p-type hexagonal boron nitride films with bis(cyclopentadienyl) magnesium as a doping gas in halide vapor phase epitaxy

• Published in: Applied physics letters Vol. 123; no. 20
• Main Authors: Liu, Xiaohang, Fan, Shengda, Chen, Xi, Liu, Jingrun, Zhao, Jihong, Liu, Xiuhuan, Hou, Lixin, Gao, Yanjun, Chen, Zhanguo
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 13-11-2023
• Subjects: Applied physics; Boron nitride; Carbon; Chemical bonds; Doping; Electrical resistivity; Impurities; Magnesium; Photoelectrons; Room temperature; Temperature dependence; Thin films; Vapor phase epitaxy; Vapor phases; X ray photoelectron spectroscopy
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/5.0176165

We report an in situ carbon doping method for fabricating p-type hexagonal boron nitride thin films with a halide vapor phase epitaxy system by introducing bis(cyclopentadienyl) magnesium as a doping gas. The hBN films exhibited a growth rate of 3 μm/h, while the doped hBN films showed a considerable reduction in resistivity by 8 orders of magnitude. Hall measurements demonstrated that the doped hBN films were p-type conductive. At room temperature, the doped hBN films exhibited a free hole concentration of ∼1015 cm−3 and a resistivity of about 1000 Ω cm. X-ray photoelectron spectroscopy demonstrated the doping of carbon impurities into the hBN films and the formation of chemical bonds with B by mainly replacing nitrogen. Temperature-dependent I–V properties indicated that the ionization energy of the carbon impurities was about 320 meV.