INTERFACE-STATE MEASUREMENTS 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 × 1012 cm-2 eV-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.