A New High Voltage 4H-SiC Lateral Dual Sidewall Schottky (LDSS) Rectifier: Theoretical Investigation and Analysis

摘要

In this paper, we report a new 4H-SiC Lateral Dual Sidewall Schottky (LDSS)rectifier on a highly doped drift layer consisting of a high-barrier sidewallSchottky contact on top of the low-barrier Schottky contact. Usingtwo-dimensional device simulation, the performance of the proposed device hasbeen evaluated in detail by comparing its characteristics with those of thecompatible Lateral Conventional Schottky (LCS) and Lateral Trench SidewallSchottky (LTSS) rectifiers on 4H-SiC. From our simulation results, it isobserved that the proposed LDSS rectifier acts as a low-barrier LTSS rectifierunder forward bias conditions and as a high-barrier LTSS rectifier underreverse bias conditions making it an ideal rectifier. The LDSS rectifierexhibits an on/off current ratio (at 1 V / -500 V) of 5.5x10e7 for an epitaxiallayer doping of 1x10e17 /cm^3. Further, the proposed LDSS structure exhibits avery sharp breakdown similar to that of a PiN diode in spite of using onlySchottky junctions in the structure. We have analyzed the reasons for theimproved performance of the LDSS.