One dimensional lithographic proximity correction using DRC shape functions

US5900340A · kind A · utility

Assignee

• Motorola, Inc. · US

Inventors

• Alfred J. Reich · Austin, US
• Kevin Lucas · Austin, US
• Michael E. Kling · Austin, US
• Warren D. Grobman · Austin, US
• Bernard J. Roman · Austin, US

Key dates

• Filing date: Mar 3, 1997
• Grant date: May 4, 1999
• Expiry date: Mar 3, 2017

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F1/36
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Integrated circuit designs are continually shrinking in size. Lithographic processes are used to pattern these designs onto a semiconductor substrate. These processes typically require that the wavelength of exposure used during printing be significantly shorter than the smallest dimension of the elements within the circuit design. When this is not the case, the exposure radiation behaves more like a wave than a particle. Additionally, mask manufacturing, photoresist chemical diffusion and etch effects cause pattern transfer distortions. The result is that circuit elements do not print as designed. To counter this effect the designs themselves can be altered so that the final printed results better match the initial desired design. The process of altering designs in this way is called Lithographic Proximity Correction (LPC). Edge assist shapes and edge biasing features are added to integrated circuit designs by shape manipulation functions to perform one dimensional (1-D) LPC.