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. 30, 2021

Filed:

Mar. 18, 2020
Applicant:

Taiwan Semiconductor Manufacturing Co., Ltd., Hsin-Chu, TW;

Inventors:

Hung-Ling Shih, Tainan, TW;

Chieh-Fei Chiu, Tainan, TW;

Po-Wei Liu, Tainan, TW;

Wen-Tuo Huang, Tainan, TW;

Yu-Ling Hsu, Tainan, TW;

Yong-Shiuan Tsair, Tainan, TW;

Shih Kuang Yang, Tainan, TW;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 29/778 (2006.01); H01L 27/11521 (2017.01); H01L 29/788 (2006.01); H01L 21/308 (2006.01); H01L 21/768 (2006.01); H01L 21/027 (2006.01); H01L 21/762 (2006.01); H01L 21/28 (2006.01);
U.S. Cl.
CPC ...
H01L 27/11521 (2013.01); H01L 21/0274 (2013.01); H01L 21/3085 (2013.01); H01L 21/76224 (2013.01); H01L 21/76877 (2013.01); H01L 29/40114 (2019.08); H01L 29/788 (2013.01);
Abstract

In some embodiments, a method for forming a semiconductor device is provided. The method includes forming a pad stack over a semiconductor substrate, where the pad stack includes a lower pad layer and an upper pad layer. An isolation structure having a pair of isolation segments separated in a first direction by the pad stack is formed in the semiconductor substrate. The upper pad is removed to form an opening, where the isolation segments respectively have opposing sidewalls in the opening that slant at a first angle. A first etch is performed that partially removes the lower pad layer and isolation segments in the opening so the opposing sidewalls slant at a second angle greater than the first angle. A second etch is performed to round the opposing sidewalls and remove the lower pad layer from the opening. A floating gate is formed in the opening.


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