Performance results of large field mix-match lithography

For an increasing number of semiconductor manufacturers, mix-and-match lithography has grown from a curiosity to an economic necessity. Significant cost of ownership savings can be derived from mix-and-match strategies maximizing the utilization of low to medium cost 1× optical systems for imaging non-critical levels, while high cost reduction or e-beam systems are dedicated to critical levels. Paramount to successful mix-and-match strategy are the resolution and overlay registration of the 1× tools. However, while much can be said about resolution, this discussion will focus on the overlay registration metric. More specifically, data will be presented which illustrates the overlay performance of Ultratech´s new generation 1× i-line stepper, the 2244i, to that of an SVGL Microscan reduction stepper