E-beam lithography has for some years been the leading edge lithography tool in many advanced technology programs and in research and development. More recently it has found its place in the production of mask and reticles for a wide variety of products, both at 1X and for magnification applications. The traditional systems have utilized spot beam optics with relatively low current density and, whether raster scan or vector scan systems, have resulted in many cases in long job times for some of the most advanced device requirements. The inherent cost benefits of direct write lithography have seldom been met with such tools due to the 'cost per level' factor resulting from a low throughput approach. During the last few years variable shaped beam systems have become commercially available and these systems have substantially improved system throughputs for most applications and have, for the first time, enabled E-beam lithography tools to be considered viable production approaches for the future. This paper will discuss the features and benefits of Hitachi's E-beam lithograph systems and will demonstrate performance by reference to application work from a number of references as well as from Hitachi's own internal use of the tools. Attention will be given to many of the key issues facing present and future lithography, including the manufacture of X-ray masks, reticles and direct write of advanced DRAM devices, proximity effects and new technologies in mask making including phase shifted masks.
William V. Colbran,
"Hitachi e-beam lithography tools for advanced applications", Proc. SPIE 1496, 10th Annual Symp on Microlithography, (1 March 1991); doi: 10.1117/12.29760; https://doi.org/10.1117/12.29760