JP2004273786A - Manufacturing method of hydrophobic porous sog film - Google Patents
Manufacturing method of hydrophobic porous sog film Download PDFInfo
- Publication number
- JP2004273786A JP2004273786A JP2003062879A JP2003062879A JP2004273786A JP 2004273786 A JP2004273786 A JP 2004273786A JP 2003062879 A JP2003062879 A JP 2003062879A JP 2003062879 A JP2003062879 A JP 2003062879A JP 2004273786 A JP2004273786 A JP 2004273786A
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- heat treatment
- sog film
- hydrophobic
- hydrophobic porous
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Abstract
Description
【０００１】
【発明の属する技術分野】
本発明は疎水性多孔質ＳＯＧ膜（ＳｉＯ２膜）の作製方法に関し、特に疎水性多孔質ＳＯＧ膜の機械的特性を向上せしめるための熱処理方法に関するものである。
【０００２】
【従来の技術】
近年、ＬＳＩの分野において銅配線と共に、低誘電率を特徴とする層間絶縁膜の導入が盛んに研究開発されている。この層間絶縁膜として低誘電率を持つ酸化物膜を多孔質にすることが提案されているが、多孔質にすることで機械的強度の低下や空孔内への空気中の水分の吸着などの問題が引き起こされている。この問題に対して、本出願人は、多孔質ＳＯＧ膜の疎水化方法を提案した（例えば、特許文献１参照。）。この他に、平成１３年１２月２０日付け出願の特願２００１−３８８１４４号でも同様の疎水化方法を提案している。
【０００３】
【特許文献１】
特開２００１−３５１９１１号公報（第１頁）
【０００４】
【発明が解決しようとする課題】
上記先願中で提案した多孔質ＳＯＧ膜の疎水化方法では、多孔質ＳＯＧ膜へ疎水性機能を持たせるために疎水基を導入しているが、その際に、得られる疎水性多孔質シリカ材料は疎水基の導入による機械的特性の低下を招くという問題がある。
本発明の課題は、上記のような従来の疎水化ＳＯＧ膜の持つ機械的特性の問題を解決するもので、疎水性多孔質ＳＯＧ膜の持つ疎水性機能を損なうことなく、かつ比誘電率への影響が小さく、機械的特性の向上を可能とする多孔質ＳＯＧ膜の作製方法を提供することにある。
【０００５】
【課題を解決するための手段】
本発明の疎水性多孔質ＳＯＧ膜（ＳｉＯ２膜）の作製方法は、疎水性ＳＯＧ膜の熱処理を酸素含有ガスの存在下で行うことを特徴とする。
上記熱処理を、酸素分圧５Ｅ＋３Ｐａ以上の酸素含有ガス中で行うことを特徴とする。酸素分圧が５Ｅ＋３Ｐａ未満であると、ＳＯＧ前駆体の縮重合の促進が不十分であるため、作製されるＳＯＧ膜の機械的特性が改善されない。
上記熱処理を疎水性ＳＯＧ膜中に含まれた界面活性剤の熱分解温度から１０００℃までの温度、好ましくは３００℃〜１０００℃、より好ましくは３００〜５００℃で行うことを特徴とする。３００℃未満であると、疎水性ＳＯＧ膜中に含まれている界面活性剤が熱分解し難く、所望の多孔質体が得られない。また、１０００℃を超えると、得られたＳＯＧ膜の疎水性が損なわれる恐れがある。
【０００６】
上記熱処理を少なくとも２段階で行い、第１段階熱処理を疎水性ＳＯＧ膜中に含まれた有機溶媒の蒸発温度以上からＳＯＧ膜中に含まれた界面活性剤の熱分解温度より下の温度で行い、第２段階熱処理又は第２段階以降で少なくとも一部の熱処理を界面活性剤の熱分解温度以上から配線として使用する金属の融点より下の温度で行うことを特徴とする。
上記第２段階熱処理又は第２段階以降の熱処理の際に、ＳＯＧ膜中に含まれた界面活性剤の熱分解温度から１０００℃までの間の所定の熱処理温度への昇温を酸素を含まない雰囲気中で行うことを特徴とする。
【０００７】
上記熱処理を２段階で行い、第１段階熱処理を６０℃からＳＯＧ膜中に含まれた界面活性剤の熱分解温度より下の温度、好ましくは６０℃から３００℃より下の温度で行い、第２段階熱処理を界面活性剤の熱分解温度から１０００℃までの温度、好ましくは３００〜１０００℃で行うことを特徴とする。６０℃未満であると疎水性ＳＯＧ膜中に含まれている有機溶媒が蒸発せず残留してしまう。
【０００８】
上記第２段階熱処理の際に、界面活性剤の熱分解温度から１０００℃までの間の所定の熱処理温度、好ましくは３００〜１０００℃の間の所定の熱処理温度への昇温を酸素を含まない雰囲気中で行うことを特徴とする。
上記熱処理を１段階で行い、この際に、室温から直接４００℃に昇温して所定の時間この温度を保持した後、酸素分圧５Ｅ＋３Ｐａ以上、好ましくは１Ｅ＋４Ｐａ以上の酸素含有ガスを導入して所定の温度で熱処理を行うことを特徴とする。
