Very low EOT and high oxidation state interfacial layer in Ge MOS devices

The equivalent oxide thickness in Ge MOS device is scaled down to 0.39 nm, and the leakage current is decreased as well. The improvement can be attributed to the in-situ Ge sub-oxide desorption process in an ALD chamber at 370 ^°C. About 95% Ge⁴⁺ in HfGeO_x interfacial layer are obtained by H₂O plasma process together with in-situ desorption before atomic layer deposition.