Electrically active defects in 4H-SiC introduced by radiation

Ni/4H-SiC Schottky diode n-tipa ozračene su termalnim i brzim neutronima te implantirane s 2MeV He ionima. Zatim, izvršena je karakterizacija strujno-naponskim, kapacitivno-naponskim te mjerenjima tranzijentne spektroskopije dubokih nivoa. Ozračivanje termalnim neutronima u dozama do 1 x 1010 cm-2 nije uzrokovalo promjene karakteristika, što je u skladu s velikom otpornošću SiC na oštećenja pri ozračivanju. Ozračivanje brzim neutronima (pri dozi 1 x 1013 cm-2) je unijelo novi ET2 duboki nivo, dok se koncentracija Z1/2 dubokog nivoa povećala. Brzi neutroni energije oko 0.8 MeV (koji su korišteni u ovom radu) mogu unijeti samo vakancije i intersticije u SiC, stoga opaženi duboki nivoi su vezani uz njih. Kompenzacija je opažena pri dozi 1 x 1014 cm-2 brzih neutrona. Implantacija 2MeV He iona unijela je ET1, Z11/2 i ET2 duboke nivoe te uzrokovala kompenzaciju u području dosega 2MeV He iona u 4H-SiC.N-type Ni/4H-SiC Schottky diodes were irradiated by thermal and fast neutrons and implanted with 2MeV He ions. Afterwards, characterization by current-voltage, capacitance-voltage and deep level transient spectroscopy measurements was carried out. Irradiation with thermal neutrons at fluences up to 1 x 1010 cm-2 didn’t cause change of characteristics, which is in agreement with high radiation hardness of SiC. Irradiation with fast neutrons (fluence 1 x 1013 cm-2) has introduced a new ET2 deep level, while the concentration of Z1/2 has increased. Fast neutrons with an energy around 0.8 MeV (as used in this study) can introduce only vacancies and interstitials in SiC, so observed deep levels are related to them. Compensation was observed at fluence 1 x 1014 cm-2 of fast neutrons. Implantation of 2MeV He ions introduced ET1, Z1/2 and ET2 deep levels and caused compensation in the area of reach of 2MeV He ions