JP4299376B2 - Method for forming conductive film and method for forming metal oxide film - Google Patents

Description

表１に示されるように、紫外線照射や加熱処理が施されていない未処理の試料Ａに比べ、波長４００ｎｍ以下の紫外線照射を施した試料Ａ１は抵抗率が低下した。また、この試料Ａ１は未処理の試料Ａに比べ結晶性が低下し結晶化は生じておらず、一方、伝導電子の密度が高くなっており、この伝導電子密度の向上によって低抵抗化が達成されたと考えられる。
【００４０】
また、紫外線照射や加熱処理が施されていない未処理の試料Ｂ、および、波長４００ｎｍ以下の紫外線照射を施した試料Ｂ１においても、上記の試料Ａおよび試料Ａ１と同様のことが確認された。
【００４１】
これに対して、波長４００ｎｍを超える光を用いて光照射処理を行った比較試料１は、伝導電子密度の向上がみられず抵抗率は低下しなかった。
【００４２】
一方、試料Ａに加熱処理を施した比較試料２は、抵抗率の低下がわずかであった。また、この比較試料２は未処理の試料Ａに比べて結晶性が向上しているものの、伝導電子の密度の増大はみられなかった。
（実施例２）
厚み１．１ｍｍのガラス基板をスパッタリング装置の基板ホルダー上に載置し、また、ターゲット材取り付け板にターゲット材（Ｉｎ₂ Ｏ₃ −ＳｎＯ₂ 燒結体（ＳｎＯ₂ １０重量％）を取り付けた。
【００４３】
次に、真空チャンバー内にアルゴン（Ａｒ）ガスを導入して雰囲気圧力を５mTorr とし基板温度を２５℃として、下記の成膜条件で基板上に厚さ約０．３μｍの導電膜（ＩＴＯ膜）を形成した。
【００４４】
（ＩＴＯ成膜条件）
・雰囲気ガス ： Ａｒ＝１００ｓｃｃｍ，Ｏ₂ ＝２ｓｃｃｍ
・雰囲気圧力 ： ５ mTorr
・水素分圧 ： １０×１０^-9Torr以下
・ＤＣパワー ： ２．５ｋＷ
・成膜レート ： ２Å／秒
次に、この導電膜（ＩＴＯ膜）を形成した基板に対して、Ｈｇ−Ｘｅ紫外線ランプ（波長のメインピーク＝３６０ｎｍ）を用いて１０，１５，２０，４０，６０，１００，２００，５００分間の８種の照射時間による処理を行った。
【００４５】
上記のように紫外線照射処理を行った各導電膜および未処理の導電膜について、伝導電子の密度と抵抗率を実施例１と同様に測定して結果を図１に示した。
【００４６】
図１に示されるように、１０分間の紫外線照射処理により伝導電子の密度が向上し、同時に抵抗率の低下がみられ、照射時間が長くなるにしたがって更に伝導電子密度の向上と抵抗率の低下がみられた。
（実施例３）
厚み１．１ｍｍのガラス基板をスパッタリング装置の基板ホルダー上に載置し、また、ターゲット材取り付け板にターゲット材（Ｉｎ₂ Ｏ₃ −ＳｎＯ₂ 燒結体（ＳｎＯ₂ １０重量％）を取り付けた。
【００４７】
次に、真空チャンバー内にアルゴン（Ａｒ）ガスを導入して雰囲気圧力を５mTorr とし、基板温度を２５℃として下記の成膜条件で基板上に厚さ約１５００Åの導電膜（ＩＴＯ膜）を形成して試料Ｃを作製した。
【００４８】
（ＩＴＯ成膜条件）
・雰囲気ガス ： Ａｒ＝１００ｓｃｃｍ，Ｏ₂ ＝３ｓｃｃｍ
・雰囲気圧力 ： ５ mTorr
・水素分圧 ： １０×１０^-9Torr以下
・ＲＦパワー ： ２５０Ｗ
・成膜レート ： ２．６Å／秒
上記のように導電膜（ＩＴＯ膜）を形成した基板（試料Ｃ）に対して、Ｘｅ−Ｃｌ（波長３０８ｎｍ）エキシマレーザーを用いて下記の条件で照射を行って試料Ｃ１〜Ｃ３を作製した。
【００４９】
（レーザー照射条件）
・照射エネルギー ： 最大３００ｍＪ／ｃｍ²
・レーザー照射重ね率： ５０％
・照射雰囲気 ： 大気中
上記のように作製した試料Ｃ、試料Ｃ１〜Ｃ３について、実施例１と同様にしてＩＴＯ膜の結晶性、伝導電子の密度、抵抗率を測定評価して、結果を下記の表２および図２に示した。
【００５０】
【表２】

表２および図２に示されるように、レーザー照射処理が施されていない未処理の試料Ｃに比べ、Ｘｅ−Ｃｌエキシマレーザーを照射した試料Ｃ１と試料Ｃ２は抵抗率の低下がみられ、試料Ｃ２で抵抗率は最小（５．８７×１０^-4Ω・ｃｍ）となり、このとき、結晶化は生じておらず、伝導電子の密度が高くなっている。そして、照射エネルギーがさらに高い試料Ｃ３では、結晶化が急激に進み、抵抗率の増大がみられる。このことから、試料ＣにおけるＸｅ−Ｃｌエキシマレーザー照射では、照射エネルギーの最適値は約１００ｍＪ／ｃｍ² であるといえる。（実施例４）
イオンプレーティング装置を用い、基板温度を２５℃として下記の成膜条件で厚み１．１ｍｍのガラス基板上に厚さ約０．３μｍの導電膜（ＩＴＯ膜）を形成して試料Ｄを作製した。
【００５１】
（ＩＴＯ成膜条件）
・雰囲気ガス ： Ａｒ＝１００ｓｃｃｍ，Ｏ₂ ＝３ｓｃｃｍ
・雰囲気圧力 ： ５ mTorr
・水素分圧 ： １０×１０^-9Torr以下
・蒸発源 ： Ｉｎ₂ Ｏ₃ −ＳｎＯ₂ 燒結体（ＳｎＯ₂ １０重量％）
・ＲＦパワー ： ２５０Ｗ
・成膜レート ： ２．６Å／秒
上記のように導電膜（ＩＴＯ膜）を形成した基板（試料Ｄ）に対して、Ｈｇ−Ｘｅ紫外線ランプ（波長のメインピーク＝３６０ｎｍ）を用いて下記表３に示される照射エネルギーとなるように紫外線照射を行って試料Ｄ１を作製した。
【００５２】
また、基板温度を３００℃とした他は、上記の試料Ｄと同様にして基板上に厚さ約０．３μｍの導電膜（ＩＴＯ膜）を形成し試料Ｅを作製し、この基板（試料Ｅ）に対して、Ｈｇ−Ｘｅ紫外線ランプ（波長のメインピーク＝３６０ｎｍ）を用いて下記表３に示される照射エネルギーとなるように紫外線照射を行って試料Ｅ１を作製した。
【００５３】
一方、上記のように導電膜（ＩＴＯ膜）を形成した基板（試料Ｄ）に対して、Ｈｅ−Ｎｅレーザー（波長６３３ｎｍ）を用いて下記表３に示される照射エネルギーとなるように照射を行って比較試料１を作製した。
【００５４】
また、上記のように導電膜（ＩＴＯ膜）を形成した基板（試料Ｄ）に対して、１００℃、２時間の加熱処理を施して比較試料２を作製した。
【００５５】
上記のように作製した試料Ｄ、試料Ｄ１、試料Ｅ、試料Ｅ１、比較試料１、２について、実施例１と同様にしてＩＴＯ膜の結晶性、伝導電子の密度、抵抗率を測定評価して、結果を下記の表３に示した。
【００５６】
【表３】

