On the interface states and series resistance profiles of (Ni/Au)-Al 0.22Ga0.78N/AlN/GaN heterostructures before and after 60Co (γ-ray) irradiation


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Demirezen S., Altndal S., Ozcelik S. , Ozbay E.

Radiation Effects and Defects in Solids, vol.165, no.12, pp.920-929, 2010 (Journal Indexed in SCI Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 165 Issue: 12
  • Publication Date: 2010
  • Doi Number: 10.1080/10420150.2010.487905
  • Title of Journal : Radiation Effects and Defects in Solids
  • Page Numbers: pp.920-929

Abstract

The values of interface states (NSS) and series resistance (RS) of (Ni/Au)-Al0.22Ga0.78N/AlN/GaN heterostructures were obtained from admittance and current-voltage measurements before and after 250kGy 60Co irradiation. The analyses of these data indicate that the values of capacitance and conductance decrease, as the R S increases with increasing dose rate due to the generation of N SS. The increase in RS with increasing dose rate was attributed to two main models. According to the first model, it has been attributed to a direct decrease in the donor concentration in semiconductor material as a result of the elimination of shallow donor states. According to the second model, it is a result of irradiation because of the formation of deep acceptor centers in the semiconductor bulk, and electrons from the shallow donor centers are captured by these acceptors. © 2010 Taylor & Francis.