Bottom spacer formation for vertical transistor
First Claim
1. A method of forming a semiconductor structure, the method comprising:
- forming at least one semiconductor fin extending upward from a surface of a substrate, wherein a bottom source/drain region is located at the footprint, and on each side, of the at least one semiconductor fin;
forming a dielectric material stack of, from bottom to top, a silicon dioxide layer and a silicon nitride layer on exposed surfaces of each bottom source/drain region and the at least one semiconductor fin;
carbonizing an upper surface of each horizontal portion of the silicon nitride layer;
removing non-carbonized vertical portions of the silicon nitride layer;
removing the carbonized portions of the silicon nitride layer; and
removing vertical portions of the silicon dioxide layer from sidewalls of the at least one utilizing each remaining portion of the silicon nitride layer as an etch mask to provide a bottom spacer structure located on each bottom source/drain region, each bottom spacer structure comprises a remaining portion of the silicon dioxide layer and the remaining portion of the silicon nitride layer.
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Accused Products
Abstract
A bilayer of silicon dioxide and silicon nitride is formed on exposed surfaces of at least one semiconductor fin having a bottom source/drain region located at the footprint, and on each side, of the at least one semiconductor fin. An upper surface of each horizontal portion of the silicon nitride layer is then carbonized, and thereafter non-carbonized vertical portions of the silicon nitride layer are removed. Next, the carbonized portions of the silicon nitride layer are removed, and thereafter the vertical portions of the silicon dioxide layer are removed from sidewalls of the at least one semiconductor fin utilizing each remaining portion of the silicon nitride layer as an etch mask A bottom spacer structure is provided on each bottom source/drain region in which each bottom spacer structure includes a remaining portion of the silicon dioxide layer and the remaining portion of the silicon nitride layer.
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Citations
10 Claims
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1. A method of forming a semiconductor structure, the method comprising:
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forming at least one semiconductor fin extending upward from a surface of a substrate, wherein a bottom source/drain region is located at the footprint, and on each side, of the at least one semiconductor fin; forming a dielectric material stack of, from bottom to top, a silicon dioxide layer and a silicon nitride layer on exposed surfaces of each bottom source/drain region and the at least one semiconductor fin; carbonizing an upper surface of each horizontal portion of the silicon nitride layer; removing non-carbonized vertical portions of the silicon nitride layer; removing the carbonized portions of the silicon nitride layer; and removing vertical portions of the silicon dioxide layer from sidewalls of the at least one utilizing each remaining portion of the silicon nitride layer as an etch mask to provide a bottom spacer structure located on each bottom source/drain region, each bottom spacer structure comprises a remaining portion of the silicon dioxide layer and the remaining portion of the silicon nitride layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification