2000 Fiscal Year Final Research Report Summary
Study on growth kinetics of Si clusters in silane plasmas
| Project/Area Number |
11450037
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B).
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Applied physics, general
|
|---|
| Research Institution | KYUSHU UNIVERSITY |
|---|
Principal Investigator |
WATANABE Yukio KYUSHU UNIVERSITY, Grad. School of Info. Sci. and Electrical Eng., Prof, システム情報科学研究院・電子デバイス工学部門, 教授 (80037902)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KOGA Kazunori KYUSHU UNIVERSITY, Grad. School of Info. Sci. and Electrical Eng., Research Associate, システム情報科学研究院・電子デバイス工学部門, 助手 (90315127)
SHIRATNI Masaharu KYUSHU UNIVERSITY, Grad. School of Info. Sci. and Electrical Eng., Associate Prof., システム情報科学研究院・電子デバイス工学部門, 助教授 (90206293)
|
|---|
| Project Period (FY) |
1999 – 2000
|
| Keywords | silane plasma / cluster / a-Si : H / thermophoretic force / gas viscous force / pulse discharges / microstructure parameter / fill factor |
|---|
| Research Abstract |
Although a-Si : H-based solar cells are promissing as solar cells for electrical power source, the light-induced degradation of a-Si : H films deposited at a high rate has been the most important issue over twenty years. Recently, clusters below a few nanometers in size formed in silane radio frequency (rf) discharges have been pointed out to be a possible cause of light-induced degradation of a-Si : H films deposited using the discharges. This research has been carried out in order to clarify growth kinetics of Si clusters in silane rf discharges using two novel in-situ methods for measurements of size and density of clusters, and also to reveal correlation between growth suppression of clusters and quality of deposited films. Main results obtain in this research are as follows :
1) Large amount of clusters exist in the discharges even under the device-quality deposition conditions.
2) Cluster amount can be significantly suppressed using the thermophoretic force, gas viscous force, pulse modulation of discharges, and hydrogen dilution.
3) A cluster-suppressed plasma CVD reactor is developed. By using this reactor, a-Si : H films of microstructure parameter below 0.02 and fill factors of Schottky cell after light degradation above 0.53 can be deposited at a rate of 0.2 nm/s. These results show that suppression of clusters makes it possible to deposite ultra-high quality a-Si : H films. As the future work, it is important to establish techniques for depositing ultra-high quality a-Si : H films for solar cells at higher rate by developing results mentioned above.
|
