Growth of AlInAs using low-oxygen-content metalorganic precursors and application to HEMT structures

An AlInAs layer and high electron mobility transistor (HEMT) structures were grown using low-oxygen-content metalorganic precursors by metalorganic vapor phase epitaxy (MOVPE). The oxygen concentration in the AlInAs layer measured by secondary ion mass spectrometry (SIMS) was 7 × 10¹⁵ cm^-3. Moreover, the mobility and sheet carrier concentrations of the AlInAs/InP HEMT structure in which a 2.5 μm-thick AlInAs buffer layer was inserted to reduce the diffusion of impurities from the substrate surface, were 5,500 cm²/Vs and 1.0 × 10¹² cm^-2 at 300 K, and 110,000 cm²/Vs and 8.7 × 10¹¹ cm^-2 at 77 K, respectively. For the AlInAs/GaInAs HEMT structure with the same buffer layer, mobility and sheet carrier concentrations were 12,000 cm²/Vs and 1.2 × 10¹² cm^-2 at 300 K, and 92,000 cm²/Vs and 1.2 × 10¹² cm^-2 at 77 K, respectively.