Study of neutron irradiation effects in Depleted CMOS detector structures
physics.ins-det
/ Authors
I. Mandić, V. Cindro, J. Debevc, A. Gorišek, B. Hiti, G. Kramberger, P. Skomina, M. Zavrtanik, M. Mikuž, E. Vilella
and 5 more authors
C. Zhang, S. Powell, M. Franks, R. Marco-Hernandez, H. Steininger
/ Abstract
In this paper results of Edge-TCT and I-V measurements with passive test structures made in LFoundry 150 nm HV-CMOS process on p-type substrates with different initial resistivities ranging from 0.5 to 3 k$Ω$cm are presented. Samples were irradiated with reactor neutrons up to a fluence of 2$\cdot$10$^{15}$ n$_{\mathrm{eq}}$/cm$^2$. Depletion depth was measured with Edge-TCT. Effective space charge concentration $N_{\mathrm{eff}}$ was estimated from the dependence of depletion depth on bias voltage and studied as a function of neutron fluence. Dependence of $N_{\mathrm{eff}}$ on fluence changes with initial acceptor concentration in agreement with other measurements with p-type silicon. Long term accelerated annealing study of $N_{\mathrm{eff}}$ and detector current up to 1280 minutes at 60$^\circ$C was made. It was found that $N_{\mathrm{eff}}$ and current in reverse biased detector behaves as expected for irradiated silicon.