| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1994: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1993: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1992: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Research Abstract |
The results obtained in this resarch were summarized as follows.
1.alpha-Si thin films were deposited by electron-beam evaporation under a high vacuum condition. From the SIMS measurments, it was found that the amount of hydrogen atoms incorporated into our alpha-Si films was less than that into the films deposited by a conventional low-pressure chemival vapor deposition. As a result, when our films were annealed by a laser irradiation, a hydrogen evaporation from the Si surfaces was suppressed, so that, the excellent thin films could be obtained without the damages.
2.In order to homogenize the light energy, the light reflector was constructed by multi-mirrors. By using this homogenizer, the alpha-Si films were crystallized uniformly.
3.The grain size of the Si polycrystals depended upon the film thickness. When the thickness was less than the melting depth, the crystallization rate became lower. This result indicated that a store of energy in the thinner films increased. that is, it was considered that the thinner films were easy to be kept under a thermal equilibrium condition. The above effect was important to increase the grain size.
4.The Si thin films were heated during the laser annealing because of the continuance of thermal equilibrium. Therefore, the grain size of Si polycrystals increased, and, the crystallization uniformity was enhanced.
5.The quality of Si polycrystals depended on the laser power, hence, it was necessary to select an optimum power. In particular, many hillocks were observed on the Si surfaces irradiated at a higher power.
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