Method of making sub-resolution pillar structures using undercutting technique

US8076056B2 · kind B2 · utility

Assignee

• SanDisk 3D LLC · US

Inventors

• Chun-Ming Wang · Fremont, US
• Steven Maxwell · Santee, US
• Paul Wai Kie Poon · Fremont, US
• Yung-Tin Chen · Santa Clara, US

Key dates

• Filing date: Oct 6, 2008
• Grant date: Dec 13, 2011
• Expiry date: Jul 25, 2030

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/0338
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method of making a device includes forming an underlying mask layer over an underlying layer, forming a first mask layer over the underlying mask layer, patterning the first mask layer to form first mask features, undercutting the underlying mask layer to form underlying mask features using the first mask features as a mask, removing the first mask features, and patterning the underlying layer using at least the underlying mask features as a mask.