ABSTRACT
MIT Materials Science and Engineering, 77 Massachusetts Ave., Cambridge, MA 02139
ABSTRACT: The concept of relaxed graded layers is applied to the SiGe/Si, InGaAs/GaAs, and InGaP/GaP systems in order to achieve new flexibility in semiconductor integration. In graded composition layers, the threading dislocation density should remain constant once an equilibrium density is achieved. Deviations from this ideal case, resulting in higher threading dislocation densities, are due to microstructural features that inhibit dislocation flow. By eliminating the obstruction in each material system, a steady-state residual threading dislocation density can be achieved resulting in high quality lattice mismatched materials on commercially available binary compound substrates.
