Dielectric constant of boron nitride films synthesized by plasma-assisted chemical vapor deposition

Polycrystalline boron nitride (BN) films are synthesized by plasma-assisted chemical vapor deposition using BCl3 and N-2 as source gases. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared absorption (FTIR) measurements are carried out to characterize the BN films. Capacitance-voltage (C-V) characteristics are measured for Au/BN/p-Si samples. The dielectric constant is estimated from the capacitance in the accumulation region and the film thickness. A dielectric constant as low as 2.2 is achieved for the BN film. It is found that incorporation of carbon atoms into BN films is effective in reducing the dielectric constant.