Dislocation Reduction in HgCdTe Mesa Structures Formed on CdTe/Si

Mercury cadmium telluride (MCT) epilayers have been grown on CdTe/Si using molecular beam epitaxy and 8- μ m-deep mesa structures formed using plasma etching. Following previous work done on etching mesas and subjecting material to thermal cycle annealing, we set out to determine the limits and underlying physics of dislocation reduction in mesa-etched and annealed MCT. This paper describes the dependence of dislocation reduction on anneal time, cycle annealing, temperature, and etch depth. We show dislocation density reduction below 3 × 10 5 cm −2 in 10- μ m-wide, long-bar mesas along the [ 0 1 ¯ 1 ] orientation with only a 5-min anneal at 400°C.