Interface-state measurement on SOS using the charge-pumping technique on gated-diode test structures

The radiation-induced interface-state density in CMOS/SOS was measured with the charge-pumping technique using a gated-diode test structure. The results were compared to the interface-state density measured with the subthreshold slope method in n- and p- channel MOSFET devices after exposure to Co-60 radiation. Experimental results using the two methods on both depleted and nondepleted SOS-substrates were analyzed. With a combination of both methods, the interface-state density at the Si-sapphire interface was 1.3*10/sup 12/ cm/sup -2/ eV/sup -1/. A direct method of measuring the interface-state density at the interface to the substrate isolation oxide using a charge-pumping technique is described. The test structures can be implemented in a standard CMOS/SOS test die.<
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