Part I: Mixed-Signal Performance of Various High-Voltage Drain-Extended MOS Devices

摘要

In this paper, the optimization issues of various drain-extended devices are discussed for input/output applications. The mixed-signal performance, impact of process variations, and gate oxide reliability of these devices are compared. Lightly doped drain MOS (LDDMOS) was found to have a moderate performance advantage as compared to shallow trench isolation (STI) and non-STI drain-extended MOS (DeMOS) devices. Non-STI DeMOS devices have improved circuit performance but suffer from the worst gate oxide reliability. Incorporating an STI region underneath the gate–drain overlap improves the gate oxide reliability, although it degrades the mixed-signal characteristics of the device. The single-halo nature of DeMOS devices has been shown to be effective in suppressing the short-channel effects.