DURABLE MINIATURE GAS COMPOSITION DETECTOR HAVING FAST RESPONSE TIME
First Claim
1. A method, comprising:
- forming a miniature Hall effect sensor in a silicon substrate;
coating a glass substrate with a metal film;
patterning the metal film to form a mask;
etching a micro-channel in the glass substrate through the mask, the micro-channel having a micro-channel depth;
forming openings to the micro-channel; and
bonding the glass and silicon substrates.
1 Assignment
0 Petitions
Accused Products
Abstract
A miniature oxygen sensor makes use of paramagnetic properties of oxygen gas to provide a fast response time, low power consumption, improved accuracy and sensitivity, and superior durability. The miniature oxygen sensor disclosed maintains a sample of ambient air within a micro-channel formed in a semiconductor substrate. O2 molecules segregate in response to an applied magnetic field, thereby establishing a measurable Hall voltage. Oxygen present in the sample of ambient air can be deduced from a change in Hall voltage with variation in the applied magnetic field. The magnetic field can be applied either by an external magnet or by a thin film magnet integrated into a gas sensing cavity within the micro-channel. A differential sensor further includes a reference element containing an unmagnetized control sample. The miniature oxygen sensor is suitable for use as a real-time air quality monitor in consumer products such as smart phones.
6 Citations
20 Claims
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1. A method, comprising:
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forming a miniature Hall effect sensor in a silicon substrate; coating a glass substrate with a metal film; patterning the metal film to form a mask; etching a micro-channel in the glass substrate through the mask, the micro-channel having a micro-channel depth; forming openings to the micro-channel; and bonding the glass and silicon substrates. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method, comprising:
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forming a miniature Hall effect sensor on a silicon substrate; forming micro-channels in a glass substrate; exposing the micro-channels; bonding the silicon and glass substrates together; dicing the bonded substrates into sensor chips; and assembling the sensor chips into packages with other integrated circuit chips. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A method, comprising:
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forming integrated circuits in a first substrate, the integrated circuits including contact pads; forming a gas sensing unit in a second substrate, the gas sensing unit including a gas-filled cavity and a thin film permanent magnet integrated with the gas-filled cavity; bonding the first and second substrates; and attaching wires to the contact pads to access the gas-filled cavity. - View Dependent Claims (19, 20)
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Specification