Characterization of Ultra-Thin Gate Oxide Prepared by Using Atomic Layer Deposition

Ultra-thin hafnium-oxide films were deposited by using atomic layer deposition. The impurity distribution and the film properties were studied in the deposition temperature range between $200\;^{\circ}C\;and\;400\;^{\circ}C$. Suppressed crystallization with effective Cl impurity reduction was obtained at medium temperature ($300\;^{\circ}C$), which resulted in a hafnium-oxide film with a low leakage current ($2.06{\times}10^{-7}\;A/cm^2$ at -2.0 MV/cm) and a small equivalent oxide thickness value (23.9 ${\AA}$) at the same time.