A Novel 700-V SOI LDMOS With Double-Sided Trench

Abstract

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> A novel silicon-on-insulator (SOI) high-voltage device structure with double-sided trenches on the buried oxide layer (DT SOI) is proposed and its breakdown characteristics are investigated theoretically and experimentally in this letter. Theoretically, the charges implemented in the DTs, whose density changes with the drain voltage, increase the electric field in the buried layer and modulate the electric field in the drift region, which results in the enhancement of the breakdown voltage (BV). Experimentally, the BV of 730 V is obtained for the first time in SOI LDMOS with DT on 20-<formula formulatype="inline"><tex>$\mu\hbox{m}$</tex></formula> SOI layer and 1- <formula formulatype="inline"><tex>$\mu\hbox{m}$</tex></formula> buried oxide layer. </para>