Study of the Ge Wafer Surface Hydrophilicity after Low-Temperature Plasma Activation

Plasma activation has been investigated for its ability to induce a strong bonding energy even at low-temperature annealing. In this paper, Ge, Si, and SiO 2 surface hydrophilicities with oxygen and nitrogen plasma activation are analyzed by contact angle measurement. Compared to wet chemical treatments, such as solutions containing ammonium hydroxide, the hydrophilicity of Ge wafer surface is strongly enhanced by O 2 or N 2 plasma activation. For germanium, a highly hydrophilic and smooth surface has been obtained by O 2 plasma activation only for 10 s. The contact angle measurements indicate that O 2 plasma is more remarkable than N 2 plasma in the same activation conditions. A higher surface roughness, which is only observed in the O 2 plasma activated sample, is decreased greatly after rinsing in deionized water.