表３に示されるように、紫外線照射や加熱処理が施されていない未処理の試料Ｄに比べ、波長４００ｎｍ以下の紫外線照射を施した試料Ｄ１は抵抗率が低下した。また、この試料Ｄ１は未処理の試料Ｄに比べ結晶性が低下し結晶化は生じておらず、一方、伝導電子の密度が高くなっており、この伝導電子密度の向上によって低抵抗化が達成されたと考えられる。
【００５７】
また、紫外線照射や加熱処理が施されていない未処理の試料Ｅ、および、波長４００ｎｍ以下の紫外線照射を施した試料Ｅ１においても、上記の試料Ｄおよび試料Ｄ１と同様のことが確認された。
【００５８】
これに対して、波長４００ｎｍを超える光を用いて光照射処理を行った比較試料１は、伝導電子密度の向上がみられず抵抗率は低下しなかった。
【００５９】
一方、試料Ｄに加熱処理を施した比較試料２は、未処理の試料Ｄに比べて結晶性が向上しているものの、伝導電子の密度の増大はほとんどみられず、抵抗率の低下がわずかであった。
（実施例５）
真空蒸着装置を用い、基板温度を２５℃として下記の成膜条件で厚み１．１ｍｍのガラス基板上に厚さ約０．３μｍの導電膜（ＩＴＯ膜）を形成して試料Ｆを作製した。
【００６０】
（ＩＴＯ成膜条件）
・雰囲気圧力 ： ５ mTorr
・水素分圧 ： １０×１０^-9Torr以下
・蒸発源 ： Ｉｎ₂ Ｏ₃ −ＳｎＯ₂ 燒結体（ＳｎＯ₂ １０重量％）
・ＲＦパワー ： ２５０Ｗ
・成膜レート ： ２．６Å／秒
上記のように導電膜（ＩＴＯ膜）を形成した基板（試料Ｆ）に対して、Ｈｇ−Ｘｅ紫外線ランプ（波長のメインピーク＝３６０ｎｍ）を用いて下記表４に示される照射エネルギーとなるように紫外線照射を行って試料Ｆ１を作製した。
【００６１】
また、基板温度を３００℃とした他は、上記の試料Ｆと同様にして基板上に厚さ約０．３μｍの導電膜（ＩＴＯ膜）を形成し試料Ｇを作製し、この基板（試料Ｇ）に対して、Ｈｇ−Ｘｅ紫外線ランプ（波長のメインピーク＝３６０ｎｍ）を用いて下記表４に示される照射エネルギーとなるように紫外線照射を行って試料Ｇ１を作製した。
【００６２】
一方、上記のように導電膜（ＩＴＯ膜）を形成した基板（試料Ｆ）に対して、Ｈｅ−Ｎｅレーザー（波長６３３ｎｍ）を用いて下記表４に示される照射エネルギーとなるように照射を行って比較試料１を作製した。
【００６３】
また、上記のように導電膜（ＩＴＯ膜）を形成した基板（試料Ｆ）に対して、１００℃、２時間の加熱処理を施して比較試料２を作製した。
【００６４】
上記のように作製した試料Ｆ、試料Ｆ１、試料Ｇ、試料Ｇ１、比較試料１、２について、実施例１と同様にしてＩＴＯ膜の結晶性、伝導電子の密度、抵抗率を測定評価して、結果を下記の表４に示した。
【００６５】
【表４】

表４に示されるように、紫外線照射や加熱処理が施されていない未処理の試料Ｆに比べ、波長４００ｎｍ以下の紫外線照射を施した試料Ｆ１は抵抗率が低下した。また、この試料Ｆ１は未処理の試料Ｆに比べ結晶性が低下しており、結晶化は生じておらず、一方、伝導電子の密度が高くなっており、この伝導電子密度の向上によって低抵抗化が達成されたと考えられる。
【００６６】
また、紫外線照射や加熱処理が施されていない未処理の試料Ｇ、および、波長４００ｎｍ以下の紫外線照射を施した試料Ｇ１においても、上記の試料Ｆおよび試料Ｆ１と同様のことが確認された。
【００６７】
これに対して、波長４００ｎｍを超える光を用いて光照射処理を行った比較試料１は、伝導電子密度の向上がみられず抵抗率は低下しなかった。
【００６８】
一方、試料Ｆに加熱処理を施した比較試料２は、抵抗率の低下がわずかであり、また、未処理の試料Ｆに比べて結晶性が向上しているものの、伝導電子の密度の増大はみられなかった。
（実施例６）
厚み１．１ｍｍのシリコンウエハー上にＰｔＮｉ合金を形成した基板を、スパッタリング装置の基板ホルダー上に載置し、また、ターゲット材取り付け板にターゲット材（Ｚｒ／Ｔｉ合金板、ＰｂＯペレット）を取り付けた。
【００６９】
次に、真空チャンバー内にアルゴン（Ａｒ）ガスを導入して雰囲気圧力を１０mTorr 、基板温度を４００℃として下記の成膜条件で基板上に厚さ約０．２μｍの強誘電体薄膜（ＰｂＺｒＴｉＯ₃ 、以下ＰＺＴ膜とする）を形成して試料Ｈを作製した。
【００７０】
（ＰＺＴ成膜条件）
・雰囲気ガス ： Ａｒ＝１００ｓｃｃｍ，Ｏ₂ ＝２ｓｃｃｍ
・雰囲気圧力 ： １０ mTorr
・水素分圧 ： １０^-8Torr以下
・ＤＣパワー ： ２０００Ｗ
・成膜レート ： ０．２ｎｍ／秒
上記のように強誘電体薄膜（ＰＺＴ膜）を形成した基板（試料Ｈ）に対して、Ｈｇ−Ｘｅ紫外線ランプ（波長のメインピーク＝３６０ｎｍ）を用いて下記表５に示される照射エネルギーとなるように、室温、大気圧下で紫外線照射を行って試料Ｈ１を作製した。
【００７１】
一方、上記のように強誘電体薄膜（ＰＺＴ膜）を形成した基板（試料Ｈ）に対して、Ｈｅ−Ｎｅレーザー（波長６３３ｎｍ）を用いて下記表５に示される照射エネルギーとなるように照射を行って比較試料１を作製した。
【００７２】
また、上記のように強誘電体薄膜（ＰＺＴ膜）を形成した基板（試料Ｈ）に対して、５００℃、１時間の加熱処理を施して比較試料２を作製した。
【００７３】
上記のように作製した試料Ｈ、試料Ｈ１、比較試料１、２について、下記の方法によりＰＺＴ膜の結晶性、Ｄ−Ｅヒステリシス特性（残留分極Ｐｒ値の評価）を測定評価して、結果を下記の表５に示した。
【００７４】
（結晶性の評価方法）
Ｘ線回折法によりペロブスカイト型（Ｐｂ，Ｚｒ）ＴｉＯ₃ の（１１２）面および（３０１）面の回折ピークの半値幅を測定し、試料Ｈに対する変化から結晶性の変化を評価した。
【００７５】
・結晶性向上の判定：（１１２）面と（３０１）面の半値幅が減少
・結晶性低下の判定：（１１２）面と（３０１）面の半値幅が増大
（残留分極Ｐｒの測定方法）
ＰｔＮｉ電極によるＤ−Ｅヒステリシス曲線を描き、そのループより残留分極Ｐｒを求めた。
【００７６】
【表５】

