Three-dimensional memory devices and fabricating methods thereof

US10892274B2 · kind B2 · utility

Assignee

• YANGTZE MEMORY TECHNOLOGIES CO., LTD. · CN

Inventors

• Yushi Hu · 红钢城街道, CN
• Qian Tao · Singapore, SG
• Haohao Yang · 红钢城街道, CN
• Jin Wen Dong · Hubei, CN
• Jun Chen · Hubei, CN
• Zhenyu Lu · Hubei, CN

Key dates

• Filing date: Oct 17, 2018
• Grant date: Jan 12, 2021
• Expiry date: Oct 17, 2038

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10B43/35

Abstract

Embodiments of 3D memory devices and fabricating methods are disclosed. The method can comprise: forming an alternating dielectric stack on a substrate; forming a channel hole penetrating the alternating dielectric stack to expose a surface of the substrate; forming an epitaxial layer on a bottom of the channel hole; forming a functional layer covering a sidewall of the channel hole and a top surface of the epitaxial layer; forming a protecting layer covering the functional layer; removing portions of the functional layer and the protecting layer to form an opening to expose a surface of the epitaxial layer; expanding the opening laterally to increase an exposed area of the epitaxial layer at the bottom of the channel hole; and forming a channel structure on the sidewall of the channel hole and being in electrical contact with the epitaxial layer through the expanded opening.