EFFECT OF RADIATION-INDUCED INTERFACE TRAPS ON 1/F NOISE IN MOSFETS

By measuring the drain current fluctuations of X-ray irradiated and bias-annealed NMOSFET's in weak inversion over several decades of frequencies. we have demonstrated that, while the low-frequency 1/f noise is correlated with the density of oxide trapped charge (N(ot)) as previously reported, the high-frequency 1/f noise is correlated with the density of interface traps (D(it)) but not with the oxide trapped charge. In contrast, 1/f noise measured in strong inversion does not seem to correlate with D(it) because the measurement frequency is too low to distingush the effect of interface traps close to the Si conduction band.