Ultra-high resolution electron-beam lithography with a research scanning electron microscope

Abstract

An electron microscope of the type normally used for analysis has been employed as an experimental beam writing instrument. With this instrument less than 10 nm size structures have been fabricated in a variety of materials by electron beam lithography. The important parameters that determine the resolution limit are: electron beam probe size, electron beam energy, characteristics of the beam sensitive material and the nature of the substrate. These parameters were studied with a Philips 400 T TEM/STEM/SEM modified for external beam control and interfaced to a DEC MINC 11-23 computer for pattern generation. With this microscope's ability to image thick samples by secondary and backscattered electron detection conventional type lithography was done on semiconductor substrates. The general lithographic technique is described, for example, in reference 2. In addition fabrication techniques on thin films were studied. The effect of the resolution determining parameters and several examples of lithographic results are described in this paper.