In situ gravimetric monitoring of surface reactions between sapphire and NH3

Epitaxial CVD growth of sp2‐hybridized boron nitride using aluminum nitride as buffer layer

“…The XRD result suggests that the grown sp 2 BN film is highly oriented since only peaks from the (000 l ) planes are observed for this measurement. Also for the AlN buffer layer only peaks originating from the (0002) and (0004) planes are found at 36.0° and 76.2°, respectively, indicating that the AlN formed by nitridation grows as AlN (0001) on α‐Al 2 O 3 (0001), as previously reported 11, 12.…”

“…In order to reduce the lattice mismatch between α‐Al 2 O 3 and sp 2 BN (in‐plane axis 4.67 Å and 2.50 Å, respectively 4) an AlN (in‐plane axis 3.11 Å 4) buffer layer was introduced. The formation of the AlN layer was achieved through nitridation of the α‐Al 2 O 3 surface 11, 12 by introducing ammonia in the reactor with a NH 3 /H 2 molar fraction of 0.13% at the growth temperature for 10 min. The deposition of the BN film was initiated by adding TEB to the gas mixture and adjusting the ammonia flow after the nitridation step to obtain the required N/B ratio.…”

In situGravimetric Monitoring of Thermal Decomposition and Hydrogen Etching Rates of 6H-SiC(0001) Si Face

“…9) In this study, the thermal stability and hydrogen etching rates of a 6H-SiC(0001) Si-face substrate at high temperatures are investigated using an in situ gravimetric monitor-ing (GM) system. This system can provide direct information on the weight change of a submonolayer substrate in realtime at a high temperature of approximately 1500 C. It has been used for the investigation of the surface reaction mechanisms in GaAs, 18) GaN, 19) and sapphire [20][21][22] substrates. The thermal decomposition and H 2 etching mechanisms of the 6H-SiC Si-face are discussed by on the basis on direct information on the substrate weight change.…”

Epitaxial AlN on c-plane sapphire by plasma nitriding

“…It has been also shown that sapphire can be decomposed by NH 3 and/or hydrogen. [44][45][46] Compared to the past studies for the nitridation of sapphire which show formation of a few monolayer thick AlN layer after long time exposure to the N 2 RF plasma, [26][27][28][29][30][31][32]47) we can obtain ∼270 nm thick AlN layer after 30 min exposure to the nitrogen plasma with hydrogen in MW plasma. In study of nitriding of aluminum oxide in a MW discharge, Ref.…”