Temperature-dependent electrical properties of plasma-grown gate oxides on tensile-strained Si_0.993 C_0.007 layers

Ultra-thin ( < 10 nm) gate oxides have been grown directly on tensile-strained Si_0.993 C_0.007 layers at a low temperature using microwave O₂-plasma. The changes in gate voltage (ΔV_g), flat-band voltage (V_FB), oxide charge density (Q_ox/q) an interface state density (D_it) have been studied using a metal-oxide-semiconductor structure over the temperature range of 77-450 K. Inversion capacitance increases with temperature above 400 K, leading to a transition from high-frequency to low-frequency characteristics. The dominant types of charges in the oxide are found to be strongly temperature dependent. It is found that charge-trapping properties under Fowler-Nordheim (F-N) constant-current stressing are significantly improved with increasing temperature.