Authors: B. Bakeroot, P. Moens, M. Vermandel and J. Doutreloigne
Affilation: University of Gent, Belgium
Pages: 498 - 501
Keywords: MOS transistor, SOA, adaptive resurf, field plate, TCAD
Using TCAD, an n-type DEMOS (Drain Extended MOS) has been developed in a standard 0:35 mCMOS technology. The devices are optimised towards a Safe Operating Area (SOA) of 60 - 65 V using an n-type "adaptive resurf" implant under the field oxide. In this work, only two additional masks are added to the standard process flow (one ntub mask as well), rendering the implementation very cost-effective. In this paper it is shown that the optimal dose and layout of the adaptive resurf implant will strongly be determined by the SOA-breakdown voltage trade-off. Moreover,it is shown that the optimal dose is dependent on the size of the device, especially on the field plate length.