Impact of rapid thermal annealing on structural and electrical properties of ZnO thin films grown atomic layer deposition on GaAs substrates

• Thin ZnO films have been grown on GaAs substrate by atomic layer deposition.
• Arsenic atoms have doped into the ZnO films after O2 annealing.
• The p-type conduction mechanism of ZnO film is thoroughly investigated.

The effect of rapid thermal annealing temperature on the structural and electrical properties thin ZnO films grown on GaAs substrate by atomic layer deposition is thoroughly investigated. X-ray diffraction analysis show that atoms interdiffusion can be observed at the interface of ZnO/GaAs heterostructures after annealing in oxygen ambience at elevated temperatures. Moreover, the conductivity of ZnO film converts from n- to p-type after annealing at 600 °C. A hole concentration as high as 3.4 × 1020 cm−3 is also obtained for the sample annealed at 650 °C. The p-type conductivity of ZnO films is attributed to arsenic atoms diffusion into ZnO films as shallow acceptors.