The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Nov. 05, 2024

Filed:

Nov. 15, 2023
Applicant:

Semiconductor Energy Laboratory Co., Ltd., Atsugi, JP;

Inventors:

Toshikazu Kondo, Atsugi, JP;

Hideyuki Kishida, Atsugi, JP;

Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H01L 27/12 (2006.01); H01L 21/02 (2006.01); H01L 21/477 (2006.01); H01L 29/24 (2006.01); H01L 29/45 (2006.01); H01L 29/49 (2006.01); H01L 29/66 (2006.01); H01L 29/786 (2006.01); H10K 59/12 (2023.01); H10K 59/121 (2023.01); H10K 59/123 (2023.01);
U.S. Cl.
CPC ...
H01L 27/1225 (2013.01); H01L 21/02565 (2013.01); H01L 21/02614 (2013.01); H01L 21/0262 (2013.01); H01L 21/02631 (2013.01); H01L 21/477 (2013.01); H01L 27/1214 (2013.01); H01L 27/1222 (2013.01); H01L 27/124 (2013.01); H01L 27/1248 (2013.01); H01L 27/1255 (2013.01); H01L 27/1259 (2013.01); H01L 29/24 (2013.01); H01L 29/45 (2013.01); H01L 29/458 (2013.01); H01L 29/4908 (2013.01); H01L 29/66765 (2013.01); H01L 29/66969 (2013.01); H01L 29/78603 (2013.01); H01L 29/78606 (2013.01); H01L 29/78618 (2013.01); H01L 29/78663 (2013.01); H01L 29/78678 (2013.01); H01L 29/7869 (2013.01); H01L 29/78693 (2013.01); H10K 59/12 (2023.02); H10K 59/1213 (2023.02); H10K 59/123 (2023.02); H01L 21/02554 (2013.01);
Abstract

In a thin film transistor, an increase in off current or negative shift of the threshold voltage is prevented. In the thin film transistor, a buffer layer is provided between an oxide semiconductor layer and each of a source electrode layer and a drain electrode layer. The buffer layer includes a metal oxide layer which is an insulator or a semiconductor over a middle portion of the oxide semiconductor layer. The metal oxide layer functions as a protective layer for suppressing incorporation of impurities into the oxide semiconductor layer. Therefore, in the thin film transistor, an increase in off current or negative shift of the threshold voltage can be prevented.


Find Patent Forward Citations

Loading…