ングパッド( 研磨布 )が貼付されている回動しうる定盤
( プラテン )からなるＣＭＰ装置において、当該研磨布
等の研磨手段に本発明の研磨剤を担持させ、すなわち具
体的には研磨剤スラリーをこの研磨布の上に供給しなが
ら、半導体基板の平坦化を行えばよい。Polishing using this abrasive slurry can be performed according to a conventional method. For example, a polishing head provided with a driving device for rotating while holding a material to be polished such as a semiconductor substrate on an upper portion, and a rotatable platen to which a lower polishing pad (polishing cloth) opposed thereto is attached
In the CMP apparatus comprising (platen), the polishing means such as the polishing cloth carries the polishing slurry of the present invention, that is, while the polishing slurry is supplied on the polishing cloth, the semiconductor substrate is flattened. Should be performed.
【００２６】このようにして、半導体基板上に形成され
た金属層及び／又は金属化合物層の少なくとも一部を研
磨し、その金属層等の数十ｎｍ〜数千ｎｍを除去し平坦
化する。Thus, at least a part of the metal layer and / or the metal compound layer formed on the semiconductor substrate is polished, and several tens nm to several thousand nm of the metal layer and the like are removed and flattened.
【００２７】現在のところ、本発明の研磨剤の詳しい研
磨機構については完全には明確ではないが、おそらく次
のようであろうと推定される。すなわち、本発明の研磨
剤は、ＣｅＦ2 等のような水に難溶性のフッ素化合物か
らなる砥粒を含むものであるが、これをスラリーとして
水中に懸濁・分散させた状態においては、当該砥粒粒子
表面の固−液界面近傍( または境膜中 )で僅かに溶液中
に溶出しており、その一部が加水分解して少量のフッ酸
が生成していると考えられる。当該粒子が研磨中に被研
磨材層たるＴａ層表面に衝突する際に、生成したフッ酸
がＴａと反応して容易にフッ化タンタルとなり、このフ
ッ化タンタル層が、砥粒により速やかに剥離・除去され
るのではないかと推測される。これが本発明の研磨剤に
より高研磨レートが得られる理由であろう。At present, the detailed polishing mechanism of the abrasive of the present invention is not completely clear, but is presumed to be as follows. That is, the abrasive of the present invention contains abrasive grains made of a fluorine compound that is hardly soluble in water, such as CeF 2 , and when the slurry is suspended and dispersed in water as a slurry, the abrasive grains are It is slightly eluted in the solution near the solid-liquid interface (or in the boundary film) on the particle surface, and it is considered that a part of it is hydrolyzed to generate a small amount of hydrofluoric acid. When the particles collide with the surface of the Ta layer as the material layer during polishing, the generated hydrofluoric acid reacts with Ta and easily becomes tantalum fluoride, and this tantalum fluoride layer is quickly separated by abrasive grains.・ It is speculated that they may be removed. This may be the reason why a high polishing rate can be obtained by the abrasive of the present invention.
【００２８】これに対して、水溶性のフッ化物( 多くの
フッ化物は水溶性である。）を研磨砥粒として水中に投
入してスラリとした場合は全く事情が異なる。当該フッ
化物が溶解し水溶液中で生ずる遊離のフッ化物イオンや
フッ酸により、金属層等の表面で必要以上の、または余
計なエッチングや反応等が制御不可能な程度に起こるの
で、微細な半導体の金属薄膜等の表面をｎｍのオーダー
で制御して研磨しなけれならないＣＭＰ研磨剤として適
用することは困難である。また、フッ酸が研磨剤スラリ
ー中に多量に存在している場合、研磨機に腐食等を起こ
す問題や、作業性の悪化が避けられない等の問題が生ず
る。On the other hand, when water-soluble fluoride (many fluorides are water-soluble) is introduced into water as abrasive grains to form a slurry, the situation is completely different. Free fluoride ions or hydrofluoric acid generated in an aqueous solution by dissolution of the fluoride cause unnecessary or unnecessary etching or reaction on the surface of the metal layer or the like to an uncontrollable degree. It is difficult to apply as a CMP polishing agent that must control and polish the surface of a metal thin film or the like in the order of nm. Further, when a large amount of hydrofluoric acid is present in the abrasive slurry, problems such as corrosion of the polishing machine and deterioration of workability are unavoidable.
【００２９】本発明においては、敢えて水に難溶性のフ
ッ素化合物を選択して砥粒として研磨剤に含ませしめた
ものであるが、意外なことに、水溶性フッ化物のような
余計なエッチング等反応を実質的に伴うことなく、目的
のＴａ層等の研磨速度のみを顕著に向上せしめることが
できたものであり、半導体用のＣＭＰ研磨剤として非常
に有効なものである。In the present invention, a fluorine compound which is hardly soluble in water is intentionally selected and included in the abrasive as abrasive grains. However, surprisingly, unnecessary etching such as water-soluble fluoride is unnecessary. It is possible to significantly improve only the polishing rate of the target Ta layer or the like without substantially involving a reaction, and it is very effective as a CMP polishing agent for semiconductors.
