Temperature-dependent electrical properties of plasma-grown gate oxides on tensile-strained Si0.993 C0.007 layers

Abstract

Ultra-thin (<10 nm) gate oxides have been grown directly on tensile-strained Si0.993 C0.007 layers at a low temperature using microwave O2-plasma. The changes in gate voltage (ΔVg), flat-band voltage (VFB), oxide charge density (Qox/q) an interface state density (Dit) 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.