Patent ID: 9018084
Filing Date: 2015-04-28
Classification: H01L,Y02P

Abstract:
1. A method of forming a semiconductor structure comprising: forming a fin-defining mask structure over a semiconductor layer located on a substrate; forming, from said semiconductor layer, a semiconductor fin laterally extending along a lengthwise direction with a substantially rectangular vertical cross-sectional shape that adjoins a horizontal interface with a top surface of said substrate, wherein an etch residue material with a non-uniform thickness profile covers sidewalls of said semiconductor fin, wherein said non-uniform thickness profile provides an increasing thickness of said etch residue material with a vertical distance from said horizontal interface; and modifying said substantially rectangular vertical cross-sectional shape into a substantially same vertical cross-sectional shape that includes a vertically tapered portion in which a width of sidewalls increases with a vertical distance between a horizontal interface between said substrate and said semiconductor fin by a lateral etch of said semiconductor fin while a thickness profile of said etch residue material is non-uniform, wherein an upper portion of said semiconductor fin having said substantially rectangular vertical cross-sectional shape is protected from said lateral etch by a portion of said etch residue material throughout said lateral etch.