【００３０】[0030]
【実施例】以下に本発明の実施例を説明するが、本発明
の技術的範囲がこれに限定されるものではない。例１及
び例２は実施例、例３及び例４は比較例である。本発明
の研磨剤は、例１〜４のように研磨剤を製造し、以下の
方法で研磨レートの測定を行った。DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but the technical scope of the present invention is not limited thereto. Examples 1 and 2 are Examples and Examples 3 and 4 are Comparative Examples. The polishing slurry of the present invention was prepared as in Examples 1 to 4, and the polishing rate was measured by the following method.
【００３１】(Ｉ) 〔研磨スラリーの調製〕 〔例１〕市販の炭酸セリウムを湿式粉砕後、５５％フッ
化水素酸を炭酸セリウムに対し１０重量％添加し撹拌後
乾燥した。これを電気炉を用いて７００℃で焼成後、重
量平均粒径０．２５μｍになるように分級した。なお、
得られた粉体はＸ線回折装置( 島津製作所製) によるＸ
線回折測定の結果ＣｅＯ2 粒子とＣｅＯＦ粒子との混合
物（ＣｅＯ2 ／ＣｅＯＦ重量比＝９／１）であった。こ
れにイオン交換水を加え固体含量が１０重量％の研磨剤
スラリーとした。(I) [Preparation of polishing slurry] [Example 1] Commercially available cerium carbonate was wet-pulverized, 55% hydrofluoric acid was added to 10% by weight of cerium carbonate, and the mixture was stirred and dried. This was fired at 700 ° C. in an electric furnace, and then classified so as to have a weight average particle size of 0.25 μm. In addition,
The obtained powder was analyzed by X-ray diffractometer (manufactured by Shimadzu Corporation).
As a result of the line diffraction measurement, the mixture was a mixture of CeO 2 particles and CeOF particles (CeO 2 / CeOF weight ratio = 9/1). Ion-exchanged water was added thereto to obtain an abrasive slurry having a solid content of 10% by weight.
【００３２】〔例２〕市販のＣｅＦ3 を湿式粉砕し、重
量平均粒径０．２５μｍになるように分級した。これと
例３により調製された重量平均粒径０．２５μｍのＣｅ
Ｏ2 を１：９重量比の割合で混合し、混合物にイオン交
換水を加えて固体含量が１０重量％の研磨剤スラリーと
した。Example 2 Commercially available CeF 3 was wet-pulverized and classified to have a weight average particle size of 0.25 μm. This and Ce having a weight average particle size of 0.25 μm prepared according to Example 3
O 2 was mixed at a ratio of 1: 9 by weight, and ion-exchanged water was added to the mixture to obtain an abrasive slurry having a solid content of 10% by weight.
【００３３】〔例３〕市販の炭酸セリウムを湿式粉砕
後、乾燥した。これを電気炉を用いて７００℃で焼成
後、重量平均粒径０．２５μｍになるように分級した。
得られた粉体はＣｅＯ2 であった。これにイオン交換水
を加えて固体含量が１０重量％の研磨剤スラリーとし
た。Example 3 Commercially available cerium carbonate was wet-pulverized and then dried. This was fired at 700 ° C. in an electric furnace, and then classified so as to have a weight average particle size of 0.25 μm.
The obtained powder was CeO 2 . Ion-exchanged water was added thereto to obtain an abrasive slurry having a solid content of 10% by weight.
【００３４】〔例４〕市販の高純度微粉アルミナ（α−
アルミナ）を重量平均粒径０．２５μｍになるように分
級した。これにイオン交換水を添加して固体含量が重量
１０重量％の研磨剤スラリーを調製した。Example 4 A commercially available high-purity finely divided alumina (α-
(Alumina) was classified to have a weight average particle size of 0.25 μm. Ion-exchanged water was added thereto to prepare an abrasive slurry having a solid content of 10% by weight.
【００３５】（II) 〔研磨レートの測定〕 (１) 上記の例１〜例４の研磨剤スラリーについて、以
下の研磨条件で、２０分タンタル板の研磨を行い、研磨
前後のタンタル板の重量差を測定した。使用したタンタ
ル板の表面積および密度から重量減少分をタンタルの厚
さに換算し、研磨レート（Å／ｍｉｎ）を求めた。結果
を表１に示す(II) [Measurement of Polishing Rate] (1) The abrasive slurries of Examples 1 to 4 were polished on a tantalum plate for 20 minutes under the following polishing conditions, and the weight of the tantalum plate before and after polishing was obtained. The difference was measured. From the surface area and density of the used tantalum plate, the amount of weight reduction was converted into the thickness of tantalum, and the polishing rate (Å / min) was determined. The results are shown in Table 1.
