Structure and method for forming capacitors for a three-dimensional NAND

US11437464B2 · kind B2 · utility

Assignee

• YANGTZE MEMORY TECHNOLOGIES CO., LTD. · CN

Inventors

• Liang Chen · 红钢城街道, CN
• Cheng Gan · Hubei, CN
• Wei Liu · 红钢城街道, CN
• Shunfu Chen · Hubei, CN

Key dates

• Filing date: Dec 30, 2019
• Grant date: Sep 6, 2022
• Expiry date: Jul 18, 2040

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L2225/06548
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Embodiments of a three-dimensional capacitor for a memory device and fabrication methods are disclosed. The method includes forming, on a first side of a first substrate, a peripheral circuitry having a plurality of peripheral devices, a first interconnect layer, a deep well and a first capacitor electrode. The method also includes forming, on a second substrate, a memory array having a plurality of memory cells and a second interconnect layer, and bonding the first interconnect layer of the peripheral circuitry with the second interconnect layer of the memory array. The method further includes forming, on a second side of the first substrate, one or more trenches inside the deep well, disposing a capacitor dielectric layer on sidewalls of the one or more trenches, and forming capacitor contacts on sidewalls of the capacitor dielectric layer inside the one or more trenches.