193-nm contact photoresist reflow feasibility study

The patterning of very small contact hole features for the 130nm and 100nm device generations will be a difficult challenge for 193nm lithography. The depth of focus for small contacts is currently inadequate for a manufacturable process that includes both dense and isolated pitches. As higher NA 193nm scanners are not expected to improve focus margins considerably, other contact patterning methods are required which improve processing margins. In this work, we study the potential for contact photoresist reflow to be used with 193nm photoresists to increase process windows of small contact dimensions.