【００３６】（研磨条件） ラッピングマシン：６Ｂラッピングマシン 研磨対象：タンタル板( ニラコ（株）製) 研磨圧力：１５０ｇ／ｃｍ2 研磨パッド：Ｃｉｅｇａｌ２５−０( 千代田（株）製
） 回転数：上盤２８ｒｐｍ、下盤８４ｒｐｍ スラリー供給速度：２．４リットル／ｍｉｎ(Polishing conditions) Lapping machine: 6B lapping machine Polishing target: Tantalum plate (manufactured by Niraco Co., Ltd.) Polishing pressure: 150 g / cm 2 Polishing pad: Ciegal 25-0 (manufactured by Chiyoda Co., Ltd.) Number of revolutions: upper plate 28 rpm, lower plate 84 rpm Slurry supply rate: 2.4 liter / min
【００３７】[0037]
【表１】 [Table 1]
【００３８】(２) タンタル板の代わりに銅板( ニラコ
（株）製 )を用いたほかは、 (１) と同一の条件で研磨
を行い、同様にして研磨レート( Å／ｍｉｎ）を求め
た。結果を表１に示す。(2) Polishing was performed under the same conditions as in (1) except that a copper plate (manufactured by Niraco Co., Ltd.) was used instead of the tantalum plate, and the polishing rate ((/ min) was determined in the same manner. . Table 1 shows the results.
【００３９】表１を参照すれば明らかなように、本発明
の本発明の本発明フッ素化合物を研磨砥粒として含有す
る研磨剤( 例１〜例２ )は、フッ素化合物を含まない従
来のセリアやアルミナ砥粒のみからなる研磨剤( 例３〜
例４ )に比べ、Ｔａに対し極めて高い研磨レートを示す
ことが明らかである。As is apparent from Table 1, the abrasive containing the fluorine compound of the present invention of the present invention as abrasive grains (Examples 1 and 2) is a conventional ceria containing no fluorine compound. And abrasives consisting of alumina abrasive grains only (Example 3 ~
It is clear that the polishing rate is extremely high with respect to Ta as compared with Example 4).
【００４０】また、例１〜例４の銅板に対する研磨レー
トの結果を参照すれば、例１、例２においては、Ｃｕ／
Ｔａの研磨レートの比は２以下であり、Ｔａなどのバリ
ア金属層をＣｕと共に容易に研磨できることがわかる。Referring to the results of the polishing rates for the copper plates of Examples 1 to 4, in Examples 1 and 2, Cu /
The ratio of the polishing rate of Ta is 2 or less, which indicates that the barrier metal layer such as Ta can be easily polished together with Cu.
【００４１】これに対し、例３、例４においては、Ｃｕ
／Ｔａの研磨レートの比は８程度であり、層間絶縁膜表
面が露出するまでＴａ層を平坦化研磨しようとすると、
Ｃｕ層のデッシング等が生ずるおそれがあることが理解
される。On the other hand, in Examples 3 and 4, Cu
The ratio of the polishing rate of / Ta is about 8, and when trying to flatten and polish the Ta layer until the surface of the interlayer insulating film is exposed,
It is understood that dishing of the Cu layer may occur.
【００４２】以上の結果から明らかな如く、本発明のフ
ッ素化合物を砥粒として含有する研磨剤は、半導体デバ
イス製造工程における薄膜、特にバリア金属層を形成す
るＴａおよびＴａ化合物を研磨する目的で有効に利用で
きる。As is clear from the above results, the abrasive containing the fluorine compound of the present invention as abrasive grains is effective for polishing a thin film, particularly Ta and a Ta compound for forming a barrier metal layer in a semiconductor device manufacturing process. Available to
【００４３】[0043]
【発明の効果】本発明のフッ素化合物からなる砥粒を含
有する研磨剤は、ＴａおよびＴａ化合物の研磨速度がき
わめて速い。従って、半導体デバイス製造において、金
属層や金属化合物層用の研磨剤、特にＣｕ拡散防止用の
バリア金属層として用いられるＴａやＴａＮ等のＣＭＰ
用の研磨剤としてきわめて有用なものである。The polishing slurry of the present invention containing abrasive grains made of a fluorine compound has an extremely high polishing rate for Ta and the Ta compound. Therefore, in semiconductor device manufacturing, CMP such as Ta or TaN used as a polishing agent for a metal layer or a metal compound layer, particularly a barrier metal layer for preventing Cu diffusion.
It is very useful as an abrasive for polishing.
