Theory Analyses of SJ-LDMOS With Multiple Floating Buried Layers Based on Bulk Electric Field Modulation

A new theory about terminal technology is proposed for superjunction lateral double-diffused metal oxide-semiconductor field effect transistors with multiple floating buried layers (MFBL SJ-LDMOS) based on the bulk electric field (E-field) modulation in this paper for the first time. A concise and efficient analytical theory is presented to predict the vertical voltage and bulk E-field distributions of MFBL SJ-LDMOS. The analytical formulas for the breakdown voltage (BV) and the vertical peak E-field of MFBL SJ-LDMOS are derived in the closed-form equations, which starts from a single floating buried layer for the vertical E-field modulation, extending this theory to predict the vertical E-field peaks and vertical voltage distributions between the MFBLs. Quantitative analytical description has been given to explain the bulk E-field modulation for the MFBL. Moreover, the optimal spacing and the maximum BV are procedurally predicted. All analytical results are well verified by the 3-D numerical simulations, proving the applicability of the method presented in other power devices with MFBL including MFBL LDMOS, MFBL lateral insulated gate bipolar transistor, and MFBL diode.