Improved performance lateral double-diffused MOS transistor and method of fabrication thereof

摘要

A transistor has a JFET gate region (24) of a first conductivity type formed at the face of a semiconductor layer (10) to laterally and downwardly surround a drift region (26) of a second conductivity type. A thick insulator region (42) is formed on a portion of the drift region at the face. A IGFET body (30) of the first conductivity type is formed at the face to be adjacent the JFET gate region (24). This body (30) spaces a source region (34) of the second conductivity type from the drift region (26). A drain region (60) is formed at the face to be of the second conductivity type and to adjoin the drift region (26), and to be spaced from the IGFET body. A conductive gate (52) extends over the face between the source region (34) and the thick insulator region (42), with a thin gate insulator (50) spacing the gate (52) from the IGFET body (30). The enhanced doping concentration of the JFET gate region (24) with respect to the semiconductor layer (10) allows the dopant concentration of the drift region (26) to likewise be increased, thereby allowing RESURF conditions to be met at the rated voltage and with a lower rds(on).