Patent ID: 9209178
Filing Date: 2015-12-08
Classification: H01L,Y02P

Abstract:
1. A method for forming a trench for an isolation structure from a structure including excess fins formed from a layer of semiconductor material with local isolation material deposited between said fins, said method comprising steps of depositing hard mask material over a portion of said local isolation material and selected ones of said fins, patterning said hard mask material, and cyclically etching said excess fins selectively to said hard mask material and said local isolation material alternately with etching said local isolation material selectively to said excess fins and said hard mask material in respective etching cycles of a plurality of etching cycles to form a trench between said selected ones of said fins while limiting height of protrusion of portions of said excess fins above portions of said local isolation material and limiting height of protrusion of portions of said local isolation material above said portions of said excess fins.