トリメチラアルミニウムと水の原子層の沈殿半反応の解明
Ashley R Bielinski1, Ethan P Kamphaus1, Lei Cheng1
1Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States.
Journal of the American Chemical Society
|August 9, 2022
まとめ
原子層沈殿 (ALD) 研究は,新しい熱力学と運動学的洞察を明らかにします. パイロ電熱計は,ALD半反応が予測よりも多くの熱を放出し,精製された表面化学モデルが必要であることを示しています.
科学分野:
- 材料科学
- 表面化学
- ナノテクノロジー
背景:
- 原子層堆積 (ALD) は,自己限定的な前駆体反応に依存する重要な表面合成技術である.
- 領域と場所の選択的な成長を含むALDの精度を高めるには,その基礎的な表面化学をより深く理解する必要があります.
- 現存するALD熱力学と運動学の計算モデルでは,実験的現実を完全に捉えることはできません.
研究 の 目的:
- トリメチラアルミニウム (TMA) と H2O ALD 半反応の熱力学と運動学を調査する.
- これらの基本的な ALD プロセスを支配する表面化学に関する新しい洞察を提供するためです.
- 実験結果と計算上の予測を比較し,機械的理解を精進する.
主な方法:
- 高解像度測定に適正で時間解像度のある火電熱計を用いた.
- サブミリ秒の時間解像度でALD半反応中の熱放出量.
- 前駆体配達と反応運動を分析し,複数の運動速度を特定した.
主要な成果:
- TMAとH2OのALD半反応は,結晶Al2O3基板に基づいたモデルによって予測されたより大幅に多くの熱 (それぞれ3.46および2.76 eV/Al) を放出しました.
- 実験熱は標準的な形成熱と密接に一致しています.
- 両方の半反応で複数の運動速度が観察され,TMA反応はH2O反応より100倍以上速い.
- ピロ電熱計は,前駆体配送と反応運動を明確に解明した.
結論:
- 実験結果は,ALD表面化学の現在の計算モデルとの不一致を強調しています.
- この研究は,TMA/H2Oのような確立されたALD反応でも,精密な理論モデルとメカニズム理解の必要性を強調しています.
- 局所発熱計は,ALD反応のダイナミクスを解明する強力なツールです.
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