JP2001254185A - Method of depositing electrically conductive metallic thin film and electrically conductive metallic hyperfine particle-dispersed material used for the method - Google Patents
Method of depositing electrically conductive metallic thin film and electrically conductive metallic hyperfine particle-dispersed material used for the methodInfo
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- JP2001254185A JP2001254185A JP2000069129A JP2000069129A JP2001254185A JP 2001254185 A JP2001254185 A JP 2001254185A JP 2000069129 A JP2000069129 A JP 2000069129A JP 2000069129 A JP2000069129 A JP 2000069129A JP 2001254185 A JP2001254185 A JP 2001254185A
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- Prior art keywords
- conductive metal
- thin film
- dispersion
- electrically conductive
- metal
- Prior art date
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、基板上に導電性金
属薄膜を形成する方法およびその方法に用いる導電性金
属超微粒子分散物に関し、特にＬＳＩ基板等の半導体基
板上に金(Ａｕ)、銀(Ａｇ)、銅(Ｃｕ)等の導電性金属の
超微粒子分散物を利用して導電性金属薄膜を形成する方
法およびその方法に用いる導電性金属超微粒子分散物に
関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a conductive metal thin film on a substrate and a conductive metal ultrafine particle dispersion used for the method, and more particularly to a method for forming a conductive metal thin film on a semiconductor substrate such as an LSI substrate. The present invention relates to a method of forming a conductive metal thin film using a dispersion of ultrafine particles of a conductive metal such as silver (Ag) and copper (Cu) and a dispersion of ultrafine conductive metal used in the method.
【０００２】[0002]
【従来の技術】最近の半導体産業におけるＬＳＩの高集
積化および高速化により、半導体基板の配線の微細化と
多層化が進み、配線ピッチが狭まることによって配線間
容量や配線抵抗による信号遅延の問題が生じている。こ
れを避けるために、抵抗率の低い配線材料と誘電率の低
い層間絶縁膜を用いる必要に迫られ、配線材として、従
来のＡｌ合金等の代わりに抵抗率の低いかつエレクトロ
マイグレーション（ＥＭ）耐性のあるＣｕがすでに実用
化され始めている。Ｃｕ薄膜の形成法には、スパッタ
法、ＣＶＤ法、メッキ法等によりＣｕ膜を配線溝、ビア
ホール、コンタクトホール等に堆積させ、次いでＣＭＰ
(Chemical-mechanical polishing)処理するいわゆるダ
マシン法が開発されている。2. Description of the Related Art With the recent high integration and high speed of LSIs in the semiconductor industry, finer wiring and multi-layering of semiconductor substrates have been advanced, and the wiring pitch has been narrowed. Has occurred. In order to avoid this, it is necessary to use a wiring material having a low resistivity and an interlayer insulating film having a low dielectric constant. As a wiring material, instead of a conventional Al alloy or the like, a low resistivity and electromigration (EM) resistance are used. Cu with some properties has already begun to be put to practical use. For forming a Cu thin film, a Cu film is deposited in a wiring groove, a via hole, a contact hole, or the like by a sputtering method, a CVD method, a plating method, and the like, and then the CMP method
A so-called damascene method for performing (Chemical-mechanical polishing) processing has been developed.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、かかる
従来技術のＣｕ薄膜の形成法においては、次のような問
題があった。Ｃｕ薄膜の堆積法のうち、スパッタ法の場
合は、一般に、ステップカバレッジに限界があり、リフ
ロー法と併用するとしても、低誘電率膜との整合性のた
めにリフロー温度の低温化という制約があり、リフロー
によって微小溝部への埋め込みを促進することは困難で
ある。また、プロセスコストも高いという問題がある。
ＣＶＤ法の場合は、原料コストが高く、成膜速度が遅
く、プロセスコストが高いという問題がある。また、メ
ッキ法の場合は、バリヤ層の上にいわゆるシード層とし
てのＣｕの薄膜を設けることが必要であり、ボイド中へ
のメッキ液の残留等の問題がある。上記いずれの成膜法
もＣｕ薄膜の形成法としては満足すべきものではない。
更に、これらいずれの成膜法も高いアスペクト比の場合
に、配線溝等への満足すべき埋め込み性能が得られてい
ない。However, the conventional method for forming a Cu thin film has the following problems. Of the Cu thin film deposition methods, in the case of the sputtering method, there is generally a limit in the step coverage, and even when used in combination with the reflow method, there is a restriction that the reflow temperature is lowered for consistency with the low dielectric constant film. Therefore, it is difficult to promote the embedding into the minute grooves by reflow. There is also a problem that the process cost is high.
In the case of the CVD method, there are problems that the raw material cost is high, the film formation rate is low, and the process cost is high. In the case of the plating method, it is necessary to provide a thin film of Cu as a so-called seed layer on the barrier layer, and there is a problem that a plating solution remains in voids. Neither of the above film forming methods is satisfactory as a method of forming a Cu thin film.
Further, none of these film forming methods has achieved satisfactory filling performance in wiring grooves or the like when the aspect ratio is high.
【０００４】また、金属超微粒子分散液を用いた先行技
術（特願平１１−２２６４６３号）においては、より高
いアスペクト比のトレンチやビアホール等に薄膜を形成
するには、金属超微粒子分散液の半導体基板への塗布と
それに続く焼成という過程を数回繰り返す必要性があ
り、プロセスコストの低減が必要であった。In a prior art using a metal ultrafine particle dispersion (Japanese Patent Application No. 11-226463), a thin film is formed in a trench or a via hole having a higher aspect ratio by using the metal ultrafine particle dispersion. The process of application to the semiconductor substrate and subsequent baking has to be repeated several times, which has required a reduction in process cost.
