Device Performance and Reliability of P-Channel Metal-Oxide-Semiconductor Field Effect Transistors with Chemical-Vapor-Deposited Gate Oxides

Abstract

This paper reports the performance and reliability of p-channel metal-oxide-semiconductor field effect transistors (MOSFETs) with ultrathin (65 Å) low pressure chemical-vapor-deposited (LPCVD) gate oxides annealed in N2 ambient as compared to those with thermal gate oxides of identical thickness. It is shown that MOSFETs with CVD gate oxides exhibit better initial performance (transconductance, current drivability, and effective hole mobility) and enhanced reliability (transconductance degradation, threshold voltage shift, enhancement in gate-induced drain leakage, and hot-electron-induced punchthrough) than the MOSFETs with thermal gate oxides. Furthermore, significantly improved time-dependent dielectric breakdown characteristic of CVD gate oxide has been demonstrated. Strainless CVD SiO2 after proper post-deposition annealing and the substrate-independent film formation mechanism are speculated to result in the improvements in performance and reliability of CVD oxide devices.