Modeling and process implementation of implanted RESURF type devices

The relationship between breakdown voltage (B.V.) and drift layer charge (QD) for RESURF type lateral PN diodes was investigated both theoretically using a 2D computer program and experimentally. As an added variable, substrate doping variations were modeled to verify their effect on the diode B.V. rating. The importance of tight charge control in the drift layer region was demonstrated (both theoretically and experimentally). It is concluded that implantation is necessary to yield a tight B.V. distribution. Also shown experimentally is the associated degradation in B.V. that results when the N+ and/or P+ regions have reduced radii of curvature.