Making a defect free fin based device in lateral epitaxy overgrowth region

摘要

Electronic device fins may be formed by epitaxially growing a first layer of material on a substrate surface at a bottom of a trench formed between sidewalls of shallow trench isolation (STI) regions. The trench height may be at least 1.5 times its width, and the first layer may fill less than the trench height. Then a second layer of material may be epitaxially grown on the first layer in the trench and over top surfaces of the STI regions. The second layer may have a second width extending over the trench and over portions of top surfaces of the STI regions. The second layer may then be patterned and etched to form a pair of electronic device fins over portions of the top surfaces of the STI regions, proximate to the trench. This process may avoid crystalline defects in the fins due to lattice mismatch in the layer interfaces.

主权项

1. A method to form a pair of electronic device fins comprising:
epitaxially growing a first layer of a first epitaxial material on a substrate surface at a bottom of a trench formed by a plurality of shallow trench isolation (STI) regions having STI sidewalls defining a first width and a first height of the trench; epitaxially growing a second layer of a second epitaxial material on the first layer in the trench and over top surfaces of the STI regions to second height above the first height, the second layer having a second width extending over the trench and over portions of top surfaces of the STI regions; and patterning and etching the second layer to form a pair of electronic device fins over portions of the top surfaces of the STI regions, the portions each proximate to the trench sidewalls, wherein etching includes etching the second layer to remove the first width of the second layer from over and in the trench to expose at least a top surface of the first layer.