Photolithography scheme using a silicon containing resist

A method for patterning a material layer in a multilayer stack, comprising:

• depositing an amorphous carbon layer on the material layer;
• depositing a photoresist layer on top of the amorphous carbon layer;
• developing a resist pattern transferred into the photoresist layer;
• etching through the amorphous carbon layer in a patterned region defined by the resist pattern;
• forming an in situ resist layer hard mask in an outer portion of the photoresist layer during the etching process for the amorphous carbon layer;
• and
• etching through the material layer under the amorphous carbon layer using the patterned region etched into the amorphous carbon layer and the resist pattern.

A method for forming a hardmask in a resist layer, comprising:

• depositing a silicon containing photo resist layer over a material layer;
• developing a pattern in the silicon containing photo resist layer;
• etching the material layer with an oxygen based etchant to transfer the pattern into the material layer;
• and
• forming a hardmask layer in the silicon containing photo resist layer during the etching process.