Abstract
A simple model, which includes the important effects of ‘‘nonreciprocity’’ (nonlinear dependence on intensity), is developed to describe the spatial resolution of single-step focused-beam, microchemical fabrication techniques. Qualitative comparisons are made to patterning by double-step (resist) and by projected-image processes. At a given wavelength, linewidths are shown to be narrowest for microchemical processes. Linewidths <0.2 μm, i.e., narrower than the Rayleigh optical diffraction limit, are demonstrated for laser-activated deposition and doping of silicon at visible wavelengths.