High precision metal thin film liftoff technique

US9076658B1 · kind B1 · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Ari D. Brown · Ellicott City, US
• Amil Ashok Patel · Palo Alto, US

Key dates

• Filing date: Sep 25, 2014
• Grant date: Jul 7, 2015
• Expiry date: Sep 25, 2034

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/283
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A metal film liftoff process includes applying a polymer layer onto a silicon substrate, applying a germanium layer over the polymer layer to create a bilayer lift off mask, applying a patterned photoresist layer over the germanium layer, removing an exposed portion of the germanium layer, removing the photoresist layer and a portion of the polymer layer to expose a portion of the substrate and create an overhanging structure of the germanium layer, depositing a metal film over the exposed portion of the substrate and the germanium layer, and removing the polymer and germanium layers along with the overlaying metal film.