Transistor having notched fin structure and method of making the same

摘要

A transistor includes a notched fin covered under a shallow trench isolation layer. One or more notch may be used, the size of which may vary along a lateral direction of the fin. In some embodiments, The notch is formed using anisotropic wet etching that is selective according to silicon orientation. Example wet etchants are tetramethylammonium hydroxide (TMAH) or potassium hydroxide (KOH).

主权项

1. An apparatus comprising:
a semiconductor substrate; a fin field-effect transistor (FinFET) on the substrate, said fin having a notched portion and a bottom portion having a substantially constant width between the notched portion and the semiconductor substrate, wherein the notched portion has a width less than a width of the bottom portion; and, a shallow trench isolation (STI) layer covering and filling the notched portion of the notched fin, the notched portion having a surface along a (1-1-1) plane.