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 elastic property of the silicon nitride thin films was determined using the nanoindentation method on silicon nitride/silicon bilayer systems. A simple empirical formula was developed to deconvolute the film elastic modulus. The intrinsic stress gradient in the films was determined by using micrometric cantilever beams, cross-membrane structures and mechanical simulation. The deflections of the silicon nitride thin film cantilever beams and cross-membranes caused by in-thickness stress gradients were measured using optical interference microscopy. Finite-element beam models were built to compute the deflection induced by the stress gradient. Matching the deflection computed under a given gradient with that measured experimentally on fabricated samples allows the stress gradient of the PECVD silicon nitride thin films introduced from the fabrication process to be evaluated.

Resonant-cavity-enhanced Hg1−xCdxTe photoconductive detectors for midwave infrared wavelengths are investigated for use in multi- and hyper-spectral sensor systems. Resonant-cavity-enhanced performance is modeled, and compared with measured performance of fabricated devices. The responsivity of fabricated devices shows resonant cavity enhancement, with performance limited by surface recombination.

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Nanoindentation has been used to investigate the elastoplastic behavior of Hg 0.7 Cd 0.3 Te prepared by molecular beam epitaxy. It was found that Hg 0.7 Cd 0.3 Te had a modulus of elasticity of ϳ50 GPa and hardness of ϳ0.66 GPa. The HgCdTe response to nanoindentation was found to be purely elastic for low loads and developed into ϳ10% elastic and ϳ90% plastic response for higher-load indentation exhibiting significant amounts of creep. The onset of plasticity has been observed to be marked by discontinuities or "pop-in" events in the indenter load-penetration curves at sheer stresses of ϳ1.8 GPa, and has been correlated with the homogeneous nucleation and propagation of dislocations.