Method of etching a silicon containing layer using multilayer masks

摘要

A new method is provided for the etch of ultra-small patterns in a silicon based surface. Under the first embodiment, a hardmask layer over a substrate and a layer of ARC over the hardmask layer are successively patterned. The patterned layer of ARC is removed, the remaining patterned hardmask layer is used as a mask for etching the substrate. Under the second embodiment, a first hardmask layer over a substrate, a second hardmask layer over the first hardmask layer and a layer of ARC over the second hardmask layer are successively patterned. The patterned layer of ARC and the second hardmask layer are removed, the remaining first patterned hardmask layer is used as a mask for etching the substrate.