Growth of In-doped ZnO films by metalorganic chemical vapor deposition on GaN(0001) templates

摘要

We investigated the properties of indium-doped zinc oxide layers grown by metalorganic chemical vapor deposition on semi-insulating GaN(0001) templates. Specular and transparent films with n-type carrier concentrations up to 1.82 × 10~(19) cm~(-3), as determined by hall measurements, were grown. An undoped film grown under the same conditions had carrier concentration 5.4 × 10~(17) cm~(-3). An interesting trend was observed for carrier concentration dependence on In precursor flow. For low In flows, carrier concentration increased withrnTMI flow until a peak was reached for a TMI flow of 5 standard cubic centimetres per minute. Beyond this flow, carrier concentration decreased with increasing TMI flow rate. A sheet resistance as low as 185 ohm/sq was achieved for the indium-doped films, which is a significant decrease from the undoped ZnO film which had a sheet resistance of 3100 ohm/sq. The results of this In doping study show that In is an effective dopant for controlling the n-type conductivity of ZnO.