Method of forming a darkfield etch mask

US7384568B2 · kind B2 · utility

Assignee

• Palo Alto Research Center Incorporated · US

Inventors

• William S. Wong · Redwood City, US
• Scott Limb · Palo Alto, US
• Beverly Russo · Sunnyvale, US
• Michael L. Chabinyc · Mountain View, US
• Rene A. Lujan · Sunnyvale, US

Key dates

• Filing date: Mar 31, 2006
• Grant date: Jun 10, 2008
• Expiry date: Dec 2, 2026

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D86/0241
• WIPO field: Other consumer goods
• WIPO sector: Other fields

Abstract

Susceptibility of darkfield etch masks (majority of the mask area is opaque) to pinhole defects, transferred pattern, non-uniformity, etc. due to ejector dropout or drop misdirection, and long duty cycles due to large-area coverage, when using digital lithography (or print patterning) is addressed by using a clear-field print pattern that is then coated with etch resist material. The printed clear field pattern is selectively removed to form an inverse pattern (darkfield) within the coated resist layer. Etching then removes selected portions of an underlying (e.g., encapsulation, conductive, etc.) layer. Removal of the mask produces a layer with large-area features with substantially reduced defects.