Interfacial characteristics of HfO_(2) films grown on strained Si_(0.7)Ge_(0.3) by atomic-layer deposition

摘要

The interfacial characteristics of gate stack structure of HfO_(2) dielectrics on strained Si_(0.7)Ge_(0.3) deposited by atomic-layer deposition were investigated. An interfacial layer including GeO_(x) layers was grown on a SiGe substrate, and the thickness of the GeO_(x) layer at the interfacial layer was decreased after the annealing treatment, while SiO_(2) layer was increased. The ～50-A-thick HfO_(2) film with an amorphous structure was converted into a polycrystalline structure after rapid annealing at temperature of over 700℃ for 5 min. The interfacial silicate layer was effectively suppressed by GeO_(x) formation, while the silicate layer was formed after the annealing treatment. GeO_(x) formation in an as-grown film resulted in a decrease in the accumulation capacitance and an increase in the oxide trap charge.