Patent attributes
A method for forming etch features in an etch layer over a substrate is provided. An etch mask stack is formed over the etch layer. A first mask is formed over the etch mask stack. A sidewall layer is formed over the first mask, which reduces the widths of the spaces defined by the first mask. A first set of features is etched into the etch mask stack through the sidewall layer. The mask and sidewall layer are removed. An additional feature step is performed, comprising forming an additional mask over the etch mask stack, forming a sidewall layer over the additional mask, etching a second set of features at least partially into the etch mask stack. A plurality of features is etched into the etch layer through the first set of features and the second set of features in the etch mask stack.