【０００９】
【発明の実施の形態】
本発明においては、所定の酸素分圧を有する酸素含有ガスを焼成炉内に導入し、疎水性多孔質ＳＯＧ膜を作製するための熱処理を行うときに、ＳＯＧ前駆体の縮重合を導入した酸素含有ガスを用いて促進することにより、疎水性多孔質ＳＯＧ膜の機械的特性を向上させるものである。
本発明の疎水性機能を持った多孔質ＳＯＧ膜としては、例えば、上記先願中に記載したように、ＳＯＧ膜前駆体中に予め疎水基を有する化合物を含有せしめることにより、ＳＯＧ膜の形成と同時に疎水性機能が発現するもの、又は多孔質ＳＯＧ膜形成時若しくはその形成直後の多孔質膜の熱処理峙に疎水基を有する化合物へ暴露せしめることにより疎水性機能を持たせたもの等を挙げることができる。
【００１０】
疎水性多孔質ＳＯＧ膜は、例えば、以下の方法により作製できる。
例えば、特開２００１−３５１９１１号公報に記載された方法に準じて、加熱処理条件を以下述べるように変えて作製できる。まず、疎水基を有するシリコン含有化合物と、テトラエトキシシラン（ＴＥＯＳ）やテトラメトキシシラン（ＴＭＯＳ）等のような加水分解可能なシリコンアルコキシドである有機オキシシランと、水と、溶媒とを混合して溶液を調製し、所定の温度（例えば、約５５℃）で反応させて均一な前駆体溶液を得る。この前駆体溶液を酸加水分解又はアルカリ加水分解して得られる溶液に界面活性剤を添加した塗布液を半導体基板上に通常のスピンコート法等の塗布方法により塗布する。次いで、公知の赤外線加熱炉等を用いて特定の条件下で加熱処理し、塗布液中の溶媒や水、酸又はアルカリ触媒、界面活性剤等を蒸発させながら、また、反応系にその他の有機物質が含まれている場合にはその物質を取り除くことにより、多孔の形成と同時に疎水性機能を備えた疎水性多孔質ＳＯＧ膜を作製することができる。
【００１１】
上記疎水基を有する化合物は、例えば、へキサメチルジシラン、ジメチルジエトキシシラン、メチルトリメトキシシラン、メチルトリエトキシシラン、トリエトキシシラン若しくはジメチルジメトキシシラン等や、ヘキサメチルジシロキサン等や、ヘキサメチルジシラザン等のようなメチル基等の炭素数１〜６の低級アルキル基を少なくとも一つ又は水素原子を有するシラン化合物、シロキサン化合物、ジシラン化合物或いはシラザン化合物であることが好ましい。
【００１２】
溶媒としては、例えば、メチルアルコール、エチルアルコール、イソプロピルアルコール等のアルコール系溶媒であって、界面活性剤の熱分解温度、好ましくは３００℃以下で蒸発するものであれば、特に制限されることなく用いられ得る。
加水分解のために用いられる薬剤は、例えば、硝酸や塩酸などの無機酸、ギ酸などの有機酸、アンモニアなどのアルカリを挙げることができる。
【００１３】
界面活性剤としては、例えば、ラウリルトリメチルアンモニウムクロライド、ｎ−ヘキサデシルトリメチルアンモニウムクロライド、アルキルトリメチルアンモニウムブロマイド、セチルトリメチルアンモニウムクロライド、セチルトリメチルアンモニウムブロマイド、ステアリルトリメチルアンモニウムクロライド、アルキルジメチルエチルアンモニウムクロライド、アルキルジメチルエチルアンモニウムブロマイド、セチルジメチルエチルアンモニウムブロマイド、オクタデシルジメチルエチルアンモニウムブロマイド、またはメチルドデシルベンジルトリメチルアンモニウムクロライド等のハロゲン化アルキルトリメチルアンモニウム系陽イオン性界面活性剤を挙げることができる。その他に、ジメチルデシルベンジルアンモニウムクロライド、ジエチルドデシルベンジルアンモニウムクロライド、トリメチルドデシルアンモニウムブロマイド、アリルジブチルドデシルアンモニウムブロマイド、ジエチルアセトニルドデシルアンモニウムクロライド等を用いることができる。
【００１４】
上記疎水性多孔質ＳＯＧ膜を作製する際の加熱処理条件は、膜の機械的特性を向上させるために、好ましくは以下の通りである。
上記塗布液を用いて半導体基板上にスピンコートした後、公知の赤外線加熱炉を用いて、基板に対して１段階熱処理又は２段階以上の熱処理を行う。
【００１５】
２段階熱処理の場合は、第１段階熱処理では、通常、溶媒として使用している上記有機溶媒の蒸発温度（例えば、メチルアルコールであれば６５℃）以上から鋳型として使用している上記界面活性剤の熱分解温度より下の温度、好ましくは６０℃から３００℃より下の温度で熱処理を行い、鋳型物質が分解しないで存在する状態下で有機溶媒を蒸発させて硬化させる。第２段階熱処理では、所定の酸素分圧を有する酸素含有ガスの存在下で、得られるＳＯＧ膜の膜特性を損なわない範囲で、すなわち、通常、界面活性剤の熱分解温度以上から配線として使用する銅や銀等の金属の融点以下の温度（例えば、銅であれば１０８７℃以下）、好ましくは３００℃〜１０００℃、さらに好ましくは３００〜５００℃で熱処理を行い、疎水性多孔質ＳＯＧ膜を作製する。１０００℃を超えると得られたＳＯＧ膜の疎水性が損なわれることがあり、また、３００℃未満であると界面活性剤の分解が困難であって、多孔質ＳＯＧ膜が得られない。
【００１６】
