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Highly split, visible light emissions at room temperature were observed in the range from 335 to 650 nm in silicon‐rich oxide filmsdeposited in the plasma phase of a mixture of silane and oxygen. The mechanism of the light emissions is classified into two categories. The photoluminescence bands at both 365 and 469 nm are related to the intrinsic defects of the E′ center and the neutral oxygen vacancy, respectively. However, the relatively sharp peaks at 403 and 535 nm are correlated with the development of polycrystalline core of Si‐enriched parts.

We found that the use of relatively low temperatures during oxide desorption in organometallic vapor‐phase epitaxy of GaAs reduced the epilayer–substrate interface charge. No differences in Hall mobility were found between the samples grown with 550 and 650 °C desorption. O, C, Si, and S were the dominant impurities at the interface. Si and S, which are shallow donors, induce the interface‐charge accumulation. Low‐temperature desorption leaves oxygen at the surface, suppressing the activation of shallow dopants. A high level (≳1×1012/cm2) of Cl was detected on every GaAs substrate we measured, but its effect on epitaxy is not clear.

While epitaxial CaF2 films grown on Si(111) at temperatures above 550 °C exhibited flat capacitance‐voltage (C‐V) curves, suggesting a pinned CaF2/Si(111) interface, we have observed unpinned C‐V curves from as‐deposited epitaxial CaF2 grown at 300 °C. Our results demonstrate that C‐V characteristics of CaF2/Si(111) are determined by the thermal history, rather than the crystalline quality, of the CaF2 film. Correlations among CaF2/Si interface state density, thermal stress, and atomic bonding at the interface are discussed.

We have studied the use of tertiarybutylarsine (t‐BuAsH2) for organometallic vapor phase epitaxy (OMVPE) growth of AlGaAs/GaAs heterojunction bipolar transistors (HBTs). Good dc characteristics were achieved with t‐BuAsH2‐grown HBT structures, including common‐emitter current gains higher than 200 and 1000 for n‐p‐n and p‐n‐p structures, respectively. Near‐ideal current gain dependence on the collector current density was observed, indicating that the quality of AlGaAs was suitable for high‐performance HBTs. The microwave characteristics were also comparable to those of arsine‐grown HBTs. These results demonstrate that t‐BuAsH2 can successfully replace arsine for OMVPE growth of AlGaAs/GaAs HBT structures.

An examination of low‐temperature photoluminescence from chemically thinned InP illustrates the effect of multiple absorption and reemission of photons in bulk liquid‐encapsulated Czochralski grown material. Luminescence spectra show that such photon recycling dramatically increases the nonequilibrium carrier density in the material and causes excess carrier distribution to penetrate tens of micrometers beneath the sample surface, an order of magnitude more than a diffusion length. Nonequilibrium carriers also penetrate deeper with increasing excitation levels as a consequence of more efficient radiative recombination. Although these effects have not been widely recognized, they have important consequences in the interpretation of luminescence spectra and the design of electronic and optical devices based on InP that are sensitive to minority‐carrier diffusion lengths.

The diffusion of Ge into GaAs from a thin elemental source using rapid thermal processing has been investigated. Several types of encapsulants and substrates have been examined. The diffusion and activation of Ge have been found to depend on both the encapsulant and substrate growth conditions. Photoluminescence spectroscopy indicates that Ga vacancies may control dopant diffusion and activation. Very shallow n+ junctions and nonalloyed ohmic contacts to semi‐insulating GaAs have been formed.