Arylmethyl sulfones: A new class of photoacid generators

• Published in: Polymer engineering and science 1992-10, Vol.32 (20), p.1476-1480
• Main Authors: Novembre, A. E., Hanson, J. E., Kometani, J. M., Tai, W. W., Reichmanis, E., Thompson, L. F., West, R. J.
• Format: Article
• Language: English
• Subjects: Applied sciences; Electrical, magnetic and optical properties; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Properties and characterization
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.760322006

The X‐ray and deep UV radiation response is described for resist systems consisting of poly(4‐tert‐butoxycarbonyloxystyrene‐co‐sulfur dioxide) PTBSS combined with an arylmethyl sulfone. A 2:1 4‐tert‐butoxycarbonyloxystyrene (TBS): sulfur dioxide (SO2) resist has been found to function as a highly sensitive, 1.4 nm X‐ray, single‐component, chemically amplified resist. The same resist, however, exhibits reduced sensitivity to 0.8 nm X‐rays and deep UV (248 nm) radiation. Improvement in 0.8 nm X‐ray sensitivity is achieved by the addition of 12 mol% bis(3,4‐dichlorobenzyl) sulfone (DCBS) to the 2:1 TBS:SO2 resist. For this two‐component resist formulation, the 0.8 nm X‐ray sensitive improved from >375 to 125 mJ/cm2. Similarly, the sensitivity of the 3:1 TBS:SO2 copolymer to deep UV radiation improves to 40 mJ/cm2 with addition of 10 mol% DCBS. Sulfones, such as DCBS, provide two‐component resist formulations capable of