| Project/Area Number |
02402020
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Applied materials
|
|---|
| Research Institution | University of Tsukuba |
|---|
Principal Investigator |
NANNICHI Yasuo Univ.Tsukuba, Vice President, 副学長 (10133026)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
OIGAWA Haruhiro Univ.Tsukuba, Inst.Mat.Sci., Assistant, 物質工学系, 助手 (60223715)
KAWABE Mitsuo Univ.Tsukuba, Inst.Mat.Sci., Professor, 物質工学系, 教授 (80029446)
|
|---|
| Project Period (FY) |
1990 – 1992
|
| Project Status |
Completed (Fiscal Year 1992)
|
| Budget Amount *help |
¥29,000,000 (Direct Cost: ¥29,000,000)
Fiscal Year 1992: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1991: ¥5,100,000 (Direct Cost: ¥5,100,000)
Fiscal Year 1990: ¥21,400,000 (Direct Cost: ¥21,400,000)
|
|---|
| Keywords | GaAs / Surface Defects / Sulfur Treatment / Electronic Properties / Photoelectron Spectroscopy / Scanning tunneling Microscopy / X-ray Standing Wave Technique / Positron annihilation Technique / III-V族化合物半導体 / 表面物性 / 表面構造 / GaAs / IIIーV族化合物半導体 / 表面処理 / 硫化物処理 / 界面欠陥 |
|---|
| Research Abstract |
In order to improve the surface electronic properties of GaAs, we have developed a new surface chemical treatment with the (NH_4)_2S_x solution (or(NH_4)_2S_x treatment). Especially, we studied on the treatment effects in chemical, physical, and electronic scopes. Furthermore, we extended the effect to III-V compound semiconductors.
We first investigated the electrical characteristics of Schottky structure and found the Schottky barrier height becomes metal-dependent after the (NH_4)_2S_x treatment. Also studied were the C-V characteristics of MIS structure and we found that the frequency dispersion is reduced by the treatment. All these results on the Schottky characteristics, MIS C-V characteristics, and MIS DLTS measurements consistently indicate that surface state density of GaAs is significantly reduced by the (NH_4)_2S_x treatment.
Next, we investigated the surface structure by using various analysis techniques such as AES,LEELS,SRPES,CAICISS,RHEED,STM and XSW.Based on those experimental observations, we proposed a model to explain the mechanism of successful (NH_4)_2S_x treatment. The model neatly explains all the results including a generation mechanism of surface defect which was detected by SPB technique.
As a result, we concluded that (1) replacement of V atoms by sulfur at the surface first layr plays an important role in surface stabilization, and (2) both effect and structure on the (NH_4)_2S_x-treated surface are almost universal to III-V compound semiconductors in general.
|
