Abstract: A method of etching and regrowing III-V compounds in a sharply defined vertical feature. Molecular beam epitaxy is used to grow a laterally undefined vertical-cavity, surface-emitting diode laser structure from semiconducting III-V materials. The structure includes interference mirrors defining the end of a Fabry-Perot cavity and a quantum-well layer in the middle of the cavity. A tungsten mask is then defined over the areas of the intended two-dimensional array of lasers. A chemically assisted ion beam etches through to the bottom of the laser structure to from an array of high aspect-ratio pillars. A thermal chlorine gas etch removes a portion of the sidewalls of the pillars without attacking the tungsten, thereby removing ion-beam damage at the sides of the vertical-cavities and creating a lip of the tungsten mask overhanging the pillar sidewall. Organo-metallic chemical vapor deposition is used to regrow III-V material around the pillars. This growth process can quickly planarize the pillars.

Abstract: A semiconductor structure having a face with macroscopic parallel steps and its method of making. The structure is formed by cutting a face on a crystal at a vicinal angle, that is, being misoriented from a major crystal face by a few degrees. Atomic sized microsteps are formed in the vicinal face. Parallel grooves or other regular irregularities are etched in the vicinal face. Subsequent epitaxial growth causes the microsteps to coalesce into macroscopic steps. Alternatively, etching or annealing can accomplish the same coalescing. Novel electronic structures can be fabricated on the stepped structure.

Abstract: A method and apparatus for epitaxial growth of precisely one monolayer. The growth is by organometallic chemical vapor deposition in which the substrate is alternately exposed to the anion and cation of a III-V compound. During deposition of the cation, for instance Ga or Al, reflectance difference spectroscopy is performed to obtain the difference of reflected light beams polarized in orthogonal directions. A growth of a monolayer and even of a partial monolayer can be monitored in real time.

Abstract: A planar waveguide comprises a semiconductor substrate having one or more grooves along the surface of the substrate. A plurality of sequences of superlattice layers separated by a spacer layer over the grooved substrate is provided. The number of superlattice periods in each sequence changes from the base of the groove to the surface of the waveguide so as to provide a graded index of refraction in at least a portion of the region above the groove.