GROWTH OF INGAAS/INP OPTICAL MODULATOR STRUCTURES BY CHEMICAL BEAM EPITAXY

We show that the alloy composition and the period length of InGaAs/InP multiple quantum wells grown by chemical beam epitaxy is sensitive to the growth temperature and the As overpressure. Around 530-degrees-C, the inhomogeneous broadening of absorption edge due to growth temperature instability is more of a consequence of changing period length than the ternary composition. The arsenic overpressure dependence of the ternary composition is investigated by secondary ion mass spectroscopy for the first time. The Ga/In ratio becomes smaller at high arsine flow rate. Superlattices containing 50-100 periods of InGaAs/InP exhibit x-ray diffraction peak widths comparable to the InP substrate can be prepared under continuous growth mode. Clear quantum confined Stark effect is observed in the electroabsorption characteristics of a 74-period modulator.