Correlation of defect profiles with carrier profiles of InAs epilayers on GaP

The carrier profile for InAs films grown on GaP is modeled as a first-order approximation which assumes that 90 degrees edge dislocation intersections and the threading dislocation intersections act as shallow donors. Due to dislocation annihilation during growth, the threading dislocation intersect ion density decreases as the inverse of the distance x from the InAs/GaP in terface, D(x)=D(0)x(0)/(x(0)+x), where D-0 and x(0) are dislocation density at the InAs/GaP interface and the first annihilation position from the int erface, respectively. The carrier profile in InAs films can be described by a similar equation that is deduced from the threading dislocation intersec tion profile. The calculated carrier profiles agree well with measured carr ier profiles. This correlation supports our hypothesis that both the edge d islocation intersections and the threading dislocation intersections act as shallow donor sources. (C) 2001 American Institute of Physics.