Methods of Forming Etch Masks for Sub-Resolution Substrate Patterning

摘要

Techniques disclosed herein provide a method for pitch reduction (increasing pitch/feature density) for creating high-resolution features and also for cutting on pitch of sub-resolution features. Techniques include using multiple materials having different etch characteristics to selectively etch features and create cuts where specified. A sequence of materials or repeating pattern of lines of materials is used that provides selective self-alignment based on different etch resistivities. Combined with an underlying transfer or memorization layer, multiple different etch selectivities can be accessed. An etch mask defines which regions of the lines of multiple materials can be etched.

主权项

1. A method of patterning a substrate, the method comprising:
providing a substrate having mandrels positioned on an underlying layer, the mandrels comprised of a first material; forming first sidewall spacers on exposed sidewalls of the mandrels, the first sidewall spacers comprised of a second material; forming second sidewall spacers on exposed sidewalls of the first sidewall spacers, the second sidewall spacers comprised of a third material; forming fill structures that fill open spaces defined between exposed sidewalls of the second sidewall spacers that face each other, the fill structures comprised of a fourth material, wherein top surfaces of the mandrels, the first sidewall spacers, the second sidewall spacers, and the fill structures are all uncovered, and wherein the first material, the second material, the third material and the fourth material are all chemically different from each other.