US Patent 7585614 Sub-lithographic imaging techniques and processes

A method of patterning which provides images substantially smaller than that possible by lithographic techniques is provided. In the method of the invention, a substrate has a memory layer and a sacrificial layer formed thereon. An image is patterned onto the memory layer by protecting an edge during an etching step using chemical oxide removal (COR) processes, for example. Another edge is memorized in the layer. The sacrificial layer is removed to expose another memorized edge, which is used to define a pattern in an underlying layer.