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A scanning electron diffraction attachment providing for energy analysis of the scattered electrons has been constructed for use in conjunction with a J.E.M. 6AS electron microscope. This attachment permits the direct recording of diffracted electron intensities as a function of angle with an accuracy of ±0.1%. The attachment can be operated to exclude all but the elastically diffracted electrons, or, alternatively, to detect electrons with a measurable amount of energy loss. The electrostatic energy analyzer has an energy cutoff of better than 1.1 eV out of 100 keV. The angular resolution of the instrument is presently 2.2×10−4 rad, with minimum detectable electron intensity of 10−14 A. The instrument performance is demonstrated by studying the effect of inelastic scattering in the diffraction pattern of aluminum, and by recording the plasma loss spectrum of aluminum. The filtered profiles have narrower peaks than the unfiltered ones and better peak resolution, and the contrast between peaks and background is enhanced. At low values of the scattering vector where the inelastic background is very intense, its removal reveals diffraction effects which otherwise would have been invisible. The attachment does not interfere with the conventional plate microscopy and diffraction, and provides, thereby, a method of energy analyzing the direct microscope image as well.

The structure of Ge films evaporated by several methods onto room temperature substrates of NaCl and films which have been ion implanted with 3 x 1015, 30 to 40 keV Ge74 has been investigated via a scanning electron diffraction instrument with electron energy filtering. The radial distribution functions of all fil-ms are very similar and exhibit strong correlation peaks a t 2.45, 4.00, and (4.85 f 0.075) A 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 ~o /~c r y s t 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 A. The RDF, however, is identical to the as-deposited film with the exception of some changes in the correlation for r greater than 11 A.Die Struktur dunner Ge-Schichten, die auf verschiedene Arten auf NaC1-Triiger bei

The structure of hydrogenated amorphous silicon films, 100 Å thick, prepared from plasma glow discharge of silane, is investigated by electron microscopy and scanning electron diffraction. Films are prepared at plasma pressures of 0.05 and 0.3 Torr onto NaCl and KBr substrates held at room temperature and at 250 °C. The H content of the films ranges from 20 to 40 at%. The radial distribution function of these films shows a near neighbor correlation distance of (2.375 ± ± 0.05) Å (for evaporated films (2.350 ± 0.05) Å), and a second neighbor distance of (3.69 ± ± 0.05) Å. The Si—Si near neighbor coordination numbers decrease monotonically with increasing H content from 3.55 to 3.25 ± 0.1 (for evaporated Si films it is 4.0 ± 0.1). Atoms‐per‐unit volume density ratios which include H (ϱa‐Si/ϱx‐tal Si) of 0.7866, 0.7863, and 0.707 are determined for films containing 20, 25, and 40 at% H. Films prepared at room temperature with 0.3 Torr pressure have an additional small peak at 4.29 Å, not found for films at high substrate temperature and low pressure, from which it is concluded that the former films are partially polymeric. Films containing up to 25 at% H show a weak structural modulation at 4.55 Å which decreases with decreasing H content, and is not seen for evaporated amorphous Si films and films containing 40 at% H. This peak is associated with a larger number of staggered configurations in the random network. The observed radial correlations with the exception of the aforementioned differences are in general agreement with a tetrahedral random network. Bright field electron microscopy of the high pressure films shows an unhomogeneous microstructure consisting of clusters 1000 Å in diameter, with details of the morphology and size depending on the substrate temperature and type. Low pressure films have a homogeneous microstructure.

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