Design and Simulation of RF Power LDMOS on SOI and InGaAs

Abstract

Laterally diffused metal oxide semiconductor field effect transistors LDMOSFETs generally called LDMOS are widely used as power devices in the power integrated circuits PICs for many applications including automotive electronics personal communication systems portable power management systems and RF base stations The PICs provide various advantages like better reliability high performance low power consumption and reduction in volume weight and cost For RF power applications a better designed LDMOS should have high drive current ID large breakdown voltage Vbr low specific on resistance Ronsp high transconductance gm high cut off frequency fT and high maximum oscillation frequency fmax The trench technology is one of the design techniques used to enhance the performance of the LDMOS Presently silicon on insulator SOI technology is dominantly used for making the RF PICs due to its mature fabrication process with well studied native oxide As the silicon based power devices are approaching their physical limits new materials are needed to overcome the challenges faced by the Si technology The III V group compound semiconductors are emerging as the promising channel material for LDMOS due to their outstanding transport properties High electron mobility InGaAs is an attractive material which can replace Si in power devices Therefore motive of this work is to propose new LDMOS structures on SOI and InGaAs using trench technology for better performance the device In the proposed structures more than one channels are created in the p-base which carry drain current in parallel from drain to source This provides enhancement in current conduction and reduction in on resistance The proposed trench structures also achieve a better reduced surface field RESURF effect leading to higher breakdown voltage Further due to a simultaneous control of drain current by multiple gates the proposed LDMOS devices show higher transconductance leading to a better frequency response