Contact hole fabrication with the aid of mutually crossing sudden phase shift edges of a single phase shift mask

US6635388B1 · kind B1 · utility

Assignee

• Infineon Technologies AG · DE

Inventors

• Christoph Friedrich · Hersbruck, DE
• Uwe Griesinger · Hersbruck, DE
• Rainer Pforr · Dresden, DE
• Dietrich Widmann · Unterhaching, DE
• Andreas Grassmann · Villach, AT

Key dates

• Filing date: Oct 29, 1999
• Grant date: Oct 21, 2003
• Expiry date: Oct 29, 2019

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/2022
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

The invention relates to a phase shift mask for lithographically producing small structures at the limit of a resolution that is predetermined by the wavelength of the exposure radiation. The phase shift mask has first regions A and second regions B that effect a phase-shift relative to the first regions. The second regions are arranged beside the first regions for producing a sudden phase shift along the boundaries between the first and the second regions. Individual first regions touch one another via corners at points, at which the second regions also touch one another via corners. The result is that the boundaries between first and second regions merge at these points and these points are opaque to the radiation. The invention makes it possible to expose extremely small contact holes with just a single exposure and thus leads to a reduction of costs in the fabrication of integrated semiconductor circuits.