Growth of hexagonal boron nitride on (111) Si for deep UV photonics and thermal neutron detection

Hexagonal boron nitride (hBN) growth was carried out on (111) Si substrates at a temperature of 1350 °C using a cold wall chemical vapor deposition system. The hBN phase of the deposited films was identified by the characteristic Raman peak at 1370 cm−1 with a full width at half maximum of 25 cm−1, corresponding to the in-plane stretch of B and N atoms. Chemical bonding states and composition of the hBN films were analyzed by X-ray photoelectron spectroscopy; the extracted B/N ratio was 1.03:1, which is 1:1 within the experimental error. The fabricated metal-hBN-metal devices demonstrate a strong deep UV (DUV) response. Further, the hBN growth on the vertical (111) surfaces of parallel trenches fabricated in (110) Si was explored to achieve a thermal neutron detector. These results demonstrate that hBN-based detectors represent a promising approach towards the development of DUV photodetectors and efficient solid-state thermal neutron detectors.