Negative tone developer for extreme ultraviolet lithography

A lithography method comprising:

• forming a negative tone resist layer over a workpiece;
• exposing the negative tone resist layer to extreme ultraviolet (EUV) radiation;
• and
• removing an unexposed portion of the negative tone resist layer in a negative tone developer, thereby forming a patterned negative tone resist layer, wherein the negative tone developer includes an organic solvent having a log P value greater than 1.82, and further wherein the organic solvent is an ester acetate derivative represented by R1COOR2, where R1 and R2 are hydrocarbon chains having four or less carbon atoms.

A lithography method comprising:

• spin coating a resist material over a workpiece;
• performing a pre-exposure baking process on the resist material;
• illuminating the resist material with patterned extreme ultraviolet (EUV) radiation, thereby forming an exposed portion and an unexposed portion of the resist material;
• performing a post-exposure baking process on the resist material;
• and
• applying a developer to the resist material that dissolves the unexposed portion of the resist material, wherein the developer includes an organic solvent having a log P value greater than 1.82, and further wherein the organic solvent is an ester acetate derivative represented by R1COOR2, where R1 and R2 are hydrocarbon chains having four or less carbon atoms.