Abstract: Disclosed is a sensor comprising a substrate, a source contact region, a drain contact region, and the gate oxide of a transistor. A gate electrode is disposed between the gate oxide and a detection electrode made of a nonconducting material. The contact area Asens between the gate electrode and the detection electrode is larger than the contact area Agate between the gate electrode and the gate oxide, whereby the receptor can be immobilized on the surface of the detection electrode in a technically simple manner while the small contact area Agate between the gate electrode and the transistor provides for high sensitivity for detecting the analyte. According to the inventive method for detecting at least one analyte, at least one analyte is brought into contact with a receptor immobilized at the detection electrode so as to modify the electrical charge at the surface of the detection electrode. The analyte is detected by detecting the modified voltage in the transistor.

Abstract: The invention concerns a semiconductor structure comprising at least one first material region and a second material region, whereby the second material region epitaxially surrounds the first material region and forms a boundary surface. The structure is characterized in that Fermi level pinning is present on the non-epitaxial boundary surface of the second material region located opposite the boundary surface of both material regions, and the first material region forms a quantum well for free charge carriers.

Abstract: Disclosed is a sensor comprising a substrate, a source contact region, a drain contact region, and the gate oxide of a transistor. A gate electrode is disposed between the gate oxide and a detection electrode made of a nonconducting material. The contact area Asens between the gate electrode and the detection electrode is larger than the contact area Agate between the gate electrode and the gate oxide, whereby the receptor can be immobilized on the surface of the detection electrode in a technically simple manner while the small contact area Agate between the gate electrode and the transistor provides for high sensitivity for detecting the analyte. According to the inventive method for detecting at least one analyte, at least one analyte is brought into contact with a receptor immobilized at the detection electrode so as to modify the electrical charge at the surface of the detection electrode. The analyte is detected by detecting the modified voltage in the transistor.

Abstract: A multiplicity of components form a photodiode array on a substrate. Each of the components consists of a transistor of the p-n-p type with the outermost p-doped layer being transformed into an optical filter by control of the anodic etching operation utilizing transistor characteristics of the respective transistor. The result can provide red, blue and green filters in a color camera.

Abstract: An interference filter having a layer with an area consisting of a porous material extending from the surface of the layer to the interior, the dimensions of the porous layer area in a direction normal to the layer surface have different values to provide for varying reflection or, respectively, transmission characteristics.

Abstract: In an interference filter having a layer with an area consisting of a porous material extending from the surface of the layer to the interior, the dimensions of the porous layer area in a direction normal to the layer surface have different values to provide for varying reflection or, respectively, transmission characteristics.

Abstract: A porous layer produced from silicon, germanium or aluminum by applying a wedge-shaped mask to the surface of the layer and by controlled elecrochemical etching along the mask.

Abstract: A multiplicity of components form a photodiode array on a substrate. Each of the components consists of a transistor of the p-n-p type with the outermost p-doped layer being transformed into an optical filter by control of the anodic etching operation utilizing transistor characteristics of the respective transistor. The result can provide red, blue and green filters in a color camera.

Abstract: A pH sensitive microsensor which comprises a substrate on which a sensor membrane is formed by laser ablation of a target and depositing the target material on the substrate.

Abstract: In an analytic process using porous silicon, a substance is detected or its concentration in a fluid is determined based on the change in the optical property of porous silicon as a function of the refractive index of the substance present in the pores of the porous silicon, or of the fluid containing the substance. An analytic device for detecting a substance or for determining the concentration of a substance in a fluid with the use of porous silicon comprises a component at least partly consisting of porous silicon, the optical property of which is dependent upon the refractive index of the substance or of the fluid containing the substance, whereby a change in the optical property of the porous silicon is measurable to indicate detection of the substance or to determine the concentration of such substance in the pores of the porous silicon.

Abstract: In a biosensor system for detecting trace compounds resulting from a fire or from plants damaged by destructive insects, a live chemoreceptor is provided for sensing the trace compounds, and a semiconductor component is connected to the chemoreceptor for providing sensor signals when the chemoreceptor senses the presence of trace compounds.