表５に示されるように、紫外線照射や加熱処理が施されていない未処理の試料Ｈに比べ、波長４００ｎｍ以下の紫外線照射を施した試料Ｈ１は残留分極値が増大した。また、この試料Ｈ１は未処理の試料Ｈに比べ結晶性は変化しておらず、膜形態の変化によって高残留分極化が達成されたと考えられる。
【００７７】
これに対して、波長４００ｎｍを超える光を用いて光照射処理を行った比較試料１は、残留分極値の増加がみられなかった。
【００７８】
一方、試料Ｈに加熱処理を施した比較試料２は、未処理の試料Ｈに比べて結晶性が向上しているが、残留分極値の増大はわずかであった。
（実施例７）
厚み１．１ｍｍのガラス基板をスパッタリング装置の基板ホルダー上に載置し、また、ターゲット材取り付け板にターゲット材（Ｍｎ／Ｚｎ合金板、Ｆｅ₃ Ｏ₄ ペレット）を取り付けた。
【００７９】
次に、真空チャンバー内にアルゴン（Ａｒ）ガスを導入して雰囲気圧力を５mTorr 、基板温度を４５０℃として下記の成膜条件で基板上に厚さ約０．２μｍの強誘電体薄膜（（Ｍｎ，Ｚｎ）Ｏ・Ｆｅ₂ Ｏ₃ 、以下ＭｎＺｎフェライト膜とする）を形成して試料Ｉを作製した。
【００８０】
（ＭｎＺｎフェライト成膜条件）
・雰囲気ガス ： Ａｒ＝１００ｓｃｃｍ，Ｏ₂ ＝２ｓｃｃｍ
・雰囲気圧力 ： ５ mTorr
・水素分圧 ： １０^-8Torr以下
・ＤＣパワー ： ２０００Ｗ
・成膜レート ： ０．５ｎｍ／秒
上記のように強磁性薄膜（ＭｎＺｎフェライト膜）を形成した基板（試料Ｉ）に対して、Ｈｇ−Ｘｅ紫外線ランプ（波長のメインピーク＝３６０ｎｍ）を用いて下記表６に示される照射エネルギーとなるように、室温、大気圧下で紫外線照射を行って試料Ｉ１を作製した。
【００８１】
一方、上記のように強磁性薄膜（ＭｎＺｎフェライト膜）を形成した基板（試料Ｉ）に対して、Ｈｅ−Ｎｅレーザー（波長６３３ｎｍ）を用いて下記表６に示される照射エネルギーとなるように照射を行って比較試料１を作製した。
【００８２】
また、上記のように強磁性薄膜（ＭｎＺｎフェライト膜）を形成した基板（試料Ｉ）に対して、５００℃、１時間の加熱処理を施して比較試料２を作製した。
【００８３】
上記のように作製した試料Ｉ、試料Ｉ１、比較試料１、２について、下記の方法によりＭｎＺｎフェライト膜の結晶性、磁気ヒステリシス特性（保磁力Ｈｃ値の評価）を測定評価して、結果を下記の表６に示した。
【００８４】
（結晶性の評価方法）
Ｘ線回折法によりスピネル型フェライトの（１１１）面および（１１０）面の回折ピークの半値幅を測定し、試料Ｉに対する変化から結晶性の変化を評価した。
【００８５】
・結晶性向上の判定：（１１１）面と（１１０）面の半値幅が減少
・結晶性低下の判定：（１１１）面と（１１０）面の半値幅が増大
（保磁力Ｈｃの測定方法）
振動試料型磁力計（ＶＳＭ）により、試料の磁気ヒステリシス曲線を描き、そのループより保磁力Ｈｃを求めた。
【００８６】
【表６】

