Method for forming cornered images on a substrate and photomask formed thereby

US5959325A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• William J. Adair · Underhill, US
• Richard A. Ferguson · Pleasant Valley, US
• Mark C. Hakey · Saint Albans, US
• Steven J. Holmes · Colchester, US
• David V. Horak · South Burlington, US
• Robert K. Leidy · Burlington, US
• William H. Ma · Wappingers Falls, US
• Ronald M. Martino · Danbury, US
• Song Peng · Shenzhen, TW

Key dates

• Filing date: Aug 21, 1997
• Grant date: Sep 28, 1999
• Expiry date: Aug 21, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S438/942
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method for forming square shape images in a lithographic process is disclosed wherein a first plurality of lines running in a first direction is defined in a first, usually sacrificial, layer, and then a second resist is defined wherein the lines run in an intersecting pattern to those of the first layer, thereby creating cornered images wherever the first and second layer intersect and in the open areas between the lines. Methods are proposed for developing the square intersecting areas and the square angle areas defined by the openings. Additionally, a photomask is disclosed in which the length and width of the cornered images are independently patterned using the two-exposure process.