Investigation of nanopatterned c-plane sapphire Substrates for Growths of polar and nonpolar GaN epilayers

Achieve high-quality GaN films on La0.3Sr1.7AlTaO6 (LSAT) substrates by low-temperature molecular beam epitaxy

“…As comparison, Table 1 lists the up-to-date results for deviceready GaN films grown on the three most popular substrates for GaN including sapphire, SiC, and Si substrates using conventional high-temperature growth techniques such as MOCVD, HVPE (hydride vapour phase epitaxy) or MBE. [19][20][21][22][23][24][25][26] The surface roughness for these films varies from 0.2 to 2.3 nm, which is about the same level as what we have achieved for GaN grown on LSAT at 500 uC. Clearly, the GaN film grown on LSAT at low temperature has a very smooth and deviceready surface.…”

“…For comparison, Table 1 gives the recently reported results for device-ready GaN films grown at high temperature on those three popular substrates. [19][20][21][22][23][24][25][26] It can be found that GaN film grown on LSAT at 500 uC is competitive with those grown on the commercially popular substrates in terms of film crystallinity. Actually, we believe the crystallinity of GaN grown on LSAT can be further improved given more effort is taken.…”

Epitaxial growth and its mechanism of GaN films on nitrided LiGaO2(001) substrates by pulsed laser deposition

“…It is reported that up-to-date RMS roughness for device-ready GaN films is about 1.1 nm, which is achieved in the three most popular substrate cases, sapphire, SiC, and Si substrates, using conventional high-temperature growth techniques such as MOCVD, HVPE (hydride vapour phase epitaxy) or MBE. [26][27][28][29][30][31][32][33] Clearly, the up-to-date RMS roughness value is similar to that of the GaN films grown on nitrided LiGaO 2 substrates in this work. Apparently, the GaN film on the nitrided LiGaO 2 substrate shows a very smooth and device-ready surface.…”

Epitaxial growth of GaN films on unconventional oxide substrates

“…Furthermore, the surface roughness of GaN grown on LSAT at 500 C is in the same level as the up-todate results for device-ready GaN lms grown on sapphire, SiC, and Si substrates using conventional high temperature growth techniques such as MOCVD, HVPE (hydride vapour phase epitaxy), PLD or MBE. [65][66][67][68][69][70][71][72][73][74] Evidently, a low temperature GaN buffer layer is an effective way to achieve high-quality GaN lms for GaN-based devices.…”