Patent ID: 9449822
Filing Date: 2016-09-20
CPC Classification: H01L

Claim Text:
1. A method of forming a semiconductor structure, comprising: forming a set of shapes on top of a substrate; applying a layer of copolymer covering said substrate; causing said copolymer to form a plurality of cylindrical blocks both inside and outside said set of shapes, said cylindrical blocks inside said set of shapes being same in both shape and size as said cylindrical blocks outside said set of shapes; forming a pattern of contact holes from said plurality of cylindrical blocks; and transferring said pattern of contact holes to said substrate to form said semiconductor structure, wherein said set of shapes is a set of rings each having an inner sidewall and an outer sidewall and forming said set of shapes comprises forming said set of rings to be equally spaced along a first and a second direction with said second direction being 90-degree perpendicular to said first direction and a first distance between two neighboring rings along said first direction being same as a second distance between two neighboring rings along said second direction; and applying said layer of copolymer covering said substrate comprises forming said layer of copolymer directly next to said inner sidewall and said outer sidewall of said set of rings.