Method of manufacturing a moisture sensor
AssigneeEndress u. Hauser GmbH u. Co.
InventorsErnst Luder, Traugott Kallfass
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Abstract
A moisture sensor is manufactured by applying a thin layer of tantalum oxide to a moisture insensitive substrate and placing at least two electrodes on the tantalum oxide layer. The tantalum oxide layer comprises the oxide of a highly resistive low density tantalum where the tantalum in the layer applied to the substrate has a density of less than 15 g/cm.sup.3. The low density tantalum may be applied by cathode sputtering and the oxide may be formed by anodic oxidation.
Claims40
A method making a moisture sensor, said method comprising applying on a moisture insensitive substrate by cathode sputtering of tantalum, a layer of highly resistive low density tantalum having a density of less than 15 g/cm.sup.3, converting the tantalum layer at least over a portion of its thickness by oxidation to a tantalum oxide layer, and placing at least two electrodes on the tantalum oxide layer spaced apart from each other.
A method of making a moisture sensor, said method comprising applying a layer of tantalum oxide on a moisture insensitive substrate by (a) cathode sputtering of tantalum and (b) oxidation during the sputtering, the parameters in the application being set so that the tantalum oxide layer has the same structure as a tantalum oxide layer produced by oxidation of highly resistive low density tantalum having a density of less than 15 g/cm.sup.3, and placing at least two electrodes on the tantalum oxide layer spaced apart from each other.
A method of making a moisture sensor, said method comprising applying on a moisture insensitive substrate by cathode sputtering of tantalum oxide a layer of tantalum oxide, the parameters in the application being set so that the tantalum oxide layer has the same structure as a tantalum oxide layer produced by oxidation of highly resistive low density tantalum having a density of less than 15 g/cm.sup.3, and placing at least two electrodes on the tantalum oxide layer spaced apart from each other.
Dependencies are inferred from the claim text.