Influence of Growth Conditions on Amorphous Germanium Films Prepared by Vacuum-Evaporation

Amorphous germanium films under various growth conditions are investigated by X-ray diffraction and the method of densimetry. The density decreases continuously with decreasing deposition rate, and when the deposition rate ranges from 1.7 ×10 -3 to 5.1 nm/s, the density changes from 2.77 to 4.63 g/cm 3 . Furthermore, the densities are 2.91 g/cm 3 at a pressure of 0.12 Pa and ∼4.3 g/cm 3 at ∼10 -4 Pa under the same deposition rate of 0.38 nm/s. It can be concluded that the most possible origin for the low density is the existing residual gas.