Selective deposition of carbon on photoresist layer for lithography applications

A method for etching a film stack, comprising:

• forming a bottom anti-reflective coating layer on a film stack;
• forming a hardmask layer comprising a metal-containing material on the bottom anti-reflective coating layer;
• forming a photoresist layer comprising an organometallic material on the hardmask layer;
• exposing the photoresist layer to ultraviolet radiation through a mask having a selected pattern, creating irradiated areas and un-irradiated areas of the photoresist layer;
• removing the irradiated or the un-irradiated areas of the photoresist layer to pattern the photoresist layer;
• forming a passivation layer comprising a carbon-containing material only on a top surface of the patterned photoresist layer;
• etching the hardmask layer exposed by the removed irradiated or un-irradiated areas of the patterned photoresist layer having the passivation layer formed thereon to pattern the hardmask layer;
• etching the bottom anti-reflective coating layer exposed by the patterned hardmask layer to pattern the bottom anti-reflective coating layer;
• and
• etching the film stack exposed by the patterned bottom anti-reflective coating layer.

A method for selectively forming a passivation layer on a patterned photoresist layer, comprising:

• exposing a photoresist layer comprising an organometallic material to ultraviolet radiation through a mask, creating irradiated areas and un-irradiated areas of the photoresist layer;
• removing the irradiated or the un-irradiated areas of the photoresist layer;
• and
• forming a passivation layer comprising a carbon-containing material only on a top surface of the photoresist layer.