Electron beams have unlimited resolution, for practical purposes in lithography. The historical limitation of e-beam lithography is throughput. There are two reasons for the throughput limitation in present-day probe forming systems: (1) E-beam lithography is a serial process, in contrast to optical lithography, which exposes an entire chip in one flash or scan. (2) Useful writing current is limited by Coulomb scattering among beam electrons, which degrades resolution. Many examples exist of systems which add parallelism to the exposure process by using multiple pixels per flash. These include variable shaped beams, cell projection, e-beam projection, and many multibeam systems. Invariably, the Coulomb interaction has imposed a practical upper limit on writing current for a given resolution. There exists a class of system, called a distributed system, which is both highly parallel, and which is not limited in usable writing current by the Coulomb interaction. The purpose of this study is to survey the historical throughput limitation of e-beam lithography, and assess the hope for significantly improving throughput by using distributed system concepts.

Date Published: 2 June 2004
PDF: 5 pages
Proc. SPIE 5504, 20th European Conference on Mask Technology for Integrated Circuits and Microcomponents, (2 June 2004); doi: 10.1117/12.568030

Published in SPIE Proceedings Vol. 5504:
20th European Conference on Mask Technology for Integrated Circuits and Microcomponents
Uwe F. W. Behringer, Editor(s)