Chemical vapor deposition of sp2-boron nitride on Si(111) substrates from triethylboron and ammonia: Effect of surface treatments

Abstract

Thin films of the sp2-hybridized polytypes of boron nitride (BN) are interesting materials for several electronic applications such as UV devices. Deposition of epitaxial sp2-BN films has been demonstrated on several technologically important semiconductor substrates such as SiC and Al2O3 and where controlled thin film growth on Si would be beneficial for integration of sp2-BN in many electronic device systems. The authors investigate the growth of BN films on Si(111) by chemical vapor deposition from triethylboron [B(C2H5)3] and ammonia (NH3) at 1300 °C with focus on treatments of the Si(111) surface by nitridation, carbidization, or nitridation followed by carbidization prior to BN growth. Fourier transform infrared spectroscopy shows that the BN films deposited exhibit sp2 bonding. X-ray diffraction reveals that the sp2-BN films predominantly grow amorphous on untreated and pretreated Si(111), but with diffraction data showing that turbostratic BN can be deposited on Si(111) when the formation of Si3N4 is avoided. The authors accomplish this condition by combining the nitridation procedure with reactions from the walls on which BxC had previously been deposited.