公开(公告)号：US10978584B2

公开(公告)日：2021-04-13

申请号：US15737523

申请日：2016-08-17

Applicant: UNIVERSITY OF ELECTRONIC SCIENCE AND TECHNOLOGY OF CHINA ,  CHONGQING PINGWEI ENTERPRISE CO., LTD.

Inventor： Jiangfeng Du ,  Zhenchao Li ,  Dong Liu ,  Zhiyuan Bai ,  Qi Yu ,  Shuzhou Li

IPC: H01L29/78 ,  H01L29/861 ,  H01L29/06 ,  H01L23/31 ,  H01L29/739

Abstract: A semiconductor structure, a semiconductor assembly and a power semiconductor device. The semiconductor structure includes: a P-type semiconductor material layer; an N-type semiconductor material layer adjacent to the P-type semiconductor material layer, wherein the N-type semiconductor material layer and the P-type semiconductor material layer together from a PN junction; and a plurality of insulating material layers located outside the PN junction and distributed along the superposition direction of the P-type semiconductor material layer and the N-type semiconductor material layer, wherein the relative dielectric constants of the adjacent insulating material layers are different. The semiconductor structure in the present invention significantly optimizes the distribution of an electric field during the off-state high voltage operation of a device, greatly improves the breakdown voltage of the device, avoids the premature breakdown of the device caused by the concentration effect of the electric field at the edge of the junction.

公开(公告)号：US11366152B2

公开(公告)日：2022-06-21

申请号：US16666428

申请日：2019-10-29

Applicant: University of Electronic Science and Technology of China

Inventor： Dong Liu ,  Yan Yan ,  Xiaoting Xiao ,  Bin Gao ,  Guiyun Tian

IPC: G01R29/22 ,  H03H9/17 ,  H03H9/19

Abstract: A method for measuring equivalent circuit parameters and resonant frequency of a piezoelectric resonator, by which the phase-frequency curve of the piezoelectric resonator is measured, and the resonant frequency and the anti-resonant frequency are obtained. Then, the slopes of the phase-frequency curve at the resonant frequency and the anti-resonant frequency are respectively measured. The resonant angular frequency and the anti-resonant angular frequency are also calculated. Finally, the equivalent circuit parameters of the piezoelectric resonator are obtained by solving a system of nonlinear equations.