表６に示されるように、紫外線照射や加熱処理が施されていない未処理の試料Ｉに比べ、波長４００ｎｍ以下の紫外線照射を施した試料Ｉ１は保磁力が減少した。また、この試料Ｉ１は未処理の試料Ｉに比べ結晶性は変化しておらず、膜形態の変化によって結晶粒界が低減し、その結果として低保磁力化が達成されたと考えられる。
【００８７】
これに対して、波長４００ｎｍを超える光を用いて光照射処理を行った比較試料１は、保磁力の低下がみられなかった。
【００８８】
一方、試料Ｉに加熱処理を施した比較試料２は、未処理の試料Ｉに比べて結晶性が向上しているが、保磁力の低減はわずかであった。
【００８９】
【発明の効果】
以上詳述したように、本発明によれば基板上に導電膜を形成した後、この導電膜に結晶化を生じさせないように波長４００ｎｍ以下の光を照射することにより、導電膜中の伝導電子の密度が高められて導電性向上がなされ、導電膜の抵抗率を低下させることができ、この低抵抗化はアニール処理を行わないため基板に対して熱の悪影響が及ばず、耐熱性の低い基板においても低抵抗の導電膜を形成することができる。また、基板上の金属酸化膜を形成した後、この金属酸化膜に結晶化を生じさせないように波長４００ｎｍ以下の光を照射することにより、金属酸化膜の有する特性を変えること、たとえば、強誘電体薄膜としての金属酸化膜の膜形態を変化させるによって残留分極率を増大することや、強磁性薄膜としての金属酸化膜の膜形態の変化によって結晶粒界を低減させ保磁力を低下させること等ができ、成膜後にアニール処理を施すことなく所望の金属酸化膜を形成することができる。
【図面の簡単な説明】
【図１】導電膜に対する紫外線照射時間と、導電膜の伝導電子密度および抵抗率との関係を示すための図である。
【図２】導電膜に対するレーザー照射エネルギーと抵抗率との関係を示すための図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for forming a conductive film having a low resistivity, and a method for forming a metal oxide film such as a ferroelectric thin film having a high remanent polarizability or a ferromagnetic thin film having a low coercive force.
[0002]
[Prior art]
Conventionally, conductive films and transparent conductive films have been used for various electronic components, image display devices, etc. For example, transparent conductive films include indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO).₂ ) And the alloys thereof and the like, and a film forming method such as a sputtering method, a vacuum evaporation method, and a CVD method.
[0003]
Among the film forming methods described above, in the sputtering method, for example, an ITO oxide target material is sputtered with Ar ions to form an ITO film on the substrate. Such an ITO film was formed at a substrate temperature of 200 to 300 ° C. and then annealed at 200 to 300 ° C. to reduce the resistance.
[0004]
However, as the demand for forming a conductive film on a substrate with low heat resistance in an electronic component, an image display device, or the like increases, the formation of a low-resistance conductive film at a low temperature of room temperature to 200 ° C. has become an important issue. . Usually, an ITO film formed at a low temperature by a sputtering method at a substrate temperature of 200 ° C. or lower has a high resistivity and is difficult to use as it is in various electronic parts, image display devices, and the like. For this reason, it is necessary to reduce the resistance by annealing the ITO film formed at a low temperature by the sputtering method.
[0005]
On the other hand, ferroelectric thin films composed of metal oxide films are expected to be applied to pyroelectric sensors, nonvolatile memories, etc., and ferroelectric thin films with high remanent polarizability for practical application to such devices. The formation of is required.
[0006]
Further, ferromagnetic thin films made of metal oxide films have been developed for use in thin film magnetic head materials and recording materials. As a method for forming this ferromagnetic thin film, a vapor deposition method, a sputtering method, a coating method, etc. are generally known, and a ferromagnetic thin film having practically sufficient characteristics has been obtained. The demand for improvement in recording density characteristics for magnetic thin films is becoming stricter year by year.
[0007]
[Problems to be solved by the invention]
The annealing treatment after the film formation at the low temperature in the above-described conductive film formation cannot be performed at a high temperature in order to protect the substrate having low heat resistance, and therefore there is a problem that a sufficiently low resistance cannot be achieved. It was. In addition, even for a conductive film formed on a substrate having a high heat resistance at a substrate temperature of 200 to 300 ° C., the above annealing treatment results in a low resistance treatment on the entire surface of the ITO film, and only a desired region and pattern are crystallized. A method capable of reducing resistance without changing the degree of conversion is desired.
[0008]
In addition, in order to form the above-described ferroelectric thin film having a high remanent polarizability, strict control is required for the film forming conditions, and a fatigue phenomenon that has recently become a problem (residual polarizability in a repetitive polarization inversion test). Therefore, it is necessary to perform a treatment for increasing the remanent polarizability on the ferroelectric thin film after film formation. However, in reality, there is no effective processing method other than the annealing process after the film formation.
[0009]
Furthermore, the improvement of the recording density characteristics of the above-mentioned ferromagnetic thin film is important in terms of magnetic characteristics, especially the low coercive force. By reducing the crystal grain boundary in the magnetic material that causes the coercive force, a low magnetic field is achieved. Therefore, it is necessary to manufacture a ferromagnetic thin film that can easily move the domain wall. However, since formation of such a ferromagnetic thin film requires strict control of the film forming conditions, a method capable of easily forming a ferromagnetic thin film having a low coercive force is desired.
[0010]
The present invention has been made in view of the above circumstances, and a method for forming a conductive film capable of forming a low-resistance conductive film, a ferroelectric thin film having a high remanent polarizability, and a low coercive force. It is an object of the present invention to provide a metal oxide film forming method capable of forming a metal oxide film such as a ferromagnetic thin film.
[0011]
[Means for Solving the Problems]
  In order to achieve such an object, the method for forming a conductive film of the present invention comprises:By any of sputtering, vacuum deposition, and ion plating methodsAfter the conductive film is formed on the substrate, when the conductive film is amorphous, when the conductive film is crystalline with irradiation energy in a range that does not cause crystallization of the conductive film, The irradiation energy is within a range that maintains or lowers the crystallinity of the conductive film, and light having a wavelength of 400 nm or less is irradiated.
[0012]
In addition, the method for forming a conductive film of the present invention is configured such that the substrate temperature at the time of forming the conductive film is set in the range of room temperature to 200 ° C.
[0014]
  The method for forming a metal oxide film of the present invention includes:By any of sputtering, vacuum deposition, and ion plating methodsAfter the metal oxide film is formed on the substrate, if the metal oxide film is amorphous, the metal oxide film is crystalline with an irradiation energy within a range that does not cause crystallization of the metal oxide film. In some cases, the light was irradiated with light having a wavelength of 400 nm or less with irradiation energy within a range that maintains or lowers the crystallinity of the metal oxide film.
[0016]
In the present invention as described above, the light with a wavelength of 400 nm or less irradiated so as not to cause crystallization of the conductive film formed on the substrate has the effect of increasing the density of conductive electrons in the conductive film. The conductivity of the film is improved (resistance is reduced).
[0017]
In addition, the light having a wavelength of 400 nm or less irradiated so as not to cause crystallization of the metal oxide film formed on the substrate has a residual polarizability, for example, when the metal oxide film is a ferroelectric thin film. When the metal oxide film is a ferromagnetic thin film, the crystal grain boundary in the metal oxide film is eliminated.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
Method for forming conductive film
In the conductive film formation method of the present invention, the conductive film formed on the substrate is irradiated with light having a wavelength of 400 nm or less at an irradiation energy amount that does not cause crystallization of the conductive film. It increases the density of conduction electrons and decreases the resistivity.
[0019]
Formation of the conductive film in the present invention can be performed by any conventionally known sputtering method, vacuum deposition method, ion plating method, CVD method or the like.
[0020]
For example, when forming a conductive film by sputtering, first, a desired target material is attached to a target material attachment plate in a vacuum chamber, and a substrate is mounted on a substrate holder. The target material mounting plate can be applied with a voltage from an external power source, and the substrate holder is disposed at a position facing the target material mounting plate. The substrate holder can be provided with heating means for heating the placed substrate to a predetermined temperature. Next, after the pressure inside the vacuum chamber is reduced to a predetermined pressure by the exhaust pipe, an atmospheric gas such as argon (Ar) gas is supplied from the gas supply pipe into the vacuum chamber until the predetermined pressure is reached. Next, by applying a voltage to the target material from an external power source, the target material is sputtered and formation of a conductive film is started on the substrate maintained at a temperature set appropriately from a temperature range of room temperature to 350 ° C. .
[0021]
After the conductive film is formed on the substrate with a desired thickness as described above, the conductive film on the substrate is irradiated with light having a wavelength of 400 nm or less, preferably 150 to 400 nm. When the wavelength of the irradiated light exceeds 400 nm, the conduction electron density in the conductive film cannot be increased, and the effects of the present invention cannot be achieved. As a light source for such light irradiation, ultra-high pressure, high pressure, medium pressure, low pressure metal vapor gas, rare gas, hydrogen, Xe₂ , Kr-Cl, Xe-Cl light sources such as high pressure mercury lamps and excimer lamps, excimer lasers, dye lasers, Ar ion lasers, F₂ Lasers such as lasers can be used. More specifically, an Hg-Xe ultraviolet lamp (wavelength main peak = 360 nm), a low-pressure Hg lamp (wavelength main peak = 254 nm), a Kr—Cl excimer lamp (wavelength main peak = 222 nm), or Xe− Excimer laser such as Cl (308 nm), Xe-F (351 nm), Xe-Br (282 nm), Kr-F (249 nm), Kr-Cl (222 nm), Ar ion laser second harmonic (257.2 nm), Dye laser second harmonic crystal (β-BaB₂ ・ BO_Four , 205nm), F₂ A laser (157 nm) can be used. Such a light source is disposed in the vacuum chamber, and the conductive film can be irradiated with light by irradiating the substrate mounting surface of the substrate holder.
[0022]
The irradiation energy in this light irradiation is such a condition that the density of conductive electrons in the conductive film is increased without causing crystallization of the conductive film and the resistivity is lowered, and the conductive film material used, the thickness of the conductive film It can be set as appropriate according to the light source used, the purpose of use of the conductive film, and the like. Here, not causing crystallization of the conductive film means not causing crystallization in the amorphous conductive film, or maintaining or lowering the crystallinity in the crystalline conductive film. As an example of the irradiation energy, when an Xe-Cl excimer laser is used to irradiate a 1500 mm thick indium tin oxide (ITO) film formed at room temperature by sputtering, the irradiation energy is about 100 mJ / cm.² When the irradiation energy is too high, crystallization proceeds and the resistivity increases rapidly.
[0023]
The conductive film that can be formed by the present invention includes, for example, a conductive film made of a metal such as Au, Ag, Pt, Cu, and Rh, tin-indium oxide (ITO), zinc oxide (ZnO), and tin oxide (SnO).₂ ), Lanthanum titanate (LaTi0)_Three ), Indium zinc oxide (In₂ O_Three -ZnO), antimony tin oxide (SbSnO)₂ ), Indium oxide (In₂ O_Three ), Zinc-tin-indium oxide ((Zn, Sn) In₂ O_Three ), Alumina / Zinc Oxide (ZnO-Al₂ O_Three ), Gallium / zinc oxide (ZnO-Ga)₂ O_Three ), Cadmium tin oxide (Cd₂ SnO_Four ), Cadmium oxide (CdO), cadmium indium oxide (CdIn)₂ O_Four ) And the like, and alloys thereof, and the thickness thereof can be set as appropriate. Examples of the substrate on which the conductive film is formed include a glass substrate, a ceramic substrate, a silicon substrate, a polycarbonate resin, a polyethylene terephthalate resin, a polyester resin, an epoxy resin, an acrylic resin, a polystyrene resin, or a metal substrate. The thickness can be appropriately set according to the purpose of use.
Method for forming metal oxide film
In the method for forming a metal oxide film of the present invention, a metal oxide film formed on a substrate is irradiated with light having a wavelength of 400 nm or less at an irradiation energy amount that does not cause crystallization of the metal oxide film. A desired change is caused in the physical properties of the metal oxide film.
[0024]
Examples of the metal oxide film that can be formed by the present invention include metal oxide films such as ferroelectric materials, conductive materials, optical materials, magnetic materials, and superconductive materials exemplified below.
(Ferroelectric material)
Barium titanate (BaTiO_Three ), Strontium titanate (SrTiO)_Three ), Lead titanate (PbTiO_Three ), Zirconium titanate (ZrTiO)_Three ), Strontium barium titanate ((Ba, Sr) TiO)_Three ), Lanthanum titanium oxide (La₂ Ti₂ O₇ ), Strontium zirconate barium ((Ba, Sr) (Ti, Zr) O)_Three ), Titanium / lead zirconate (Pb (Zr, Ti) O)_Three ), Strontium niobium titanate ((Nb) SrTiO_Three ), Tin barium titanate (Ba (Ti, Sn) O)_Three ), Yttrium manganate (YMnO_Three )
(Conductive material)
Tin indium oxide (ITO), zinc oxide (ZnO), tin oxide (SnO)₂ ), Lanthanum titanate (LaTi0)_Three ), Indium zinc oxide (In₂ O_Three -ZnO), antimony tin oxide (SbSnO)₂ ), Indium oxide (In₂ O_Three ), Zinc-tin-indium oxide ((Zn, Sn) In₂ O_Three ), Alumina / Zinc Oxide (ZnO-Al₂ O_Three ), Gallium / zinc oxide (ZnO-Ga)₂ O_Three )
(Optical material)
Titanium oxide (TiO₂ ), Aluminum oxide (Al₂ O_Three ), Zirconium oxide (ZrO)₂ ), Lithium niobate (LiNbO)_Three ), Lithium iodate (LiIO_Three ), Potassium niobate (KNbO)_Three ), Beryllium oxide (BeO), lead molybdate (PbMoO)_Three ), Zinc tungstate (PbWO_Four ), Lead oxide (PbO), tungsten oxide (WO_Three ), Cobalt oxide (CoO), chromium oxide (Cr₂ O_Three )
(Magnetic material)
Manganese zinc ferrite ((Mn, Zn) O · Fe₂ O_Three ), Manganese copper ferrite ((Mn, Cu) O.Fe₂ O_Three ), Barium ferrite (BaO · 6Fe)₂ O_Three ), Iron oxide (Fe_Three O_Four )
(Superconducting material)
YBaCuO-based oxide
The formation of the metal oxide film in the present invention can be performed by any conventionally known sputtering method, vacuum deposition method, ion plating method, CVD method or the like. The substrate temperature at the time of forming the metal oxide film can be appropriately set from a temperature range of room temperature to 550 ° C., and the thickness of the metal oxide film can be appropriately set in consideration of the purpose of use, for example, , And can be set within a range of about 100 to 10,000 mm.
[0025]
The light irradiated to the metal oxide film formed on the substrate is light having a wavelength of 400 nm or less, preferably 150 to 400 nm. If the wavelength of the irradiated light exceeds 400 nm, the effect of the present invention can be obtained. Can not. As the light source for such light irradiation, the same light source as mentioned in the above-described method for forming a conductive film can be used.
[0026]
The irradiation energy in this light irradiation is a condition that does not cause crystallization in the metal oxide film, and depends on the metal oxide film material used, the thickness of the metal oxide film, the light source used, the purpose of use of the metal oxide film, etc. Can be set as appropriate. Here, the fact that the crystallization of the metal oxide film is not caused means that the amorphous metal oxide film is not crystallized, or the crystallinity is maintained or lowered in the crystalline metal oxide film. . As an example of irradiation energy, when irradiating a tin indium oxide (ITO) film having a thickness of 2000 mm formed at 350 ° C. by DC sputtering using a Xe-Cl excimer laser, the irradiation energy is about 150 mJ / cm.² When the irradiation energy is too high, crystallization proceeds, and as a result, the conduction electron density decreases and a high resistance film is formed.
[0027]
By the light irradiation as described above, for example, an increase in residual polarizability in a metal oxide film made of a ferroelectric material, a decrease in resistivity in a metal oxide film made of a conductive material, and a refractive index in a metal oxide film made of an optical material. Increases, reduction of coercive force in a metal oxide film made of a magnetic material, and film quality with few crystal defects or irregularities in a metal oxide film made of a superconductive material.
[0028]
As the substrate for forming the metal oxide film, for example, a glass substrate, a ceramic substrate, a silicon substrate, a polycarbonate resin, a polyethylene terephthalate resin, a polyester resin, an epoxy resin, an acrylic resin, a polystyrene resin or the like, or a metal substrate is used. The thickness can be appropriately set according to the purpose of use.
[0029]
【Example】
Next, the present invention will be described in more detail with reference to examples.
Example 1
A glass substrate having a thickness of 1.1 mm is placed on a substrate holder of a sputtering apparatus, and a target material (In₂ O_Three -SnO₂ Sintered body (SnO₂ 10% by weight) was attached.
[0030]
Next, argon (Ar) gas is introduced into the vacuum chamber to set the atmospheric pressure to 5 mTorr, the substrate temperature to 25 ° C., and a conductive film (ITO film) having a thickness of about 0.3 μm on the substrate under the following film formation conditions. To form a sample A.
[0031]
(ITO film forming conditions)
Atmospheric gas: Ar = 100 sccm, O₂ = 2sccm
・ Atmospheric pressure: 5 mTorr
・ Hydrogen partial pressure: 10 × 10^-9Below Torr
・ DC power: 2.5kW
・ Deposition rate: 2cm / sec
With respect to the substrate (sample A) on which the conductive film (ITO film) is formed as described above, the irradiation energy shown in Table 1 below is obtained using an Hg-Xe ultraviolet lamp (wavelength main peak = 360 nm). Sample A1 was produced by ultraviolet irradiation.
[0032]
In addition, the substrate temperature was set to 300 ° C., and a conductive film (ITO film) having a thickness of about 0.3 μm was formed on the substrate under the following film formation conditions to prepare a sample B. For this substrate (sample B), Sample B1 was produced by performing ultraviolet irradiation using a Hg—Xe ultraviolet lamp (wavelength main peak = 360 nm) so that the irradiation energy shown in Table 1 below was obtained.
[0033]
  (ITO film forming conditions)
    Atmospheric gas: Ar = 10 sccm, O₂= 3.5sccm
    ・ Atmospheric pressure: 5 mTorr
    ・ Hydrogen partial pressure: 10 × 10^-9Below Torr
    ・ DC power: 150W
    ・ Deposition rate: 9mm / sec
  On the other hand, the substrate (sample A) on which the conductive film (ITO film) is formed as described above is irradiated with the irradiation energy shown in Table 1 below using a He-Ne laser (wavelength 633 nm).IrradiationA comparative sample 1 was prepared.
[0034]
Further, a comparative sample 2 was manufactured by subjecting the substrate (sample A) on which the conductive film (ITO film) was formed as described above to a heat treatment at 100 ° C. for 2 hours.
[0035]
For the sample A, sample A1, sample B, sample B1, and comparative samples 1 and 2 fabricated as described above, the crystallinity, conduction electron density, and resistivity of the ITO film were measured and evaluated by the following methods. The results are shown in Table 1 below.
[0036]
(Evaluation method for crystallinity)
The full width at half maximum of the following diffraction peak is measured by X-ray diffractometry.
The change in crystallinity was evaluated from the change.
[0037]
2θ = 30.08 ° (222)
2θ = 35.12 ° (400)
2θ = 60.08 ° (622)
-Determination of crystallinity improvement: The full width at half maximum of the (222) plane is not reduced or changed, and the full width at half maximum of the (622) plane is reduced.
・ Degradation of crystallinity: The full width at half maximum of the (222) plane and the (400) plane is increased, and the full width at half maximum of the (622) plane is decreased or unchanged.
(Method of measuring the density of conduction electrons)
Hall measurement was performed by the VAN DER PAUW method.
[0038]
(Measurement method of resistivity)
Measurement was performed by the four-terminal method or the VAN DER PAUW method.
[0039]
[Table 1]

