Superconductivity in Heavily Boron-Doped Diamond Films Prepared by Electron Assisted Chemical Vapour Deposition Method

Heavily boron-doped thick diamond films with higher superconducting transition temperatures have been prepared by electron assisted chemical vapour deposition method. The results of scanning electron microscopy, Raman spectroscopy, x-ray diffraction, and Hall effect indicate that the films have nice crystalline facets, a notable decrease in the growth rate, and an increase in the tensile stress. Meanwhile, the film resistivity decreases with the increase of the carrier concentration. Our measurements show that the films with 4.88×10²⁰cm^-3 and 1.61×10²¹cm^-3 carrier concentration have superconductivity, with onset temperatures of 9.7K (8.9K for zero resistance) and 7.8K (6.1K for zero resistance), respectively.