【０００５】本発明は、このような従来技術の問題点を
解決するためになされたものであり、アスペクト比の大
きい細孔、細溝（配線溝、ビアホールやコンタクトホー
ル等）の凹部を有する基板に対しても、該凹部にボイド
（空洞）を生じることなく導電性金属を埋め込み、プロ
セステップ数を少なくして、低プロセスコストで導電性
金属薄膜を形成する方法およびその方法に使用する導電
性金属超微粒子分散物を提供することを課題としてい
る。SUMMARY OF THE INVENTION The present invention has been made to solve such problems of the prior art, and has a substrate having a fine hole (a wiring groove, a via hole, a contact hole, etc.) having a large aspect ratio. Also, a method of forming a conductive metal thin film at low process cost by burying a conductive metal in the concave portion without generating voids (cavities) and reducing the number of process steps, and a method of forming a conductive metal used in the method. It is an object to provide a dispersion of ultrafine metal particles.
【０００６】[0006]
【課題を解決するための手段】本発明の導電性金属薄膜
の形成方法は、アスペクト比１以上の細孔、細溝（配線
溝、ビアホール、コンタクトホール等）を有する基板上
に導電性金属超微粒子独立分散物を塗布し、これを加熱
して、該分散物中の揮発性物質を除去し、導電性金属を
焼成して該細孔、細溝の凹部内に導電性金属薄膜を形成
する方法において、該加熱による揮発性物質除去、導電
性金属焼成の工程を行う雰囲気を、まず真空排気した雰
囲気にした後に、０．１〜１０気圧（ゲージ圧）の不活
性ガス含有雰囲気にして、該工程を行うことからなる。
このようにして金属薄膜が形成された後、通常、該凹部
以外の基板上にある余分の金属薄膜を除去して平坦化
し、該凹部内に金属薄膜を形成する。According to the method of forming a conductive metal thin film of the present invention, a conductive metal thin film is formed on a substrate having pores and fine grooves (wiring grooves, via holes, contact holes, etc.) having an aspect ratio of 1 or more. A fine particle independent dispersion is applied, heated to remove volatile substances in the dispersion, and baked with a conductive metal to form a conductive metal thin film in the concave portions of the pores and narrow grooves. In the method, the atmosphere in which the steps of removing volatile substances by heating and sintering the conductive metal are performed is first evacuated to atmosphere, and then to an inert gas-containing atmosphere of 0.1 to 10 atm (gauge pressure). Performing this step.
After the metal thin film is formed in this manner, usually, the excess metal thin film on the substrate other than the concave portion is removed and flattened, and the metal thin film is formed in the concave portion.
【０００７】本発明は更に、加熱処理中に不活性ガス雰
囲気による加圧効果を利用することで、より高濃度の金
属超微粒子分散物（以下、金属超微粒子分散液と称する
こともある。）を用いて、アスペクト比が１以上である
配線溝、ビアホール、コンタクトホール等の凹部を埋め
込むことを可能にし、半導体基板上に良質な金属薄膜を
形成することからなる。加熱処理中の不活性ガスによる
加圧は、塗布液が乾燥するに従って体積収縮するのを補
うように、配線溝等の直上およびその周辺の塗膜層から
の凹部内への流動埋め込みを行う効果がある。その効果
は０．１気圧（ゲージ圧）以上で顕著になるが、１０気
圧（ゲージ圧）を超えると通常の半導体製造プロセスと
しては安全上等の理由で望ましくない。加熱処理中の不
活性ガス雰囲気の圧力は０．５〜２気圧（ゲージ圧）付
近にするのが好ましい。このような不活性ガスによる加
圧効果で凹部周辺の塗膜層からの凹部内への流動を促進
して埋め込むことをねらっているので、塗布する厚みは
細孔、細溝の深さの所定の倍数とすることが好ましい。
使用する不活性ガスは、例えばヘリウム（Ｈｅ）、アル
ゴン（Ａｒ）、またはキセノン（Ｘｅ）等が好ましい。[0007] The present invention further utilizes a pressurizing effect of an inert gas atmosphere during the heat treatment to further increase the concentration of the ultrafine metal particle dispersion (hereinafter sometimes referred to as a metal ultrafine particle dispersion). This makes it possible to bury recesses such as wiring grooves, via holes, and contact holes having an aspect ratio of 1 or more, and to form a high-quality metal thin film on a semiconductor substrate. Pressurization with an inert gas during the heat treatment has the effect of performing fluid embedding into the recesses from the coating layer immediately above and around the wiring groove so as to compensate for the volume contraction as the coating liquid dries. There is. The effect becomes remarkable at 0.1 atm (gauge pressure) or more. However, when the pressure exceeds 10 atm (gauge pressure), it is not desirable as a normal semiconductor manufacturing process for safety reasons. The pressure of the inert gas atmosphere during the heat treatment is preferably around 0.5 to 2 atm (gauge pressure). Since the pressurizing effect of such an inert gas is intended to promote the flow from the coating layer around the concave portion into the concave portion and to embed the concave portion, the thickness to be applied is determined by the predetermined depth of the pores and narrow grooves. Is preferably a multiple of.
The inert gas used is preferably, for example, helium (He), argon (Ar), xenon (Xe), or the like.
【０００８】使用する導電性金属超微粒子分散物の濃度
は、塗布時の粘度等の流動性に密接な関係がある。この
分散物は導電性金属超微粒子と分散媒とを有し、その金
属微粒子の含有量は５〜７０重量％、好ましくは１０〜
６０重量％であり、残部の分散媒は沸点１５０℃以上の
有機液体を主成分とするものである。下限の５重量％
は、最終的に金属膜になるまでに細孔、細溝を埋め込む
ために流し込まなければならない量が過大とならない用
にする最低限であり、上限の７０重量％は、塗布液の粘
度が実用上過大とならない限度である。分散媒の沸点以
下で多少の加熱をする等の塗布方法をとっても、金属超
微粒子含有量が７０重量％を超える濃度ではスピンコー
トができるほどの低い粘度は得られない。The concentration of the conductive metal ultrafine particle dispersion used is closely related to fluidity such as viscosity during coating. This dispersion has conductive metal ultrafine particles and a dispersion medium, and the content of the metal fine particles is 5 to 70% by weight, preferably 10 to 70% by weight.