上記第２段階を実行する際に、多孔質ＳＯＧ膜の空孔を形成するための鋳型として使用する界面活性剤が熱分解を起こす温度以上から１０００℃までの所定の熱処理温度への昇温及びその保持時間の間は、酸素を含まない雰囲気中で行うことが望ましい。この昇温における昇温時間及び保持時間は、得られるＳＯＧ膜の膜特性を損なわない範囲で適宜選択すれば良い。
【００１７】
また、１段階熱処理の場合は、室温から例えば直接４００℃までの所定の温度へ昇温して５分以上の間この温度を保持した後、好ましくは酸素分圧１Ｅ＋４Ｐａ以上の酸素含有ガスを炉内に導入して、所定の温度で熱処理することにより、所望の機械的特性を有する疎水性多孔質ＳＯＧ膜を作製することができる。この場合、所定の温度への昇温及びその保持時間の間は、酸素を含まない雰囲気中で行い、この昇温における昇温時間及び保持時間は、得られるＳＯＧ膜の膜特性を損なわない範囲で適宜選択すれば良い。
上記酸素含有ガスとしては、例えば、水分を含まない純空気、窒素やアルゴン等の不活性ガスに酸素分圧が上記の値以上になるように酸素を混合した混合ガス等を用いることができる。
【００１８】
【実施例】
以下、本発明の実施例を説明する。
（実施例１）
多孔質ＳＯＧ（ＳｉＯ２）のＳｉ半導体基板上への成膜を、以下の通り行った。
テトラエトキシシラン（ＴＥＯＳ）１モル、Ｈ２Ｏ１１モル、へキサメチルジシロキサン（ＨＭＤＳＯ）０．１５モル、ヘキサデシルトリメチルアンモニウムクロライド（Ｃ１６ＴＡＣ）０．２５モルを酸性（ｐＨ：ｌ−３）の溶剤中に添加・混合し、この混合物を５５℃で反応させて均一なＳＯＧ前駆体塗布液を得た。
【００１９】
この塗布液を用いて半導体基板上に１５００回転／分の条件でスピンコートした後、公知の赤外線加熱炉を用いて、基板を２段階熱処理した。１段目として空気中１００℃で熱処理を行い、次いで３Ｐａ以下の雰囲気中で４００℃まで昇温し、１５分間４００℃を保持した後、酸素分圧が１Ｅ＋４Ｐａになるまで純空気を炉内に導入し、４００℃のまま３０分間の２段目の熱処理を行った。
上記熱処理で得られた多孔質ＳＯＧ膜について、水銀プローブ法で電気的特性を、エリプロメトリーを用いて膜厚を測定し、比誘電率を算出した。また、ナノインデンテーション法により、機械的強度を測定した。結果を第１表に示す。
【００２０】
また、温度・昇温時間及び保持時間を上記と同一にし、酸素含有ガスを導入しない従来の熱処理を行い、得られたＳＯＧ膜の測定結果も合わせて第１表に示す。
表１から明らかなように、酸素含有ガスを導入せずに従来の熱処理を行った多孔質ＳＯＧ膜と、酸素含有ガスを導入して得られた多孔質ＳＯＧ膜とを比較すると、後者は、前者よりも機械的強度が約２．５〜３．５倍に向上し、かつ比誘電率の上昇は６％程度に収まっていることが分かる。図１に酸素含有ガスを導入して得られた多孔質ＳＯＧ膜を湿度４０％、２３℃の室内に放置したときの比誘電率の経時変化を示す。図１に示されたように、本熱処理による疎水性への影響は見られず、１４日後の比誘電率の変化は△ｋ〜０．３％であった。
【００２１】
（実施例２）
実施例１で用いた塗布液を基板上にスピンコートした後、基板を１段目２５０℃で６０分間熱処理を行い、３Ｐａ以下に減圧した雰囲気中で４５０℃に昇温した。その温度に２０分間保持した後、５Ｅ＋３Ｐａの酸素分圧になるように純空気を炉内に導入し、その後３０分間熱処理を行った。得られたＳＯＧ膜について、実施例１と同様な評価を行い、その結果を表１に併記する。
本実施例で得られた多孔質ＳＯＧ膜においても、得られた比誘電率は、酸素含有ガスを導入せずに従来の熱処理を行った多孔質ＳＯＧ膜と比較して、４％程度の上昇に過ぎず、また、機械的強度は２〜３倍になった。
【００２２】
（実施例３）
実施例１で用いた塗布液を基板上にスピンコートした後、基板を３Ｐａ以下の圧力下で４００℃まで昇温し、次いで２Ｅ＋４Ｐａの酸素分圧になるように純空気を導入して３０分間熱処理を行った。得られたＳＯＧ膜について、実施例１と同様な評価を行い、その結果を表１に併記する。
本実施例で得られた多孔質ＳＯＧ膜の比誘電率は、酸素含有ガスを導入せずに従来の熱処理を行った多孔質ＳＯＧ膜と比較して、２％程度の上昇に過ぎず、また、機械的強度はｌ．５〜２倍になった。
【００２３】
（表１）
【発明の効果】
本発明によれば、熱処理プロセスの所定に時期に酸素含有ガスを焼成炉内に導入し、疎水性多孔質ＳＯＧ膜を作製するための熱処理を行っているので、ＳＯＧ前駆体の縮重合を導入した酸素ガスによって促進し、ＳＯＧ膜形成と同時に行う熱処理の方法により、疎水性多孔質ＳＯＧ膜本来の電気的特性には、ほとんど影響を与えずに、その機械的特性の向上を実現することができる。
【図面の簡単な説明】
【図１】実施例１で得られた疎水性多孔質ＳＯＧ膜を湿度４０％、温度２３℃の室内に放置したときの膜の比誘電率の変化を示すグラフ。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a hydrophobic porous SOG film (SiO 2 film), and more particularly to a heat treatment method for improving mechanical properties of a hydrophobic porous SOG film.