  As shown in Table 1, the resistivity of the sample A1 subjected to ultraviolet irradiation with a wavelength of 400 nm or less was lower than that of the untreated sample A that was not subjected to ultraviolet irradiation or heat treatment. Further, the sample A1 has lower crystallinity than the untreated sample A and no crystallization occurs. On the other hand, the density of conduction electrons is high, and the resistance is lowered by improving the density of conduction electrons. It is thought that it was done.
[0040]
Moreover, the same thing as said sample A and sample A1 was confirmed also in untreated sample B which has not been subjected to ultraviolet irradiation or heat treatment, and sample B1 which has been subjected to ultraviolet irradiation with a wavelength of 400 nm or less.
[0041]
On the other hand, Comparative Sample 1 subjected to the light irradiation treatment using light having a wavelength exceeding 400 nm did not show an improvement in the conduction electron density and the resistivity did not decrease.
[0042]
On the other hand, Comparative Sample 2 obtained by subjecting Sample A to heat treatment had a slight decrease in resistivity. In addition, although the comparative sample 2 has improved crystallinity as compared with the untreated sample A, the density of conduction electrons was not increased.
(Example 2)
A glass substrate having a thickness of 1.1 mm is placed on a substrate holder of a sputtering apparatus, and a target material (In₂ O_Three -SnO₂ Sintered body (SnO₂ 10% by weight) was attached.
[0043]
Next, argon (Ar) gas is introduced into the vacuum chamber, the atmospheric pressure is set to 5 mTorr, the substrate temperature is set to 25 ° C., and a conductive film (ITO film) having a thickness of about 0.3 μm is formed on the substrate under the following film forming conditions. Formed.
[0044]
(ITO film forming conditions)
Atmospheric gas: Ar = 100 sccm, O₂ = 2sccm
・ Atmospheric pressure: 5 mTorr
・ Hydrogen partial pressure: 10 × 10^-9Below Torr
・ DC power: 2.5kW
・ Deposition rate: 2cm / sec
Next, the substrate on which the conductive film (ITO film) is formed is subjected to 10, 15, 20, 40, 60, 100, 200, 500 minutes using an Hg-Xe ultraviolet lamp (wavelength main peak = 360 nm). The treatment by 8 kinds of irradiation time was performed.
[0045]
About each electrically conductive film which performed the ultraviolet irradiation process as mentioned above, and an untreated electrically conductive film, the density and resistivity of a conduction electron were measured like Example 1, and the result was shown in FIG.
[0046]
As shown in FIG. 1, the conduction electron density is improved by the ultraviolet irradiation treatment for 10 minutes, and the resistivity is reduced at the same time. The conduction electron density is further improved and the resistivity is lowered as the irradiation time is increased. Was seen.
(Example 3)
A glass substrate having a thickness of 1.1 mm is placed on a substrate holder of a sputtering apparatus, and a target material (In₂ O_Three -SnO₂ Sintered body (SnO₂ 10% by weight) was attached.
[0047]
Next, argon (Ar) gas is introduced into the vacuum chamber, the atmospheric pressure is set to 5 mTorr, the substrate temperature is set to 25 ° C., and a conductive film (ITO film) having a thickness of about 1500 mm is formed on the substrate under the following film forming conditions. Thus, sample C was prepared.
[0048]
(ITO film forming conditions)
Atmospheric gas: Ar = 100 sccm, O₂ = 3sccm
・ Atmospheric pressure: 5 mTorr
・ Hydrogen partial pressure: 10 × 10^-9Below Torr
・ RF power: 250W
・ Deposition rate: 2.6 Å / sec
Samples C1 to C3 were prepared by irradiating the substrate (sample C) on which the conductive film (ITO film) was formed as described above using a Xe-Cl (wavelength 308 nm) excimer laser under the following conditions.
[0049]
(Laser irradiation conditions)
・ Irradiation energy: Max 300mJ / cm²
・ Laser irradiation overlap rate: 50%
・ Irradiation atmosphere: In air
For the sample C and samples C1 to C3 produced as described above, the crystallinity of ITO film, the density of conduction electrons, and the resistivity were measured and evaluated in the same manner as in Example 1, and the results are shown in Table 2 and FIG. It was shown to.
[0050]
[Table 2]

