US Patent 7977706 Tri-gate field-effect transistors formed by aspect ratio trapping

Semiconductor structures include a trench formed proximate a substrate including a first semiconductor material. A crystalline material including a second semiconductor material lattice mismatched to the first semiconductor material is formed in the trench. Process embodiments include removing a portion of the dielectric layer to expose a side portion of the crystalline material and defining a gate thereover. Defects are reduced by using an aspect ratio trapping approach.