[0002]
[Prior art]
In recent years, in the field of LSI, research and development of copper wiring and introduction of an interlayer insulating film characterized by a low dielectric constant have been actively conducted. It has been proposed that an oxide film having a low dielectric constant be made porous as the interlayer insulating film, but by making it porous, the mechanical strength is reduced and moisture in the air is absorbed into the pores. The problem is being caused. In response to this problem, the present applicant has proposed a method for making a porous SOG film hydrophobic (for example, see Patent Document 1). In addition, Japanese Patent Application No. 2001-388144, filed on December 20, 2001, also proposes a similar hydrophobizing method.
[0003]
[Patent Document 1]
JP 2001-351911 A (page 1)
[0004]
[Problems to be solved by the invention]
In the method for hydrophobizing a porous SOG film proposed in the above-mentioned prior application, a hydrophobic group is introduced in order to impart a hydrophobic function to the porous SOG film. The material has a problem that the introduction of a hydrophobic group causes a decrease in mechanical properties.
An object of the present invention is to solve the problem of the mechanical characteristics of the conventional hydrophobic SOG film as described above, and without impairing the hydrophobic function of the hydrophobic porous SOG film and increasing the relative dielectric constant. It is an object of the present invention to provide a method for producing a porous SOG film, which is less affected by the influence of the SOG film and can improve the mechanical characteristics.
[0005]
[Means for Solving the Problems]
The method for producing a hydrophobic porous SOG film (SiO 2 film) of the present invention is characterized in that the heat treatment of the hydrophobic SOG film is performed in the presence of an oxygen-containing gas.
The heat treatment is performed in an oxygen-containing gas having an oxygen partial pressure of 5E + 3 Pa or more. If the oxygen partial pressure is less than 5E + 3 Pa, the promotion of polycondensation of the SOG precursor is insufficient, so that the mechanical properties of the produced SOG film are not improved.
