公开(公告)号：US20220376098A1

公开(公告)日：2022-11-24

申请号：US17325643

申请日：2021-05-20

Applicant: Wolfspeed, Inc.

Inventor： Kyoung-Keun Lee ,  Fabian Radulescu ,  Scott Sheppard

IPC: H01L29/778 ,  H01L29/10 ,  H01L29/66

Abstract: A transistor device ac includes a semiconductor epitaxial layer structure including a channel layer and a barrier layer on the channel layer, wherein the barrier layer has a higher bandgap than the channel layer, a source contact and a drain contact on the barrier layer, and a gate contact on the barrier layer between source contact and the drain contact. The device further includes a plurality of selective modified access regions at an upper surface of the barrier layer opposite the channel layer. The selective modified access regions include a material having a lower surface barrier height than the barrier layer, and the plurality of selective modified access regions are spaced apart on the barrier layer along a length of the gate contact.

公开(公告)号：US11502178B2

公开(公告)日：2022-11-15

申请号：US17081476

申请日：2020-10-27

Applicant: Wolfspeed, Inc.

Inventor： Kyle Bothe ,  Jia Guo ,  Terry Alcorn ,  Fabian Radulescu ,  Scott Sheppard

IPC: H01L29/40 ,  H01L29/417 ,  H01L29/66 ,  H01L29/778

Abstract: A transistor device includes a semiconductor layer, a surface dielectric layer on the semiconductor layer, and at least a portion of a gate on the surface dielectric layer. The surface dielectric layer includes an aperture therein that is laterally spaced apart from the gate. The transistor device includes an interlayer dielectric layer on the surface dielectric layer, and a field plate on the interlayer dielectric layer. The field plate is laterally spaced apart from the gate, and at least a portion of the field plate includes a recessed portion above the aperture in the surface dielectric layer.