60% by weight, and the remainder of the dispersion medium is mainly composed of an organic liquid having a boiling point of 150 ° C. or higher. 5% by weight of lower limit
Is the minimum amount for which the amount that has to be poured in order to fill the pores and narrow grooves until the metal film is finally formed does not become excessively large. It is a limit that does not become excessive. Even if a coating method such as slightly heating below the boiling point of the dispersion medium is used, if the content of the ultrafine metal particles exceeds 70% by weight, a viscosity low enough to allow spin coating cannot be obtained.
【０００９】前記焼成を不活性ガス含有雰囲気中で行う
際に、Ａｕ、Ａｇ、Ｃｕ等のような低酸素分圧下で加熱
することで金属に還元されるような金属の場合は、加熱
焼成時に生じることのある炭素残渣をなくすために、微
量のＯ2の存在下又はＨ2ＯやＣＯ2の存在下で行うこと
が望ましく、１５０〜５００℃で、好ましくは１０分〜
１時間の間行われる。この加熱焼成温度は、Ｃｕ以外に
Ａｕ、Ａｇ、Ａｇ合金等のほかの更に低温度で焼結する
低抵抗金属を使っても、２００℃未満では結晶化が不十
分であるという問題があり、また、この焼成温度は、１
５０℃未満だと分散媒が十分に除去されないという問題
がある。さらに、５００℃を超えると半導体素子に熱的
ダメージを与えるという問題がある。前記焼成の後、焼
成雰囲気と同じ雰囲気中で、しかし３００〜５００℃
で、好ましくは１５〜３０分の間加熱すれば、金属薄膜
の結晶化、および該金属薄膜の該凹部の内側表面への密
着性を向上せしめることができる。When the calcination is performed in an atmosphere containing an inert gas, if the metal is reduced to a metal by heating under a low oxygen partial pressure, such as Au, Ag, Cu, etc. In order to eliminate a carbon residue that may be generated, the reaction is preferably performed in the presence of a trace amount of O 2 or in the presence of H 2 O or CO 2 , at 150 to 500 ° C., preferably for 10 minutes to
It takes place for one hour. Even if a low-resistance metal other than Cu, such as Au, Ag, or an Ag alloy, which sinters at a lower temperature is used, there is a problem that crystallization is insufficient at less than 200 ° C. The firing temperature is 1
If the temperature is lower than 50 ° C., there is a problem that the dispersion medium is not sufficiently removed. Further, when the temperature exceeds 500 ° C., there is a problem that the semiconductor element is thermally damaged. After the firing, in the same atmosphere as the firing atmosphere, but at 300-500 ° C
By heating for preferably 15 to 30 minutes, the crystallization of the metal thin film and the adhesion of the metal thin film to the inner surface of the concave portion can be improved.
【００１０】金属超微粒子の粒子サイズは０．１μｍ以
下が望ましい。本発明が半導体基板上の微細な溝、ビア
ホールやコンタクトホールの中に導電性金属を埋め込む
ことを目的としており、半導体分野でこれらの溝、ビア
ホールやコンタクトホールはすでに０．２５μｍ以下の
時代であるので、これら溝、孔の凹部内に金属をスムー
スに埋め込むには、金属粒子の粒度分布を十分小さくし
た上でもなお０．１μｍ以下が必要条件であり、望まし
くは０．０１μｍ以下がよい。The ultrafine metal particles preferably have a particle size of 0.1 μm or less. An object of the present invention is to embed a conductive metal in fine grooves, via holes and contact holes on a semiconductor substrate, and these grooves, via holes and contact holes are already in the era of 0.25 μm or less in the semiconductor field. Therefore, in order to smoothly embed the metal in the recesses of the grooves and holes, even if the particle size distribution of the metal particles is sufficiently reduced, the condition is still 0.1 μm or less, and preferably 0.01 μm or less.
【００１１】[0011]
【発明の実施の形態】以下、本発明の実施の形態につい
て説明する。Embodiments of the present invention will be described below.
【００１２】本発明の導電性金属薄膜の形成方法では、
導電性金属超微粒子分散物を塗布する厚みは細孔、細溝
の深さの０．１〜２０倍とすることが好ましい。下限の
０．１倍では細孔、細溝の深さを全て埋めきることはで
きないが、凹部内に緻密な密着のよい導電性金属膜をつ
くれるので、この値でも十分応用が可能な範囲である。
そして、前記したような金属超微粒子分散物の濃度にも
依存するが、該厚みを１〜５倍とすることが望ましく、
このとき細孔、細溝の深さいっぱいにＣｕ等の導電性金
属を充填することができる。２０倍を超えると、後工程
としてのＣＭＰ（化学的機械的研磨）処理による研磨作
業が過大になってしまい、プロセスコスト高くつく。In the method for forming a conductive metal thin film according to the present invention,
The thickness at which the conductive metal ultrafine particle dispersion is applied is preferably 0.1 to 20 times the depth of the pores and narrow grooves. At 0.1 times the lower limit, it is not possible to completely fill the pores and the depths of the narrow grooves, but it is possible to make a conductive metal film with good adhesion in the recesses, so that this value is within the range that can be sufficiently applied. is there.
And, depending on the concentration of the metal ultrafine particle dispersion as described above, the thickness is desirably 1 to 5 times,
At this time, a conductive metal such as Cu can be filled to the entire depth of the pores and the narrow grooves. If it exceeds 20 times, the polishing operation by the CMP (Chemical Mechanical Polishing) process as a post-process becomes excessive, and the process cost increases.
【００１３】前記金属超微粒子分散物の塗布方法には制
限はなく、通常の塗布方法であればよく、例えば、スピ
ンコーティング、浸漬、スプレーによる塗装等の方法が
用いられる。前記平坦化工程は、例えばいわゆるＣＭＰ
処理を用いたダマシン法により行われ、焼成後に塗膜表
面に残存する過剰の金属層が除去される。The method for applying the ultrafine metal particle dispersion is not limited, and any ordinary application method may be used. For example, methods such as spin coating, dipping, and spray coating are used. The flattening step is performed, for example, by so-called CMP.
