Forming crown active regions for FinFETs

摘要

A method includes forming a first mask over a substrate through a double patterning process, wherein the first mask comprises a horizontal portion and a plurality of vertical portions protruding over the horizontal portion, and wherein the vertical portions are spaced apart from each other, applying a first etching process to the first mask until a top surface of a portion of the substrate is exposed, applying a second etching process to the substrate to form intra-device openings and inter-device openings, wherein the inter-device openings are formed at the exposed portion of the substrate, filling the inter-device openings and the intra-device openings to form inter-device insulation regions and intra-device insulation regions and etching back the inter-device insulation regions and the intra-device insulation regions to form a plurality of fins protruding over top surfaces of the inter-device insulation regions and the intra-device insulation regions.

主权项

1. A method comprising:
receiving a semiconductor substrate; etching the semiconductor substrate to simultaneously form a plurality of intra-device openings and a first and a second inter-device opening in the semiconductor substrate, wherein a first depth of the plurality of intra-device openings is less than a second depth of the first and the second inter-device openings; filling the plurality of intra-device openings to form a plurality of intra-device insulation regions, and filling the first and the second inter-device openings to form a first and a second inter-device insulation region, respectively, wherein the step of filling the plurality of intra-device openings and the step of filling the first and the second inter-device openings are performed simultaneously, and wherein the plurality of intra-device insulation regions are between the first and the second inter-device insulation regions; etching back the plurality of intra-device insulation regions and the first and the second inter-device insulation regions, wherein remaining portions of the semiconductor substrate above top surfaces of the plurality of intra-device insulation regions form a plurality of semiconductor fins; forming a gate dielectric on top surfaces and sidewalls of the plurality of semiconductor fins; and forming a gate electrode on the gate dielectric.