Impurity gettering effect in Pr₂O₃-added InGaAs liquid phase epitaxy

InGaAs epilayers were grown on semi-insulating (SI) InP substrates by liquid phase epitaxy (LPE) with a rare-earth (RE) compound Pr₂O₃ added into the growth melt during the epitaxial process for the first time. Without the growth melt baking process, the corresponding Hall measurements indicate that the background concentration of these InGaAs-grown layers will decrease from a value of 1.6 × 10¹⁶ cm^-3 to 2.0 × 10¹⁵ cm^-3. Their corresponding 77K mobility also increases significantly from a value of 15321 cm²/V·s to 32171 cm²/V·s. The X-ray diffraction measurements, secondary ion mass measurements (SIMS) and photoluminescence (PL) spectra of Pr₂O₃-added InGaAs epitaxial layers all demonstrate that the grown layers exhibit pure crystalline quality. Finally, InGaAs/InGaAs/InP pin diodes were fabricated, and a smaller leakage current and better response for the Pr₂O₃-added samples were reported.