Patent ID: 6998198
Filing Date: 2006-02-14
Classification: G03F,H01L

Abstract:
1. A method of creating closely spaced contact holes, comprising: (1) providing a substrate, said substrate having been provided with a first layer of material for creation of a pattern of contact holes; (2) exposing said first layer of material with a first mask, said first mask comprising a first and a second pattern of contact holes having a first and second critical dimension, said first and second pattern being interspersed; (3) creating openings in said first layer of material in accordance with said first and second pattern of contact holes; (4) depositing a second layer of material over said first layer of material, including said openings created in said first layer of material in accordance with said first and second pattern of holes; (5) exposing said second layer of material with a mask selected from the group consisting of: (i) a second mask comprising a third pattern of holes having a third critical dimension, said third pattern of holes being aligned with said second pattern of holes, said third pattern of holes being a transparent pattern of holes with a surrounding opaque background surface, said third critical dimension comprising a range of critical dimensions being equal to or larger than said second critical dimension; (ii) a third mask comprising a third pattern of holes having a third critical dimension, said third pattern of holes being aligned with said second pattern of holes, said third pattern of holes being an opaque pattern of holes with a surrounding transparent background surface, said third critical dimension comprising a range of critical dimensions being equal to or larger than said second critical dimension; (iii) a fourth mask comprising a fourth pattern of holes having a fourth critical dimension, said fourth pattern of holes being aligned with said first pattern of holes, said fourth pattern of holes being a transparent pattern of holes with a surrounding opaque background surface, said fourth critical dimension comprising a range of critical dimensions being equal to or larger than said first critical dimension; (iv) a fifth mask comprising a fourth pattern of holes having a fourth critical dimension, said fourth pattern of holes being aligned with said first pattern of holes, said fourth pattern of holes being an opaque pattern of holes with a surrounding transparent background surface, said fourth critical dimension comprising a range of critical dimensions being equal to or larger than said first critical dimension; and (6) creating openings in said second layer of material in accordance with said third or fourth pattern of holes.