Abstract: Method for forming metal alkyl compounds by the direct combination of metal halide, lithium metal, and alkyl or aryl halide and for purifying metal alkyl compounds by repeated sublimation/pumping cycles. The method can be used to produce metal alkyl compounds which are substantially free of volatile impurities.

Abstract: Semiconductor grade tungsten hexafluoride (WF.sub.6) is produced by reacting tungsten metal with a recirculating flow of gaseous WF.sub.6 containing a small concentration of fluorine in a heated reactor. The high purity WF.sub.6 produced is useful for deposition of tungsten metallization in fabricating VLSI integrated circuitry.

Abstract: The present invention provides for improved methods of fabricating layered materials which are epitaxially grown on an electrically conductive single crystal substrate. The improved methods comprise the step of applying an electrochemical potential between the layered material/substrate and a counter electrode to oxidize and dissolve a thin etch layer positioned between the film and substrate, to thereby free the layered material from the substrate.

Abstract: A visual display system is disclosed which utilizes one- and/or two-dimensional arrays of visible emitting vertical-cavity surface-emitting lasers (VCSELs) in order to provide a desired visual display within an observer's field of view. Sweep and subscanning techniques are employed, individually or in combination, to create a full M.times.N image from 1.times.L or K.times.L arrays of VCSELs, where M and N are multiple integers of K and L, respectively. Preferably, the VCSELs are contained within a display housing which may be attached to the head of the user by an attachment mechanism or may alternatively be hand held or mounted to a surface. The circular symmetry and low divergence of the emitted VCSEL radiation as well as the availability of multiple wavelengths, particularly, red, blue and green, allow high resolution monochrome or color images to be generated.

Abstract: Optoelectronic integrated circuits are disclosed comprising a vertical-cavity surface emitting laser (VCSEL) and a transistor. The VCSEL comprises a laser cavity sandwiched between two distributed Bragg reflectors. The laser cavity comprises a pair of spacer layers surrounding one or more active, optically emitting quantum-well layers having a bandgap in the visible range which serve as the active optically emitting material of the device. The thickness of the laser cavity is m .lambda./2n.sub.eff where m is an integer, .lambda. is the free-space wavelength of the laser radiation and n.sub.eff is the effective index of refraction of the cavity. Electrical pumping of the laser is achieved by heavily doping the bottom mirror and substrate to one conductivity-type and heavily doping the regions of the upper mirror with the opposite conductivity type to form a diode structure and applying a suitable voltage to the diode structure.

Abstract: A three-dimensional optical interconnection is disclosed having a stack of vertically aligned optoelectronic integrated (OEIC) modules. Each OEIC module includes an array of vertical cavity surface emitting lasers (VCSEL), receivers and electronic logic which are monolithically integrated on a single semiconductor substrate. Communication between the OEIC modules is effectuated by the free space propagation of laser radiation from the VCSELs to corresponding receivers on an adjacent OEIC module. Transistors, such as heterojunction bipolar transistors, may be used to drive the VCSELS.

Abstract: Vertical-cavity surface-emitting lasers (VCSELs) are disclosed having various intra-cavity structures to achieve low series resistance, high power efficiencies, and TEM.sub.00 mode radiation. In one embodiment of the invention, a VCSEL comprises a laser cavity disposed between an upper and a lower mirror. The laser cavity comprises upper and lower spacer layers sandwiching an active region. A stratified electrode for conducting electrical current to the active region is disposed between the upper mirror and the upper spacer. The stratified electrode comprises a plurality of alternating high and low doped layers for achieving low series resistance without increasing the optical absorption. The VCSEL further comprises a current aperture as a disk shaped region formed in the stratified electrode for suppressing higher mode radiation. The current aperture is formed by reducing or eliminating the conductivity of the annular surrounding regions.