Development of compact extreme ultraviolet interferometry for on-line test of lithography cameras

Technical Report · Wed Dec 30 23:00:00 EST 1998

DOI:https://doi.org/10.2172/638237· OSTI ID:638237

Ray-Chaudhuri, A K; Nissen, R P; Krenz, K D; Stulen, R H ^[1]; Sweatt, W C; Warren, M E; Wendt, J R; Kravitz, S H ^[2]; Bjorkholm, J E ^[3]

---

1. Sandia National Labs., Livermore, CA (United States)
2. Sandia National Labs., Albuquerque, NM (United States)
3. AT and T Bell Labs., Holmdel, NJ (United States)

Extreme ultraviolet lithography (EUVL) is a candidate technology for the microelectronics industry with design rules for 0.1 {micro}m features and beyond. When characterizing an extreme ultraviolet (EUV) lithographic optical system, visible light interferometry is limited to measuring wavefront aberration caused by surface figure error while failing to measure wavefront errors induced by the multilayer coatings. This fact has generated interest in developing interferometry at an EUV camera`s operational wavelength (at-wavelength testing), which is typically around 13 nm. While a laser plasma source (LPS) is being developed as a lithography production source, it has generally been considered that only an undulator located at a synchrotron facility can provide the necessary laser-like point source for EUV interferometry. Although an undulator-based approach has been successfully demonstrated, it would be advantageous to test a camera in its operational configuration. The authors are developing the latter approach by utilizing extended source size schemes to provide usable flux throughput. A slit or a grating mounted in front of the source can provide the necessary spatial coherence for Ronchi interferometry. The usable source size is limited only by the well-corrected field of view of the camera under test. The development of this interferometer will be presented.

• Research Organization: Sandia National Labs., Livermore, CA (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 638237
• Report Number(s): SAND--95-8711C; ON: DE97051375
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
42 ENGINEERING
EXPERIMENTAL DATA
EXTREME ULTRAVIOLET RADIATION
INTERFEROMETRY
MASKING
MICROELECTRONICS
ON-LINE MEASUREMENT SYSTEMS
OPTICAL SYSTEMS
WIGGLER MAGNETS