Due to its direct wide bandgap of 3.37eV, Zinc oxide (ZnO) has become the focus of many studies. Devices such as detectors, lasers and diodes operating in the ultra-violet (UV) and blue regions of the spectrum have been reported. It has previously been reported that the carrier removal rate in ZnO by MeV protons is almost two orders of magnitude lower than that in GaN. To investigate if this is due to a material property of the ZnO, or perhaps a case of radiation enhanced annealing, He⁺ irradiation were performed at room temperature as well as at low temperatures. ZnO Schottky barrier diodes (SBD's) were fabricated with 20/80/40/80 nm Ti/Al/Pt/Au ohmic contacts on the O face and circular 0.5 mm in diameter 500 nm thick Ru Schottky contacts in the Zn face. The carrier concentration of the ZnO prior to irradiation was approximately 5×10¹⁶ cm^-3. These diodes were irradiated with 1.8 MeV He⁺ with fluences ranging from 1×10¹² cm^-2 to 5×10¹³ cm^-2. Deep level transient spectroscopy (DLTS) was used to study the defects introduced. These measurements revealed that this implantation introduced a defect with an energy level at 0.54 eV below the conduction band. The introduction rate of this defect for 1.8 MeV He ions was calculated to be 220 cm^-1. This appears to be the same defect that is introduced during proton implantation of ZnO.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/7777 must be provided.

1. Optical characterization of GaN doping superlattices as grown, hydrogen implanted and annealed.