The role of hydrogen in carbon incorporation and surface roughness of MOCVD-grown thin boron nitride

Chemical Vapor Deposition Growth of BN Thin Films Using B2H6 and NH3

“…The Raman shift at 1369 cm −1 , which is attributed to the first‐order E 2g symmetry vibrational mode in h ‐BN owing to the in‐plane stretching of B and N atoms, is observed. The sample exposed to 1000 cycles showed a FWHM of 20 cm −1 , comparable with the reported values for BN films fabricated by MBE or by CVD . Considering other III‐nitrides, the FWHM of the Raman spectrum depends on the dislocation density along with stacking faults, misalignment, tilt, and mosaic spread.…”

“…In this respect, wafer‐scale thin‐film growth methods, such as CVD or molecular beam epitaxy (MBE), are preferable to realize device applications. Many research groups have reported thermal CVD of BN thin films with a wide variety of boron precursors, such as borazine (B 3 N 3 H 6 ), boron‐halides (BF 3 , BCl 3 , and BBr 3 ), and triethyl boron ((C 2 H 5 ) 3 B, TEB), on sapphire, SiC, Ni, and Cu substrates. For borazine, it is difficult to control the N/B ratio, which leads to turbostratic boron nitride ( t ‐BN), a disordered phase of h ‐BN.…”

“…Using diborane (B 2 H 6 ) gas, which is one of the most widely used precursor materials for B doping in the semiconductor industry, is expected to result in high‐purity BN films because it does not contain Cl, Br, or C atoms in the raw material . However, there have been only a few reports of h ‐BN growth on Al 2 O 3 substrates using B 2 H 6 .…”

Growth Temperature Effects of Chemical Vapor Deposition‐Grown Boron Nitride Layer Using B2H6 and NH3

“…Honeycomb‐like wrinkle patterns were clearly observed when the T g of 1360 and 1220 °C were applied. These features are often observed with CVD‐grown h ‐BN films on Al 2 O 3 substrates and can be explained by the difference in the in‐plane thermal expansion coefficients between h ‐BN and Al 2 O 3 . h ‐BN has a negative in‐plane thermal expansion coefficient of −2.7 × 10 −6 K −1 , whereas Al 2 O 3 has a positive coefficient of 5.0 × 10 −16 K −1 .…”

“…Many research groups have reported BN growth by thermal chemical vapor deposition (CVD), plasma‐assisted CVD, and molecular beam epitaxy (MBE) . The growth conditions include a wide varieties of boron precursors of borazine (B 3 N 3 H 6 ), boron halides (BF 3 , BCl 3 , BBr 3 ), triethylboron ((C 2 H 5 ) 3 B, TEB), trimethylboron ((CH 3 ) 3 B, TMB), and diborane (B 2 H 6 ) . Also, various substrates for BN growth were investigated, such as sapphire, SiC, Ni, and Cu …”