Patent ID: 9543165
Date: 2017-01-10
CPC Classifications: H01L

Claim:
1. A method comprising: forming a first hard mask (HM) layer over a material layer; forming a patterned second HM layer over the first HM layer, wherein the patterned second HM layer has a first trench extending along a first direction; forming a patterned resist layer over the patterned second HM layer, wherein the patterned resist layer has a first line opening extending along a second direction, which is perpendicular to the first direction, the first line opening overlapping the first trench and exposing a portion of the patterned second HM layer, wherein the patterned resist layer further includes a second line opening that is parallel to the first line opening and overlaps the first trench, wherein the patterned second HM layer exposed within the second line opening defines a first opening having a first width and a second opening having a second width, which is smaller than the first width; etching the first HM layer by using the patterned resist layer and the exposed portion of the patterned second HM layer as an etch mask together to form a first hole feature in the first HM layer, wherein etching the first HM layer by using the patterned resist layer and the exposed portion of the patterned second HM layer as the etch mask includes etching the first HM layer through the first opening to form a second hole feature in the first HM layer and etching the first HM layer through the second opening to form a second trench in the first HM layer; depositing a sacrificial layer to fully fill in the second trench and partially fill in the first hole feature; removing the sacrificial layer from the first hole feature while the sacrificial layer remains in the second trench; and with the remaining sacrificial layer in the second trench, etching the material layer through the first hole feature to form a third hole feature.