LPE growth of InP and InGaAs and applications in fibre optics

Liquid phase epitaxy (LPE) is a very suitable growth technique for InGaAs detectors. The growth of high purity epitaxial layez wth low electron concentrationl0 cm however requires prolonged baking to reduce background impurity concentrations. This work reports the use of novel rare earth (RE) gettering technique to reduce background carrier concentration with nominal baking tirne. At a RE concentration of 8xlO atomic fraction the highest mobility was obtained. Beyond this while the carrier concentration and etch pit density decreased inonotonically , the mobility also decreased. SIMS and photoluininescence (PL) studies showed that the gettering effect was due to removal of silicon . For InGaAs similar results were obtained except that the layer showed type conversion at high RE concentrt5ion.Otimised layers with n = 2.4 x 10 cm ?ave been characterized through resistivity, Hall effect, PL and DXRD measurements. The narrow linewidths showed the exellent quality of the layers and interface.The present status of fiber-optic detectors grown by LPE as well as MOVPE will be compared as regards sensitivity, frequency response and data rate. The performwice of integrated fiber-optic receivers with GaAs FET preamplifier will also be discused.