2003 Fiscal Year Final Research Report Summary
Behavior of Hydrogen Atoms Incorporated into Specific Structures between Platinum and CVD Diamond Films
| Project/Area Number |
13450128
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Electronic materials/Electric materials
|
|---|
| Research Institution | Osaka University |
|---|
Principal Investigator |
ITO Toshimichi Osaka Univ., Graduate School of Engineering, 大学院・工学研究科, 教授 (00183004)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TERAJI Tokuyuki Osaka Univ., Graduate School of Engineering, Assistant Prof., 大学院・工学研究科, 助手 (50332747)
|
|---|
| Project Period (FY) |
2001 – 2003
|
| Keywords | platinum thin film / diamond thin film / platinum particles / buried structure / hydrogen / microwave plasma / self-assembly / CVD |
|---|
| Research Abstract |
We have found that nm-sized sphere-like platinum particles can be fabricated through self-assembly of platinum thin films deposited on CVD diamond substrates which occurs during CVD plasma processes using microwave plasma including hydrogen. The size of the particles, which can be. well controlled simply by changing the thickness of the platinum films, determines the crystalline quality of the particles. There is a tendency that the particles are polycrystalline when the size is larger than 20 nm while they are single-crystalline whose crystalline directions are correlated with those. of the diamond substrate when it is less than 10 nm. It has also been verified from TEM and SIMS analyses that such self-organized Pt particles are expanded by about 30 %, which results from absorption of a substantial amount of hydrogen atoms in the particles. This is self-consistent with the fact that the lattice constant can be reduced to the original value of bulk Pt through desorption of the absorbed hydrogen atoms when the expanded particles are annealed in vacuum at high temperatures. Temperature-programmed thermal desorption measurements of the H-contained Pt particles reveal that the H desorption substantially occurs at temperatures between 600. and 800℃. Iteration of the present platinum deposition and subsequent diamond growth processes leads to multi-layered structure of Pt particles buried in CVD diamond films. Furthermore, selective etching of diamond in the Pt-diamond multi-layer resulted in a substantial increase in the density of Pt particles on the specimen surface. We have also indicated that H atoms can exist relatively much more near the interface between the buried Pt particles and diamond overlayer than in the diamond overlayer.
|
