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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.
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