| 研究実績の概要 |
Previously,the polarity of ScAlN was succesfully inversed from Al-polar to N-polar by addition of Si or Ge or Sn. However, addition of carbon (C) or 2+ cation such as Mg or Zn into ScAlN could not cause polarity inversion. This fiscal year we found via XPS measurement that Si or Ge indeed exist as 4+ cation in the thin film that occupied metal site forming aluminum or cation vacancy. However C was found to form carbon-metal bond which suggested that C sits on nitrogen sites forming nitrogen or anion vacancy which transform metal bond coordination and led to polarity inversion. Thus, the presence of cation vacancy is critical for polarity inversion. On the contrary, anion vacancy caused phase transition that did not facilitate polarity inversion.
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