Method to induce strain in finFET channels from an adjacent region
AssigneeSTMicroelectronics S.r.l.
InventorsPierre Morin, Nicolas Loubet
Life of this patent
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Abstract
Methods and structures for forming strained-channel finFETs are described. Fin structures for finFETs may be formed using two epitaxial layers of different lattice constants that are grown over a bulk substrate. A first thin, strained, epitaxial layer may be cut to form strain-relieved base structures for fins. The base structures may be constrained in a strained-relieved state. Fin structures may be epitaxially grown in a second layer over the base structures. The constrained base structures can cause higher amounts of strain to form in the epitaxially-grown fins than would occur for non-constrained base structures.
Claims20
A device, comprising:
- a substrate having a first surface and a second surface;
- a base structure of a first material on the first surface of the substrate;
- a fin structure of a second material on the base structure, the first material being different from the second material, the fin structure having a first surface on the base structure and a second surface opposite the first surface;
- a constraining material having a first surface on the second surface of the substrate and a second surface opposite the first surface, the first surface and the second surface of the fin structure being between the first surface and the second surface of the constraining material;
- and
- an insulating layer on the second surface of the substrate.
A device, comprising:
- a substrate having a first surface;
- a base structure of a first material on the first surface of the substrate;
- a fin structure of a second material that is different from the first material, the base structure being between the fin structure and the substrate, the fin structure extending to a first height;
- and
- a constraining structure on the substrate, the constraining structure extending to a second height that is greater than the first height.
A method, comprising:
- forming a base structure of a first material on a first surface of a substrate;
- forming a fin structure of a second material on the base structure, the second material being different from the first material, the base structure being between the fin structure and the substrate, the fin structure extending to a first height;
- and
- forming a constraining structure on the substrate, the constraining structure extending to a second height that is greater than the first height.
Dependencies are inferred from the claim text.