As shown in Table 2 and FIG. 2, compared to the untreated sample C that was not subjected to the laser irradiation treatment, the samples C1 and C2 irradiated with the Xe-Cl excimer laser showed a decrease in resistivity. C2 has minimum resistivity (5.87 × 10^-FourΩ · cm). At this time, no crystallization occurs and the density of conduction electrons is high. And in the sample C3 with higher irradiation energy, crystallization progresses rapidly and an increase in resistivity is observed. From this, in the Xe-Cl excimer laser irradiation on the sample C, the optimum value of the irradiation energy is about 100 mJ / cm.² You can say that. (Example 4)
Using an ion plating apparatus, a sample D was prepared by forming a conductive film (ITO film) having a thickness of about 0.3 μm on a glass substrate having a thickness of 1.1 mm under the following film forming conditions at a substrate temperature of 25 ° C. .
[0051]
(ITO film forming conditions)
Atmospheric gas: Ar = 100 sccm, O₂ = 3sccm
・ Atmospheric pressure: 5 mTorr
・ Hydrogen partial pressure: 10 × 10^-9Below Torr
・ Evaporation source: In₂ O_Three -SnO₂ Sintered body (SnO₂ 10% by weight)
・ RF power: 250W
・ Deposition rate: 2.6 Å / sec
For the substrate (sample D) on which the conductive film (ITO film) is formed as described above, the irradiation energy shown in Table 3 below is obtained using an Hg-Xe ultraviolet lamp (wavelength main peak = 360 nm). Ultraviolet irradiation was performed to prepare Sample D1.
[0052]
  Further, except that the substrate temperature was set to 300 ° C., a sample E was prepared by forming a conductive film (ITO film) having a thickness of about 0.3 μm on the substrate in the same manner as the sample D described above.Sample E) Was irradiated with ultraviolet rays using a Hg—Xe ultraviolet lamp (wavelength main peak = 360 nm) so as to have the irradiation energy shown in Table 3 below, to prepare Sample E1.
[0053]
  On the other hand, for the substrate (sample D) on which the conductive film (ITO film) is formed as described above, the irradiation energy shown in Table 3 below is obtained using a He—Ne laser (wavelength 633 nm).IrradiationA comparative sample 1 was prepared.
[0054]
Further, the substrate (sample D) on which the conductive film (ITO film) was formed as described above was subjected to a heat treatment at 100 ° C. for 2 hours to prepare a comparative sample 2.
[0055]
Sample D, Sample D1, Sample E, Sample E1, and Comparative Samples 1 and 2 produced as described above were measured and evaluated for the crystallinity of ITO film, the density of conductive electrons, and the resistivity in the same manner as in Example 1. The results are shown in Table 3 below.
[0056]
[Table 3]

  As shown in Table 3, the resistivity of the sample D1 that was irradiated with ultraviolet light having a wavelength of 400 nm or less was lower than that of the untreated sample D that was not subjected to ultraviolet irradiation or heat treatment. Further, the sample D1 has lower crystallinity than the untreated sample D and no crystallization occurs. On the other hand, the density of conduction electrons is high, and the resistance is reduced by improving the density of conduction electrons. It is thought that it was done.
[0057]
Moreover, the same thing as said sample D and sample D1 was confirmed also in the untreated sample E which has not been subjected to ultraviolet irradiation or heat treatment, and sample E1 which has been subjected to ultraviolet irradiation with a wavelength of 400 nm or less.
[0058]
On the other hand, Comparative Sample 1 subjected to the light irradiation treatment using light having a wavelength exceeding 400 nm did not show an improvement in the conduction electron density and the resistivity did not decrease.
[0059]
On the other hand, Comparative Sample 2 obtained by subjecting Sample D to heat treatment has improved crystallinity as compared with untreated Sample D, but almost no increase in the density of conduction electrons was observed, and the resistivity decreased slightly. Met.
(Example 5)
A sample F was prepared by forming a conductive film (ITO film) having a thickness of about 0.3 μm on a glass substrate having a thickness of 1.1 mm on a glass substrate having a thickness of 1.1 mm under the following film forming conditions using a vacuum deposition apparatus at 25 ° C.
[0060]
(ITO film forming conditions)
・ Atmospheric pressure: 5 mTorr
・ Hydrogen partial pressure: 10 × 10^-9Below Torr
・ Evaporation source: In₂ O_Three -SnO₂ Sintered body (SnO₂ 10% by weight)
・ RF power: 250W
・ Deposition rate: 2.6 Å / sec
For the substrate (sample F) on which the conductive film (ITO film) is formed as described above, the irradiation energy shown in Table 4 below is obtained using an Hg-Xe ultraviolet lamp (wavelength main peak = 360 nm). Sample F1 was produced by ultraviolet irradiation.
[0061]
  Further, except that the substrate temperature was set to 300 ° C., a sample G was prepared by forming a conductive film (ITO film) having a thickness of about 0.3 μm on the substrate in the same manner as the sample F described above.Sample G) Was irradiated with ultraviolet rays using a Hg—Xe ultraviolet lamp (wavelength main peak = 360 nm) so as to have the irradiation energy shown in Table 4 below, to prepare a sample G1.
[0062]
  On the other hand, the substrate (sample F) on which the conductive film (ITO film) is formed as described above is irradiated with the irradiation energy shown in Table 4 below using a He-Ne laser (wavelength 633 nm).IrradiationA comparative sample 1 was prepared.
[0063]
Further, the substrate (sample F) on which the conductive film (ITO film) was formed as described above was subjected to heat treatment at 100 ° C. for 2 hours to produce a comparative sample 2.
[0064]
Sample F, Sample F1, Sample G, Sample G1, and Comparative Samples 1 and 2 prepared as described above were measured and evaluated for the crystallinity of ITO film, the density of conductive electrons, and the resistivity in the same manner as in Example 1. The results are shown in Table 4 below.
[0065]
[Table 4]

  As shown in Table 4, the resistivity of the sample F1 that was irradiated with ultraviolet rays having a wavelength of 400 nm or less was lower than that of the untreated sample F that was not subjected to ultraviolet irradiation or heat treatment. In addition, the sample F1 has lower crystallinity than the untreated sample F, and no crystallization occurs. On the other hand, the density of conduction electrons is high. It is thought that conversion was achieved.
[0066]
In addition, it was confirmed that the untreated sample G not subjected to ultraviolet irradiation or heat treatment and the sample G1 subjected to ultraviolet irradiation with a wavelength of 400 nm or less were the same as the above sample F and sample F1.
[0067]
On the other hand, Comparative Sample 1 subjected to the light irradiation treatment using light having a wavelength exceeding 400 nm did not show an improvement in the conduction electron density and the resistivity did not decrease.
[0068]
On the other hand, Comparative Sample 2 obtained by subjecting Sample F to heat treatment has a slight decrease in resistivity, and although the crystallinity is improved as compared with untreated Sample F, the increase in the density of conduction electrons is It was not seen.
(Example 6)
A substrate in which a PtNi alloy was formed on a silicon wafer having a thickness of 1.1 mm was placed on a substrate holder of a sputtering apparatus, and a target material (Zr / Ti alloy plate, PbO pellet) was attached to a target material mounting plate. .
[0069]
Next, an argon (Ar) gas is introduced into the vacuum chamber, the atmospheric pressure is 10 mTorr, the substrate temperature is 400 ° C., and a ferroelectric thin film (PbZrTiO) having a thickness of about 0.2 μm is formed on the substrate under the following film formation conditions._Three A sample H was prepared by forming a PZT film).
[0070]
(PZT film forming conditions)
Atmospheric gas: Ar = 100 sccm, O₂ = 2sccm
・ Atmospheric pressure: 10 mTorr
・ Hydrogen partial pressure: 10^-8Below Torr
・ DC power: 2000W
・ Deposition rate: 0.2 nm / second
For the substrate (sample H) on which the ferroelectric thin film (PZT film) is formed as described above, the irradiation energy shown in Table 5 below is obtained using an Hg-Xe ultraviolet lamp (wavelength main peak = 360 nm). As described above, sample H1 was manufactured by performing ultraviolet irradiation at room temperature and atmospheric pressure.
[0071]
  On the other hand, the substrate (sample H) on which the ferroelectric thin film (PZT film) is formed as described above is irradiated with the irradiation energy shown in Table 5 below using a He—Ne laser (wavelength 633 nm).IrradiationA comparative sample 1 was prepared.
[0072]
In addition, the substrate (sample H) on which the ferroelectric thin film (PZT film) was formed as described above was subjected to a heat treatment at 500 ° C. for 1 hour to produce a comparative sample 2.
[0073]
For the sample H, the sample H1, and the comparative samples 1 and 2 manufactured as described above, the crystallinity and DE hysteresis characteristic (evaluation of residual polarization Pr value) of the PZT film are measured and evaluated by the following method. The results are shown in Table 5 below.
[0074]
(Evaluation method for crystallinity)
Perovskite type (Pb, Zr) TiO by X-ray diffraction_Three The half-value widths of diffraction peaks on the (112) plane and the (301) plane were measured, and the change in crystallinity was evaluated from the change relative to the sample H.
[0075]
-Judgment of improvement in crystallinity: the half-value width of (112) plane and (301) plane decreases
-Judgment of decrease in crystallinity: The half-value width of (112) plane and (301) plane increases.
(Measurement method of residual polarization Pr)
A DE hysteresis curve with a PtNi electrode was drawn, and the residual polarization Pr was determined from the loop.
[0076]
[Table 5]

