Porous silicon dioxide moisture sensor and method for manufacture of a moisture sensor
AssigneeInternational Business Machines Corporation
InventorsPaul Johannes Burkhardt, Michael Robert Poponiak
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Abstract
A method and resulting structure for a relative humidity monitor which can be built into an integrated circuit chip. A small area on a silicon chip is made porous by anodic etching. This region is then oxidized and a metal counter electrode is deposited over part of the porous area. The surface area in the dielectric under the counter electrode is very high and because of the openness of the structure, ambient moisture can quickly diffuse into the dielectric under the electrode and adsorb onto the silicon dioxide surface. Changes in ambient humidity will then be reflected by measurable changes in capacitance or conductance of the device.
Claims13
A moisture sensor comprising a monocrystalline silicon body;
- a region within the said body of high porosity silicon dioxide;
- a metal counter electrode on a part of said porous silicon dioxide area;
- and
- said porous silicon dioxide having a porosity sufficient that ambient moisture can quickly diffuse into the porous silicon dioxide under the said electrode, adsorb onto the silicon dioxide surface and cause measurable changes in the said device.
A semiconductor device comprising:
- a monocrystalline silicon body;
- an integrated circuit in said body;
- and
- a moisture sensor in said body.
Dependencies are inferred from the claim text.