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 ( $\text{V}_{\mathrm {BD}}$ ) and ON-resistance ( $\text{R}_{\mathrm {ON}}$ ) 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.

Keywords

• Drain extended MOS (DeMOS)
• double RESURF
• triple RESURF
• space charge modulation (SCM)
• quasi-saturation (QS)
• ON-state breakdown