| abstract |
Roughly described, a patterned first layer is provided over a second layer which is formed over a substrate. In a conversion process, first layer material is consumed at feature sidewalls to form third layer material at the feature sidewalls. The width of third layer material at each of the sidewalls is greater than the width of first layer material consumed at the respective sidewall in the conversion process. The second layer is patterned using the third layer material as mask. A fourth layer of material is formed over the substrate, and planarized or otherwise partially removed so as to expose the top surfaces of the features in the first layer through the fourth layer. The exposed first layer material is removed to expose portions of the second layer through the fourth layer, and the second layer is further patterned using the fourth layer material as a mask. |