Three-dimensional memory devices and fabricating methods thereof

US11476277B2 · kind B2 · utility

Assignee

• YANGTZE MEMORY TECHNOLOGIES CO., LTD. · CN

Inventors

• Lei Ding · Plano, US
• Jing Gao · 红钢城街道, CN
• Chuan Yang · Chongqing, CN
• Lan Yu · Beijing, CN
• Ping Yan · Nanhu, CN
• Sen Zhang · 安丰镇, CN
• Bo Xu · Beijing, CN

Key dates

• Filing date: Dec 4, 2020
• Grant date: Oct 18, 2022
• Expiry date: Dec 4, 2040

Classification

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

Abstract

A method for forming a gate structure of a 3D memory device is provided. The method comprises: forming, on a substrate, an alternating dielectric stack including a plurality of dielectric layer pairs, each of the plurality of dielectric layer pairs comprising a first dielectric layer and a second dielectric layer different from the first dielectric layer; forming a slit penetrating vertically through the alternating dielectric stack and extending in a horizontal direction; removing the plurality of second dielectric layers in the alternating dielectric stack through the slit to form a plurality of horizontal trenches; forming a gate structure in each of the plurality of horizontal trenches; forming a spacer layer on sidewalls of the slit to cover the gate structures, wherein the spacer layer has a laminated structure; and forming a conductive wall in the slit, wherein the conductive wall is insulated from the gate structures by the spacer layer.