Patent ID: 8642483

Claim:
A substrate processing method that processes a substrate including a processing target layer, an intermediate layer, and a mask layer as stacked in that order, wherein the intermediate layer includes an Si-ARC (Si-containing Anti-Reflection Coating) film and the mask layer has a first opening exposing a part of the Si-ARC film, the method comprising: a shrink etching step during which an opening width reduction process and an etching process are performed concurrently, wherein in the opening width reduction process, deposits are formed on a sidewall surface of the first opening of the mask layer by a plasma generated from a gaseous mixture of an anisotropic etching gas and one of a depositive gas and H 2 gas, wherein in the etching process performed concurrently with the opening width reduction process, the Si-ARC film forming a bottom portion of the first opening is etched to form a second opening extending through the Si-ARC film to expose the target layer, and further wherein during said shrink etching step deposits are foamed on a sidewall surface of said Si-ARC film in said second opening such that upon completion of said shrink etching step deposits are on the sidewall surface of the first opening through the mask layer and deposits are also on the sidewall surface of the second opening through the Si-ARC film; wherein the target layer is an amorphous carbon film; and the method further comprising, after said shrink etching step, performing an etching step through said second opening to etch said amorphous carbon film exposed through said second opening.