Method for fabricating a MIM capacitor having increased capacitance density and related structure

US7268038B2 · kind B2 · utility

Assignee

• Newport Fab, LLC · US

Inventors

• Dieter Dornisch · Carlsbad, US
• Kenneth M. Ring · Waterville, US
• Tinghao Wang · Eden Prairie, US
• David J. Howard · Irvine, US
• Guangming Li · Shifang, CN

Key dates

• Filing date: Nov 23, 2004
• Grant date: Sep 11, 2007
• Expiry date: May 23, 2025

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D1/68

Abstract

According to one embodiment of the invention, a method for fabricating a MIM capacitor in a semiconductor die includes a step of depositing a first interconnect metal layer. The method further includes depositing a layer of silicon nitride on the first interconnect layer. The layer of silicon nitride is deposited in a deposition process using an ammonia-to-silane ratio of at least 12.5. The method further includes depositing a layer of MIM capacitor metal on the layer of silicon nitride. The method further includes etching the layer of MIM capacitor metal to form an upper electrode of the MIM capacitor. According to this exemplary embodiment, the method further includes etching the layer of silicon nitride to form a MIM capacitor dielectric segment and etching the first interconnect metal layer to form a lower electrode of the MIM capacitor. The MIM capacitor has a capacitance density of at least 2.0 fF/um2.