Introduction CR-39 detectors are widely used for Radon and progeny measurement in the air. In this paper, using the Monte Carlo simulation, the possibility of using the CR-39 for direct measurement of Radon and progeny in water is investigated. Materials and Methods Assuming the random position and angle of alpha particle emitted by Radon and progeny, alpha energy and angular spectrum that arri...

Recently, porous materials on the base of semiconductor crystals arouse greater interest as photon crystals in terms of opto-electronic applications and formation of arrays of nano-elements with oneand zero-dimensionality. The crystals of porous silicon have been developed best to date. The obvious trends in this field now are towards using other materials for electrolytic etching, decreasing t...

There are many techniques available for two-dimensional machining and patterning of semiconductor surfaces for optoelectronic and microelectronic applications. These mainly use photolithography, electron beam or X-ray lithography or reactive ion etching. Smooth surfaces and high-aspect ratio sidewalls can be produced, but they are all limited to creating a single etch depth per processing stage...

An electrochemical etching technique has been developed that provides continuous control over the porosity of a porous silicon layer as a function of etching depth. Thin films with engineered porosity gradients, and thus a controllable gradient in the index of refraction, have been used to demonstrate broadband antireflection properties on silicon wafer and solar cell substrates. A simulation w...

Atomic mixing and preferential sputtering impose a depth resolution limit on the use of sputter sectioning to measure the composition of metal-semiconductor interfaces. Experimental evidence obtained with the Pt-Si system is used to .demonstrate ion-induced atomic mixing and then its effect on sputter etching and depth profiling. Starting with discrete layer structures, a relatively low ion dos...

Monte Carlo simulations of pattern-dependent charging during oxide etching predict that the etch rate scaling with aspect ratio breaks down when surface discharge currents are significant. Under conditions of ion-limited etching and no inhibitor deposition, the etch depth depends on the maximum incident ion energy, reaction threshold, and surface discharge threshold, and is the same irrespectiv...

We have developed a thin quarter-wave plate (QWP) operating at low terahertz frequency of 0.51 THz by etching micro-grating on a silicon substrate. The grating period is 30 μm, and the etching depth is 156 μm. Stokes parameters are used to characterize the QWP. The QWP shows a high transmission coefficient of 0.93 and a low polarization dependent loss (PDL) of 1.4 dB at 0.51 THz. © 2013 Society...

An all-metal structural color printing platform based on aluminum plasmonic metasurfaces is proposed and demonstrated with high color performance using only a one-step etching process on aluminum surface. A wide visible color range is realized with the designed metallic square-shaped disk arrays by simply adjusting the geometrical parameters of the disk etching depth, disk width and unit cell p...

Etching high aspect ratio trenches (HART’s) in silicon is becoming increasingly important for MEMS applications. Currently, the most important technique is dry reactive ion etching (ME). This paper presents solutions for the most notorious problems during etching HART’s: tilting and the aspect ratio dependent etching effects such as bowing, RIE lag, bottling, and micrograss or black silicon. To...

The fabrication of the 2D GaN-based photonic crystal structure at optical scales, a subμm scale in our case is very challenging. In our work, a double-etching method proved to be feasible to achieve the periodic GaN/air variation. The pattern was defined in a PMMA resist by electron-beam lithography and transferred to SiO2 by reactive ion etching (RIE) in a CF4 plasma and further into GaN by RI...