Control of surface recombination of Si wafers by an external electrode

Citation
M. Ichimura et al., Control of surface recombination of Si wafers by an external electrode, JPN J A P 2, 38(3B), 1999, pp. L292-L294
Citations number
6
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Volume
38
Issue
3B
Year of publication
1999
Pages
L292 - L294
Database
ISI
SICI code
0021-4922(19990315)38:3B<L292:COSROS>2.0.ZU;2-A
Abstract
A transparent electrode was placed close to a Si wafer, and a negative or p ositive voltage up to 2kV was applied to the electrode with respect to the wafer. The wafer was irradiated through the electrode with a pulsed laser, and the decay of the excess carriers was monitored by the microwave reflect ance photoconductivity decay (mu-PCD) method. The carrier lifetime of p- an d n-type as-polished wafers was increased by a factor of 3 by application o f a 2 kV negative voltage to the electrode. This showed that the surface re combination velocity was controlled by the external electrode. A different tendency was observed for the oxidized wafers, and these results were expla ined by considering the surface charge and the surface state.