Zn contamination in InGaAsP/InP DH structure grown by LPE

The Zn auto-doping phenomenon of DH structures grown by LPE was evaluated, using photoluminescence (PL) and SIMS analyses. From these analyses, it was found that Zn contamination of an undoped epitaxial film is rather large when a highly Zn-doped melt is adjacent to an undoped melt, and this amount is 5% of the total Zn doping level. But, if the melts are separated, the contamination can be much decreased to only 0.5% and as a result the undoped InGaAsP epi-layer contains much less Zn introduced from the heavily Zn doped InP layer.