发表机构
Kyushu University; Research Institute for Applied Mechanics, Kyushu University; NuFlare Technology Inc.; Tohoku University（九州大学; 九州大学应用力学研究所; 纽弗莱科技有限公司; 东北大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过从头算方法，揭示了CVD中C/Si比超过1.0时台阶边缘状态转变导致邻晶面4H-SiC(000-1)上氮掺入不连续增加的现象。
AI 中文摘要
在实验研究中，提高化学气相沉积（CVD）源气体比例（C3H8/SiH4；C/Si比）会导致生长速率单调增加，而氮掺入量则相应趋于减少；然而，观察到一种独特现象，即在C/Si比介于1.0和1.5之间时，氮掺入量出现不连续增加。该现象特定于邻晶面4H-SiC(000-1) C面，在邻晶面4H-SiC(0001) Si面上未观察到。本研究采用基于从头算的方法，研究了CVD过程中邻晶面C面上的N掺入行为。计算结果表明，当C/Si比小于1.0时，Si终止的台阶边缘是稳定的；而当C/Si比超过1.0时，C-H终止的台阶边缘（其N取代能低于前者）的存在概率急剧增加。这种跨越C/Si=1.0时台阶边缘状态的变化被认为是N掺入量不连续增加的原因。
英文摘要
In experimental studies, increasing the ratio of source gases (C3H8/SiH4; C/Si ratio) for chemical vapor deposition (CVD) causes the growth rate to increase monotonically, and nitrogen incorporation tends to decrease accordingly; however, a unique phenomenon has been observed in which nitrogen incorporation increases discontinuously in the range of C/Si ratio between 1.0 and 1.5. This phenomenon is specific to the vicinal 4H-SiC(000-1) C-face and is not observed on the vicinal 4H-SiC(0001) Si-face. In this study, N incorporation behavior on a vicinal C-face during CVD is investigated using an ab initio-based approach. The calculation results suggest that when C/Si ratio is less than 1.0, the Si-terminated step edge is stable, whereas when C/Si ratio exceeds 1.0, the existence probability of the C-H-terminated step edge, where the N substitution energy is lower than in the former case, increases sharply. This change in the step-edge state across C/Si = 1.0 is thought to be the cause of the discontinuous increase in N incorporation.
Comments10 pages, 9 figures, 1 table
