We have investigated the surface activated bonding (SAB) of deposited Al2O3 films by chemical vapor deposition under a short-time condition at room temperature. Although energy for was very low, that film/sapphire approximately 1 J m − 2 and more than sapphire/sapphire bonding. Transmission electron microscopy showed an amorphous-like intermediate layer nm thick, observed interface Al2O3/Al2O3,...

The SAPPHIRE system is a powerful, extensible, object-oriented toolkit allowing researchers to rapidly build and configure customized speech analysis tools. Implemented in Tcl/Tk and C, the current version of SAPPHIRE provides a wide range of functionality, including the ability to configure and run the SUMMIT speech recognition system. We now use SAPPHIRE widely in almost all aspects of our sp...

Metalorganic vapor phase epitaxy (MOVPE) nucleation studies of GaN on planar sapphire and nanopatterned AGOG (Deposition of Aluminum, Growth of Oxide, and Grain growth) sapphire substrates were conducted. The use of abbreviated GaN growth mode, which utilizes a process of using 15 nm low-temperature GaN buffer and bypassing etch-back and recovery processes during epitaxy, enables the growth of ...

In the last few years aluminium nitride (AlN) has attracted much attention due to its extremely large direct band gap of approximately 6.0 eV and its impressive chemical and thermal stability. Thus AlN and AlxGa1-xN ternary alloys are promising materials for high-power high temperature electronic applications and optoelectronic devices in UV range. For group-III nitride wafers are still not ava...

Gallium nitride (GaN) thin films on sapphire substrates were successfully separated and transferred onto Si substrates by pulsed UVlaser processing. A single 600 mJ/cm, 38 ns KrF excimer laser pulse was directed through the transparent substrate to induce a rapid thermal decomposition of the GaN at the GaN/sapphire interface. The decomposition yields metallic Ga and N2 gas that allows separatio...

Abstract We design, fabricate, optically and mechanically characterize wearable ultrathin coatings on various substrates, including sapphire, glass silicon wafer. Extremely hard ceramic materials titanium nitride (TiN), aluminium (AlN), (TiAlN) are employed as reflective, isolated absorptive coating layer, respectively. Two types of have been demonstrated. First, we deposit TiAlN after TiN subs...

Hollow-sapphire and metal-dielectric-coated hollow-glass waveguides have been used to deliver CO(2) laser power for industrial laser applications. The transmission, bending loss, and output-beam properties of these waveguides are described. The bore sizes of the hollow-sapphire waveguides were 1070 and 790 μm, and the hollow-glass waveguide had a bore of 700 μm. The waveguides ranged in length ...

AlGaN/GaN high electron mobility transistors (HEMTs) are very promising for high power applications at microwave frequencies. The heterostructures are usually grown on SiC or sapphire substrates. Sapphire substrates are relatively cheap, but their low thermal conductivity is a major disadvantage. To improve the thermal performance, a hybrid integration of the HEMT onto an AlN carrier substrate ...

We have constructed a sliding block cryotribometer designed to measure friction at cryogenic temperatures and UHV conditions. An optical cryostat and high speed video was used to monitor the motion of the block. The temperature range of the measurements was 4–460 K. Both the static and dynamic friction coefficients were determined for a steel ball on stainless steel, sapphire, and PTFE (Teflon)...