Patent ID: 9437497
Filing Date: 2016-09-06
CPC Classification: H01L

Claim Text:
1. A method for fabricating a fin-like field-effect transistor (FinFET) device, the method comprising: receiving a substrate having a hard mask; forming a plurality of mandrel features over the substrate; performing a first cut to remove one or more mandrel features to form a first space; performing a second cut to remove a portion of one or more mandrel features to form a line-end and an end-to-end space; after the first and the second cuts, etching the substrate, using the mandrel features with the first space and the end-to-end space as an etch mask, to form fins, wherein etching the substrate to form fins includes etching the hard mask using the mandrel features as the etch mask to form a trench that extends through the hard mask and into the substrate between a first fin and a second fin; depositing a spacer layer to fully fill in a space between adjacent fins and cover sidewalls of the fins adjacent to the first space and the end-to-end space, wherein fully filling in the space between adjacent fins includes fully filling the trench that extends through the hard mask and into the substrate between the first fin and the second fin; etching the spacer layer to form sidewall spacers on the fins adjacent to the first space and the end-to-end space and expose the hard mask; and after etching the spacer layer to form sidewall spacers on the fins adjacent to the first space and the end-to-end space and expose the hard mask, forming an isolation trench in the first space and the end-to-end space with the sidewall spacers covering the fins and the spacer layer filling in the space between the adjacent fins, wherein the trench extending through the hard mask and into the substrate between the first fin and the second fin remains fully filled with the spacer layer while forming the isolation trench.