2001 Fiscal Year Final Research Report Summary
Atomic-scale investigation and its device application for GaN crystal growth
| Project/Area Number |
11355002
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 展開研究 |
|---|
| Research Field |
表面界面物性
|
|---|
| Research Institution | Tohoku University |
|---|
Principal Investigator |
SAKURAI Toshio Tohoku University, Institute for Materials Research, Professor, 金属材料研究所, 教授 (20143539)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
OHNO Takahisa National Research Institute of Metals, the head of a laboratory, 金属材料技術研究所・第二研究室, 室長
XUE Q.k. Tohoku University, Institute for Materials Research, Research Associate, 金属材料研究所, 助手 (90270826)
HASEGAWA Yukio Tohoku University, Institute for Materials Research, Associate Professor, 物性研究所, 助教授 (80252493)
FUJIKAWA Yasunori Tohoku University, Institute for Materials Research, Research Associate, 金属材料研究所, 助手 (70312642)
KOBAYASHI Tsutomu ULVAC-PHI, Inc., Senior Researcher, 主任研究員
|
|---|
| Project Period (FY) |
1999 – 2000
|
| Keywords | GaN / STM / epitaxy / device fabrication / surface structure / etching |
|---|
| Research Abstract |
In this project, we have studied on the following subjects as listed below; (1) establishing the general principles for the surface energy minimization and surface reconstruction of GaN surface by MBE-STM (2) understanding the atomistic process for the dopant incorporation and defect formation in GaN epitaxial layers. (3) clarifying the effect of dopant incorporation on the surface electronic properties (4) clarifying the atomistic process in dry etching and its application for the device fabrication. Based on those results, atomic interaction, growth dynamics, surface energetics, strain, and surface/film electronic properties, etc. which are the fundamental process for device fabrication, have been discussed.
We have performed systematic investigations of surface reconstructions on Wurtzite GaN(0001) by MBE-STM. Various reconstructions on the GaN(0001) surface are studied and based on the comparison between the STM observations and first-principles total energy calculations, we propose an adatom scheme for the basic 2x2 and 4x4 structures, and others as well. Also, in order to understand atomistic process underlying dry etching processes of Wurtzite GaN, which is of great important for device application, we have carried out STM study of thermally activated dry etching of GaN surface by Cl_2 molecules. Our extensive studies show that at low temperature (〜650C) the dominated etching of Ga-rich GaN(0001) is anti-step-flow etching. On the other hand, at the higher temperature(〜700C), triangular etching pits on terraces start to form. Its single-step depth implies the bilayer-by-bilayer etching.
|
