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Trimethylarsenic as an alternative to arsine in the metalorganic vapor phase epitaxy of device quality In0.53Ga0.47As/InP Appl.High-quality In 0.53 Ga 0.47 As epilayers have been grown on semi-insulating ͑100͒ Fe-doped InP substrates. The growths were performed by liquid phase epitaxy ͑LPE͒ using rare-earth-doped melts in a graphite boat. The rare-earth elements studied were Yb, Gd and Er which act as gettering agents of impurities. Hall measurements show an elevated electron mobility for rare-earth-treated samples over undoped samples, e ϭ11 470 cm 2 /V s at 300 K and reduced carrier concentration ͑n-type͒, 9.33ϫ10 13 cm Ϫ3 . The Hall results indicate an improvement in layer quality, but suggests that the treated layers are compensated. Photoluminescence ͑PL͒ studies show that the layers grown from rare-earth-doped melts have higher integrated PL efficiency with narrower PL linewidths than the undoped melt growths. The grown materials were fully characterized by Fourier transform infrared spectroscopy, double-crystal x-ray diffraction, energy dispersive spectroscopy, secondary-ion-mass spectroscopy, and deep level transient spectroscopy ͑DLTS͒. Compositional measurements reveal no measurable incorporation of rare-earth elements into the grown epilayers. DLTS measurements indicate the creation of two deep levels with rare-earth treatment, which is attributed to either the rare earth elements or impurities from within the rare-earth elements. Subsequent glow discharge mass spectrometry measurements reveal many impurities within the rare-earth elements which preferentially might lead to p-type doping centers and/or deep levels. Thus, rare-earth doping of LPE melts clearly improves epitaxial layer quality, however, the purity of commercially available rare-earth elements hinders optimal results.

The hole concentrations and lattice mismatch with the GaAs substrate of heavily carbon-doped epilayers (4.7×1019 and 9.8×1019 cm−3) were increased and the mobilities were decreased as compared with the as-grown samples by rapid thermal annealing silicon nitride capped samples at temperatures from 500 to 900 °C. However, for the more heavily doped sample, the hole concentration, mobility, and lattice mismatch decreased with increasing annealing temperature for annealing temperatures higher than 700 °C, but the hole concentration and lattice mismatch were still larger than those of the as-grown samples. Secondary ion mass spectroscopy results showed that annealing produced no change in the C concentration or distribution, but the hydrogen concentration decreased. Cross-sectional transmission electron microscopy indicated that no mismatch dislocations formed at the interface.