Computer-controlled, three-electron-gun, multisubstrate evaporator for the preparation of multilayer thin films

Abstract

We have developed a novel multisource electron-beam evaporator to prepare high-quality multicomponent, multilayer thin films. The essential parts of the evaporator consist of three electron guns, a shutter turntable, and a multisubstrate turntable; the latter can be loaded with up to 20 substrates. A very attractive feature of the system is the implementation of computer control over the movement of the stepping motors. The two turntables are driven by separate stepping motors with optical encoders, and are used to: (i) position a selected substrate over a specified electron gun, and (ii) gate the flux for a desired time. With a suitable programming of the movement of the stepping motors, up to 20 different thin films, with individually tailored layers deposited sequentially from the three sources, can be prepared in a single run. The deposition rate and the sublayer thickness of the three constituents of a multilayer film are individually monitored by three film deposition controllers which communicate directly to the computer and the electron-gun power supply. Predictable and reproducible deposition of thin films is accomplished by accurate, digital control of the deposition process. High-quality films of YBaCuO have been prepared with this system.