Introduction of EUV lithography using soft X-ray at wavelength of 13.5 nm has been started because of demand for miniaturization at low cost in mass production of semiconductor devices. Chemically amplified resist (CAR) has been utilized for many years and is also one of the promising materials for EUV resist. However, resist performances (resolution, line edge roughness, and sensitivity) show trade-off relationship and the searching for the solution has been still a serious problem. In the previous work, our group has shown that addition of Di-p-tolyl sulfone (DTS) into CAR increases acid generation efficiency (acid-generating promoter (AGP)). DTS acts as deprotonation promoter and recombination inhibitor between ionized polymer and electron. The resist performance upon exposure to electron beams (EB) was improved. In this study, we investigate the sensitivity of CAR to 13.5 nm EUV light upon adding new diphenyl sulfone derivatives. EB lithographic effects by adding some diphenyl sulfone derivatives were also studied. And the detail roles of AGP are also discussed.
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