EFFECTS OF RAPID THERMAL ANNEALING ON THE ELECTRICAL-PROPERTIES OF HEAVILY CARBON-DOPED INGAAS

The effects of rapid thermal annealing (RTA) on the electrical propert ies of carbon-doped InGaAs epilayers have been analyzed by the Van der Pauw-Hall measurement. After RTA, the highest hole concentration of 3 .3 x 10(20) cm(-3) at In0.09Ga(0.91)As epilayer was obtained. RTA proc esses cause the inactivated carbon atoms to be active by breaking C-H or C-H, bonds in the epilayers. This leads to the increase of the hole concentration. Below the InAs mole fraction of 0.35, we have obtained the maximum activation efficiency of the carbon atoms at the RTA temp erature of 650 degrees C. The activation efficiency decreased with inc reasing InAs mole fraction. The type conversion from p-type to n-type took place after RTA at the InAs mole fraction of 0.44, while it occur red at that of 0.48 in the as-grown. The reason for the shift of the t ype conversion to the lower value after RTA would be due to the outdif fusion of In atoms in the InGaAs epilayer, and the activated carbon at oms would more effectively enter into In sites than As sites due to th e outdiffusion of In atoms.