Effect of growth condition on electrical properties of MBE and MOCVD-AlInAs

The characterization of Al/sub x/In/sub 1-x/As layers grown on n/sup +/-InP substrates by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition has been carried out by I-V-T, C-V, deep level transient spectroscopy and admittance spectroscopy measurements. Three defect levels E1, E2, and E3 were observed in both material systems and their densities were found to increase rapidly from /spl sim/10/sup 12/ cm/sup -3/ to /spl sim/10/sup 16/ cm/sup -3/ as the growth temperature was decreased from 740/spl deg/C to 500/spl deg/C. The increased defect density was found to be correlated with the decrease of the barrier height of the Schottky diodes, and the appearance of defect-assisted tunneling current in MBE-diodes. The activation energy of the defect E3 was found to increase with increasing AlAs mole fraction, and likely correlating with the /spl Gamma/-conduction band of AlInAs materials.<>