LIQUID-PHASE EPITAXY GROWTH OF INGAAS WITH RARE-EARTH GETTERING - CHARACTERIZATION AND DEEP-LEVEL TRANSIENT SPECTROSCOPY STUDIES

The liquid phase epitaxial growth of high purity InGaAs layers lattice matched to InP has been studied using rare earth dysprosium (Dy) as a n impurity getter. Using this getter, the electron concentration decre ased from 1.2 x 10(18) cm(-3) to 1 x 10(15) cm(-3) while the mobility at 300K increased from 3920 to 10200 cm(2)/V-s. The epilayers were cha racterized by resistivity, Hall effect, electrochemical capacitance-vo ltage profiling, photoluminescence, secondary ion mass spectroscopy, d ouble crystal x-ray diffractometry, and deep level transient spectrosc opy (DLTS). Significant improvement was observed in both electrical an d optical properties of the layers with an increasing amount of Dy in the melt. The amount of Dy was thus optimized (6 x 10(-4) atomic fract ion) for the highest purity layer. The major background impurity was i dentified as silicon. The gettering of both accepters, as well as dono rs, by Dy was established and gettering of oxygen was confirmed for th e first time through DLTS studies.