It is performed by a damascene method using a treatment, and an excessive metal layer remaining on the coating film surface after firing is removed.
【００１４】本発明の金属薄膜の形成方法では、その前
処理として、配線溝、ビアホール、コンタクトホール等
の凹部の内表面を含む基板表面に、指向性スパッタのよ
うなスパッタ又はＣＶＤによりＴｉＮ、Ｔａ、ＴａＮ、
ＷＮ等のバリヤ膜を形成し、次いでその上に指向性スパ
ッタのようなスパッタ又はＣＶＤでシード膜を形成して
もよい。In the method of forming a metal thin film according to the present invention, as a pretreatment, TiN, Ta is deposited on the substrate surface including the inner surfaces of the recesses such as wiring grooves, via holes and contact holes by sputtering such as directional sputtering or CVD. , TaN,
A barrier film such as WN may be formed, and then a seed film may be formed thereon by sputtering such as directional sputtering or CVD.
【００１５】以下、導電性金属としてＣｕを用いる例を
代表として説明する。Hereinafter, an example in which Cu is used as the conductive metal will be described as a representative.
【００１６】本発明の導電性金属薄膜の形成方法で用い
ることのできる金属超微粒子独立分散物は、例えば、半
導体基板上に金属配線を形成する際の乾燥・焼成工程で
蒸発するような有機溶媒、好ましくは１５０℃以上で蒸
発する有機溶媒と、粒径０．１μｍ以下、好ましくは
０．０１μｍ以下のＣｕ金属含有超微粒子とを混合して
なり、該金属超微粒子の表面が該有機溶媒で覆われて個
々に独立して分散している粘度が２０℃で１００ｃＰ以
下の分散液であることが好ましい。The metal ultrafine particle independent dispersion which can be used in the method for forming a conductive metal thin film of the present invention is, for example, an organic solvent which evaporates in a drying / firing step when forming metal wiring on a semiconductor substrate. An organic solvent that preferably evaporates at 150 ° C. or higher, and a Cu metal-containing ultrafine particle having a particle size of 0.1 μm or less, preferably 0.01 μm or less are mixed, and the surface of the metal ultrafine particle is mixed with the organic solvent. It is preferable that the dispersion liquid has a viscosity of 100 cP or less at 20 ° C. which is covered and independently dispersed.
【００１７】前記有機溶媒としては、α−テルピネオー
ル、ミネラルスピリット、トリデカン、ドデシルベンゼ
ン又はそれらの混合物等を使用することが好ましく、前
記Ｃｕ金属含有超微粒子として、Ｃｕ、ＣｕＯ又は該Ｃ
ｕとＣｕＯとの混合物からなる超微粒子を使用して、Ｃ
ｕ金属含有分散液を調整することができる。また、前記
Ｃｕ金属含有超微粒子の濃度は、１〜７０重量％、好ま
しくは１５〜５０重量％である。該粒子の濃度が７０重
量％を超えると、粘度が高くなりすぎ、また、該粒子の
濃度が１重量％未満だと膜厚が小さすぎるという問題が
ある。前記Ｃｕ金属含有超微粒子は、Ｃｕ金属元素以外
にＣｕへの溶解度が低く、かつ半導体基板の基材と反応
しやすい金属又はこれらの金属を含む化合物を少なくと
も一種含有していてもよく、これにより基材との密着性
が向上されうる。このＣｕ金属元素以外の具体的な例と
しては、例えば、Ｍｇ、Ａｌ、Ｂ、Ｔａ、ＮｂおよびＶ
から選ばれる金属又はこれら金属を含む化合物が挙げら
れる。これらの金属を含む化合物には、例えば(Ｃ17Ｈ
35ＣＯＯ)2Ｍｇ、(Ｃ17Ｈ35ＣＯＯ)3Ａｌが挙げられ
る。これらの金属又は化合物のＣｕ超微粒子への添加量
は、超微粒子の全重量基準で、好ましくは０．５〜５重
量％である。本発明で用いるＣｕ超微粒子独立分散液の
粘度は２０℃で１００ｃＰ以下、好ましくは１０ｃＰ以
下であれば、Ｃｕ金属含有超微粒子は、該Ｃｕ超微粒子
独立分散液の形態で、半導体基板上の１以上、好ましく
は１〜３０のようなアスペクト比の大きい配線溝、ビア
ホール、コンタクトホール等の凹部に対して何らの問題
もなく入り込み、完全にこれらの凹部を埋設して、基板
表面に平坦な液膜を形成する。そして、所定の雰囲気
中、所定の温度・時間で加熱することにより、該分散液
の分散媒が蒸発し、Ｃｕ等の金属超微粒子同士が融着し
て凹部に隙間なく埋設され、半導体基板に金属薄膜が形
成される。また、かかる分散液を適用するＣｕ薄膜形成
方法ではほとんど金属原料のロスもなく、また、この形
成方法では真空装置を用いてもよいが基本的には真空装
置を必要としない。As the organic solvent, α-terpineol, mineral spirit, tridecane, dodecylbenzene or a mixture thereof is preferably used. As the Cu metal-containing ultrafine particles, Cu, CuO or C
Using ultrafine particles consisting of a mixture of u and CuO, C
The u-metal-containing dispersion can be prepared. The concentration of the Cu metal-containing ultrafine particles is 1 to 70% by weight, preferably 15 to 50% by weight. When the concentration of the particles exceeds 70% by weight, the viscosity becomes too high, and when the concentration of the particles is less than 1% by weight, the film thickness becomes too small. The Cu metal-containing ultrafine particles have a low solubility in Cu other than the Cu metal element, and may contain at least one metal or a compound containing these metals that easily reacts with the substrate of the semiconductor substrate. Adhesion with the substrate can be improved. Specific examples other than the Cu metal element include, for example, Mg, Al, B, Ta, Nb and V
Or a compound containing these metals. Compounds containing these metals include, for example, (C 17 H
35 COO) 2 Mg and (C 17 H 35 COO) 3 Al. The amount of these metals or compounds added to the ultrafine Cu particles is preferably 0.5 to 5% by weight based on the total weight of the ultrafine particles. When the viscosity of the Cu ultrafine particle independent dispersion used in the present invention is 100 cP or less at 20 ° C., and preferably 10 cP or less, the Cu metal-containing ultrafine particles are in the form of the Cu ultrafine particle independent dispersion on the semiconductor substrate. As described above, it is preferable to enter the recesses such as wiring grooves, via holes, and contact holes having a large aspect ratio such as 1 to 30 without any problem, completely bury these recesses, and form a flat liquid on the substrate surface. Form a film. Then, by heating in a predetermined atmosphere at a predetermined temperature and for a predetermined time, the dispersion medium of the dispersion liquid evaporates, the metal ultrafine particles of Cu or the like are fused and buried in the concave portions without gaps, and are embedded in the semiconductor substrate. A metal thin film is formed. In addition, in the method of forming a Cu thin film using such a dispersion, there is almost no loss of the metal raw material. In this method of forming a vacuum, a vacuum device may be used, but basically no vacuum device is required.
