PECVD synthesis of hexagonal boron nitride nanowalls from a borazine plus ammonia mixture

Hexagonal boron nitride nanowalls have been grown by plasma-enhanced chemical vapor deposition (PECVD) from a mixture of borazine (B3N3H6) and ammonia. As the deposition temperature increases from 100 to 700A degrees C, the structure of the films changes from amorphous to nanocrystalline, made up of three-dimensional nanowalls normal to the substrate. The ability to produce nanowalls depends on film growth conditions. We have examined the effect of synthesis temperature on the elemental composition and surface morphology of the films. The structure of the nanowalls has been determined by transmission electron microscopy, and the presence of a transition layer between the h-BN film and Si(100) substrate has been demonstrated. The lowest temperature at which nanowalls can be grown by PECVD is 300A degrees C. The films have high transmission in a wide spectral range (350-3200 nm). Their parameters suggest that the nanostructures in question can find application in microelectronics, optics, and catalysis.