Accession Number : ADP007905

Title :   Electronically Induced Modifications of a-Si:H(P) Films by Scanning Tunneling Microscopy,

Corporate Author : UNIVERSITAET DER BUNDESWEHR MUENCHEN NEUBIBERG (GERMANY F R)

Personal Author(s) : Hartman, E. ; Koch, F. ; Behm, R. J.

Report Date : 22 MAY 1992

Pagination or Media Count : 1

Abstract : We report local electronic modifications of phosphorus doped, hydrogenated amorphous silicon films (a-si:H(P)), on a nm-scale, by use of a Scanning Tunneling Microscope. High-quality a-Si:H(P) layers (5 at.% hydrogen) were deposited by rf glow discharge techniques on heavily doped p-type Si substrate material. The film was doped by adding 1 % PH 3 to the SiH 4 flux, resulting in a layer resistivity of 100 Ohm cm. Film thicknesses ranged between 300 OA to 5000 A. Depending on the tunnel conditions, mainly tunnel current and tunnel voltage, the STM can be operated in an imaging mode (read cycle') or in a surface modifying mode ('write cycle'). Under normal tunneling conditions, at + 3 V applied at the sample and 1 nA tunnel current, STM imaging does not alter the surface and the same area can be repeatedly scanned without any changes in the images.

Descriptors :   *HYDROGEN, *SILICON, *ADSORPTION, ELECTRONICS, FILMS, GLOW DISCHARGES, IMAGES, LAYERS, MODIFICATION, QUALITY, SCALE, SUBSTRATES, SURFACES, VOLTAGE, TUNNELING(ELECTRONICS), ELECTRON MICROSCOPY, SCANNING ELECTRON MICROSCOPES, GERMANY.

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE