Super-flat interfaces in In0.53Ga0.47As/In0.52Al0.48As quantum wells grown on (411)A InP substrates by molecular beam epitaxy

High-quality InAlAs layers grown on (411)A-oriented InP substrates by molecular beam epitaxy

“…1,2 Photoluminescence ͑PL͒ linewidths ͑4.2 K͒ of ͑411͒A GaAs/AlGaAs QWs are much narrower than those of QWs grown on conventional ͑100͒ substrates, and they are comparable to those of split peaks of ͑100͒ growthinterrupted QWs. 3 In our recent studies, the ͑411͒A super-flat interfaces have been also achieved in MBE grown pseudomorphic In x Ga 1Ϫx As/Al 0.3 Ga 0.7 As QWs with xϳ0.08 4 and xϳ0.15 5 and In 0.53 Ga 0.47 As/In 0.52 Al 0.48 As QWs lattice matched to InP substrates, 6 which are important materials for ultrahigh speed devices such as high electron mobility transistors ͑HEMTs͒, resonant tunneling diodes ͑RTDs͒, and long-wavelength optical devices. In order to achieve highquality InGaAs/InAlAs heterostructures with the ͑411͒A super-flat interfaces, MBE growth of a high-quality InAlAs barrier layer is essential.…”

Super-flat interfaces in pseudomorphic In0.72Ga0.28As/In0.52Al0.48As quantum wells grown on (411)A InP substrates by molecular beam epitaxy

“…6 In the ͑100͒ QWs, smooth surfaces and flat interfaces were obtained at T s ϭ480°C under V/IIIϭ14, while PL linewidths observed from (411)A QWs were broader than those from ͑100͒ QWs and about twice broader than those from ͑411͒ QWs grown under the best growth conditions. In the case of the lattice-matched QWs, the (411)A super-flat interfaces were realized at high growth temperature (T s ϭ540°C) under low As 4 pressure ͑V/III ϭ8͒, while rough surfaces were observed for the ͑100͒ samples.…”

DC and RF Performance of 50 nm Gate Pseudomorphic In0.7Ga0.3As/In0.52Al0.48As High Electron Mobility Transistors Grown on (411)A-Oriented InP Substrates by Molecular-Beam Epitaxy

“…Details of the growth conditions were described elsewhere. 5,6) The epitaxial layers consisted of, from bottom to top, a 25-nm-thick In 0.53 Ga 0.47 As buffer layer, a 300-nm-thick In 0.52 Al 0.48 As buffer layer, a 12nm-thick pseudomorphic In 0.7 Ga 0.3 As channel layer, a 3-nmthick In 0.52 Al 0.48 As spacer layer, a Si delta-doping sheet with a density of 1.06×10 13 cm −2 , a 20-nm-thick In 0.52 Al 0.48 As substrate. The electron mobility in the (411)A HEMT was 1.3 times higher than that in the (100) HEMT even at 298 K; 10500 and 8000 cm 2 /V·s, respectively.…”

“…5,6) The QWs on (411)A InP substrates showed narrower linewidths of PL peaks than the QWs on conventional (100) InP substrates, indicating that InAlAs-on-InGaAs and/or InGaAs-on-InAlAs interfaces of the (411)A InP-based QWs are extremely flat compared to those of the (100) QWs. Therefore, high electron mobility can be expected in the two-dimensional electron gas formed in the (411)A InP-based HEMTs since the interface roughness scattering of electrons should be suppressed drastically.…”