P-type Ga₂O₃ Epilayers Grown on Sapphire Substrate by Phosphorus-Ion Implantation Technology and Relative PN Diode Application

In this study, various phosphorus-ion implantation techniques, incorporating low, medium, and high doses, were used to investigate the electrical properties of unintentionally doped β-Ga₂O₃heteroepilayers, which were grown on sapphire substrates by metalorganic chemical vapor deposition.<br/>The low-dose implantation involved phosphorus ions at concentrations of 1.6×10¹³, 1×10¹² and 2.5×10¹² atoms/cm², administered at implantation energies of 100, 50, and 40 keV, respectively. The medium-dose implantation utilized phosphorus ions at concentrations of 1.6×10¹⁴, 1×10¹³ and 2.5×10¹³ atoms/cm², at the same implantation energies. Finally, the high-dose implantation employed phosphorus ions at concentrations of 1.6×10¹⁵, 1×10¹⁴and 2.5×10¹⁴ atoms/cm², with implantation energies of 100, 50, and 40 keV, respectively. The implantation parameters were also simulated using the Stopping and Range of Ions in Matter software, while the actual concentration of phosphorus ions was measured via secondary ion mass spectrometry. Subsequently, Ni and Au were deposited on the annealed phosphorus-implanted β-Ga₂O₃ epilayers, followed by rapid thermal annealing at 600°C in a nitrogen environment for one minute, for Hall measurement. The electrical properties of the phosphorus-implanted β-Ga₂O₃ epilayers were assessed through Hall measurements. Notably, the β-Ga₂O₃ epilayers implanted with middle and high doses displayed p-type behavior.<br/>The phosphorus-ion implanted Ga₂O₃ was not only demonstrated to be the p-type. Special epilayer structure has also been designed to obtain the pn diode. It was the UID Ga₂O₃ layer first, then ion implanted phosphorus into Ga₂O₃ and thermal annealing to active phosphorus and obtain p-type Ga₂O₃. After, regrew the n-type Ga₂O₃ on the p-type epilayer. Finally, the pn diode was fabricated using the mesa and electrodes deposition. Detailed processing and device performance will be discussed detail in the conference.