公开(公告)号：US11257722B2

公开(公告)日：2022-02-22

申请号：US16629602

申请日：2018-07-18

Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.

Inventor： Kazuki Tanemura ,  Etsuko Kamata ,  Hiromi Sawai ,  Daisuke Matsubayashi

IPC: H01L21/84 ,  H01L21/822 ,  H01L27/12

Abstract: A semiconductor device with a high threshold voltage is provided. A first conductor positioned over a substrate, a first insulator positioned over the first conductor, a first oxide positioned in contact with the top surface of the first insulator, a second insulator positioned in contact with the top surface of the first oxide, a second oxide positioned over the second insulator, a third insulator positioned over the second oxide, and a second conductor positioned over the third insulator are included. A mixed layer is formed between the first insulator and the first oxide. The mixed layer contains at least one of atoms contained in the first insulator and at least one of atoms contained in the first oxide. The mixed layer has fixed negative charge.