Method of making pillars using photoresist spacer mask

US8080443B2 · kind B2 · utility

Assignee

• SanDisk 3D LLC · US

Inventors

• Yung-Tin Chen · Santa Clara, US
• Chun-Ming Wang · Fremont, US
• Steven J. Radigan · Fremont, US

Key dates

• Filing date: Oct 27, 2008
• Grant date: Dec 20, 2011
• Expiry date: Apr 17, 2030

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/0337
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method of making a device includes forming a first hard mask layer over an underlying layer, forming first features over the first hard mask layer, forming a first spacer layer over the first features, etching the first spacer layer to form a first spacer pattern and to expose top of the first features, removing the first features, patterning the first hard mask using the first spacer pattern as a mask to form first hard mask features, removing the first spacer pattern. The method also includes forming second features over the first hard mask features, forming a second spacer layer over the second features, etching the second spacer layer to form a second spacer pattern and to expose top of the second features, removing the second features, etching the first hard mask features using the second spacer pattern as a mask to form second hard mask features, and etching at least part of the underlying layer using the second hard mask features as a mask.