RADIATION-INDUCED TRAP LEVELS IN SIMOX OXIDES - LOW-TEMPERATURE THERMALLY STIMULATED LUMINESCENCE

Thermally Stimulated Luminescence (TSL) properties of SIMOX oxides, in duced by x-irradiation, have been studied in the temperature range 100 -400 K. For the first time studied in SIMOX, a series of TSL peaks at 110, 150 and 200 K appear clearly. A continuous distribution of trap l evels ranging from 0.4 to 1.1 eV has been found to be responsible for the broad and intense peak observed at 200 K; moreover, the wavelength distribution of the emitted light has revealed the presence of an emi ssion centred at 2.7 eV. A comparison with the TSL properties of synth etic silica is presented, and the results are discussed also in the li ght of previous characterizations of trap levels obtained by electrica l techniques. This study gives new insight concerning the electron and hole traps structures in SIMOX compared to bulk silica.