Three-inch (100) gallium arsenide wafers were bonded to (1102) sapphire in a micro-cleanroom at room temperature under hydrophilic or hydrophobic surface conditions. Subsequent heating up to 500 ◦C increased the bond energy of the GaAs-on-sapphire (GOS) wafer pair close to the fracture energy of the bulk material. The bond energy was measured as a function of the temperature. Since the thermal ...

Current best practice in epitaxial growth of rhombohedral SiGe onto (0001) sapphire (Al2O3) substrate surfaces requires extreme conditions to grow a single crystal SiGe film. Previous models described the sapphire surface reconstruction as the overriding factor in rhombohedral epitaxy, requiring a high temperature Al-terminated surface for high quality films. Temperatures in the 850-1100°C rang...

We studied the sapphire and germanium fibers to determine which optical fiber best transmits Erbium:YAG laser for intracorporeal lithotripsy. Human calculi were ablated with an Erbium:YAG laser in contact mode using two fibers. Optical outputs at the distal end of fibers were measured before and after laser lithotripsy. Upon the irradiation on the calculus with the 50 mJ and 100 mJ pulse energy...

Copper films deposited on mand r-plane sapphire substrates have been dewetted in either the solid or the liquid state, and equilibrated at 1253 K. The orientation relationships (ORs) between the dewetted copper crystals and the sapphire substrates have been investigated by electron backscatter diffraction. In addition, the shape of the copper/sapphire interface has been studied by scanning elec...

GaN avalanche photodiodes APDs were grown on both conventional sapphire and low dislocation density free-standing FS c-plane GaN substrates. Leakage current, gain, and single photon detection efficiency SPDE of these APDs were compared. At a reverse-bias of 70 V, APDs grown on sapphire substrates exhibited a dark current density of 2.7 10−4 A /cm2 whereas APDs grown on FS-GaN substrates had a s...

We report on Gd ion implantation and magnetic characterization of GaN films on sapphire substrates and of bare sapphire and Si substrates to shed light on the mechanism underlying the induced magnetism upon Gd ion implantation. For all three hosts, giant magnetic moments per Gd ion were observed at temperatures of 5 through 300 K. The maximum moment per Gd in GaN was 1800μB , while the moments ...

In order to provide secure clamping with a low thermal conductance, some temperature detectors are held point contact sapphire ball clamps. While this method is increasingly common, the conductance across interface has not been well studied. We present direct measurement of such clamps between 200 and 600 mK, force approximately $$2.7\,\pm 0.3\,\hbox {N}/\hbox {clamp}$$ . The single sapphire-on...

Sapphire (Al2O3) crystals are used below 100 GPa as anvils and windows in dynamic-compression experiments because of their transparency and high density. Above 100 GPa shock pressures, sapphire becomes opaque and electrically conducting because of shock-induced defects. Such effects prevent temperature and dc conductivity measurements of materials compressed quasi-isentropically. Opacities and ...

UV InGaN and GaN single-quantum well structure light-emitting diodes (LEDs) were grown on epitaxially laterally overgrown GaN (ELOG) and sapphire substrates. When the emission wavelength of UV InGaN LEDs was shorter than 380 nm, the external quantum efficiency (EQE) of the LED on ELOG was much higher than that on sapphire, but only for highcurrent operation. At low-current operation, both LEDs ...

Primarily on the basis of data derived from the Stenting and Angioplasty With Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trial,1 the US Food and Drug Administration (FDA) has approved the use of carotid stents (CASs) in high-risk patients. The SAPPHIRE trial was published and much heralded as a randomized trial demonstrating that CASs were not inferior to carotid endarter...