Non-lithographic hole pattern formation

摘要

A metal layer is deposited over a material layer. The metal layer includes an elemental metal that can be converted into a dielectric metal-containing compound by plasma oxidation or nitridation. A hard mask portion is formed over the metal layer. A plasma impermeable spacer is formed on at least one first sidewall of the hard mask portion, while at least one second sidewall of the hard mask portion is physically exposed. Plasma oxidation or nitridation is performed to convert physically exposed surfaces of the metal layer into the dielectric metal-containing compound. A sequence of a surface pull back of the hard mask portion, cavity etching, another surface pull back, and conversion of top surfaces into the dielectric metal-containing compound are repeated to form a hole pattern having a spacing that is not limited by lithographic minimum dimensions.

主权项

1. A method of forming a patterned structure comprising:
forming a metal layer on a material layer; forming a hard mask portion on said metal layer; forming a plasma-resistant spacer on sidewalls of said hard mask portion by deposition and an anisotropic etch of a conformal dielectric layer, wherein, upon formation of said plasma-resistant spacer, said plasma-resistant spacer contacts, and laterally surrounds, said hard mask portion as a contiguous structure and a portion of a top surface of said metal layer is physically exposed; physically exposing at least one sidewall of said hard mask portion by removing a portion of said plasma-resistant spacer; converting a first surface portion of said metal layer into a dielectric metal-containing compound portion employing said hard mask portion and a remaining portion of said plasma-resistant spacer as masking structures; and physically exposing a top surface of a second surface portion of said metal layer by isotropically recessing physically exposed surfaces of said hard mask portion while said etch-resistant spacer protects a portion of said hard mask portion from removal, wherein an outer edge of said second surface portion coincides with an inner edge of said dielectric metal-containing compound portion.