Effects of fluorine incorporation and forming gas annealing on high-k gated germanium metal-oxidesemiconductor with Ge O 2 surface passivation Appl. Phys. Lett. 93, 073504 (2008); 10.1063/1.2966367Electronic structure and thermal stability of nitrided Hf silicate films using a direct N plasma

A modified aqueous sol-gel route was developed using ultrasonic power for the silica coating of indium tin oxide (ITO) nanoparticles. In this approach, organosilane with an amino functional group was first used to cover the surface of as-received nanoparticles. Subsequent silica coating was initiated and sustained under power ultrasound irradiation in an aqueous mixture of surface-treated particles and epoxy silane. This process resulted in a thin but homogeneous coverage of silica on the particle surface. Particles coated with a layer of silica show better dispersability in aqueous and organic media compared with the untreated powder. Samples were characterized by high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and the zeta potential.

Inductively coupled plasma etching of InP using HBr/O 2 -based chemistry is reported. With the introduction of oxygen in the HBr plasma, high etching rate, smooth surface morphology, and vertical sidewall profile were achieved due to sidewall passivation and enhancement of ion-assisted chemical etching. The etching behavior was systematically studied by varying different process parameters, i.e., O 2 flow rate, pressure, reactive ion etching power, and inductively coupled plasma power, in a ridge array structure with a ridge width of 1 m and a ridge spacing of 1 m. InP nanopillars with an aspect ratio of ϳ6.7 were demonstrated using this chemistry. The X-ray photoelectron spectroscopy results suggested that the etched sample surface was P-rich.Plasma etching has the advantages over chemical etching for the possibility of obtaining an anisotropic etching profile and better uniformity over the entire wafer. InP has been used extensively for the fabrication of various photonic devices, such as semiconductor lasers with an emission wavelength around ϳ1.55 m for optical communication purpose. High aspect ratio etching is often required for photonic crystals, distributed Bragg reflectors, ridge structures, etc. The critical part in realizing high aspect ratio etching is to get a straight vertical profile. Most of the plasma etchings for InP-based material systems employ either CH 4 /H 2 -or Cl 2 -based chemistries. 1-3 Etching of InP using CH 4 /H 2 is complicated because of the slow etching rate, indium enrichment, and polymer formation. 4 A substrate temperature over 200°C is required to produce highly anisotropic sidewalls using Cl 2 -based chemistry. 5 Thus, there is a strong motivation to find an alternative chemistry to achieve a better control of the etching properties. There were reports on inductively coupled plasma ͑ICP͒ etching of InP using HBr-based chemistry. 4,6-8 Bromine-based chemistry has the advantage that the reaction product, InBr 3 , has a higher vapor pressure than that of InCl 3 when using chlorine-based chemistry. 5 Furthermore, GaBr 3 and InBr 3 have a more closely matched function of vapor pressures vs temperature as compared to their chloride counterparts. This property is beneficial for the fabrication of photonic devices that often require the etching of InGaAsP quaternary materials. Several methods had been tried to improve the InP ICP etching properties using HBr chemistry. For example, Ar was mixed with HBr to improve the anisotropy of InP etching at room temperature. 6 CH 4 and N 2 were added into the plasma to passivate the sidewall and reduce the undercuts that were observed when using HBr only at elevated temperature. 4,7,8 Recently, a Cl 2 /O 2 mixture in ICP etching of InP was reported to be able to produce a highly anisotropic profile. 9 In this paper, we report the use of HBr/O 2 chemistry for the etching of InP to achieve high aspect ratio and no undercut in an ICP etching system. The etching behavior was systematically studied by varying different process parameters, i.e., O 2 ...

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