Electron scattering effects in master mask fabrication by single layer process for submicron x-ray lithography

A single layer process in electroplated master mask making is discussed. The results of a Monte Carlo simulation are utilized in order to calculate the proximity function and compare theory with experimental test patterns. Silicon membranes are utilized (2 ?m thick) and the variables investigated are resist thickness (10000 and 5000 Å), metallic layer plating base (varying thickness) and electron accelerating voltage (20-40 kV). The results show quantitatively how high resolution patterns mainly depend on forward scattering in the resist (thus on resist thickness) and back-scattering from the metallic layer. In particular, 500Å of Au plating base may hinder the possibility of high resolution, which can be improved by lowering either the thickness or the Z of the metallic layers. Finally the possibility of obtaining high-contrast master masks down to 0.3 ?m linewidth by a single layer process is demonstrated.