Abstract

A novel method for directly applying material on only a very small area of a substrate (selective deposition) at low temperature has been reported by applying a gas-substrate interface^1-7). When an electron beam is irradiated onto a substrate in electron beam Chemical Vapor Deposition (CVD), source gas molecules, adsorbed on a substrate, are dissociated into nonvolatile and volatile materials. Nonvolatile materials are deposited on a substrate, which volatile materials are evacuated. Nanometer structures can be fabricated by electron beam CVD, using electron beam induced surface reaction, because beam diameters as small as 5 Å can be formed with conventional electron equipment⁸⁾. Computer controlled direct writing also is possible for electron beam CVD. Metals, semiconductors, and inorganic materials can be deposited by this means. Thus, electron beam CVD has some excellent advantages over other CVD methods. Namely, processing methods in microelectronic devices can be simplified and new structure devices with nanometer dimensions can be realized. When source gas molecules adsorbed on a substrate are dissociated by electron beam irradiation, Auger electrons are emitted from deposited materials at the same time. Therefore, the deposited material growth process can be observed in situ by Auger electron spectroscopy (AES)^3,7). Moreover, the deposited material growth process can be observed in situ by transmission electron microscopy (TEM), if source gas molecules are adsorbed on a TEM specimen^5,6). This paper presents results obtained for AES and TEM W electron beam CVD observation in situ, using the WF₆ source.

© 1989 Optical Society of America