| Project/Area Number |
17560003
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Applied materials science/Crystal engineering
|
|---|
| Research Institution | TOHOKU UNIVERSITY |
|---|
Principal Investigator |
HUANG Xinming Tohoku University, INSTITUTE FOR MATERIALS RESEARCH, ASSOCIATE PROFESSOR, 金属材料研究所, 助教授 (80375104)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
UDA Satoshi Tohoku University, INSTITUTE FOR MATERIALS RESEARCH, PROFESSOR, 金属材料研究所, 教授 (90361170)
KOH Shinji Tohoku University, INSTITUTE FOR MATERIALS RESEARCH, RESEARCH ASSOCIATE, 金属材料研究所, 助手 (50323663)
CHEN Mingwei Tohoku University, INSTITUTE FOR MATERIALS RESEARCH, PROFESSOR, 金属材料研究所, 教授 (20372310)
HOSHIKAWA Keigo SHINSHU UNIVERSITY, FACULTY OF EDUCATION, PROFESSOR, 教育学部, 教授 (10231573)
|
|---|
| Project Period (FY) |
2005 – 2006
|
| Project Status |
Completed (Fiscal Year 2006)
|
| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2005: ¥2,700,000 (Direct Cost: ¥2,700,000)
|
|---|
| Keywords | CRYSTAL ENGINERRING / CRYSTAL GROWTH / SILICA CRUCIBLE / 電場印加 |
|---|
| Research Abstract |
Large sized, high quality Czochralski (CZ) Si crystals are increasingly required for the LSI fabrication, and current Si crystal production has shifted from 200 mm to 300 mm diameter crystals. Failure of dislocation-free crystal growth for such large Si crystals results in a significant loss of time and resources. Small particles peeling from the so-called brownish ring which grows inhomogeneously on the inner surface of a silica crucible, cause dislocation formation in Si crystals during growth due to attachment of the particles to the growth front. In this research project, the reaction at the interface between the Si melt and Ba-doped silica glass has been investigated by in situ observations, DSC, EPMA and X-ray diffraction for understanding the effects of Ba doping in a silica crucible. It was found that brownish spots were generated at the reacted interface between the Si melt and the silica glass with a Ba concentration lower than 30 ppm and white spots were generated in the samples with higher doping amounts of Ba. The brownish spots were oxygen-deficient cristobalite, and they were generated via silica glass dissolution in the Si melt, oxygen diffusion in the Si melt, and precipitation of cristobalite in the Si melt at the growth front of the brownish spots. On the other hand, the white spots were chemically stoichiometric cristobalite, and they were grown directly from the silica glass via phase transition. The generation of brownish cristobalite was suppressed completely by Ba doping in the silica glass when the Ba concentration was higher than 30 ppm. Ba doping increased the growth rate of the white uniform cristobalite, which counteracted the growth of the brownish cristobalite and suppressed its amount. A decrease in the activation energy for the crystallization process of cristobalite by Ba doping was responsible for the increase in the growth rate of the white cristobalite.
|
