Photoacid generator, photoresist, coated substrate, and method of forming an electronic device

A photoacid generator compound having the formula (1)

• wherein
• n is zero or 1;
• and
• R1 and R2 are each independently halogen, unsubstituted or substituted C1-20 linear or branched alkyl, unsubstituted or substituted C1-20 cycloalkyl, unsubstituted or substituted C6-20 aryl, unsubstituted or substituted C3-20 heteroaryl, or a monovalent group having the structure
• *L-Z−M+]
• wherein L is an unsubstituted or substituted C1-50 divalent group;
• Z− is a monovalent anionic group selected from carboxylate, sulfate, sulfonate, sulfamate, sulfonamidate, and sulfonimidate;
• and M+ is a cation selected from disubstituted iodonium ions and trisubstituted sulfonium ions;
• wherein R′ and R2 can be taken together to form a ring;
• R3, R4, R5, and R6 are each independently hydrogen, halogen, unsubstituted or substituted C1-20 linear or branched alkyl, unsubstituted or substituted C1-20 cycloalkyl, unsubstituted or substituted C6-20 aryl, unsubstituted or substituted C3-20 heteroaryl, or a monovalent group having the structure
• *L-Z−M+]
• wherein L is an unsubstituted or substituted C1-50 divalent group;
• Z− is a monovalent anionic group selected from carboxylate, sulfate, sulfonate, sulfamate, sulfonamidate, and sulfonimidate;
• and M+ is a cation selected from disubstituted iodonium ions and trisubstituted sulfonium ions;
• wherein
• R3 and R4 can be taken together to form a ring and/or
• R5 and R6 can be taken together to form a ring,
• provided that no more than two rings are collectively formed by R1, R2, R3, R4, R5, and R6, and
• provided that one of R′, R2, R3, R4, R5, and R6 has the structure
• *L-Z−M+], or
• R1 and R2 are taken together to form
• *L-Z−M+], or
• R3 and R4 are taken together to form
• *L-Z−M+], or
• R5 and R6 are taken together to form
• *L-Z−M+].