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Ultra-thin Si[O.sub.2]/Si gate dielectric structures exposed to heavy X-ray irradiation exhibit optical emission characteristic of interface traps. Low energy electron-excited luminescence spectroscopy with nanometer-scale depth resolution yields a characteristic spectral energy and excitation depth dependence. Ultra-thin (5 nm) oxide films on Si substrates exposed to 10 keV, 7.6 Mrad(Si[O.sub.2]) [13.7 Mrad (Si)] X-ray irradiation introduces trap densities on the order of [10.sup.11] [cm.sup.-2]e[V.sup.-1], localized near the intimate Si[O.sub.2]-Si interface. This density is consistent with the trapped oxide and interface charge densities expected based on observed capacitance- voltages shifts of thicker oxides, their corresponding charge densities, and the proportionally smaller charge densities expected for the thinner oxide layers in this study.

We have characterized high-electron mobility transistors and corresponding unprocessed material as a function of 1.8 MeV proton fluence. Electrical data shows degradation of the electrical contacts at low fluences (1011-1014p+cm²)and degradation of thechannel properties for higher fluence. In conjunction with the electrical data, cathodoluminescence and secondary-ion mass spectrometry results suggest mechanisms for the higher fluence degradation. [ABSTRACT FROM AUTHOR]

Presents a study that examined nitride-transistor structures before and after proton irradiation with the use of low-energy electron-excited nanoscale-luminescence (LEEN) spectroscopy. Background on nitride-based heterostructure devices; Assessment of the correlation of radiation-induced transistor performance degradation with spectroscopic characterization of device materials; Analysis of the LEEN spectra of the modulation-doped field-effect transistor.