A Scanning Electron Diffraction Study of Vapor‐Deposited and Ion Implanted Thin Films of Ge (I)

Abstract

The structure of Ge films evaporated by several methods onto room temperature substrates of NaCl and films which have been ion implanted with 3 × 1015, 30 to 40 ke V Ge74 has been investigated via a scanning electron diffraction instrument with electron energy filtering. The radial distribution functions of all films are very similar and exhibit strong correlation peaks at 2.45, 4.00, and (4.85 ± 0.075) Å with coordinations of 4, 12, and ≈ 7, respectively. The remaining major peaks for higher r deviate substantially from the diamond cubic form of Ge. From the RDF analysis a density ratio ϱ0/ϱcryst of 0.86 to 0.95 is determined. Thermal anneal experiments showed that the films may be annealed to a density of ≈0.97 of crystalline density without crystallization. Amorphous films which have been ion implanted with the same energy and dose as the polycrystalline films show a considerable concentration of pores and voids of a maximum diameter of 100 Å. The RDF, however, is identical to the as‐deposited film with the exception of some changes in the correlation for r greater than 11 Å. Copyright © 1973 WILEY‐VCH Verlag GmbH & Co. KGaA