Device structure for increasing coupling ratio of body-tied fin structure flash memory cell

US11282968B2 · kind B2 · utility

Assignee

• Shanghai Huali Integrated Circuit Corporation · CN

Inventors

• Zhi Tian · Shanghai, CN
• Juanjuan Li · Shanghai, CN
• Hua Shao · Nanhu, CN
• Haoyu Chen · Hefei, CN

Key dates

• Filing date: Jul 30, 2020
• Grant date: Mar 22, 2022
• Expiry date: Jul 30, 2040

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D30/62

Abstract

The present disclosure provides a device structure for increasing the coupling ratio of a body-tied fin flash memory cell. The device includes a plurality of elongate fin structures arranged in parallel in an active layer on a substrate, a floating gate disposed on the top surface and the opposing sidewalls of each of the fin structures and at a predetermined location on the elongated fin, and dispersed structure. The dispersed structure comprises a plurality of stacked layers parallel to the substrate, spaced evenly apart; and two adjacent fin structures share one dispersed structure at their sidewalls. This device increases the distance between adjacent floating gates, reduces coupling capacitance, and reduces the disturbance between the cells, which is conducive to increasing the drain voltage, improving the programming speed, and further reducing the gate voltage. More optimization options for subsequent shrinking of the flash memory cells can be provided.