【００１８】[0018]
【実施例】以下、本発明の実施例を説明する。 （実施例１）ヘリウム圧力０．５Ｔｏｒｒの条件下でＣ
ｕを蒸発させ、ガス中蒸発法によりＣｕの超微粒子を生
成する際に、生成過程のＣｕ超微粒子にα−テルピネオ
ールの蒸気を接触させて冷却回収し、α−テルピネオー
ル溶媒中に独立した状態で分散している平均粒子径０．
００８μｍのＣｕ超微粒子を４０ｗｔ％含有するＣｕ超
微粒子独立分散液を作製した。この分散液は粘度が室温
で１００ｃＰ、１５０℃で３ｃＰであった。Embodiments of the present invention will be described below. (Example 1) C under the condition of helium pressure 0.5 Torr
When evaporating u and producing ultrafine particles of Cu by an in-gas evaporation method, the vapor of α-terpineol is brought into contact with the ultrafine particles of Cu in the course of the production and cooled and recovered, and in an independent state in an α-terpineol solvent. Average dispersed particle diameter
A Cu ultrafine particle independent dispersion containing 40 wt% of 008 μm Cu ultrafine particles was prepared. This dispersion had a viscosity of 100 cP at room temperature and 3 cP at 150 ° C.
【００１９】次いで、上記Ｃｕ超微粒子独立分散液を用
いて、Ｓｉ基板上に設けられたビアホールを処理した。
このＳｉ基板に形成されている絶縁膜としてのＳｉＯ2
膜には孔径０．１５μｍ（アスペクト比５）、０．２５
μｍ（アスペクト比４）のビアホールが開けられてお
り、ビアホールの内表面を含む基板の表面にはスパッタ
により、ＴａＮのバリヤ膜が厚さ０．０２μｍで形成さ
れており、またこのバリヤ膜の表面にはスパッタにより
Ｃｕのシード膜が形成されている。Next, the via holes provided on the Si substrate were treated using the above-mentioned independent dispersion liquid of Cu ultrafine particles.
SiO 2 as an insulating film formed on the Si substrate
The membrane has a pore size of 0.15 μm (aspect ratio 5), 0.25
A via hole of μm (aspect ratio 4) is opened, and a TaN barrier film having a thickness of 0.02 μm is formed on the surface of the substrate including the inner surface of the via hole by sputtering. Is formed with a Cu seed film by sputtering.
【００２０】上記の基板をスピンコータにセットして２
０００ｒｐｍで回転させ、その上方から加熱した状態の
上記Ｃｕ超微粒子独立分散液を滴下することによって、
乾燥後の膜厚が１．０μｍになるよう、スピンコーティ
ングした。５０℃以上に加熱した状態でスピンコーティ
ングすることにより、ビアホール内にはＣｕ超微粒子独
立分散液が充填され、基板の表面には平坦な該分散液の
液膜が形成された。この状態の基板を初めは真空排気し
た雰囲気中で、次いで不活性ガス（Ｈｅ）雰囲気中、２
００℃の温度で、２分間加熱して有機溶媒を蒸発させ、
その後温度を３００℃に上げて、Ｈｅガス０．０５、
０．１、０．３、０．５、１．０、５．０、１０．０気
圧（ゲージ圧）のそれぞれの雰囲気中で微量の酸素ガス
の存在下（酸素分圧：１０-9Ｔｏｒｒ）、６０分間焼成
した。さらに、温度を４００℃に上げて、酸素を除去し
た不活性ガス中で３０分間焼成した。０．０５気圧（ゲ
ージ圧）では空洞を埋め切れなかったが、０．１〜１
０．０気圧（ゲージ圧）でＣｕ超微粒子が相互に融着し
て、ビアホール内がＣｕで空洞なく埋め込まれ、縮みや
割れのないＣｕ薄膜が形成された。次いで、該ビアホー
ルの内部以外のＣｕ膜をＣＭＰ処理したところ、基板表
面の余分なＣｕ膜が除去され、ビアホール内に平坦な表
面を有するＣｕ薄膜が形成された。その比抵抗は２．０
μΩｃｍであった。 （実施例２）実施例１におけるＣｕ超微粒子独立分散液
の代わりに、ヘリウムガス中に０．０１ＴｏｒｒのＯ2
ガスを混合した雰囲気中でＣｕを蒸発させ、有機溶媒に
ミネラルスピリットを用いて粒子径０．０１μｍのＣｕ
Ｏ超微粒子独立分散液を作製した。この分散液の粘度は
２０℃で５ｃＰであった。The above substrate was set on a spin coater and 2
By rotating at 000 rpm and dropping the above Cu ultrafine particle independent dispersion in a heated state from above,
Spin coating was performed so that the film thickness after drying was 1.0 μm. By spin coating at a temperature of 50 ° C. or higher, the via holes were filled with the Cu ultrafine particle independent dispersion, and a flat liquid film of the dispersion was formed on the surface of the substrate. The substrate in this state is initially evacuated to an atmosphere and then to an inert gas (He) atmosphere.
