Analysis of the electron-beam-induced current of a polycrystalline p-n junction when the diffusion lengths of the material on either side of a grain boundary differ
The short circuit current generated by the electron beam of a scanning electron microscope in p-n junctions is reduced by enhanced recombination at grain boundaries in polycrystalline material. Frequently, grain boundaries separate the semiconductor into regions possessing different minority carrier life times. This markedly affects the short circuit current I/sub SC/ as a function of scanning distance from the grain boundary. It will be shown theoretically that (a) the minimum of the I/sub SC/ in crossing the grain boundary with the scanning electron beam is shifted away from the grain boundary toward the region with smaller life time (shorter diffusion length), (b) the magnitude of the minimum differs markedly from those calculated under the assumption of equal diffusion lengths on either side of the grain boundary, and (c) the minimum disappears altogether for small surface recombination velocities (s<10/sup 4/ cm/s). These effects become however negligible for large recombination velocities s at grain boundaries. For p-type silicon this happens for s> or =10/sup 5/ cm/s.
- Research Organization:
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109
- OSTI ID:
- 6788079
- Journal Information:
- J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 55:12; ISSN JAPIA
- Country of Publication:
- United States
- Language:
- English
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360603* -- Materials-- Properties
42 ENGINEERING
420800 -- Engineering-- Electronic Circuits & Devices-- (-1989)
CARRIER LIFETIME
CARRIER MOBILITY
CHARGE CARRIERS
CRYSTAL STRUCTURE
CRYSTALS
DIFFUSION LENGTH
DIMENSIONS
ELECTRICAL FAULTS
ELECTRON MICROSCOPY
ELEMENTS
GRAIN BOUNDARIES
JUNCTIONS
LENGTH
LIFETIME
MICROSCOPY
MICROSTRUCTURE
MOBILITY
P-N JUNCTIONS
POLYCRYSTALS
RECOMBINATION
SCANNING ELECTRON MICROSCOPY
SEMICONDUCTOR JUNCTIONS
SEMIMETALS
SILICON