Shallow trench isolation structures and contact patterning
A dual layer shallow isolation trench region for semiconductor structures including field effect transistors (FETs) and methods for making the same. The first layer of the shallow trench isolation region includes a dielectric material disposed between adjacent FETs. The second layer is an etch resistant material disposed on the dielectric material and has an increased etch resistance relative to the dielectric material. The etch resistant material overlays the shallow trench region to provide the dual layer shallow trench isolation region, which permits self-alignment of contacts to the source and/or drain of FETs.
1. A semiconductor structure comprising:
a plurality of vertical fin field effect transistors (Fin FET), each FinFET separated from an adjacent FinFET by a shallow trench isolation region,
wherein each of the shallow trench isolation regions consists of a first layer and a second layer, the first layer comprising a dielectric material, and the second layer comprising an etch resistant material disposed on the dielectric material,
wherein the etch resistant material has an increased etch resistance relative to the dielectric material, and
wherein a dielectric layer is provided in local areas between fins within a FinFET; and
a conductive contact to a top source or drain region of the FinFET, wherein the contact is aligned to the etch resistant material overlaying the shallow trench region.
2. The semiconductor structure of claim 1 , wherein the etch resistant material comprises a nitride material.
3. The semiconductor structure of claim 1 , wherein the etch resistant material comprises silicon nitride, silicon borocarbontiride, or silicon oxycarbonitride.
4. The semiconductor structure of claim 1 , wherein the self-aligned metal contact comprises tungsten.