Surface structure of molecular beam epitaxy (211)B HgCdTe

The as-grown molecular beam epitaxy (MBE) (211)B HgCdTe surface has variable surface topography, which is primarily dependent on substrate temperature and substrate/epilayer mismatch. Nano-ripple formation and cross-hatch patterning are the predominant structural features observed. Nano-ripples preferentially form parallel to the [111] and are from 0 angstrom to 100 angstrom in height with a wavelength between 0.1 mu m and 0.8 mu m. Cross-hatch patterns result from slip dislocations in the three {111} planes intersecting the (211) growth surface. The cross-hatch step height is 4 +/- angstrom (limited data set). This indicates that only a bi-layer slip (Hg/Cd + Te) in the {111} slip plane occurs. For the deposition of MBE (211)B HgCdTe/CdTe/Si, the reorientation of multiple nano-ripples coalesced into "packets" forms cross-hatch patterns. The as-grown MBE (211)B CdTe/Si surface is highly variable but displays nanoripples and no cross-hatch pattern. Three types of defects were observed by atomic force microscopy (AFM): needle, void/hillock, and voids.