Semi-insulating In_0.49Ga_0.51P grown at reduced substrate temperature by low-pressure metalorganic chemical vapor deposition

High-resistivity unintentionally-doped In_0.49Ga_0.51P lattice matched to GaAs has been grown via low-pressure metalorganic chemical vapor deposition at a reduced growth temperature. These layers have excellent surface quality and are single crystal. The resistivity increases exponentially as the growth temperature is decreased from 550 to 490 °C, resulting in a resistivity of ∼10⁹ Ω cm for samples grown at 490 °C. In addition, the photoluminescence intensity decreases exponentially for growth temperatures below 550 °C, indicating an increase in nonradiative recombination related to an increasing trap concentration. For samples grown at 550 °C, constant capacitance deep level transient spectroscopy measurements show a strong broad peak at ∼200 °K with an ionization energy of 0.40±0.04 eV, verifying the presence of an electron trap. The gummel plot and I–V characteristics of an InGaP/GaAs heterojunction bipolar transistor (HBT) with a 2000-Å-thick InGaP buffer layer grown at 500 °C are identical to that of an HBT grown without the InGaP buffer layer, indicating that the semi-insulating InGaP layer is compatible with GaAs-based device epitaxy. © 1997 American Institute of Physics.