Abstract: Biomaterial such as an enzyme, cell, antigen or antibody is immobilized by covalent bonding to a substrate having an Si.sub.3 N.sub.4 surface containing Si--NH.sub.2 groups that provide reactive NH.sub.2 groups. A heterobifunctional cross-linking agent having an NH.sub.2 -reactive group and a biomaterial-reactive group is reacted with the NH.sub.2 groups of the surface and then with the biomaterial or the heterobifunctional cross-linking agent is reacted with the biomaterial and then with the NH.sub.2 groups of the surface. The Si.sub.3 N.sub.4 surface containing Si--NH.sub.2 groups can be formed by precipitating on a substrate a 10-1000 nm thick Si.sub.3 N.sub.4 layer from a SiH.sub.4 /NH.sub.3 mixture, and providing reactive NH.sub.2 groups on the surface of the layer by subjecting the surface to hydrolyzing cleaning.

Abstract: A process for producing a structured area of porous silicon on a substrate, in which silicon is etched and structured by means of illumination, includes selectively aiming the illumination during or after the formation of the porous silicon directly at a selected area of a p-doped substrate in order to effect etching and structuring of the porous silicon in another area. A device for carrying out the process includes an illuminating system for supporting the etching process and for structuring the porous silicon, in which the illuminating system is selectively aimed during or after the formation of the porous silicon directly at a selected area of p-doped substrate in order to effect etching and structuring of the porous silicon in another area.

Abstract: A three-dimensional structure of porous silicon considerably improves the anchorage of sensor-active material such as, for example, enzymes, antibodies, etc., on or in the substrate surface of chemical sensors, in particular silicon-based biosensors. This structure is produced by means of suitable etching which forms pore apertures adapted to the penetrability of the sensor-active material. The pore walls advantageously receive a non-conductive boundary layer which consists of oxides of Si and/or Al or Ta or silicon nitride and are preferably 1-100 nm thick. The porous layer is advantageously between 10 nm and 100 .mu.m thick and the pores are preferably in the form of branched ducts whose average diameter is 1 nm-10 .mu.m and in particular 10-1000 nm. The sensor-active material can optionally be distributed in a glass, solid, plastics or polymer membrane.

Abstract: An electronic component has electrically activatable layer, e.g. in electroluminescent layer of porous silicon on a body of which two multiarthogonal grids are buried. A conductive layer on the electrically activatable layer forms a drain and another conductor forms the source, the grid bars being independently energizable to form current channels through the electrically activatable layer.

Abstract: The invention relates to an optical component consisting of transparent thin layers of differing thickness and refractive indices. Such optical components are used, for example, as interference filters and mirrors. Optical components made of layers with gradually changing refractive indices are also known as waveguides of anti-reflective coatings. The invention achieves the aim of using, instead of layers of ordinary materials, another material by means of a component in which the layers consist of porous silicon. The special advantages of porous silicon as a coating material arises not only from the ease and economy of manufacture, but also in the facility for obtaining gradual refractive index transitions. It is therefore very easily possible to make waveguides on a silicon chip.

Abstract: An optoelectronic device, e.g. for integrated circuits, has an Si, II-VI or III/V semiconductor layer and an LaF.sub.3 or La.sub.1-x X.sub.x F.sub.3 insulating layer which is doped with Nd or Er to generate an optical signal whose wavelength is determined by the 4f ions used. The insulating layer can be grown epitaxially on the semiconductor layer and the lanthanide element ion substituting for a metal ion of the material forming the insulating layer has the same valence as the metal for which it is substituted.

Abstract: An electronic component especially a permeable base transister is provided as a composite of homoepitaxially grown layers so that space-charge zones defined by the permeable base are formed as pn-junctions between an n-conducting layer and a p-conducting layer.

Abstract: An electronic component especially a permeable base transistor is provided as a composite of homoepitaxially grown layers so that space-charge zones defined by the permeable base are formed as pn-junctions between an n-conducting layer and a p-conducting layer.