Evaluation of interface states and minority carrier generation lifetime for strained Si/SiGe wafers using transient capacitance method

Interface states intensity (Nss) and minority carrier generation lifetime (τ_g) were evaluated for strained Si (St-Si)/SiGe wafers using deep level transient spectroscopy (DLTS) and metal-oxide-semiconductor (MOS) transient capacitance (C-t) methods. The dependences of Nss and τ_g on St-Si thickness (d_Si) and Ge fraction (Ge%) were shown clearly. By the same gate film fabrication and electrical measurements for a bulk Si MOS, the values of Nss and τ_g of St-Si MOS are similar to those of bulk Si MOS, showing good wafer quality.