Electron beam lithography: Its applications

Abstract

This paper addresses the various aspects of e-beam lithography as they relate to device fabrication at and below 0.25 μm. These dimensions will eventually be necessary for the fabrication of 256 MB DRAM chips. It is important to evaluate how key components in lithography have to be integrated to provide this necessary early learning. E-beam lithography tools today may consist of Gaussian round and variable shape beam systems. The understanding of the performance of the tool goes hand in hand with directly related issues such as electron-resist interaction, proximity effect correction, etc. Since each of these parameters can be optimized independently, but not simultaneously as a complete set, tradeoffs will have to be made. The discussion will therefore focus on compromises between critical issues such as beam profile, throughput, image quality, process latitude, degree of accuracy in proximity effect correction, and overall process engineering for very high resolution lithography. All of these aspects are strategically important components in support of device technology research. The implementation of an ‘‘integrated e-beam lithography’’ operation as it relates to fully scaled and partially scaled device programs will be discussed. Current work on device fabrication below 0.25 μm demonstrates the capability of integration of all sectors of e-beam lithography to provide early research work for ULSI device technology.