The heat treatment is performed at a temperature from the thermal decomposition temperature of the surfactant contained in the hydrophobic SOG film to 1000 ° C., preferably 300 ° C. to 1000 ° C., and more preferably 300 ° C. to 500 ° C. If the temperature is lower than 300 ° C., the surfactant contained in the hydrophobic SOG film is hardly thermally decomposed, and a desired porous body cannot be obtained. If the temperature exceeds 1000 ° C., the hydrophobicity of the obtained SOG film may be impaired.
[0006]
The heat treatment is performed in at least two stages, and the first heat treatment is performed at a temperature equal to or higher than the evaporation temperature of the organic solvent contained in the hydrophobic SOG film and lower than the thermal decomposition temperature of the surfactant contained in the SOG film. The method is characterized in that at least part of the heat treatment in the second stage or after the second stage is performed at a temperature not lower than the thermal decomposition temperature of the surfactant and lower than the melting point of the metal used as the wiring.
In the second stage heat treatment or the heat treatment after the second stage, the temperature is raised from the thermal decomposition temperature of the surfactant contained in the SOG film to a predetermined heat treatment temperature between 1000 ° C. without containing oxygen. It is characterized in that it is performed in an atmosphere.
[0007]
The heat treatment is performed in two stages, and the first heat treatment is performed at a temperature of 60 ° C. to a temperature lower than the thermal decomposition temperature of the surfactant contained in the SOG film, preferably a temperature of 60 ° C. to lower than 300 ° C. It is characterized in that the two-stage heat treatment is performed at a temperature from the thermal decomposition temperature of the surfactant to 1000 ° C, preferably 300 to 1000 ° C. When the temperature is lower than 60 ° C., the organic solvent contained in the hydrophobic SOG film does not evaporate and remains.
[0008]
In the second stage heat treatment, the temperature is increased to a predetermined heat treatment temperature between the thermal decomposition temperature of the surfactant and 1000 ° C., preferably 300 to 1000 ° C. without containing oxygen. It is characterized in that it is performed in an atmosphere.
The heat treatment is performed in one stage. At this time, the temperature is directly raised from room temperature to 400 ° C., and after maintaining this temperature for a predetermined time, an oxygen-containing gas having an oxygen partial pressure of 5E + 3 Pa or more, preferably 1E + 4 Pa or more is introduced. The heat treatment is performed at a predetermined temperature.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
In the present invention, an oxygen-containing gas having a predetermined oxygen partial pressure is introduced into a firing furnace, and heat treatment for producing a hydrophobic porous SOG film is performed. By promoting the use of the contained gas, the mechanical properties of the hydrophobic porous SOG film are improved.
As the porous SOG film having a hydrophobic function of the present invention, for example, as described in the above-mentioned prior application, an SOG film is formed by adding a compound having a hydrophobic group to an SOG film precursor in advance. At the same time, those exhibiting a hydrophobic function or those imparting a hydrophobic function by exposing the porous film to a compound having a hydrophobic group at the time of heat treatment of the porous SOG film or immediately after its formation are given. be able to.
[0010]
The hydrophobic porous SOG film can be produced, for example, by the following method.
For example, it can be produced according to the method described in JP-A-2001-351911, with the heat treatment conditions changed as described below. First, a silicon-containing compound having a hydrophobic group, an organic oxysilane that is a hydrolyzable silicon alkoxide such as tetraethoxysilane (TEOS) or tetramethoxysilane (TMOS), water, and a solvent are mixed together to form a solution. Is prepared and reacted at a predetermined temperature (for example, about 55 ° C.) to obtain a uniform precursor solution. A coating solution obtained by adding a surfactant to a solution obtained by subjecting this precursor solution to acid hydrolysis or alkali hydrolysis is applied onto a semiconductor substrate by an ordinary application method such as a spin coating method. Then, heat treatment under specific conditions using a known infrared heating furnace or the like, while evaporating the solvent and water, acid or alkali catalyst in the coating solution, a surfactant, and the like, and other organic to the reaction system When a substance is contained, by removing the substance, a hydrophobic porous SOG film having a hydrophobic function at the same time as the formation of porosity can be produced.
[0011]
Examples of the compound having a hydrophobic group include hexamethyldisilane, dimethyldiethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, triethoxysilane, dimethyldimethoxysilane, and the like; hexamethyldisiloxane; and hexamethyldisiloxane. It is preferably a silane compound, a siloxane compound, a disilane compound or a silazane compound having at least one lower alkyl group having 1 to 6 carbon atoms such as a methyl group such as silazane or a hydrogen atom.
[0012]
Examples of the solvent include, but are not particularly limited to, alcohol solvents such as methyl alcohol, ethyl alcohol, and isopropyl alcohol, which can be evaporated at a thermal decomposition temperature of a surfactant, preferably 300 ° C. or lower. Can be used.
Examples of agents used for hydrolysis include inorganic acids such as nitric acid and hydrochloric acid, organic acids such as formic acid, and alkalis such as ammonia.
