Transient conductance spectroscopy measurements of defect states in y-irradiated n-channel silicon field effect transistors with possible y-dosemeter applications

Abstract

A deep level transient capacitance spectroscopy (DLTS) system modified for the measurement of transient conductance has been used to observe gamma-ray induced defect centres in the gate junction of 2N4416 Si field effect transistors. The defect concentrations increased linearly wth gamma-dose in the range 50 kGy to 10 x 10 3 kGy (5-1000 Mrad) for the common E(c) - 0.17 eV level and in the range 500 kGy to 10 x 10 3 kGy (50- 1000 Mrad) for the levels E(c) - 0.22 eV and E(c) - 0.44 eV. Another common level a hole trap at E(v) + 0.42 eV was the only minority trap observed. The technique may be useful for measuring gamma-fluxes in situations inaccessible to standard dosemeters (e.g. flux-mapping).