Alpha and Omega Semiconductor (cayman) Ltd.

Alpha & Omega Semiconductor Corporation

Alpha and Omega Semiconductor International LP

Lingbing Chen

Lingpeng Guan

Wenjun Li

Jian Wang

Madhur Bobde

Karthik Padmanabhan

Hongyong Xue

Lei Zhang

Wim Aarts

Yiming Gu

Boxiu Cai

A semiconductor device includes a semiconductor body having a base region incorporating a field stop zone where the base region and the field stop zone are both formed using an epitaxial process. Furthermore, the epitaxial layer field stop zone is formed with an enhanced doping profile to realize improved soft-switching performance for the semiconductor device. In some embodiments, the enhanced doping profile includes multiple doped regions with peak doping levels where a first doped region adjacent to a first side of the field stop zone has a first peak doping level that is not higher than a last peak doping level of a last doped region adjacent to the base region. The epitaxial layer field stop zone of the present invention enables complex field stop zone doping profiles to be used to obtain the desired soft-switching characteristics in the semiconductor device.

Semiconductor device incorporating epitaxial layer field stop zone

Transistor device and method of making thereof comprising a substrate heavily doped with a first conductivity type and an epitaxial layer lightly doped with the first conductivity type on top of the substrate. A body region doped with a second conductivity type is formed in the epitaxial layer wherein the second conductivity type is opposite the first conductivity type and a source region doped with the first conductivity type is formed in the body region of the epitaxial layer. An integrated planar-trench gate having a planar gate portion is formed on the surface of the epitaxial layer that is contiguous with a gate trench portion formed in the epitaxial layer.

Integrated planar-trench gate power MOSFET

A method for manufacturing and a Super Junction MOSFET are disclosed. The Super Junction MOSFET comprises a lightly doped epitaxial layer of a first conductivity type on a heavily doped substrate of the first conductivity type. A deep trench is formed in the epitaxial layer. The deep trench having an insulating layer with a thickness gradient formed on surfaces of the deep trench. One or more regions of the epitaxial layer proximate to sidewalls of the deep trench is doped of a second conductivity type, wherein the second conductivity type is opposite the first conductivity type. Finally, MOSFET device structures are formed in the epitaxial layer.

Gas dopant doped deep trench super junction high voltage MOSFET

A semiconductor device includes a semiconductor body having a base region incorporating a field stop zone where the base region and the field stop zone are both formed using an epitaxial process. Furthermore, the epitaxial layer field stop zone is formed with an enhanced doping profile to realize improved soft-switching performance for the semiconductor device. In some embodiments, the enhanced doping profile formed in the field stop zone includes varying, non-constant doping levels. In some embodiments, the enhanced doping profile includes one of an extended graded doping profile, a multiple stepped flat doping profile, or a multiple spike doping profile. The epitaxial layer field stop zone of the present invention enables complex field stop zone doping profiles to be used to obtain the desired soft-switching characteristics in the semiconductor device.

A method of monitoring an epitaxial growth geometry shift is disclosed. First, second and third trenches are formed on a semiconductor wafer. An epitaxial layer is grown. The epitaxial layer covers the first trenches and the second trenches but not the third trenches. First and second recesses on a top surface of the epitaxial layer are formed. First and second openings aligned with the first and the second recesses and a third openings aligned with the third trenches are formed in a photoresist layer. A corresponding first offset between a top center and a bottom center of each first recess is measured. An offset value of the top center from the bottom center of said each first recess is determined. A corresponding second offset between a top center of each second recess and a center of corresponding second opening is determined. A corresponding third offset between a center of each third trench and a center of corresponding third opening is measured. A corresponding offset value of each second recess from the difference between corresponding second offset and corresponding third offset is determined.

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Portland, OR, United States of America

Lingbing Chen