STUDY OF DEEP LEVELS IN MESA-TYPE HGCDTE DEVICE

The deep levels in the p(+)-on-n mesa-type Hg1-xCdxTe (x = 0.222) devi ce fabricated on the Si substrate by the molecular beam epitaxy method have been studied using the isothermal capacitance transient spectros copy (ICTS) method and the spectral analysis of deep level transient s pectroscopy (SADLTS) method. The value of the activation energy and th e capture cross section could not be determined by means of ICTS becau se the apparent peaks were not obtained in the ICTS spectrum. However, five deep levels have been confirmed by SADLTS and the activation ene rgies and the capture cross sections for each level were calculated. T he confirmed levels existed from 19.7 meV to 45.7 meV below the conduc tion band edge. Three deeper levels are considered to be related to th e Hg vacancy, whereas two shallower levels are considered to be relate d to the impurity in the II-type region, Moreover it is suggested that three deeper levels may assist the tunneling current in the reverse b ias region. On the other hand? the obtained values of the capture cros s sections ranged from 10(-18) to 10(-11) cm(2).