Preparatory Study for the Matrix-Pattern Imaging, EB System

A new method for electron-beam lithography –called matrix-pattern imaging (MPI)– for use as a high-throughput exposure system has been proposed. In MPI, the electron sources are arranged in a matrix so that they produce an electron beam in the shape of a circuit-pattern element; the beam is focused on the target. An evaluation system for measuring the properties of the MIM cathode, a promising candidate for the electron source of an MPI-based system, was constructed. The measured current density (at the cathode) is 2.5 mA/cm2, and the brightness is 1×102 A/cm2/sr (at an accelerating voltage of 50 kV). An image of the cathode was successfully projected onto the target, and delineated on a wafer. Moreover, the composition of the exposure system was optimized so as to increase throughput with an MIM cathode, and the throughput of the resulting MPI system was estimated as one six-inch reticle per hour.