Investigating the degradation mechanisms caused by the TID effects in 130 nm PDSOI I/O NMOS

Abstract

This paper evaluates the radiation responses of 3.3V I/O NMOSFETs from 130nm partially-depleted silicon-on-insulator (PDSOI) technology. The data obtained from 60Co ionizing radiation experiments indicate that charge trapped in the shallow trench isolation, particularly at the bottom region of the trench oxide, should be the dominant contributor to the off-state drain-to-source leakage current under ON bias. The body doping profile and device dimension are two key factors affecting the performance degradation of the PDSOI transistors after radiation. Significant front gate threshold voltage shift is observed in the T-shape gate device, which is well known as the Radiation Induced Narrow Channel Effect (RINCE). The charge trapped in the buried oxide can induce large threshold voltage shift in the front gate transistor through coupling effect in the low body doping device. The coupling effect is evaluated through three-dimensional simulation. A degradation of the carrier mobility which relates to shallow trench isolation (STI) oxide trapped charge in the narrow channel device is also discussed.