CD optimization methodology for extending optical lithography

Abstract

This paper describes the joint development and optimization of an advanced critical dimension (CD) control methodology at IBM's 300 mm semiconductor facility. The work is initially based on 22 nm critical level gate CD control, but the methodology is designed to support both the lithography equipment (1.35 NA scanners) and processes for 22, 20, 18, and 14 nm node applications. Specifically, this paper describes the CD uniformity of processes with and without enhanced CD control applied. The control methodology is differentiated from prior approaches1 by combining independent process tool compensations into an overall CD dose correction signature to be applied by the exposure tool. In addition, initial investigations of product specific focus characterization and correction are also described. © 2013 SPIE.