ELECTRICAL-PROPERTIES OF RAPID THERMAL ANNEALED CARBON-DOPED INGAAS GROWN BY ATMOSPHERIC-PRESSURE METALORGANIC CHEMICAL-VAPOR-DEPOSITION

We present the changes in the carrier concentration and the mobility o f heavily carbon-doped InGaAs epilayers caused by rapid thermal anneal ing (RTA). In the region of low InAs mole fraction, the hole concentra tion shows a peak at a RTA temperature of 650 degrees C. Beyond this t emperature, the hole concentration decreases. However, its value is st ill higher than that of as-grown InGaAs epilayers. The maximum value o f the hole concentration is measured to be 3.3x10(20) cm(-3) at an InA s mole fraction of 0.09 after RTA. The type conversion from p-type to n-type is observed at an InAs mole fraction of 0.44 and 0.48 for the r apid thermal annealed and the as-grown carbon-doped InGaAs epilayers. For the case of In0.52Ga0.48As epilayers, the carrier concentration in creases gradually with increment of annealing temperature. This can be explained by the fact that carbon atoms broken by thermal energy occu py the substitutional In sites in the In0.52Ga0.48As epilayer.