Electrical characterization of H+ ion irradiated n-ZnO

Abstract

Schottky barrier diodes (SBD’s) were fabricated with 20/80/40/80nm Ti/Al/Pt/Au ohmic contacts on the O face and circular 0.5mm in diameter, 50nm thick Ru Schottky contacts in the Zn face. Current (I) deep level transient spectroscopy (I-DLTS) was used to study the shallow level defects introduced during 1.8MeV proton irradiations with fluences ranging from 1×1013cm−2 to 2.4×1014cm−2. These measurements revealed that this irradiation introduced a defect with an energy level at 0.03–0.036eV below the conduction band and with an electron capture cross section of 9×10−16 to about 1.4×10−15cm2. This defect may be hydrogen-related as theory has predicted that hydrogen forms a shallow donor in ZnO, or it may be due to the ZnI, as it was reported that electron irradiation with an energy of >1.6MeV produces the ZnI in ZnO which is a shallow level defect at 0.03eV below the conduction band.