Reverse tone STI formation and epitaxial growth of semiconductor between STI regions

摘要

A method includes forming a hard mask over a substrate, patterning the hard mask to form a first plurality of trenches, and filling a dielectric material into the first plurality of trenches to form a plurality of dielectric regions. The hard mask is removed from between the plurality of dielectric regions, wherein a second plurality of trenches is left by the removed hard mask. An epitaxy step is performed to grow a semiconductor material in the second plurality of trenches.

主权项

1. A method comprising:
forming dielectric patterns on a top surface of a semiconductor substrate, wherein portions of the semiconductor substrate are exposed through spaces between the dielectric patterns; performing an epitaxy to grow epitaxy regions in the spaces, wherein the epitaxy regions are grown from the semiconductor substrate, and wherein the epitaxy regions and the semiconductor substrate are formed of essentially a same semiconductor material, with the epitaxy regions having respective top surfaces no higher than top surfaces of the dielectic patterns; and forming a transistor at one of the top surfaces of the epitaxy regions.