Crystalline characteristic of vacuum-deposited Ge films as function of substrate conditions

• Main Authors: Rong-Chinq Chen, 陳榮慶
• Other Authors: Chin-Cheng Chen
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/83865285288880779667

碩士 === 國立成功大學 === 化學工程研究所 === 81 === The structure of Ge films grown by thermal vacuum evaporation has been approached as functions of the different substrates including Si(100)﹑Si(111)﹑GaAs(100) and fused silica, deposi- tion temperature as well as layer thickness by SEM (scanning electron microscopy),Raman scattering, X-ray diffraction and UV- Vis spectroscopy analysis. It is found the structure of Ge films is amorphous for layer thickness 1,000o and substrate temperature below 58℃, yet its crystalline quality strongly depends on the substrate temper- ature. The crystalline grains deposited in lower temperature main growth direction are Ge(111),Ge(220) and Ge(311) faces, but it is epitaxial growth at higher temperature. The epitaxial growth occurs on Si(100) and Si(111) substrates as substrates temperature gets to 250℃ and layer thickness reaches 2,500o. The transmisttance of Ge films is very poor at light wavelength below 600nm. In addition, the transmisttance of crystalline film is harder than amorphous one from 600nm to 1,100nm.