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ABSTRACTS ON MICROELECTRONICS AND RELIABILITY ELE£TRONBFAMTEMOLOGY
Read;n~ and writing with electron beams. JOHN FIzammT, JR., Electronics, May (1966), p. 80. Electron-beam recording is any method of storing information, temporarily or permanently, in which a beam or cloud of electrons either modifies the recording medium or prepares it for modification by another means, such as exposure to light. A variety of recording schemes exist which incorporate electron-beam recording techniques. In one, electromagnetic recording, an electron beam scans a multigap recording head, energizing each of the recording elements sequentially. Magnetic tape passing over the head is magnetized in accordance with the signal which modulates the electron beam. In another method, electrons deposited on thermoplastic form a charge pattern, or latent image of the information. The material is heated and the charge pattern causes it to take on the appearance of a topographical map, with the surface ripples representative of the recorded information. Electron beams can also record information by depositing charges on a dielectric material, by exposing photographic film to form a latent image of the recorded data, and by machining thin films.
Electron beam gun in an exploratory fabrication system. D. ZEH~, N. H. Kl~XTZXRand D. G. CULLUM, 1966 IEEE Int. Cowo. Record, Part 9, March 21-25 (1966), p. 39. A semi-automatic versatile system for fabrication of integrated arrays was constructed and tested. The work tool consists of a finely focused electron beam which is digitally controlled. Resolution is one part in 4096. Input information is provided via magnetic tape. Mechanical positioning of the work piece is by stepping motors with resolution of 0.0002 in. Accurate registration for multi-access applications is provided utilizing secondary emission. Electron-microscope replica study of epitaxial silicon nucleation on silicon. T. G. R. I~WLINS and L. E. BRossm_~,~u, Tra~. Metal[. Soc. A I M E 236, March (1966), p. 280. Direct platinum carbon replicas have been used to study substrates prior to growth and after initial nucleation of the layer. Replicas have been directly stripped and correlations have been made with other replica techniques. Mechanically polished substrates are very fiat with occasional areas of "dirt", which is apparently silicon. When such substrates are etched in hydrochloric acid gas, scratches and hexagonal defects (thought to be polishing compound) are revealed, together with areas of apparent redesposition. Chemically polished substrates are much less fiat although much more homogeneous in appearance. Heat treatments have no effect. Nuclei deposited on these surfaces, using a normal silicon tetrachloride system, have been examined. Nuclei on mechanically polished substrates occur in random areas only, whereas on chemically polished surfaces they are more uniformly distributed.