Spatial-frequency tripling and quadrupling processes for lithographic application

摘要

A number of spatial-frequency tripling and quadrupling technologies are invented to pattern features with their pitch size reduced to ⅓ and ¼ of the minimum pitch size resolvable with a conventional lithographic technology. Both spatial-frequency tripling and quadrupling can be achieved with two processes. Each process comprises a series of lithographic and etching steps, wherein the more accurate control of the critical dimension (CD) of patterned features is achieved by deposition, etching and using a hard mask. They provide production worthy methods for the whole semiconductor industry to continue device scaling to sub-32 nm generations with no need of expensive next-generation lithography technologies.