Resist formulation which minimizes blistering during etching

US6207353A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Michael D. Armacost · Winooski, US
• Willard E. Conley · San Diego, US
• Tina J. Cotler-Wagner · Newburgh, US
• Ronald A. DellaGuardia · Poughkeepsie, US
• David M. Dobuzinsky · New Windsor, US
• Michael L. Passow · West Hurley, US
• William C. Wille · Red Hook, US

Key dates

• Filing date: Dec 10, 1997
• Grant date: Mar 27, 2001
• Expiry date: Dec 10, 2017

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/31144
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A resist formulation minimizes blistering during reactive ion etching processes resulting in an increased amount of polymer by-product deposition. Such processes involve exciting a gaseous fluorocarbon etchant with sufficient energy to form a high-density plasma, and the use of an etchant having a carbon-to-fluorine ratio of at least 0.33. In addition to a conventional photoactive component, resists which minimize blistering under these conditions include a resin binder which is a terpolymer having: (a) units that contain acid-labile groups; (b) units that are free of reactive groups and hydroxyl groups; and (c) units that contribute to aqueous developability of the photoresist. After the photoresist is patterned on the silicon oxide layer and the high-density plasma is formed, the high-density plasma is introduced to the silicon oxide layer to etch at least one opening in the silicon oxide layer. Preferably, the terpolymer is made up of about 70% 4-hydroxystyrene, about 20% styrene, and about 10% t-butylacrylate.