Optimization and New Structure of Superjunction With Isolator Layer

An optimization theory is developed for the balanced symmetric superjunction with the interface isolator layer (I-SJ) in this paper. The theory includes two parts: the electric field calculation by the Taylor series method; the design formulas by the minimum specific onresistance RON,min optimization. Based on the theory, a new I-SJ structure with a single cell is proposed, which shows the minimum RON among the superjunction (SJ) devices with the 1 μm shallow depths. RON of the new device is reduced by 53.5% compared with that of the conventional SJ lateral double diffused metal-oxide-semiconductor field effect transistor (LDMOS) and 67.6% with the conventional LDMOS under the same breakdown voltage V
_B
of 658 V.