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The inductively coupled plasma-reactive ion etching (ICP-RIE) of SiC single crystals using the C 2 F 6 /O 2 gas mixture was investigated. It was observed that the etch rate increased as the ICP power and bias power increased. With increasing sample-coil distance, O 2 concentration, and chamber pressure, the etch rate initially increased, reached a maximum, and then decreased. Mesas with smooth surfaces (roughness Յ 1 nm) and vertical sidewalls (ϳ85°) were obtained at low bias conditions with a reasonable etch rate of about 100 nm/min. A maximum etch rate of 300 nm/min could be obtained by etching at high bias conditions (Ն300 V), in which case rough surfaces and the trenched sidewall base were observed. The trenching effect could be suppressed by etching the samples on anodized Al plates, although mesas with sloped (60-70°) sidewalls were obtained. Results of various surface characterization indicated little contamination and damage on the etched SiC surfaces. 210Kong, Choi, Lee, Han, and Lee Fig. 1. Etch characteristics of 6H-SiC and 4H-SiC as a function of (a) ICP source power, (b) bias power, (c) pressure, (d) O 2 percentage in C 2 F 6 /O 2 , and (e) the distance between the substrate holder and the source coil.

ZnO nanostructures are proposed to enhance the performance of surface plasmon resonance (SPR). The ZnO nanostructures on a 50 nm-thick Au thin-film are composed of nano-holes with a period of 300 nm. The ZnO nano-holes coupled SPR was simulated using the three-dimensionanl finite-difference time-domain method. The ZnO nano-holes have been fabricated by a laser interference lithography and wet etching process. The measured resonance angle of 47.5°was obtained; this agreed well with the simulated result. In comparison with the author's previous report, the figure of merit of ZnO nano-holes coupled SPR was two times higher than that of the ZnO grating structure.Introduction: Surface plasmon resonance (SPR) sensors have been extensively studied for chemical and biological sensing applications. Recently, SPR sensors with the ZnO dielectric medium on the metal layer have been focused on biosensors and gas sensors owing to their advantages, such as chemical sensitivity to volatile and other radical gases, high chemical stability, non-toxicity, and low cost [1]. However, the SPR spectrum becomes broader owing to the presence of the ZnO layer, which means the full width half maximum (FWHM) becomes larger. As a result, the efficiency of SPR is degraded, which has affected the resolution and reliability of SPR sensors. In order to achieve reliable and accurate detection of trace amounts, high performance of SPR is essential. Nanostructures can be an attractive SPR sensing platform because they provide strong light confinement and localisation of electric fields even in the case of structures with low refractive index difference [2]. Most studies on the properties of nanostructures coupled SPR reported so far have been based on a one-dimensional nanostructure of grating [3,4]. In this study, a two-dimensional (2D) ZnO nanostructure was suggested to enhance the coupling between localised surface plasmon resonances (LSPs) and propagating surface plasmons (SPs). Then we demonstrated Au/glass SPR structures with arrays of 2D ZnO nano-holes. The SPR characteristics of 2D ZnO nano-holes were calculated using the three-dimensional finite-difference time-domain method (3D-FDTD) method, such as the resonance spectrum and electric field profile. The 2D ZnO nano-holes were realised on the Au layer using a laser interference lithography (LIL) process. The properties of SPR were measured using an attenuated total reflection method, and compared with our previous report [5].

Single-crystalline 3C-SiC heteroepitaxial layers were grown on silicon-on-insulator (SOI) and Si wafers, to investigate effects of SOI substrates on the film quality. Residual stress measurement using a laser scan method and the Raman scattering spectroscopy indicated that internal stress within SiC films on SOI were indeed reduced, when compared with that of SiC films on Si.

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