ABSTRACT
GaAs/InGaAs strained quantum well (QW) structures are expected to be useful in such device applications as high-speed lasers and infrared photodetectors [1,2]. It is now well known that misfit dislocations are formed at the interfaces between the two materials when the layer thickness becomes more than a critical value. The introduction of misfit dislocations degrades the electronic and optical properties in these structures, because such dislocations act as electrically active defects [3]. Hence many attempts have been made to evaluate the critical layer thickness and to understand the formation mechanism of misfit dislocations.
