Abstract: An apparatus (295) using specular reflection spectroscopy to measure a temperature of a substrate (135). By reflecting light (100) from a substrate, the temperature of the substrate can be determined using the band-edge characteristics of the substrate. This in situ apparatus can be used as a feedback control in combination with a variable temperature substrate holder to more accurately control the processing conditions of the substrate. By utilizing a multiplicity of measurement sites, the variation of the temperature across the substrate can also be measured.

Abstract: The invention discloses improved structures of light-processing (e.g. light-emitting and light-absorbing/sensing) devices, in particular Vertical Cavity Surface Emitting Lasers (VCSELs), such as may find use in telecommunications applications. The disclosed VSCAL devices and production methods provide for an active region having a quantum well structure grown on GaAs-containing substrates, thus providing processing compatibility for light having wavelength in the range 1.0 to 1.6 ?m. The active region structure combines strain-compensating barriers with different band alignments in the quantum wells to achieve a long emission wavelength while at the same time decreasing the strain in the structure. The improved functioning of the devices disclosed results from building them with multicomponent alloy layers having a large number of constituents.

Abstract: A method of fabricating a semiconductor device, such as a high electron mobility transistor, a vertical cavity surface emitting laser, an edge emitting laser, a heterostructure bipolar transistor, a resonant tunneling diode, and the like, is disclosed that includes the steps of depositing a plurality of layers of semiconductor material including at least one active area with opposed major surfaces and a cladding layer adjacent each opposed major surface. In the disclosure, the semiconductor material is in an aluminum/gallium arsenide semiconductor system. At least one of the active area and the cladding layers are deposited at relatively low temperatures in the presence of a surfactant, such as antimony, indium, bismuth or thallium to produce greatly improved carrier mobility and surface morphology.

Abstract: An apparatus (295) using specular reflection spectroscopy to measure a temperature of a substrate (135). By reflecting light (100) from a substrate, the temperature of the substrate can be determined using the band-edge characteristics of the substrate. This in situ apparatus can be used as a feedback control in combination with a variable temperature substrate holder to more accurately control the processing conditions of the substrate. By utilizing a multiplicity of measurement sites, the variation of the temperature across the substrate can also be measured.

Abstract: A compound semiconductor device is provided that includes a substrate and an active region disposed above the substrate. The active region includes at least two different pseudomorphic layers, the first layer having the form InxGa1−xPyAszSb1−y−z, and the second layer having the form InqGa1−qPrAssSb1−r−s. The first layer includes at least In, Ga, and As, and the second layer includes at least Ga, As, and Sb. It is preferable for the substrate to be GaAs or AlpGa1−pAs (0<p<1), or to have a lattice constant close to or equal to that of GaA For the first layer, it is preferable if x is between 0.05 and 0.7, y is between 0 and 0,35, z is between 0.45 and 1, and 1−y−z is between 0 and 0.25. For the second layer, it is preferable if q is between 0 and 0.25 and 1−r−s is between 0.25 and 1.