Forming fence conductors using spacer etched trenches

摘要

A spacer etching process produces ultra-narrow conductive lines in a plurality of semiconductor dice. Trenches are formed in a first dielectric then a sacrificial film is deposited onto the first dielectric and the trench surfaces formed therein. Planar sacrificial film is removed from the face of the first dielectric and bottom of the trenches, leaving only sacrificial films on the trench walls. A gap between the sacrificial films on the trench walls is filled in with a second dielectric. A portion of the second dielectric is removed to expose tops of the sacrificial films. The sacrificial films are removed leaving ultra-thin gaps that are filled in with a conductive material. The tops of the conductive material in the gaps are exposed to create “fence conductors.” Portions of the fence conductors and surrounding insulating materials are removed at appropriate locations to produce desired conductor patterns comprising isolated fence conductors.

主权项

1. A method for forming fence conductors in a semiconductor integrated circuit die, said method comprising the steps of:
depositing a first dielectric on a face of a semiconductor substrate; creating at least one elongated trench in the first dielectric, each elongated trench having a depth and a length extending perpendicular to the depth; depositing a sacrificial film on the first dielectric including walls and a bottom of the at least one elongated trench; removing portions of the sacrificial film from a face of the first dielectric and the bottom of the at least one elongated trench, wherein only sacrificial films remain on the walls of the at least one elongated trench, wherein the sacrificial films remaining on the walls of each elongated trench define an elongated rectangular loop extending perpendicular to the depth of the trench; depositing a second dielectric between the sacrificial films on the walls of the at least one trench; removing the first and second dielectrics until top portions of the sacrificial film are exposed between the first and second dielectrics; removing the sacrificial films between the first and second dielectrics leaving at least one narrow channel extending in an elongated rectangular loop-shaped; depositing conductive material into the at least one elongated rectangular loop-shaped narrow channel; removing portions of the conductive material until only tops of the conductive material are exposed in the at least one elongated rectangular loop-shaped narrow channel, thereby defining at least one elongated rectangular loop-shaped fence conductor; and for each elongated rectangular loop-shaped fence conductor, etching portions of the loop-shaped fence conductor to separate the elongated rectangular loop-shaped fence conductor into independent, spaced-apart fence conductors.