GaN lattice matched ZnO/Pr2O3 film as gate dielectric oxide layer for AlGaN/GaN HEMT

In this work, we perform AlGaN/GaN MOS-HEMT by using ZnO/Pr₂O₃ as gate dielectric. After 600°C annealing, the XRD analysis shows ZnO thin films with highly crystalline characteristics, which exhibit a lattice constant (a = 3.2498, c = 5.2066) matched to GaN (a = 3.1890, c = 5.1855). The gate leakage current can be improved significantly by inserting ZnO/Pr₂O₃ dielectric layer; meanwhile, ZnO/Pr₂O₃ MOS-HEMT shows superior breakdown voltage performance toward ZnO MOS-HEMT and conventional Ni/Au HEMT. From these results, ZnO/Pr₂O₃ dielectric is promising for low leakage current of AlGaN/GaN based MOS- HEMT.