Slow electrons impinging on dielectric solids. II. Implantation profiles, electron mobility, and recombination processes

Journal Article · Tue Jul 01 04:00:00 EDT 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.56.2241· OSTI ID:527019

Miotello, A ^[1]; Dapor, M ^[2]

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1. INFM and Dipartimento di Fisica dellUniversita di Trento, I-38050 Povo, Trento (Italy)
2. INFM and Centro Materiali e Biofisica Medica, Istituto Trentino di Cultura, I-38050 Povo, Trento (Italy)

When an insulator is subject to electron irradiation, a fraction of electrons is absorbed while the rest is backscattered. The injected electrons cannot be definitely trapped but they must instead recombine with positive charges left near the irradiated surface when secondary electrons are emitted; this is justified on the basis that dielectric breakdown is not observed during specific experiments of electron irradiation of insulators. The dynamics of the absorbed electrons depend on a number of parameters: the number of trapped electrons, the charge-space distribution, the mobility, and the number of secondary electrons emitted from the region near the surface of the dielectric. The time evolution of the surface electric has been studied by integration of the continutity equation for the relevant transport processes of the injected charge by adopting, as the charge source term, the distribution of the absorbed electrons as obtained by a Monte Carlo simulation. The image charge has been also introduced in the calculation in order to take into account the change in the dielectric constant when passing from the material to the vacuum. Selected computational results are reported to illustrate the role of the relevant parameters which control the charging effects in electron-irradiated insulators. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 527019
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 4 Vol. 56; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BACKSCATTERING
BREAKDOWN
DIELECTRIC MATERIALS
ELECTRICAL INSULATORS
ELECTRON COLLISIONS
ELECTRON MOBILITY
PERMITTIVITY
RECOMBINATION
SURFACES
TRAPPED ELECTRONS