High-performance multilayer mirrors for soft x-ray projection lithography

Conference · Tue Sep 17 00:00:00 EDT 1991

OSTI ID:5835828

Stearns, D G; Rosen, R S ^[1]; Vernon, S P ^[2]

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1. Lawrence Livermore National Lab., CA (United States)
2. Vernon Applied Physics, Torrance, CA (United States)

We present a comparative study of three metal-Si multilayer coatings, Mo-Si, Ru-Si and Rh-Si, designed for optimum normal incidence reflectivity at x-ray wavelengths near 130 {Angstrom}. The ML structures are characterized using x-ray diffraction and high-resolution electron microscopy, and the results are correlated with the normal incidence reflectivity measured using synchrotron radiation. It is found that interlayers of mixed composition are formed to various degrees in the as-deposited structures for all three material compositions. The thinnest interlayers are observed in Mo-Si and the most intermixing occurs in Rh-Si, where the pure Rh layers are completely consumed. The stoichiometry of the interlayers in all cases in most consistent with the formation of the Si-rich silicide. The highest peak normal incidence reflectivity of 61% at {approximately}130{Angstrom} is achieved with Mo-Si, whereas the highest integrated reflectivity of 4.4{Angstrom} is achieved with the Ru-Si. In a separate study, the formation of the interlayers in as-deposited Mo-Si multilayer coatings is investigated by systematically varying the thickness of either the Mo or Si layers. We observe a contraction of the multilayer period which is consistent with formation of MoSi{sub 2} at the interfaces. The presence of MoSi{sub 2} interlayers decreases the normal incidence reflectivity, thereby limiting the x-ray throughput in soft x-ray projection lithography applications. 17 refs.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5835828
• Report Number(s): UCRL-JC-108299; CONF-9107115-71; ON: DE92008615
• Resource Relation: Conference: Society of Photo-Optical Instrumentation Engineers (SPIE) meeting, San Diego, CA (United States), 21-26 Jul 1991
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
MIRRORS
MOLYBDENUM
REFLECTIVITY
RHODIUM
RUTHENIUM
DEPOSITION
ELECTRON MICROSCOPY
MICROSTRUCTURE
OPTICS
REFLECTIVE COATINGS
SILICON
X-RAY DIFFRACTION
COATINGS
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
ELEMENTS
METALS
MICROSCOPY
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PLATINUM METALS
SCATTERING
SEMIMETALS
SURFACE PROPERTIES
TRANSITION ELEMENTS
360104* - Metals & Alloys- Physical Properties
360101 - Metals & Alloys- Preparation & Fabrication