Improved Reliability by Reduction of Hot-Electron Damage in the Vertical Impact-Ionization MOSFET (I-MOS)

This letter presents experimental results and explanations on the reduced degradation caused by hot carriers of the vertical impact-ionization MOSFET (I-MOS) compared to the lateral device. The control and reduction of hot-carrier damage in an impact-ionization device is an important issue to make it a serious alternative for the conventional MOSFET to overcome the kT/q limit for the subthreshold slope of 60 mV/dec at room temperature. The vertical I-MOS shows an excellent subthreshold slope of about 13 mV/dec combined with a suppression of hot-carrier damage for the most part for many tens of thousands of switching cycles. We will explain the effects, which lead to this stability and validate it by measurements and simulations