[0013]
Examples of the surfactant include lauryl trimethyl ammonium chloride, n-hexadecyl trimethyl ammonium chloride, alkyl trimethyl ammonium bromide, cetyl trimethyl ammonium chloride, cetyl trimethyl ammonium bromide, stearyl trimethyl ammonium chloride, alkyl dimethyl ethyl ammonium chloride, and alkyl dimethyl ethyl. Alkyl trimethyl ammonium halide-based cationic surfactants such as ammonium bromide, cetyl dimethyl ethyl ammonium bromide, octadecyl dimethyl ethyl ammonium bromide, and methyl dodecyl benzyl trimethyl ammonium chloride can be exemplified. In addition, dimethyldecylbenzylammonium chloride, diethyldodecylbenzylammonium chloride, trimethyldodecylammonium bromide, allyldibutyldodecylammonium bromide, diethylacetonyldodecylammonium chloride and the like can be used.
[0014]
The heat treatment conditions for producing the hydrophobic porous SOG film are preferably as follows in order to improve the mechanical properties of the film.
After spin-coating on a semiconductor substrate using the above coating solution, the substrate is subjected to one-step heat treatment or two or more-step heat treatment using a known infrared heating furnace.
[0015]
In the case of the two-step heat treatment, in the first step heat treatment, the above-mentioned surfactant used as a template is usually used at a temperature higher than the evaporation temperature of the organic solvent used as a solvent (for example, 65 ° C. for methyl alcohol). The heat treatment is performed at a temperature lower than the thermal decomposition temperature, preferably at a temperature lower than 60 ° C. to lower than 300 ° C., and the organic solvent is evaporated and cured in a state where the template substance is present without decomposition. In the second stage heat treatment, in the presence of an oxygen-containing gas having a predetermined oxygen partial pressure, the SOG film is used as a wiring within a range that does not impair the film properties of the obtained SOG film, that is, usually from the thermal decomposition temperature of the surfactant or higher. Heat treatment at a temperature lower than the melting point of a metal such as copper or silver (eg, 1087 ° C. or lower for copper), preferably 300 ° C. to 1000 ° C., and more preferably 300 ° C. to 500 ° C. to form a hydrophobic porous SOG film. Is prepared. If the temperature exceeds 1000 ° C., the hydrophobicity of the obtained SOG film may be impaired. If the temperature is lower than 300 ° C., it is difficult to decompose the surfactant, and a porous SOG film cannot be obtained.
[0016]
When performing the second step, the temperature is increased from a temperature at which a surfactant used as a template for forming pores of the porous SOG film to cause thermal decomposition to a predetermined heat treatment temperature up to 1000 ° C. During the holding time, it is desirable to perform in an atmosphere containing no oxygen. The heating time and the holding time in this heating may be appropriately selected within a range that does not impair the film characteristics of the obtained SOG film.
[0017]
In the case of the one-step heat treatment, the temperature is raised directly from room temperature to a predetermined temperature of, for example, 400 ° C., and maintained at this temperature for 5 minutes or more. And heat-treated at a predetermined temperature to produce a hydrophobic porous SOG film having desired mechanical properties. In this case, the heating to the predetermined temperature and the holding time are performed in an atmosphere containing no oxygen, and the heating time and the holding time in this heating are within a range that does not impair the film characteristics of the obtained SOG film. May be selected as appropriate.
As the oxygen-containing gas, for example, pure air containing no water, a mixed gas in which oxygen is mixed with an inert gas such as nitrogen or argon so that the oxygen partial pressure is equal to or higher than the above value, or the like can be used.
[0018]
【Example】
Hereinafter, examples of the present invention will be described.
(Example 1)
Film formation of porous SOG (SiO 2 ) on a Si semiconductor substrate was performed as follows.
1 mol of tetraethoxysilane (TEOS), 11 mol of H 2 O, 0.15 mol of hexamethyldisiloxane (HMDSO), 0.25 mol of hexadecyltrimethylammonium chloride (C16TAC) are acidified (pH: 1-3) solvent. The mixture was added and mixed, and the mixture was reacted at 55 ° C. to obtain a uniform SOG precursor coating solution.
[0019]
After spin coating was performed on a semiconductor substrate at 1500 rpm using this coating solution, the substrate was subjected to a two-stage heat treatment using a known infrared heating furnace. As the first step, heat treatment is performed in air at 100 ° C., then the temperature is raised to 400 ° C. in an atmosphere of 3 Pa or less, and after maintaining at 400 ° C. for 15 minutes, pure air is introduced into the furnace until the oxygen partial pressure becomes 1E + 4 Pa. Then, the second heat treatment was performed at 400 ° C. for 30 minutes.
