Patent ID: 9112053
Filing Date: 2015-08-18
Classification: H01L

Abstract:
1. A method for producing a semiconductor device with a dielectric layer, the method comprising: providing a semiconductor body with a first trench extending into the semiconductor body, the first trench having a bottom and a sidewall; forming a first dielectric layer on the sidewall in a lower portion of the first trench; forming a first plug in the lower portion of the first trench so as to cover the first dielectric layer, the first plug leaving an upper portion of the sidewall uncovered; forming a sacrificial layer on the sidewall in the upper portion of the first trench; forming a second plug in the upper portion of the first trench; removing the sacrificial layer, so as to form a second trench having sidewalls and a bottom; forming a second dielectric layer in the second trench and extending to the first dielectric layer; and forming a source region and a body region in the second plug.