The parameter extraction including field-plate effect of 0.25 µm 12 V LDMOSFETs

Abstract

This paper presents the parameter extraction including the field-plate effect of a 0.25 µm 12 V lateral diffused metal-oxide-semiconductor field effect transistor (LDMOSFET). As LDMOSFET is capable of sustaining high-voltage signals between source and drain, it is appropriately used for power and radio frequency (RF) IC applications. For RF applications, a complete parameter extraction including the parasitic components of the devices used is necessary for accurately predicting the performance of the circuits. In this study, we propose a method to extract the parameters of the small-signal equivalent model containing the field-plate capacitance (Cfp) of a LDMOSFET. The simulated results of this LDMOSFET RF small-signal model agree well with the measured results from 0.5 to 3 GHz. The extracted parameters show that the Cfp forms an additional signal path which degrades the effective drain-side resistance and should be considered in RF applications.