The electrical characteristics of the porous SOG film obtained by the heat treatment were measured by a mercury probe method, and the film thickness was measured by ellipsometry to calculate a relative dielectric constant. Further, the mechanical strength was measured by a nanoindentation method. The results are shown in Table 1.
[0020]
Table 1 also shows the measurement results of the SOG film obtained by performing the conventional heat treatment without introducing the oxygen-containing gas at the same temperature, temperature rise time and holding time as described above.
As is clear from Table 1, when the porous SOG film subjected to the conventional heat treatment without introducing the oxygen-containing gas is compared with the porous SOG film obtained by introducing the oxygen-containing gas, the latter is as follows. It can be seen that the mechanical strength is improved by about 2.5 to 3.5 times as compared with the former, and the rise of the relative permittivity is limited to about 6%. FIG. 1 shows the change over time in the relative dielectric constant when a porous SOG film obtained by introducing an oxygen-containing gas is left in a room at a humidity of 40% and a temperature of 23 ° C. As shown in FIG. 1, the effect of the main heat treatment on the hydrophobicity was not observed, and the change in the relative dielectric constant after 14 days was Δk to 0.3%.
[0021]
(Example 2)
After the coating liquid used in Example 1 was spin-coated on the substrate, the substrate was subjected to a first-stage heat treatment at 250 ° C. for 60 minutes, and then heated to 450 ° C. in an atmosphere reduced to 3 Pa or less. After maintaining at that temperature for 20 minutes, pure air was introduced into the furnace so as to have an oxygen partial pressure of 5E + 3 Pa, and then heat treatment was performed for 30 minutes. The obtained SOG film was evaluated in the same manner as in Example 1, and the results are shown in Table 1.
Also in the porous SOG film obtained in the present example, the obtained relative dielectric constant is increased by about 4% as compared with the porous SOG film subjected to the conventional heat treatment without introducing the oxygen-containing gas. And the mechanical strength doubled or tripled.
[0022]
(Example 3)
After the coating liquid used in Example 1 was spin-coated on the substrate, the substrate was heated to 400 ° C. under a pressure of 3 Pa or less, and then pure air was introduced to an oxygen partial pressure of 2E + 4 Pa for 30 minutes. Heat treatment was performed. The obtained SOG film was evaluated in the same manner as in Example 1, and the results are shown in Table 1.
The relative dielectric constant of the porous SOG film obtained in this example is only about 2% higher than that of a conventional heat-treated porous SOG film without introducing an oxygen-containing gas. , Mechanical strength is l. 5-2 times.
[0023]
(Table 1)
【The invention's effect】
According to the present invention, since the oxygen-containing gas is introduced into the firing furnace at a predetermined time during the heat treatment process and the heat treatment for producing the hydrophobic porous SOG film is performed, the polycondensation of the SOG precursor is introduced. By the heat treatment method which is promoted by the oxygen gas and is performed simultaneously with the formation of the SOG film, it is possible to improve the mechanical characteristics of the hydrophobic porous SOG film without substantially affecting the original electric characteristics. it can.
[Brief description of the drawings]
FIG. 1 is a graph showing a change in relative dielectric constant of a hydrophobic porous SOG film obtained in Example 1 when left in a room at a humidity of 40% and a temperature of 23 ° C.
Claims (12)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003062879A JP2004273786A (en) | 2003-03-10 | 2003-03-10 | Manufacturing method of hydrophobic porous sog film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003062879A JP2004273786A (en) | 2003-03-10 | 2003-03-10 | Manufacturing method of hydrophobic porous sog film |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2010137418A Division JP2010251784A (en) | 2010-06-16 | 2010-06-16 | Manufacturing method of hydrophobic porous sog film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2004273786A true JP2004273786A (en) | 2004-09-30 |
Family
ID=33124621
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2003062879A Pending JP2004273786A (en) | 2003-03-10 | 2003-03-10 | Manufacturing method of hydrophobic porous sog film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2004273786A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006114718A (en) * | 2004-10-15 | 2006-04-27 | Jsr Corp | Composition for surface hydrophobing, method of hydrophobing surface, semiconductor device and its manufacturing method |
| JP2007134420A (en) * | 2005-11-09 | 2007-05-31 | Ulvac Japan Ltd | Embedding method inside structure by hydrophobic porous silica material |
