Reliability of high performance standard two-edge and radiation hardened by design enclosed geometry transistors

Abstract

It was recently shown that radiation hardened by design (RHBD) annular-gate MOSFETs not only provide totaldose radiation tolerance, but can also improve the hot-carrier reliability of advanced CMOS circuits. In this paper, the hotcarrier reliability of standard two-edge and enclosed geometry transistors intended for use in space and strategic environments is demonstrated. Hot-carrier reliability measurements on standard two-edge, standard enclosed, gate under-lap enclosed, and annular transistors fabricated in the same 90 nm high performance technology indicate an improvement in hot-carrier lifetime in the enclosed geometry and multi-finger transistor designs when compared to a conventional single stripe MOSFET. Two-dimensional device simulations, along with experimental measurements, provide physical insight into the reliability response of each device type.