Three-dimensional memory devices and fabricating methods thereof

US11751385B2 · kind B2 · utility

Assignee

• YANGTZE MEMORY TECHNOLOGIES CO., LTD. · CN

Inventors

• Jiaqian XUE · Hubei, CN
• Tingting Gao · 红钢城街道, CN
• Lei Xue · 红钢城街道, CN
• Wanbo Geng · 红钢城街道, CN
• Xiaoxin Liu · 红钢城街道, CN
• Bo Huang · 红钢城街道, CN

Key dates

• Filing date: Aug 28, 2020
• Grant date: Sep 5, 2023
• Expiry date: Feb 5, 2041

Classification

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

Abstract

A method for forming a 3D memory device is provided. The method comprises forming a sacrificial layer on a substrate, forming an alternating dielectric stack on the sacrificial layer, forming a plurality of channel holes vertically penetrating the alternating dielectric stack and the sacrificial layer, and forming a first channel layer in each channel hole. The method further comprises forming a second channel layer on the first channel layer in each channel hole, such that a merging point of the second channel layer is higher than a bottom surface of the alternating dielectric stack. The method further comprises removing the sacrificial layer to form a horizontal trench, and forming a selective epitaxial growth layer in the horizontal trench.