Gas source chemical vapor deposition of hexagonal boron nitride on C-plane sapphire using B2H6 and NH3

Chemical vapor deposition (CVD) of hexagonal boron nitride (hBN) using diborane (B2H6) and ammonia (NH3) is reported. The effect growth conditions on hBN rate continuous vs. flow modulation epitaxy (FME) method investigated to gain insight into the role gas-phase chemistry during film deposition. In mode, decreases with increase in temperature, reactor pressure, decrease gas velocity. This attributed increased polymerization intermediate products such as borazine (B3N3H6) which forms high molecular weight species that do not contribute growth. Using FME method, increases by ~ 25 times compared mode exhibits a strong positive dependence substrate temperature an activation energy 61.1 kcal/mol, indicative kinetically limited process. results provide additional effects reactions CVD hBN.