| JP2007158066A (en) * | 2005-12-06 | 2007-06-21 | Ulvac Japan Ltd | Insulation film, manufacturing method thereof, and multilayer wiring structure using same |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000039028A1 (en) * | 1998-12-23 | 2000-07-06 | Battelle Memorial Institute | Mesoporous silica film from a solution containing a surfactant and methods of making same |
| JP2002033314A (en) * | 2000-02-10 | 2002-01-31 | Applied Materials Inc | Method and integrated device for treating low dielectric constant deposition containing pecvd capping module |
| JP2002075983A (en) * | 2000-04-11 | 2002-03-15 | Applied Materials Inc | Method of forming mesoporous oxide films and dual damascene structure |
| JP2003017485A (en) * | 2001-06-29 | 2003-01-17 | Rohm Co Ltd | Semiconductor device and method for manufacturing the same |
-
2003
- 2003-03-10 JP JP2003062879A patent/JP2004273786A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000039028A1 (en) * | 1998-12-23 | 2000-07-06 | Battelle Memorial Institute | Mesoporous silica film from a solution containing a surfactant and methods of making same |
| JP2002033314A (en) * | 2000-02-10 | 2002-01-31 | Applied Materials Inc | Method and integrated device for treating low dielectric constant deposition containing pecvd capping module |
| JP2002075983A (en) * | 2000-04-11 | 2002-03-15 | Applied Materials Inc | Method of forming mesoporous oxide films and dual damascene structure |
| JP2003017485A (en) * | 2001-06-29 | 2003-01-17 | Rohm Co Ltd | Semiconductor device and method for manufacturing the same |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006114718A (en) * | 2004-10-15 | 2006-04-27 | Jsr Corp | Composition for surface hydrophobing, method of hydrophobing surface, semiconductor device and its manufacturing method |
| JP4591032B2 (en) * | 2004-10-15 | 2010-12-01 | Ｊｓｒ株式会社 | Surface hydrophobizing composition, surface hydrophobizing method, and semiconductor device manufacturing method |
| JP2007134420A (en) * | 2005-11-09 | 2007-05-31 | Ulvac Japan Ltd | Embedding method inside structure by hydrophobic porous silica material |
| JP2007158066A (en) * | 2005-12-06 | 2007-06-21 | Ulvac Japan Ltd | Insulation film, manufacturing method thereof, and multilayer wiring structure using same |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5405031B2 (en) | Solution for immersion used in the production of siliceous film and method for producing siliceous film using the same | |
| US6042994A (en) | Nanoporous silica dielectric films modified by electron beam exposure and having low dielectric constant and low water content | |
| JP3097870B2 (en) | Method for converting silica precursor to silica at low temperature using amine catalyst | |
| JPH04227980A (en) | Method for converting silica precursor into silica at low temperature | |
| KR20020025992A (en) | Nanoporous Silica Treated With Siloxane Polymers For ULSI Application | |
| JP4021131B2 (en) | Coating liquid for forming low dielectric constant silica-based coating and substrate with low dielectric constant silica-based coating | |
| JP4142643B2 (en) | Organosilicate polymer and insulating film containing the same | |
| KR20010101851A (en) | Method of forming a silica-containing coating film with a low dielectric constant and semiconductor substrate coated with such a film | |
| JP2007134420A (en) | Embedding method inside structure by hydrophobic porous silica material | |
| JP4251927B2 (en) | Method for producing porous silica membrane | |
| JPH11233506A (en) | Method of forming porous film and material for porous film | |
| JP2004273786A (en) | Manufacturing method of hydrophobic porous sog film | |
| JP2000340651A (en) | Manufacture of film having low dielectric constant | |
| JP2000077399A (en) | Silica based porous film and production thereof | |
| JPH1092804A (en) | Manufacture of porous dielectric film | |
| JP2915357B2 (en) | Semiconductor device, method of manufacturing the same, and method of forming porous film | |
| JP3618150B2 (en) | Semiconductor device and manufacturing method thereof | |
| JP3954842B2 (en) | Method for producing hydrophobic porous material | |
| JP2010251784A (en) | Manufacturing method of hydrophobic porous sog film | |
| JP2003007696A (en) | Method for manufacturing semiconductor device | |
| JP3877472B2 (en) | Method for forming interlayer insulating film | |
| JP4982012B2 (en) | Method for producing hydrophobic porous SOG film | |
| JP2851871B2 (en) | Semiconductor device and manufacturing method thereof | |
| JP2007158066A (en) | Insulation film, manufacturing method thereof, and multilayer wiring structure using same | |
| JP2001287909A (en) | Porous silicon oxide coating film |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20051208 |
|
| A977 | Report on retrieval |
Effective date: 20071220 Free format text: JAPANESE INTERMEDIATE CODE: A971007 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080108 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20080307 |
|
| RD02 | Notification of acceptance of power of attorney |
Effective date: 20081216 Free format text: JAPANESE INTERMEDIATE CODE: A7422 |
|
| RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7424 Effective date: 20081216 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20091110 |
|
| A02 | Decision of refusal |
Effective date: 20100316 Free format text: JAPANESE INTERMEDIATE CODE: A02 |