This paper describes the use of strain stiffening in fixed-fixed beam actuators to extend tuning range microelectromechanical-systems-based Fabry-Perot filters. The measured wavelength 1.615-2.425 mum is largest reported for such a filter. Curvature movable mirror was corrected using low-power oxygen plasma controllably alter stress gradient mirror. After curvature correction, linewidth filter 52 nm, close theoretical minimum our design. As proof concept, bonded broadband infrared detector,...

Commercially manufactured near-infrared (NIR) instruments became available about 50 years ago. While they have been designed for laboratory use in a controlled environment and boast high performance, are generally bulky, fragile maintenance intensive, therefore expensive to purchase maintain. Micromachining is powerful technique fabricate micromechanical parts such as integrated circuits. It was perfected the 1980s led invention of micro electro mechanical systems (MEMSs). The three...

In order to characterize the electron transport properties of two-dimensional gas (2DEG) in AlGaN/GaN modulation-doped field-effect transistors, channel magnetoresistance has been measured magnetic field range 0–12 T, temperature 25–300 K, and gate bias +0.5 −2.0 V. By assuming that 2DEG provides dominant contribution total conductivity, a one-carrier fitting procedure applied extract mobility carrier sheet density at each particular value bias. Consequently, versus obtained for measurement...

The effect of /spl gamma/-ray exposure on the electrical characteristics nickel/n-GaN Schottky barrier diodes has been investigated using current-voltage (I-V), capacitance-voltage (C-V), and deep-level transient spectroscopy (DLTS) measurements. results indicate that gamma/-irradiation induces an increase in effective height extracted from C-V Increasing radiation dose was found to degrade reverse leakage current, whereas its forward I-V negligible. Low temperature (/spl les/50)...

This paper reports an investigation on techniques for determining elastic modulus and intrinsic stress gradient in plasma-enhanced chemical vapor deposition (PECVD) silicon nitride thin films. The property of the films was determined using nanoindentation method nitride/silicon bilayer systems. A simple empirical formula developed to deconvolute film modulus. by micrometric cantilever beams, cross-membrane structures mechanical simulation. deflections beams cross-membranes caused...

The nanoscratching-induced deformation of monocrystalline Si has been investigated using transmission electron microscopy (TEM). results indicate that amorphization and formation crystalline defects are two dominant phenomena associated with the scratching processes. TEM analyses reveal occurs at extremely small loads. Stacking faults twins nucleated a smaller load than for dislocation. Dislocations start to nucleate along {111} planes when normal is greater threshold value penetrate deeper...

Transient capacitance measurements of Schottky diodes fabricated on nominally undoped n-type GaN exposed to 60Co gamma irradiation indicate the introduction two defect levels with thermal activation energies 89±6 and 132±11 meV. While emission characteristics these defects manifest significant broadening, their parameters are consistent reported electron-irradiation-induced nitrogen-vacancy related centers. Three deep-level present before exposure 265, 355, 581 meV were found remain...

The monolithic integration of a low-temperature microelectromechanical system (MEMS) and HgCdTe infrared detector technology has been implemented characterized. MEMS-based tunable optical filter, integrated with an detector, selects narrow wavelength bands in the range from 1.6 to 2.5 μm within short-wavelength (SWIR) region electromagnetic spectrum. entire fabrication process is compatible two-dimensional focal plane array technology. fabricated device consists SWIR photoconductor, two...

Temperature (11–250 K) and excitation power (5–480 mW) dependent infrared photoluminescence (PL) measurements are conducted on a HgTe/Hg0.05Cd0.95Te superlattice (SL) sample in spectral range of 5–18 μm with adequate resolution signal-to-noise ratio. Three PL components identified from the evolution lineshape temperature although full-width at half-maximum (FWHM) whole signal is only about 7 meV 11 K, for which different changes energy, FWHM, integral intensity evidenced. The mechanisms...

