Investigating the Correlation Between Space Charge Modulation and ON-State Breakdown in Multiple RESURF DeMOS Devices

Abstract

In this work, the ON-state performance of the drain-extended metal-oxide-semiconductor (DeMOS) device with multiple RESURF junctions in the drift region is explored. Although the additional RESURF implant offers a significant improvement in the breakdown voltage (VBD) and ON-resistance (RON) compared to the conventional DeMOS, it induces an early space charge modulation (SCM) initiated quasi-saturation (QS) effects and adversely impacts the ON-state breakdown of the device. Moreover, these devices are compared for a fixed breakdown voltage where a correlation between their analog/RF performance and QS effects is established. This work also presents and validates the design guideline for multiple RESURF devices that can alleviate the SCM/QS effects by 8% and improve the ON-state breakdown voltage by 35% compared to the standard device, thereby maximizing the ON-state performance of the device without compromising the OFF-state breakdown.INDEX TERMS Drain extended MOS (DeMOS), double RESURF, triple RESURF, space charge modulation (SCM), quasi-saturation (QS), ON-state breakdown.

Drain-extended MOS design using High-k dielectric to control off-state BTBT with enhanced switching performance

“…On the other hand, the I/O circuit operates at a much higher voltage; hence interface circuit devices with higher breakdown voltages should also meet the highfrequency requirements of core circuits [1]. Drain-extended NMOS (DeNMOS) is a high voltage structure suitable for an interface design application in advanced CMOS technology due to its easy integration and compatibility with advanced CMOS processes [2]. The conventional DeNMOS (C_DeNMOS) structure, on the other hand, has a large gate-to-drain overlap region, which increases surface charge accumulation and degrades switching performance [3].…”