公开(公告)号：US20240347644A1

公开(公告)日：2024-10-17

申请号：US18627560

申请日：2024-04-05

Applicant: Semiconductor Energy Laboratory Co., Ltd.

Inventor： Shun OHTA ,  Rena WAKASA ,  Jesper EKLIND ,  Yuichi SATO

IPC: H01L29/786

CPC classification number: H01L29/7869

Abstract: A semiconductor device having excellent electrical characteristics is provided. The semiconductor device includes a first conductive layer, a first insulating layer over the first conductive layer, an oxide semiconductor layer over the first insulating layer, a second conductive layer, a third conductive layer, and a second insulating layer over the oxide semiconductor layer, and a fourth conductive layer over the second insulating layer. The second conductive layer and the third conductive layer each contain tantalum and nitrogen. In each of the second conductive layer and the third conductive layer, the percentage of a first tantalum bonding state is lower than or equal to 3%, and the percentage of a second tantalum bonding state is higher than or equal to 5%. The first tantalum bonding state is a bonding state of tantalum metal and a bonding state of tantalum nitride with stoichiometrically less nitrogen per tantalum, and the second tantalum bonding state is a bonding state of tantalum nitride with stoichiometrically equal nitrogen per tantalum.