Two-stage hot-carrier degradation behavior of 0.18 μm 18 V n-type DEMOS and its recovery effect

Hot-carrier degradation of 18 V n-type drain-extended MOSFETs (DEMOS) is carefully investigated in this work. Two-stage degradation behavior and apparent recovery effect on the removal of the stress are observed. The first stage of the degradation is found to be mainly due to an increase of the drain series resistance (Rd), which results from the electron trapping in the drift region oxide. The degradation of Rd becomes saturated in the second stage, and the reduction of the carrier mobility in the channel begins to be dominated. In addition, recovery effect has been proved to origin from the decrease of Rd, and a new trapping-detrapping model is proposed to well describe the recovery effect in DEMOS.