A Novel Super-Junction Lateral Double-Diffused Metal--Oxide--Semiconductor Field Effect Transistor with n-Type Step Doping Buffer Layer
A Novel Super-Junction Lateral Double-Diffused Metal-Oxide-Semiconductor Field Effect Transistor with n-Type Step Doping Buffer Layer

A novel super-junction lateral double-diffused metal-oxide--semiconductor field effect transistor （SJ-LDMOSFET） with n-type step doping buffer layer is proposed. The step doping buffer layer almost completely eliminates the substrate-assisted depletion effect, modulates lateral electric field and achieves nearly uniform surface field. On the other hand, the buffer layer also provides another conductive path and reduces on-state resistance. In short, the proposed LDMOSFET improves trade-off performance between breakdown voltage （B V） and specific on-state resistance Ron,sp. Compared with the conventional SJ-LDMOSFET, the simulation results indicate that the BV of the SSJ-LDMOSFET is increased from saturation voltage 121.7V to 644.9 V; at the same time, the specific on-state resistance is decreased from 0.314 Ω.cm^2 to 0.14 Ω.cm^2 by virtue of 3D numerical simulations using ISE when the drift region length and the step number are taken as 48μm and 3, respectively.