Siemens Aktiengesellschaft

Dana Pitzer

Rainer Bruchhaus

Matthias Schreiter

Robert Primig

Walter Hartner

Wolfram Wersing

Gunther Schindler

Thomas Huber

Martin Nirschl

A device for detecting at least one substance of a fluid, has a piezoacoustic thin film resonator with a piezoelectric layer on which electrode layers are arranged, and an adsorption surface for adsorbing the fluid substance, wherein the piezoelectric and electrode layers and the adsorption surface are designed and arranged on each other such that by electrically activating the electrode layers, an excitation alternating field can be coupled into the piezoelectric layer. The thin film resonator can be excited to a resonance oscillation frequency fwhich depends on an amount of the substance adsorbed on the adsorption surface because of an excitation alternating field coupled into the piezoelectric layer. An electrical insulating layer is arranged directly on a side of one of the electrode layers facing away from the piezoelectric layer. Particularly advantageous is the combination of an aluminum electrode layer and a silicon dioxide insulating layer.

Device and method for detecting a substance using a thin film resonator (FBAR) having an insulating layer

In an arrangement of at least one piezoacoustic resonator on a substrate surface, the resonator has an piezoelectric layer, an electrode and a further electrode arranged such that activation of the electrodes leads to a resonance oscillation, the substrate surface is formed by an acoustic mirror integrated in the substrate for acoustically insulating substrate and resonator, and with a resonance frequency evaluation device being connected to the electrodes by tracks being routed through a mirror opening. The acoustic mirror has a Bragg reflector having &#x3bb;/4-thick layers of different acoustic impedance. The topmost layer is made of silicon dioxide acting as an insulation layer in the mirror opening for electrically insulating the conductor track and the electrically conductive Bragg reflector layers. The arrangement is used as a physical transducer of a device for detecting a substance of a fluid, in particular of a fluid in the form of a liquid (biosensor).

Arrangement of a piezoacoustic resonator on an acoustic mirror of a substrate, method for producing the arrangement and use of the arrangement

A method for producing self-polarized ferroelectric layers, in particular PZT layers, with a rhombohedral crystal structure includes providing a substrate and heating it to a temperature T Afterward the layer with a rhombohedral crystal structure is applied to the substrate by means of a sputtering method. This layer includes a Zr-deficient layer with a Curie temperature TC and a Zr-abundant layer with a Curie temperature TC wherein TC TC T After the ending of the application process, the heating of the substrate is also discontinued so that the substrate cools. As a result of the cooling the Zr-deficient layer and then the Zr-abundant layer reach their Curie temperature, and change into the ferroelectric phase and become self-polarized in the process. The polarization already present in the Zr-deficient layer induces the polarization in the Zr-abundant layer, with the result that both layers are self-polarized after the cooling process.

Method for producing self-polarized ferro-electric layers, especially PZT layers, with a rhombohedral crystal structure

Stratified structure with a ferroelectric layer and process for

A thin-film technology multi-layer capacitor with enhanced capacitance and/or reduced space requirement. The dielectric layers of which are alternately disposed between electrode layers on a substrate. Through alternate electrode layer connections, parallel interconnection of the individual capacitor layers is obtained. The result is that the individual capacitances are additive, while the temperature response can be optimized by a suitable choice or combination of different dielectric layers.

Multilayer capacitor with high specific capacitance and production

A method of producing a platinum-metal structure or pattern on a substrate, which includes the steps of applying a silicon oxide layer to the substrate; applying a mask to the silicon oxide layer which is formed with an opening at a location thereof at which the platinum-metal structure or pattern is to be produced; etching the silicon oxide layer so that the substrate surface area exposed by the opening formed in the mask is larger than the opening in the mask; applying a platinum-metal layer to the mask and the exposed substrate surface area; and removing the silicon oxide layer in an etching process, so that the platinum metal present on the mask is removed simultaneously therewith, and the platinum metal present on the substrate surface forms the platinum-metal pattern or structure.

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Unterschleissheim, Germany

Dana Pitzer