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.
Patent No.:
Date of Patent:
Jan. 07, 2020
Filed:
Jul. 26, 2018
Yangtze Memory Technologies Co., Ltd., Wuhan, Hubei, CN;
Yu Ting Zhou, Hubei, CN;
Li Hong Xiao, Hubei, CN;
Jian Xu, Hubei, CN;
Sizhe Li, Hubei, CN;
Zhao Hui Tang, Hubei, CN;
Zhaosong Li, Hubei, CN;
Yangtze Memory Technologies Co., Ltd., Wuhan, CN;
Abstract
Embodiments of a method for forming a staircase structure of 3D memory devices are disclosed. The method comprises (i) forming an alternating layer stack including multiple layers disposed on a substrate in a vertical direction; (ii) removing a portion of the alternating layer stack to form multiple step-platforms in a staircase region of the alternating layer stack; (iii) forming a hard mask layer to cover top surfaces of the step-platforms; (iv) forming multiple openings in the hard mask layer to expose a portion of each of the step-platforms; (v) forming a photoresist layer to cover the top surfaces of the step-platforms and the hard mask layer; (vi) using a same set of trim-etch processes to pattern the photoresist layer to form a set of staircases on each of the step-platforms; (vii) removing the photoresist layer and the hard mask layer; and repeating (iii), (iv), (v), (vi) and (vii) sequentially.