The SEMATECH Berkeley MET: demonstration of 15-nm half-pitch in chemically amplified EUV resist and sensitivity of EUV resists at 6.x-nm

Abstract

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Estimation of resist sensitivity for extreme ultraviolet lithography using an electron beam

“…BEUVL is considered as the next step following the 13.5 nm EUVL, and the resist materials for 6.x nm BEUVL has been discussed recently. 11,12,23,24 The resists selected were main-chain scission-type non-CA positive-tone resists such as poly (methyl methacrylate) (PMMA, M w = 350, 000, Aldrich), ZEP (1:1 copolymer of α-chloromethacrylate and α-methylstyrene, ZEP520A and ZEP7000, ZEON), and a polyhydroxystyrene (PHS)-based CA positive-tone resist OEBR-CAP112 (Tokyo Ohka Kogyo). The preparation of the samples, resist development, and exposures were performed at approximately 25…”

Resist Materials and Processes for Extreme Ultraviolet Lithography

“…1,4,18,19) A number of research groups have also shown the potential of unconventional inorganic 5,11) resists in further stretching these resolution limits. However, as discussed in previous chapters, concurrently achieving high resolution with the set of LWR/LER and sensitivity targets remains a challenge.…”

“…92,93) To improve lithography resolution, wavelength reduction has been an established procedure. The dependences of lithography resolution and sensitivity on the wavelength of the exposure tool have been reported in the wavelength range from 2 to 13.5 nm.…”

“…In particular, the effect and possible solutions to the trade-off relationship between EUV resist targets, namely, resolution, LWR/LER, and sensitivity, which have been constant topics in EUVL, [8][9][10]14,17) are described and reviewed. Recent works on resist materials focusing on conventional and nonconventional chemical platforms 1,4,5,[11][12][13]18,19) are also discussed. A review of proposed alternative resist processes, observed to focus mainly on the difficult issue of LWR/LER, is also presented.…”

“…Recent advances in these materials and process technologies are largely credited to the cooperation and focused efforts of various sectors of the resist community (e.g., industry consortia, universities, and material/ tool manufacturers). 1,[4][5][6][7][8][9][10] Specifically, industry consortia such as Selete, SEMATECH, IMEC, and recently, EIDEC have and continue to promote very conducive research environments for device manufacturers, universities, resist resin/material suppliers, and tool manufacturers. Such collaborations have led to the investigation and realization of new and exciting resist platforms 5,[11][12][13] and processes.…”