Analytical models for the electric field distributions and breakdown voltage of Triple RESURF SOI LDMOS

In this paper, analytical models for the electric field distributions and breakdown voltage of Triple RESURF SOI LDMOS are proposed. The new analytical expressions of the surface and vertical electric field distributions are presented based on which the general analytic expressions of the RESURF condition and the vertical breakdown voltage of Single, Double and Triple RESURF SOI LDMOS are derived. Dependence of the breakdown voltage and specific on-resistance on the P-layer’ parameters of Triple RESURF SOI LDMOS are discussed in detail. Both analytical and numerical results show that the specific on-resistance of Triple RESURF SOI LDMOS is reduced by 50% compared with Single RESURF SOI LDMOS at the same breakdown voltage. The analytical results are in good agreement with those of 2D simulations.

► General analytic expressions of the RESURF condition and breakdown voltage of S-, D-, T-RESURF SOI LDMOS are derived.
► The optimal vertical electric field distribution in drift region is presented.
► The P-layer is better to be at the middle of the drift region, and thinner P-layer is a good choice.
► Breakdown mechanism of bulk silicon Triple RESURF LDMOS can be explained in a similar way.