Precisely tuning feature sizes on hard masks via plasma treatment

摘要

Methods are provided for fabricating devices. A first layer is formed. A hardmask on the first layer is formed. Features on the hardmask are patterned. The sizes of features on the hardmask are reduced by applying a plasma treatment process to form reduced size features. Also, the size of features on the hardmask can be enlarged to form enlarged size features by applying the plasma treatment process and/or removing the oxidized part of the feature during plasma treatment process. Another method may include a first layer formed on a substrate and a second layer formed on the first layer. First features are patterned on the first layer, and second features are patterned on the second layer. A size of second features on the second layer is closed due to the different oxidation rate of the two layers during the plasma treatment process, to form a self-sealed channel and/or self-buried trench.