Data are presented demonstrating low-resistance Ohmic conduction across interfaces formed by high-temperature (750–1000 °C) compound semiconductor wafer bonding. Unipolar junctions formed by wafer bonding surfaces consisting of In0.5Ga0.5P/In0.5Ga0.5P, GaP/GaP, GaP/In0.5Ga0.5P, and In0.5Ga0.5P/GaAs are shown to exhibit low-resistance Ohmic conduction for both p- and n-isotype junctions. The achievement of these properties is demonstrated to be critically dependent upon the crystallographic alignment of the bonded wafer surfaces, irrespective of the lattice mismatch between the surfaces. Specifically, we show that the surface orientation of the bonded surfaces must be nominally matched while simultaneously maintaining rotational alignment of the wafers.

No abstract

No abstract

No abstract

This application discloses, to the best of our knowledge, the first unipolar laser. An exemplary embodiment of the laser was implemented in the GalnAs/AlInAs system and emits radiation of about 4.2 um wavelength. Embodiments in other material systems are possible, and the lasers can be readily designed to emit at a predetermined wavelength in a wide spectral region. We have designated the laser the "quantum 20 Claims, 5 Drawing Sheets 122 5,457,709 Page 2 OTHER PUBLICATIONS "Mid-infrared Field-tunable Intersubband Electrolumines "Staircase Solid-State Photomultipliers and Avalanche Pho-cence at Room Temperature by Photon-assisted Tunneling todiodes with Enhanced Ionization Rates Ratio," by F. led Wells by J. Fai ied Physi