Etching method and computer storage medium storing program for controlling same

An etching method comprising the steps of:

• a first process for increasing pattern widths of a pre-patterned mask layer by depositing plasma reaction products on sidewalls of the mask layer;
• and
• a second process for etching a layer to be etched by using the mask layer having the increased pattern widths as a mask,
• wherein the mask layer includes a first and a second region where patterns in the first region are disposed closer to each other than those in the second region, and widths of the patterns in the first region differ from those in the second region;
• and
• wherein the first process is performed by widening the widths of the patterns in the first and the second region such that the widths of the patterns in the first region substantially coincide with those in the second region.

An etching method comprising the steps of:

• a first process for etching sidewalls of a pre-patterned mask layer to produce a processed mask layer with reduced pattern widths;
• a second process for etching by using the processed mask layer as a mask a layer to be etched while further reducing the pattern widths of the processed mask layer by etching sidewalls thereof,
• wherein the mask layer includes a first and a second region where patterns in the first region are disposed closer to each other than those in the second region, and widths of the patterns in the first region differ from those in the second region;
• and
• wherein the first process is performed by narrowing the widths of the patterns in the first and the second region such that the widths of the patterns in the first region substantially coincide with those in the second region.