公开(公告)号：US20170047409A1

公开(公告)日：2017-02-16

申请号：US15306445

申请日：2014-05-01

Applicant: RENESAS ELECTRONICS CORPORATION

Inventor： Toshihiro IIZUKA ,  Shin KOYAMA ,  Yoshitake KATO

IPC: H01L29/20 ,  H01L21/02 ,  H01L29/66 ,  H01L29/205 ,  H01L29/778 ,  H01L29/78 ,  H01L29/51 ,  H01L29/423

Abstract: In a semiconductor device (MISFET) having a gate electrode formed over a nitride semiconductor layer with a gate insulating film interposed therebetween, the gate insulating film includes a first gate insulating film (oxide film of first metal) formed on the nitride semiconductor layer and a second gate insulating film (oxide film of second metal). The second metal (for example, Hf) has electronegativity lower than that of the first metal (for example, Al). Since the electronegativity of the second metal is lower than that of the first metal, negative charge is introduced into the oxide film of the first metal due to interfacial polarization, so that the flat-band voltage can be shifted in a positive direction. Accordingly, the threshold voltage which has become negative due to the heat treatment of the oxide film of the first metal can be shifted in the positive direction.

Abstract translation: 在半导体器件（MISFET）中，具有在栅极绝缘膜之间形成在氮化物半导体层上的栅电极，栅极绝缘膜包括形成在氮化物半导体层上的第一栅极绝缘膜（第一金属的氧化物膜）和 第二栅极绝缘膜（第二金属的氧化物膜）。 第二金属（例如，Hf）的电负性低于第一金属（例如，Al）的电负性。 由于第二金属的电负性低于第一金属的电负性，所以由于界面极化，负电荷被引入到第一金属的氧化物膜中，使得平带电压可以向正方向偏移。 因此，由于第一金属的氧化膜的热处理而变为负的阈值电压可以向正方向移动。