Showing papers on "Nanosphere lithography published in 1993"

Realization Of X-Ray Lithography Masks Based On Diamond Membranes

Abstract: Deposition parameters acting on nucleation and growth local conditions have been optimized in a bell jar microwave plasma reactor to obtain polycrystalline diamond thin films compatible with X-ray membrane requests. The microstructure and the chemical quality of the films were estimated by SEM and Raman spectroscopy respectively, the roughness was evaluated by AFM experiments and the residual stress was deduced from the substrate deflection method. Membranes were obtained by removing the silicon substrate on 15 mm diameter circular windows. The optical transparency depending on deposition conditions was optimized up to 65% at 630 nm for 1 μm thickness. A high resolution additive mask process, based on well taut membranes and low stress electroplated gold absorber, was carried out. Micrometric and submicrometric mask patterns were generated in photoresists both by electron beam lithography with a nanopattern generator and by X-ray lithography using the synchrotron radiation facility implemented at LURE-Orsay. Despite the diamond films roughness of the order of 30 nm, well defined dots and lines as narrow as 100–200 nm could be obtained.

Diamond Membranes For X-Ray Lithography Masks

Abstract: Process techniques have been developed to produce diamond membranes for application as x-ray lithography masks.* Residual stress and grain size of the films are influenced by substrate temperature, chamber pressure, and methane concentration, and optimization of these parameters narrows the range of acceptable process conditions. A reactor geometry was chosen which has the capability to produce membranes with thickness uniformity of ± 7 percent across a 50 mm diameter. A cyclic renucleation technique was developed to maintain the grain size at low levels independent of film thickness. Membranes with RMS roughness of about 25 nm, as determined by atomic force microscopy, are fabricated reproducibly. The elastic modulus of small grained membranes deviates from that of larger grained membranes. This deviation must be taken into account in membrane distortion modeling calculations.