Boston Microsystems, Inc.

Massachusetts Institute of Technology

Exponent, Inc.

Richard Mlcak

Harry L Tuller

Dharanipal Doppalapudi

Theodore D Moustakas

Stuart B Brown

Christopher L Muhlstein

Kevin R Lynch

Paulo Jorge Furtado Correia

A micromechanical device includes a single crystal micromachined micromechanical structure. At least a portion of the micromechanical structure is capable of performing a mechanical motion. A piezoelectric epitaxial layer covers at least a part of said portion of the micromechanical structure that is capable of performing a mechanical motion. The micromechanical structure and piezoelectric epitaxial layer are composed of different materials. At least one electrically conducting layer is formed to cover at least part of the piezoelectric epitaxial layer.

Micromechanical piezoelectric device

A micromechanical device includes a single crystal micromechanical structure where at least a portion of the micromechanical structure is capable of performing a mechanical motion. An epitaxial layer covers at least a portion of the micromechanical structure. In one embodiment, the micromechanical structure and the epitaxial layer are formed of different materials.

Micromechanical device with an epitaxial layer

A sensor including a p-n junction for subjecting under a reverse electrical bias. A conductive layer is formed across the p-n junction for providing an alternative conductive path across the p-n junction. The conductivity of the conductive layer in the presence of a selected substance in an atmosphere is different than in the absence of the selected substance, wherein the conductivity of the conductive layer is indicative of the presence or absence of the selected substance.

P-n junction sensor

A method of electrochemically etching a device, including forming a semiconductor substrate having a p-type semiconductor region on an n-type semiconductor region. A discrete semiconductor region is formed on the p-type semiconductor region and is isolated from the n-type semiconductor region. The n-type semiconductor region is exposed to an electrolyte with an electrical bias applied between the n-type semiconductor region and the electrolyte. The n-type semiconductor region is also exposed to radiation having energy sufficient to excite electron-hole pairs. In addition, a p-n junction reverse bias is applied between the p-type semiconductor region and the n-type semiconductor region to prevent the p-type semiconductor region and the discrete semiconductor region from etching while portions of the n-type semiconductor region exposed to the electrolyte and the radiation are etched.

Electrochemical etching process

A piezoresistor having a base substrate with a quantum well structure formed on the base substrate. The quantum well structure includes at least one quantum well layer bounded by barrier layers. The barrier layers are formed from a material having a larger bandgap than the at least one quantum well layer.

Semiconductor piezoresistor

A system and corresponding method for bulge testing films (e.g. thin films, coatings, layers, etc.) is provided, as well as membrane structures for use in bulge testing and improved methods of manufacturing same so that resulting membrane structures have substantially identical known geometric and responsive characteristics. Arrayed membrane structures, and corresponding methods, are provided in certain embodiments which enable bulge testing of a film(s) over a relatively large surface area via a plurality of different freestanding membrane portions. Improved measurements of film bulging or deflection are obtained by measuring deflection of a center point of a film, relative to non-deflected peripheral points on the film being tested. Furthermore, membrane structures are adhered to mounting structure in an improved manner, and opaque coatings may be applied over top of film(s) to be bulge tested so that a corresponding optical transducer can more easily detect film deflection/bulging. In certain embodiments, a laser triangulation transducer is utilized to measure film deflection/bulging.

System and method for performing bulge testing of films, coatings and/or layers

A method of electrochemical machining of micromechanical structures from a silicon substrate having both p and n-type regions in hydrofluoric electrolyte solution is disclosed. Only the p-type region of the silicon substrate may be selectively etched by providing means for inhibiting the injection of holes from the p-type region through the n-type region. Inhibiting the injection of holes includes forming a p-type layer over the n-type region, forming a layer of material inert to the electrochemical etchant over the n-type region, imposing a reverse electrical bias between the p-type region and n-type region, and providing recombination centers in the n-type region to induce recombination of holes injected into the n-type region.

P-N junction etch-stop technique for electrochemical etching of

A method of photo-assisted electrochemical machining of micromechanical structures from a silicon substrate having both p and n regions in a hydrofluoric electrolyte solution is disclosed. Both p and n regions of the silicon substrate may be selectively etched, with differing regions as etch stops, at controlled rates by the appropriate choice of cell bias, p-n junction bias and illumination intensity.

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Cambridge, MA, United States of America

Richard Mlcak