Abstract:
A lithographic stack over a raised structure (e.g., fin) of a non-planar semiconductor structure, such as a FinFET, includes a bottom layer of spin-on amorphous carbon or spin-on organic planarizing material, a hard mask layer of a nitride and/or an oxide on the spin-on layer, a layer of a developable bottom anti-reflective coating (dBARC) on the hard mask layer, and a top layer of photoresist. The stack is etched to expose and recess the raised structure, and epitaxial structure(s) are grown on the recess.
Abstract:
The use of two different materials for shallow trench isolation and deep structural trenches with a dielectric material therein (e.g., flowable oxide and a HARP oxide, respectively) causes non-uniform heights of exposed portions of raised semiconductor structures for non-planar semiconductor devices, due to the different etch rates of the materials. Non-uniform openings adjacent the exposed portions of the raised structures from recessing the isolation and dielectric materials are filled with additional dielectric material to create a uniform top layer of one material (the dielectric material), which can then be uniformly recessed to expose uniform portions of the raised structures.