The dependence of radiation-induced charge neutralization RICN has been studied in metal-oxide-semiconductor field-effect transistor MOSFET dosimeters. These devices were first exposed to x rays under positive bias and then to further dose increments at a selection of reverse bias levels. A nonlinear empirical trend has been established that is consistent with that identified in the data obtained in this work. Estimates for the reverse bias level corresponding to the maximum rate of RICN have been extracted from the data. These optimum bias levels appear to be independent of the level of initial absorbed dose under positive bias. The established models for threshold voltage change have been considered and indicate a related nonlinear trend for neutralization cross section N as a function of oxide field. These data are discussed in the context of dose measurement with MOSFETs and within the framework of statistical mechanics associated with neutral traps and their field dependence. © 2006 American Institute of Physics.
Copyright 2008 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in the Journal of Applied Physics, 100 (4), 2006 and may be found at http://link.aip.org/link/?JAPIAU/100/044505/1 This research relates to the use of MOSFETs under switched bias in aircraft, space systems, nuclear plant and medical applications and was borne of a collaboration with BAE SYSTEMS (Jon Silvie, 01229 874797) and the Clatterbridge Centre for Oncology, Chester. We have extracted the dependence of radiation sensitivity for this device and thus linked this rudimentary experimental measurement and the cross-section dependence with electric field across the device. This will enable users of these devices to account for their behaviour under switched bias in radiation fields and has stimulated interest from hospital users, such as Dr Glyn Shentall (Glyn.Shentall@lthtr.nhs.uk). RAE_import_type : Journal article RAE_uoa_type : General Engineering