Self-heating of stressed VDMOS devices under specific operating conditions

Abstract

This paper gives insight into the self-heating effects and combination of self-heating and NBTI effects in p-channel power VDMOS transistors. NBTI effects lead to the degradation of device parameters, where threshold voltage (VT) is the most important one, since it directly affects the device's safe operating area and lifetime. Effects were analysed using images from an infrared thermographic camera taken under different drain currents and controlling signal waveforms. Results point out that the self-heating of the previously stressed devices is more emphasized and that it proposes additional limitations in the terms of the device's reliability.