High aspect ratio etch of oxide metal oxide metal stack

US10242883B2 · kind B2 · utility

Assignee

• Lam Research Corporation · US

Inventors

• Joydeep Guha · Fremont, US
• Sirish Reddy · Hillsboro, US
• Kaushik Chattopadhyay · San Jose, US
• Thomas W. Mountsier · San Jose, US
• Aaron Eppler · Fremont, US
• Thorsten Lill · Santa Clara, US
• Vahid Vahedi · Oakland, US
• Harmeet Singh · Simsbury, US

Key dates

• Filing date: Jun 23, 2017
• Grant date: Mar 26, 2019
• Expiry date: Jun 23, 2037

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76802
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method for etching features in an OMOM stack with first layer of silicon oxide, a second layer of a metal containing material over the first layer, a third layer of silicon oxide over the second layer, and a fourth layer of a metal containing material over the third layer is provided. A hardmask is formed over the stack. The hardmask is patterned. The OMOM stack is etched through the hardmask.