A combination of uniform and variation in lateral doping (UVLD) profiles is proposed for the drift region of lateral power devices in partial SOI (PSOI) technology in order to achieve breakdown voltages above 600 V. LDMOS transistor structures incorporating the proposed doping profile are analyzed for their electrical characteristics and compared with conventional uniformly doped PSOI and thin layer SOI by extensive 2-D numerical simulations using MEDICI. The results indicate that the proposed doping profile can significantly improve the trade-off between breakdown voltage and specific on-resistance as well as the heat dissipation in comparison to uniformly doped PSOI and thin layer VLD SOL (C) 2004 Elsevier Ltd. All rights reserved.