Study of high electrical field induced degradation of channel response in metal-oxide-semiconductor field-effect transistors using an ac conductance technique

ac conductance (G) measurements in the frequency domain are used to monitor the degradation of the inversion layer response in metal-oxide-semiconductor field-effect transistors (MOSFET's) due to high field stressing. The admittance of the conduction channel of the MOSFET's is analyzed by use of a transmission line model. The time constant which governs the frequency response of the MOSFET inverted channel is extracted from the peak of the G/ω vs ω curve and is shown to be an important and sensitive parameter for studying the degradation of MOSFET interface properties after high field stressing. Measured data on 9 and 35 nm gate oxide MOSFET's showed that the channel response degradation by high field stressing depends strongly on the gate oxide thickness.