Semiconductor device with composite drift region

• Main Authors: Zuo Jiang-Kai, Yang Hongning
• Format: Patent
• Language: English
• Published: 25.10.2016
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

A device includes a semiconductor substrate, a channel region in the semiconductor substrate having a first conductivity type, and a composite drift region in the semiconductor substrate, having a second conductivity type. The composite drift region includes a first drift region and a second drift region spaced from the channel region by the first drift region. The device further includes a drain region in the semiconductor substrate, spaced from the channel region by the composite drain region, and having the second conductivity type. The first drift region has a dopant concentration profile with a first concentration level where adjacent the channel region and a second concentration level where adjacent the second drift region, the first concentration level being higher than the second concentration level. In some embodiments, the first and second drift regions are stacked vertically, with the first drift region being shallower than the second drift region.