Patent ID: 8895445
Filing Date: 2014-11-25
Classification: H01L

Abstract:
1. A method of forming via holes, said method comprising: exposing a plurality of peanut-shaped patterns in a photoresist layer, wherein the plurality of peanut-shaped patterns are arranged to have a pitch of X along a long side of the plurality of peanut-shaped patterns; developing the plurality of peanut-shaped patterns to remove a photoresist material in the plurality of peanut-shaped patterns; etching a middle layer below the photoresist layer using a polymer gas; etching a bottom layer below the middle layer to form two openings in the bottom layer for every peanut-shaped pattern, said openings in the bottom layer having a pitch of X/2; and etching a dielectric layer below the bottom layer to form via holes having a pitch of X/2.