Heating at a temperature of 00 ° C. for 2 minutes to evaporate the organic solvent,
After that, the temperature was raised to 300 ° C., and He gas 0.05,
0.1, 0.3, 0.5, 1.0, 5.0, 10.0 atmospheres (gauge pressure) in the presence of a trace amount of oxygen gas (oxygen partial pressure: 10 -9 Torr) ) And baked for 60 minutes. Further, the temperature was increased to 400 ° C., and the mixture was baked for 30 minutes in an inert gas from which oxygen had been removed. At 0.05 atm (gauge pressure), the cavity could not be filled, but 0.1 to 1
At 0.0 atm (gauge pressure), the Cu ultrafine particles were fused to each other, and the inside of the via hole was filled with Cu without any voids, and a Cu thin film without shrinkage or cracking was formed. Next, when the Cu film other than the inside of the via hole was subjected to the CMP treatment, the excess Cu film on the substrate surface was removed, and a Cu thin film having a flat surface was formed in the via hole. Its specific resistance is 2.0
μΩcm. (Example 2) Instead of the Cu ultrafine particle independent dispersion liquid in Example 1, 0.01 Torr of O 2 was contained in helium gas.
Cu is evaporated in an atmosphere in which gas is mixed, and Cu having a particle size of 0.01 μm is used as an organic solvent using mineral spirits.
O ultrafine particle independent dispersion was prepared. The viscosity of this dispersion was 5 cP at 20 ° C.
【００２１】次いで、上記分散液を用いて、不活性ガス
としてＨｅの代わりにＡｒの０．５気圧（ゲージ圧）雰
囲気で、分散液を加熱せずに基板のビアホールを埋め込
み、その後実施例１と同様にしてＣｕ膜を形成したとこ
ろ、得られた薄膜は、焼結後も縮みや割れが生じること
もなく、その比抵抗は２．０μΩｃｍであった。Then, via holes were buried in the substrate using the above dispersion liquid in an atmosphere of 0.5 atm (gauge pressure) of Ar instead of He as an inert gas without heating the dispersion liquid. When a Cu film was formed in the same manner as described above, the obtained thin film did not shrink or crack even after sintering, and had a specific resistance of 2.0 μΩcm.
【００２２】低酸素分圧下で加熱処理したことにより酸
化が進んだＣｕ超微粒子から出発したこの実施例でも導
電性金属が形成できることが確かめられた。 （実施例３）実施例１におけるＣｕ超微粒子独立分散液
の代わりに、有機溶媒としてトリデカンを用いて作製し
たＣｕ超微粒子独立分散液にＭｇ、Ａｌ、Ｂ、Ｔａ、Ｎ
ｂ又はＶの有機化合物の添加されたものを、また、Ａ
ｕ、Ａｇ超微粒子分散液を、不活性ガス雰囲気をＨｅ
０．５気圧（ゲージ圧）とした以外は実施例１と同様に
して作製した。得られた分散液の粘度はいずれも２０℃
で１０ｃＰであった。It has been confirmed that a conductive metal can be formed in this embodiment starting from ultrafine Cu particles oxidized by heat treatment under a low oxygen partial pressure. Example 3 Instead of the Cu ultrafine particle independent dispersion in Example 1, Mg, Al, B, Ta, and N were added to the Cu ultrafine particle independent dispersion prepared using tridecane as an organic solvent.
A compound to which an organic compound of b or V is added,
u, Ag ultrafine particle dispersion, and inert gas atmosphere
It was produced in the same manner as in Example 1 except that the pressure was changed to 0.5 atm (gauge pressure). The viscosity of each of the resulting dispersions was 20 ° C.
Was 10 cP.
【００２３】次いで、これらの分散液を用いて、ＴａＮ
バリア膜とＣｕシード膜とを形成する工程を省き、ヘリ
ウム雰囲気の加圧を０．５気圧（ゲージ圧）とした以外
は実施例１と同様にして基板のビアホールを埋め込み、
Ｃｕ膜を形成したところ、得られた薄膜は、焼結後もま
たＣＭＰによる平坦化処理工程中も縮みや割れが生じる
こともなく、基板との密着性も良好であり、その比抵抗
は２．１μΩｃｍであった。 （実施例４）実施例１のＣｕ超微粒子独立分散液と実施
例２のＣｕＯ超微粒子独立分散液とを混合して、粘度５
０ｃＰ（２０℃）の混合分散液を作製し、これを用いて
Ｓｉ基板上に配線パターンを形成した。このＳｉ基板上
に形成されている絶縁膜としてのＳｉＯ2 膜には幅０．
２５μｍ、深さ１μｍ（アスペクト比４）の溝がパター
ン状に形成されており、溝の内表面を含む基板の表面に
はスパッタにより、ＴａＮバリヤ膜が厚さ０．０２μｍ
で形成されており、またこのバリヤ膜の表面にはスパッ
タによりＣｕのシード膜が形成されている。Next, using these dispersions, TaN
A via hole of the substrate was buried in the same manner as in Example 1 except that the step of forming the barrier film and the Cu seed film was omitted, and the pressure of the helium atmosphere was changed to 0.5 atm (gauge pressure).
When the Cu film was formed, the obtained thin film did not shrink or crack even after sintering and during the planarization process by CMP, had good adhesion to the substrate, and had a specific resistance of 2 .1 μΩcm. (Example 4) The Cu ultrafine particle independent dispersion of Example 1 and the CuO ultrafine particle independent dispersion of Example 2 were mixed to obtain a viscosity of 5
A mixed dispersion of 0 cP (20 ° C.) was prepared and used to form a wiring pattern on a Si substrate. The SiO 2 film as an insulating film formed on the Si substrate has a width of 0.1 mm.
