Characterization of an expanded-field Schwarzschild objective for extreme ultraviolet lithography

Journal Article · Tue Nov 01 00:00:00 EST 1994 · Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena; (United States)

DOI:https://doi.org/10.1116/1.587448· OSTI ID:7154184

Kubiak, G D; Tichenor, D A; Ray-Chaudhuri, A K; Malinowski, M E; Stulen, R H; Haney, S J; Berger, K W; Nissen, R P; Wilkerson, G A; Paul, P H ^[1]; Bjorkholm, J E; Fetter, L A; Freeman, R R; Himel, M D; MacDowell, A A; Tennant, D M; Wood, II, O R ^[2]; Waskiewicz, W K; White, D L; Windt, D L ^[3] ; Jewell, T E ^[4]

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1. Sandia National Laboratories, Livermore, California 94551-0969 (United States)
2. AT T Bell Laboratories, Holmdel, New Jersey 07733-3030 (United States)
3. AT T Bell Laboratories, Murray Hill, New Jersey 07974-2070 (United States)
4. Optical Engineering Consultant, Boulder, Colorado 80304 (United States)

The performance of a new 10[times]-reduction Schwarzschild system for projection imaging at 13.4 nm wavelength is reported. The optical design is optimized to achieve 0.1 [mu]m resolution over a 0.4 mm image field of view, an increase in area of a factor of 100 over previous designs. An offset aperture, located on the convex primary, defines an unobscured 0.08 numerical aperture. The system is illuminated using extreme ultraviolet (EUV) radiation emitted from a laser plasma source and collected by an ellipsoidal condenser. A 45[degree] turning mirror is used to relay the collected EUV radiation onto a near-normal reflecting mask. Multiple sets of primary and secondary elements were fabricated, matched, and clocked to minimize the effects of small figure errors on imaging performance. Optical metrology indicates that the wave-front error within the subaperture used is within a factor of 2 of the design value. Images recorded in poly(methyl methacrylate) and ZEP 520 (Nippon Zeon) resists reveal good imaging fidelity over much of the 0.4 mm field with equal line/space gratings being resolved to 0.1 [mu]m.

• DOE Contract Number: AC04-94AL85000
• OSTI ID: 7154184
• Journal Information: Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena; (United States), Vol. 12:6; ISSN 0734-211X
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION
CAMERAS
DESIGN
IMAGE PROCESSING
SPATIAL RESOLUTION
EXTREME ULTRAVIOLET RADIATION
MASKING
PMMA
ELECTROMAGNETIC RADIATION
ESTERS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
POLYACRYLATES
POLYMERS
POLYVINYLS
PROCESSING
RADIATIONS
RESOLUTION
ULTRAVIOLET RADIATION
440600* - Optical Instrumentation- (1990-)