In this article we describe the preparation and identification of an organosilane self-assembled monolayer (octadecyltrimethoxysilane:  OTMS) on chromium oxide. The formation of the OTMS monolayer was investigated by X-ray photoelectron (XPS) spectroscopy and water contact angle measurements. Near-edge X-ray absorption fine structure (NEXAFS) spectroscopy was applied in order to determine the tilt angle of the alkyl chains in the monolayer. The degree of hydration of the chromium oxide surface was found to greatly influence the quality of the monolayer. Our work focuses on the suitability of OTMS/Cr for lithographic patterning with low-energy electrons. In addition to the sensitivity and selectivity of the SAM system, its contrast γ was determined by measuring the gradation curve of OTMS on a 20 nm thick chromium layer using an alkaline hexacyanoferrat solution as an etchant. The contrast was found to be γ ≈ 1, which is comparable to those of conventional electron resists. The structured chromium layer wa...

Formation and Characterization of Self-assembled Monolayers of Octadecyltrimethoxysilane on Chromium: Application in Low-Energy Electron Lithography

Widths of double‐crystal x‐ray rocking curves for epitaxial layers of the ternary alloy ZnCdTe are found to correlate with lattice parameter misfit between layer and substrate. Estimates of dislocation density in the layers are made using these widths. Values thus obtained are found to be in good agreement with values reported for other materials with similar misfit.

X‐ray determination of dislocation density in epitaxial ZnCdTe

Fresnel zone plate lenses with feature sizes as small as 50 nm have been constructed and used in the Stony Brook/NSLS scanning X-ray microscope with 3.1 nm radiation from Brookhaven's X-17 mini-undulator. The zone plates were fabricated at IBM using electron beam writing techniques, moire pattern techniques to monitor ellipticity, and a double development/double plating technique to provide additional thickness in the central region. A spatial resolution down to 75 nm was measured in the microscope. Using these zone plates, biological images were obtained of unaltered subcellular components. The images highlight protein concentration in unsectioned, unfixed, and unstained enzymatic granules in an aqueous environment.

Zone plate lenses for X-ray microscopy

Materials for multilayer zone plates: development of a focusing element for use in SR photo-excited processes

With the aid of a 100 keV electron beam lithography system, microzone plates have been fabricated. The system has been designed for generating structures with lateral dimensions in the below 100 nm range. The particular demands on high resolution, high efficiency imaging Fresnel zone plates and the arising problems concerning lithography and pattern transfer are discussed. We will show a step by step improvement of fabricated microzone plates with an outermost zone width of 50 nm. A thin titanium intermediate layer is used as a stable mask to generate ion milled gold absorber rings with very steep walls. The zone plates have been tested by imaging one another in an X-ray microscope, and compared to the image obtained with the holographically fabricated MZP3 microzone plate from Gottingen (Schmahl et al., /1/).

Electron beam lithography and nanometer structures-fabrication of microzone plates

A Fresnel zone plate, a focusing element that operates using diffraction, is a promising candidate for x‐ray optical elements since the index of refraction of all materials in this region is slightly less than unity. In this report, a new fabrication method for zone plates using electron beam lithography and reactive ion etching is described. By this method, it is possible to obtain a high resolution zone plate with a large aspect ratio. Focusing characteristics of fabricated zone plates are measured by synchrotron radiation. At the wavelength of 9 nm, the spot size of 2 μm is obtained at the focal point of 100 mm.

H. Aritome

Papers

X‐ray zone plates fabricated using electron beam lithography and reactive ion etching