Step dynamics on faceted macrosteps formed by discontinuous surface tension

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K05503
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics I
• Research Institution: Osaka Electro-Communication University
• Principal Investigator: Akutsu Noriko 大阪電気通信大学, 工学部, 教授 (40167862)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 表面・界面張力計算 / 非平衡定常状態 / 表面・界面荒さ / ファセット化 / マクロステップ形成 / 結晶成長 / 表面・界面の統計熱物理学 / 半導体表面

Outline of Final Research Achievements

The relationship between the macrostep height n, the growth rate, and the absolute value of the growth driving force has been clarified. This has explained the observed results on SiC and the reason why the measured n was scattered. The surface roughness of the vicinal surface formed by the faceted surfaces was calculated using the Monte Carlo method. We found the “faceted rough surface” where it grows continuously even though it grows by the nucleation process. The obtained value of the roughness exponent was close to the value observed in the experiment.
The surface roughness on a vicinal surface for the restricted solid-on-solid model was calculated by changing the temperature, the driving force for growth, and the surface slope. The crossover from Berezinskii-Kosterlitz-Thouless (logarithmic) rough surface to Kardar-Parisi-Zhang (algebraic) rough surface has been found.

Free Research Field

計算材料物理学

Academic Significance and Societal Importance of the Research Achievements

これまで平衡から遠く離れた微斜面における拡散律速な場合についてステップバンチングやステップメアンダリングが調べられてきた。拡散現象を排除した結晶成長を実際に行うことは難しいが、拡散現象を排除した模型に基づく計算機実験を行うことにより、表面張力の異常によって生じる平衡状態及び平衡状態近傍のマクロステップ形成ダイナミクスの一端を解明した。応用として、ファセット化ラフな表面になるパラメタ領域では良質な結晶育成を行える可能性を示した。低消費電力半導体の良質結晶育成に応用できるため、SDG’sに貢献できる。