A groove having a thickness of 25 μm and a depth of 1 μm (aspect ratio 4) is formed in a pattern, and a TaN barrier film having a thickness of 0.02 μm is formed on the surface of the substrate including the inner surface of the groove by sputtering.
A Cu seed film is formed on the surface of the barrier film by sputtering.
【００２４】上記の基板をスピンコータにセットして３
０００ｒｐｍで回転させ、その上方から上記の混合分散
液を滴下することによって、スピンコーティングした。
パターン状の溝内にはこの分散液が充填され、基板の表
面には平坦な該分散液の液膜が形成された。この状態の
基板を１気圧（ゲージ圧）のヘリウム雰囲気中、２００
℃の温度で、２分間加熱して有機溶媒を蒸発させ、次い
で温度を３００℃に上げて、不活性ガス雰囲気中で、更
にＨ2Ｏガスを添加（Ｈ2Ｏ分圧：１０Torr）して、６０
分間焼成した。更に、温度を４００℃に上げて、Ｈ2Ｏ
ガスを除去した不活性ガス中で３０分間焼成した。かく
して、Ｃｕ超微粒子が相互に融着して、溝内がＣｕで空
洞なく埋め込まれ、縮みや割れのないＣｕ薄膜が形成さ
れた。次いで、該溝の内部以外のＣｕ膜をＣＭＰ処理し
たところ、基板表面の余分なＣｕ膜が除去され、溝内に
平坦な表面を有するＣｕ薄膜が形成され、その比抵抗は
２．０μΩｃｍであった。The above substrate was set on a spin coater and 3
The mixture was rotated at 000 rpm, and the above mixed dispersion was dropped from above to perform spin coating.
The dispersion liquid was filled in the pattern-shaped grooves, and a flat liquid film of the dispersion liquid was formed on the surface of the substrate. The substrate in this state is placed in a helium atmosphere at 1 atm (gauge pressure) for 200 hours.
The organic solvent was evaporated by heating at a temperature of 2 ° C. for 2 minutes, then the temperature was raised to 300 ° C., and further H 2 O gas was added in an inert gas atmosphere (H 2 O partial pressure: 10 Torr). , 60
Bake for a minute. Further, the temperature is raised to 400 ° C. and H 2 O
Firing was performed for 30 minutes in an inert gas from which the gas had been removed. Thus, the Cu ultrafine particles were fused to each other, the grooves were filled with Cu without any voids, and a Cu thin film without shrinkage or cracking was formed. Next, when the Cu film other than the inside of the groove was subjected to the CMP treatment, the excess Cu film on the substrate surface was removed, and a Cu thin film having a flat surface was formed in the groove, and the specific resistance was 2.0 μΩcm. Was.
【００２５】[0025]
【発明の効果】本発明の導電性金属薄膜形成方法によれ
ば、ＬＳＩ基板のアスペクト比の大きい微細な配線溝、
ビアホール、コンタクトホール等の凹部をも、ボイドを
生じることなく完全に導電性金属で埋設することがで
き、導電性の均一な微細パターンを形成することができ
る。この際、本発明の導電性金属超微粒子を使用すれば
良好な前記効果が得られる。According to the method for forming a conductive metal thin film of the present invention, fine wiring grooves having a large aspect ratio on an LSI substrate can be obtained.
Concave portions such as via holes and contact holes can be completely buried with conductive metal without generating voids, and a fine pattern with uniform conductivity can be formed. In this case, if the conductive metal ultrafine particles of the present invention are used, the above-mentioned advantageous effects can be obtained.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｈ０１Ｌ 21/3205 Ｈ０１Ｌ 21/88 Ｒ Ｂ Ｆターム(参考） 4D075 BB24Z BB28Z BB56Z BB93Z DA06 DA32 DC21 EC02 EC10 EC53 EC54 4K044 AA11 AB10 BA06 BA08 BA12 BB10 BC14 CA24 CA29 CA53 4M104 BB04 BB08 BB09 BB32 DD51 DD79 5F033 HH11 HH13 HH14 HH32 HH35 MM01 MM12 MM13 PP15 PP26 QQ48 QQ73 RR04 WW00 WW01 WW03 WW05 XX02 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme coat ゛ (Reference) H01L 21/3205 H01L 21/88 RBF term (Reference) 4D075 BB24Z BB28Z BB56Z BB93Z DA06 DA32 DC21 EC02 EC10 EC53 EC54 4K044 AA11 AB10 BA06 BA08 BA12 BB10 BC14 CA24 CA29 CA53 4M104 BB04 BB08 BB09 BB32 DD51 DD79 5F033 HH11 HH13 HH14 HH32 HH35 MM01 MM12 MM13 PP15 PP26 QQ48 QQ73 RR04 WW00 WW01 WW03 WW03
Claims (5)
る基板上に導電性金属超微粒子分散物を塗布し、これを
加熱して、該分散物中の揮発性物質を除去し、導電性金
属を焼成して該細孔、細溝の凹部内に導電性金属薄膜を
形成する方法において、該加熱による揮発性物質除去、
導電性金属焼成の工程を行う雰囲気を、まず真空排気し
た雰囲気にした後に、０．１〜１０気圧（ゲージ圧）の
不活性ガス含有雰囲気にして、該工程を行うことを特徴
とする導電性金属薄膜の形成方法。1. A method for applying a conductive metal ultrafine particle dispersion on a substrate having pores and fine grooves having an aspect ratio of 1 or more, heating the dispersion, and removing volatile substances in the dispersion to obtain a conductive material. In the method of forming a conductive metal thin film in the pores, the recesses of the narrow grooves by firing a conductive metal, removing volatile substances by the heating,
The conductive metal firing step is performed by first setting the atmosphere to be evacuated and then setting the atmosphere to an inert gas-containing atmosphere of 0.1 to 10 atm (gauge pressure) to perform the step. A method for forming a metal thin film.