  As shown in Table 5, the residual polarization value of the sample H1 that was irradiated with ultraviolet rays having a wavelength of 400 nm or less increased compared to the untreated sample H that was not subjected to ultraviolet irradiation or heat treatment. Further, this sample H1 is not changed in crystallinity as compared with the untreated sample H, and it is considered that high remanent polarization was achieved by the change in the film form.
[0077]
In contrast, Comparative Sample 1 that was subjected to light irradiation treatment using light having a wavelength exceeding 400 nm did not show an increase in remanent polarization value.
[0078]
On the other hand, Comparative Sample 2 obtained by subjecting Sample H to heat treatment has improved crystallinity compared to untreated Sample H, but the residual polarization value increased only slightly.
(Example 7)
A glass substrate having a thickness of 1.1 mm is placed on a substrate holder of a sputtering apparatus, and a target material (Mn / Zn alloy plate, Fe_Three O_Four Pellet) was attached.
[0079]
Next, an argon (Ar) gas is introduced into the vacuum chamber, the atmospheric pressure is 5 mTorr, the substrate temperature is 450 ° C., and a ferroelectric thin film ((Mn , Zn) O.Fe₂ O_Three Sample I was manufactured by forming a MnZn ferrite film).
[0080]
(MnZn ferrite film forming conditions)
Atmospheric gas: Ar = 100 sccm, O₂ = 2sccm
・ Atmospheric pressure: 5 mTorr
・ Hydrogen partial pressure: 10^-8Below Torr
・ DC power: 2000W
・ Deposition rate: 0.5 nm / second
For the substrate (sample I) on which the ferromagnetic thin film (MnZn ferrite film) is formed as described above, the irradiation energy shown in Table 6 below is obtained using an Hg-Xe ultraviolet lamp (wavelength main peak = 360 nm). As described above, sample I1 was manufactured by performing ultraviolet irradiation at room temperature and atmospheric pressure.
[0081]
  On the other hand, for the substrate (sample I) on which the ferromagnetic thin film (MnZn ferrite film) is formed as described above, the irradiation energy shown in the following Table 6 is obtained using a He—Ne laser (wavelength 633 nm).IrradiationA comparative sample 1 was prepared.
[0082]
Further, the substrate (sample I) on which the ferromagnetic thin film (MnZn ferrite film) was formed as described above was subjected to a heat treatment at 500 ° C. for 1 hour to produce a comparative sample 2.
[0083]
With respect to Sample I, Sample I1, and Comparative Samples 1 and 2 produced as described above, the crystallinity and magnetic hysteresis characteristics (evaluation of coercive force Hc value) of the MnZn ferrite film were measured and evaluated by the following method. Table 6 shows.
[0084]
(Evaluation method for crystallinity)
The full width at half maximum of the diffraction peaks of the (111) plane and the (110) plane of spinel ferrite was measured by X-ray diffraction, and the change in crystallinity was evaluated from the change with respect to Sample I.
[0085]
-Judgment of improvement in crystallinity: half width of (111) plane and (110) plane decreased
-Judgment of decrease in crystallinity: The half width of (111) plane and (110) plane increases.
(Measurement method of coercive force Hc)
A magnetic hysteresis curve of the sample was drawn with a vibrating sample magnetometer (VSM), and the coercive force Hc was obtained from the loop.
[0086]
[Table 6]

  As shown in Table 6, the coercive force of sample I1 subjected to ultraviolet irradiation with a wavelength of 400 nm or less was reduced compared to untreated sample I that was not subjected to ultraviolet irradiation or heat treatment. In addition, the crystallinity of the sample I1 is not changed compared to the untreated sample I, and the crystal grain boundary is reduced by the change of the film form, and as a result, it is considered that the low coercive force is achieved.
[0087]
On the other hand, in Comparative Sample 1 that was subjected to the light irradiation treatment using light having a wavelength exceeding 400 nm, the coercive force did not decrease.
[0088]
On the other hand, Comparative Sample 2 obtained by subjecting Sample I to the heat treatment had improved crystallinity compared to untreated Sample I, but the coercive force was only slightly reduced.
[0089]
【The invention's effect】
As described above in detail, according to the present invention, after a conductive film is formed on a substrate, the conductive electrons in the conductive film are irradiated by irradiating light with a wavelength of 400 nm or less so as not to cause crystallization of the conductive film. The density of the conductive film is increased to improve the conductivity, and the resistivity of the conductive film can be lowered. This lowering of resistance does not have an adverse effect of heat on the substrate because annealing is not performed, and the heat resistance is low. A low-resistance conductive film can be formed also on the substrate. In addition, after forming a metal oxide film on the substrate, the metal oxide film is irradiated with light having a wavelength of 400 nm or less so as not to cause crystallization. Increasing the remanent polarizability by changing the form of the metal oxide film as a thin body film, or reducing the coercive force by reducing the grain boundary by changing the film form of the metal oxide film as a ferromagnetic thin film, etc. Thus, a desired metal oxide film can be formed without annealing after film formation.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram for illustrating a relationship between an ultraviolet irradiation time for a conductive film and a conduction electron density and resistivity of the conductive film.
FIG. 2 is a diagram for illustrating a relationship between laser irradiation energy and resistivity with respect to a conductive film.

Claims (3)

After the conductive film is formed on the substrate by any one of the sputtering method, the vacuum deposition method, and the ion plating method, in the case where the conductive film is amorphous, the range in which the conductive film is not crystallized. When the conductive film is crystalline with the irradiation energy of, the conductive film characterized by irradiating light with a wavelength of 400 nm or less with irradiation energy in a range that maintains or lowers the crystallinity of the conductive film Forming method.   2. The method for forming a conductive film according to claim 1, wherein a substrate temperature at the time of forming the conductive film is set in a range of room temperature to 200.degree. After the metal oxide film is formed on the substrate by any one of sputtering, vacuum deposition, and ion plating, if the metal oxide film is amorphous, the metal oxide film is crystallized. When the metal oxide film is crystalline with irradiation energy in a range that does not cause generation, light with a wavelength of 400 nm or less is irradiated with irradiation energy in a range that maintains or lowers the crystallinity of the metal oxide film. A method for forming a metal oxide film.

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