DISTINGUISHING THE EFFECTS OF OXIDE TRAPPED CHARGES AND INTERFACE STATES IN DDD AND LATID NMOSFETS USING PHOTON-EMISSION SPECTROSCOPY

Photon emission spectra of double-diffused drain (DDD) and large-angle -tilt-implanted-drain (LATID) submicron n-channel MOSFETs after hot-ca rrier stressing under maximum substrate current I-sub(max) and maximum gate current I-g(max) conditions were investigated. The results showe d that the difference spectra, obtained by subtracting the devices' pr e-stress spectra from the post-stress spectra, could be used for disti nguishing the effects of interface states and trapped charges. Interfa ce states cause enhanced surface scattering and therefore increase the efficiency of photon emission while trapped charges drive the current away from the surface of the channel and reduce the photon emission e fficiency.