囲気で用いる不活性ガスが、ヘリウム、アルゴン、また
はキセノンであることを特徴とする導電性金属薄膜の形
成方法。2. The method according to claim 1, wherein the inert gas used in the inert gas-containing atmosphere is helium, argon, or xenon.
粒子は、金、銀、銅およびそれら金属の合金ならびにそ
れら金属を主成分とする合金、ならびにそれら金属とそ
の酸化物との混合物から選ばれる少なくとも一種の超微
粒子であることを特徴とする導電性金属薄膜の形成方
法。3. The metal ultrafine particle according to claim 1, wherein the ultrafine metal particles are selected from gold, silver, copper, alloys of these metals, alloys containing these metals as main components, and mixtures of these metals and their oxides. At least one kind of ultrafine particles.
属超微粒子の粒径は０．１μｍ以下であることを特徴と
する導電性金属薄膜の形成方法。4. The method for forming a conductive metal thin film according to claim 1, wherein the ultrafine metal particles have a particle size of 0.1 μm or less.
電性金属超微粒子分散物であって、該金属超微粒子の含
有量が５〜７０重量％であり、残部の分散媒が沸点１５
０℃以上の有機液体を主成分とするものであることを特
徴とする導電性金属超微粒子分散物。5. The dispersion of conductive metal ultrafine particles used in any one of claims 1 to 4, wherein the content of the metal ultrafine particles is 5 to 70% by weight, and the balance of the dispersion medium is a boiling point. Fifteen
A conductive metal ultrafine particle dispersion characterized by containing an organic liquid at 0 ° C. or higher as a main component.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000069129A JP2001254185A (en) | 2000-03-13 | 2000-03-13 | Method of depositing electrically conductive metallic thin film and electrically conductive metallic hyperfine particle-dispersed material used for the method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000069129A JP2001254185A (en) | 2000-03-13 | 2000-03-13 | Method of depositing electrically conductive metallic thin film and electrically conductive metallic hyperfine particle-dispersed material used for the method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2001254185A true JP2001254185A (en) | 2001-09-18 |
Family
ID=18588077
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000069129A Withdrawn JP2001254185A (en) | 2000-03-13 | 2000-03-13 | Method of depositing electrically conductive metallic thin film and electrically conductive metallic hyperfine particle-dispersed material used for the method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2001254185A (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002141351A (en) * | 2000-10-31 | 2002-05-17 | Japan Science & Technology Corp | Circuit board and method of forming metal wiring |
| JP2003257890A (en) * | 2002-03-07 | 2003-09-12 | Seiko Epson Corp | Method for filling substance, method for forming film, device and its fabricating method |
| WO2004034456A1 (en) * | 2002-10-11 | 2004-04-22 | Tokyo Electron Limited | Method of forming wiring |
| WO2007094361A1 (en) | 2006-02-16 | 2007-08-23 | Idemitsu Kosan Co., Ltd. | Organic thin film transistor and organic thin film light-emitting transistor |
| WO2008044695A1 (en) | 2006-10-12 | 2008-04-17 | Idemitsu Kosan Co., Ltd. | Organic thin film transistor device and organic thin film light-emitting transistor |
| WO2008059816A1 (en) | 2006-11-14 | 2008-05-22 | Idemitsu Kosan Co., Ltd. | Organic thin film transistor and organic thin film light-emitting transistor |
| WO2009041254A1 (en) | 2007-09-26 | 2009-04-02 | Idemitsu Kosan Co., Ltd. | Organic thin film transistor |
| US7535626B2 (en) | 2006-06-06 | 2009-05-19 | Konica Minolta Opto, Inc. | Shape-variable optical element, optical device and image pickup apparatus |
| US7674401B2 (en) * | 2001-12-18 | 2010-03-09 | Asahi Kasei Kabushiki Kaisha | Method of producing a thin conductive metal film |
| CN105845567A (en) * | 2016-04-07 | 2016-08-10 | 上海大学 | Process for preparing nanometer schottky structure through utilizing physical method |
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2000
- 2000-03-13 JP JP2000069129A patent/JP2001254185A/en not_active Withdrawn
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002141351A (en) * | 2000-10-31 | 2002-05-17 | Japan Science & Technology Corp | Circuit board and method of forming metal wiring |
| US7674401B2 (en) * | 2001-12-18 | 2010-03-09 | Asahi Kasei Kabushiki Kaisha | Method of producing a thin conductive metal film |
| JP2003257890A (en) * | 2002-03-07 | 2003-09-12 | Seiko Epson Corp | Method for filling substance, method for forming film, device and its fabricating method |
| WO2004034456A1 (en) * | 2002-10-11 | 2004-04-22 | Tokyo Electron Limited | Method of forming wiring |
| WO2007094361A1 (en) | 2006-02-16 | 2007-08-23 | Idemitsu Kosan Co., Ltd. | Organic thin film transistor and organic thin film light-emitting transistor |
| US7535626B2 (en) | 2006-06-06 | 2009-05-19 | Konica Minolta Opto, Inc. | Shape-variable optical element, optical device and image pickup apparatus |
| WO2008044695A1 (en) | 2006-10-12 | 2008-04-17 | Idemitsu Kosan Co., Ltd. | Organic thin film transistor device and organic thin film light-emitting transistor |
| WO2008059816A1 (en) | 2006-11-14 | 2008-05-22 | Idemitsu Kosan Co., Ltd. | Organic thin film transistor and organic thin film light-emitting transistor |
| WO2009041254A1 (en) | 2007-09-26 | 2009-04-02 | Idemitsu Kosan Co., Ltd. | Organic thin film transistor |
| CN105845567A (en) * | 2016-04-07 | 2016-08-10 | 上海大学 | Process for preparing nanometer schottky structure through utilizing physical method |
| CN105845567B (en) * | 2016-04-07 | 2019-02-22 | 上海大学 | Utilize the technique of physical method preparation nanometer Schottky junction structure |
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Legal Events
| Date | Code | Title | Description |
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| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20070605 |