This paper reports on a MEMS tunable Fabry-Perot filter technology capable of achieving nanometer-scale optical flatness across large mirror area up to square centimeters without any extraneous stress management techniques. The device employs single-layer tensile silicon or germanium membrane for the suspended top mirror. Optical characterization fabricated single-membrane-based filters SWIR, MWIR, and LWIR is presented. 1000-μm dimension Si-membrane-based SWIR MWIR are demonstrated with...

This paper reports on a proof-of-concept microelectromechanical system-based Fabry-Perot filter that is capable of electrically tuning within the long-wave infrared thermal imaging band 8-12 μm. The device employs single-layer quarter-wavelength thick tensile germanium membrane for suspended top mirror in order to achieve nanometer-scale as-released flatness across an area several hundred square micrometers without any extraneous stress management techniques. Mechanical and optical...

A technique for masking porous-silicon (PS) films by optical photolithography without significant film degradation is demonstrated the first time. The chemical resistance of PS achieved low-temperature passivation via nitrogen annealing. effect various photolithographic process steps investigated determining changes in properties films. passivated are shown to be resistant strong alkaline-based solutions (dilute AZ400K developer) up 100 s with minimal reduction thickness. Fourier transform...

Silica thin films containing uniformly dispersed lanthanum hexaboride (LaB₆) nanoparticles have been prepared by spin-coating a sol-gel silica solution cetyltrimethyl ammonium bromide (CTAB)-stabilized LaB₆ onto glass substrate followed standard heat treatment. The production of this film involved three steps: (i) CTAB-stabilized nanoparticle dispersion was in water and then dried, (ii) the dried were redispersed small amount mixed with tetraethoxyorthosilane (TEOS), ethanol, little acid to...

Experimental magnetic field dependent Hall and resistivity data is presented for two modulation-doped AlGaN/GaN heterostructures in the temperature range from 6 to 300 K a up 12 T. The mobility concentration of electrons within two-dimensional electron gas (2DEG) at interface underlying GaN layer are readily separated characterized using quantitative spectrum analysis. observed transport parameters 2DEG explained classical band theory degenerate gas. Analysis dependencies indicates that...

The construction of self-supporting and suspended structures is one the fundamental challenges microelectromechanical systems (MEMS). Many technologies have been developed for fabrication such structures, which can be categorized into bulk or surface micromachining. Generally micromachining techniques rely on a high-temperature deposition process as low pressure chemical vapour to produce high-quality films. Plasma enhanced (PECVD) used deposit films at temperatures less than 300 °C. PECVD...

The effect of an abrupt CdTe∕HgCdTe passivation heterointerface on generation recombination and dark currents in n-on-p midwave infrared photodiodes with 5.2-μm cut-off wavelength has been investigated. Experimentally, it was observed that the zero-bias-dynamic resistance, R0, at low temperatures scales perimeter junction, rather than junction area, suggesting surface effects are dominant. diode current–voltage characteristics indicate significant contributions from tunneling effects, which...

Two experimental techniques have been investigated to examine residual stress in low-temperature plasma enhanced chemical vapour deposited (PECVD) SiNx thin films: one that measures the stress-induced substrate curvature, and other takes advantage of deformation freestanding diagnostic microstructures. A general linear dependence on deposition temperature is observed, with magnitude changing linearly from ∼300 MPa tensile ∼600 compressive as decreased 300 100 °C. However, results deviate by...

In this paper, the Poisson's ratio of low-temperature plasma-enhanced chemical vapor deposited silicon nitride thin films has been determined by a modified double-membrane bulge test. This test method utilizes square membrane and large-aspect-ratio rectangular that is fabricated alongside from same film. The deflections two membranes under an applied pressure. suitable for determining either stress-free or those containing low tensile residual stresses. values 0.23 0.02 0.25 0.01 were...

This paper reports on the successful demonstration of Ge/ZnS-based Fabry-Perot filters operating in longwave infrared (LWIR). The suitability thermally deposited Ge and ZnS as thin-film mirror materials for micromachined LWIR has been fully investigated, it is shown that a film growth temperature higher than 150 °C key to depositing durable films. optical constants films band reveal material pair possesses high refractive index contrast excellent transparency. Fixed-cavity with 150-μm...