Claims (6)
的機械研磨用研磨剤であって、水難溶性のフッ素化合物
からなる砥粒が含有され、半導体基板上に形成された金
属層及び／又は金属化合物層を研磨するための研磨剤。An abrasive for chemical mechanical polishing in a manufacturing process of a semiconductor device, wherein the abrasive contains a sparingly water-soluble fluorine compound, and a metal layer and / or a metal compound layer formed on a semiconductor substrate Abrasive for polishing.
ａ化合物層である請求項１記載の研磨剤。2. The method according to claim 1, wherein the metal layer is a Ta layer and the metal compound layer is a T layer.
The abrasive according to claim 1, which is an a compound layer.
ム、又はカルシウムを含むフッ素化合物である請求項１
又は２記載の研磨剤。3. The fluorine compound containing cerium, magnesium, or calcium.
Or the abrasive according to 2.
フッ化セリウム、フッ化マグネシウム、フッ化カルシウ
ム又はそれらの混合物である請求項１〜３の何れかに記
載の研磨剤。4. The abrasive according to claim 1, wherein the fluorine compound is cerium fluoride, cerium oxyfluoride, magnesium fluoride, calcium fluoride, or a mixture thereof.
に、さらに重量平均粒子径０．００５〜２．０μｍの、
酸化セリウム、酸化アルミニウム、二酸化ケイ素、酸化
ジルコニウム、酸化チタン、酸化ゲルマニウム、窒化ケ
イ素及び酸化マンガンからなる群より選択される少なく
とも一種類の砥粒が含有されている研磨剤。5. The abrasive according to claim 1, further comprising a weight average particle diameter of 0.005 to 2.0 μm,
An abrasive containing at least one abrasive selected from the group consisting of cerium oxide, aluminum oxide, silicon dioxide, zirconium oxide, titanium oxide, germanium oxide, silicon nitride, and manganese oxide.
を化学的機械研磨装置の研磨手段に担持させて、半導体
基板上に形成された金属層及び／又は金属化合物層の少
なくとも一部を研磨することを特徴とする半導体基板の
研磨方法。6. The polishing agent according to claim 1, which is carried by a polishing means of a chemical mechanical polishing apparatus, wherein at least one of a metal layer and / or a metal compound layer formed on the semiconductor substrate is formed. A method of polishing a semiconductor substrate, comprising polishing a portion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11043299A JP2000303060A (en) | 1999-04-19 | 1999-04-19 | Abrasive material for semiconductor containing fluorocompound abrasive grains |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11043299A JP2000303060A (en) | 1999-04-19 | 1999-04-19 | Abrasive material for semiconductor containing fluorocompound abrasive grains |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000303060A true JP2000303060A (en) | 2000-10-31 |
Family
ID=14535600
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11043299A Withdrawn JP2000303060A (en) | 1999-04-19 | 1999-04-19 | Abrasive material for semiconductor containing fluorocompound abrasive grains |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000303060A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002346912A (en) * | 2001-05-18 | 2002-12-04 | Nippon Sheet Glass Co Ltd | Glass substrate for information recording medium and manufacturing method therefor |
| EP1536461A1 (en) * | 2002-09-06 | 2005-06-01 | Asahi Glass Company Ltd. | Polishing agent composition for insulating film for semiconductor integrated circuit and method for manufacturing semiconductor integrated circuit |
| US6986798B2 (en) * | 2000-11-30 | 2006-01-17 | Showa Denko K.K. | Cerium-based abrasive, production process thereof |
-
1999
- 1999-04-19 JP JP11043299A patent/JP2000303060A/en not_active Withdrawn
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6986798B2 (en) * | 2000-11-30 | 2006-01-17 | Showa Denko K.K. | Cerium-based abrasive, production process thereof |
| US7470297B2 (en) | 2000-11-30 | 2008-12-30 | Showa Denko K.K. | Cerium-based abrasive and production process thereof |
| JP2002346912A (en) * | 2001-05-18 | 2002-12-04 | Nippon Sheet Glass Co Ltd | Glass substrate for information recording medium and manufacturing method therefor |
| EP1536461A1 (en) * | 2002-09-06 | 2005-06-01 | Asahi Glass Company Ltd. | Polishing agent composition for insulating film for semiconductor integrated circuit and method for manufacturing semiconductor integrated circuit |
| EP1536461A4 (en) * | 2002-09-06 | 2007-03-28 | Asahi Glass Co Ltd | Polishing agent composition for insulating film for semiconductor integrated circuit and method for manufacturing semiconductor integrated circuit |
| US7378348B2 (en) | 2002-09-06 | 2008-05-27 | Asahi Glass Company, Limited | Polishing compound for insulating film for semiconductor integrated circuit and method for producing semiconductor integrated circuit |
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