Investigation of the spatial resolution of the light-addressable potentiometric sensor

Citation
M. George et al., Investigation of the spatial resolution of the light-addressable potentiometric sensor, SENS ACTU-A, 86(3), 2000, pp. 187-196
Citations number
17
Categorie Soggetti
Instrumentation & Measurement
Journal title
SENSORS AND ACTUATORS A-PHYSICAL
ISSN journal
09244247 → ACNP
Volume
86
Issue
3
Year of publication
2000
Pages
187 - 196
Database
ISI
SICI code
0924-4247(20001115)86:3<187:IOTSRO>2.0.ZU;2-9
Abstract
The spatial resolution of the light-addressable potentiometric sensor (LAPS ) is investigated both theoretically and experimentally. For a theoretical analysis, the diffusion equation for minority charge carriers in the semico nductor was solved. The results suggest that by thinning the semiconductor wafer, the spatial resolution of the LAPS is no longer limited by thr bulk minority charge carrier diffusion length. Spatial resolution in the microme ter range should thus be possible. For an experimental analysis, the effect ive diffusion length of light-generated charge carriers parallel to the sen sor surface was measured. The results show that by increasing the doping de nsity and by thinning the semiconductor substrate, spatial resolution of ab out 15 mum is obtained. (C) 2000 Elsevier Science B.V. All rights reserved.