Integrated MOS gas or humidity sensor having a wireless transceiver
A single chip wireless sensor comprises a microcontroller connected by a transmit/receive interface to a wireless antenna. The microcontroller is also connected to an 8 kB RAM, a USB interface, an RS232 interface, 64 kB flash memory, and a 32 kHz crystal. The device senses humidity and temperature, and a humidity sensor is connected by an 18 bit ΣΔ A-to-D converter to the microcontroller and a temperature sensor is connected by a 12 bit SAR A-to-D converter to the microcontroller. The device is an integrated chip manufactured in a single process in which both the electronics and sensor components are manufactured using standard CMOS processing techniques, applied to achieve both electronic and sensing components in an integrated process.
1. An integrated sensor device, comprising:
MOS circuits in a semiconductor substrate;
a wireless transceiver formed in the MOS circuits;
interconnect levels with interconnect conductors and insulating dielectric, said levels being over the substrate and interconnecting the MOS circuits;
a sensor having electrodes, the electrodes being incorporated into at least one of the interconnect levels and being embedded in at least one of the insulating dielectrics, the sensor sensing gas or humidity, wherein at least some of the MOS circuits are directly beneath the sensor in a vertical dimension; and
a processor formed in the MOS circuits for processing gas or humidity signals from the sensor electrodes.
2. The integrated sensor device of claim 1 , wherein the wireless transceiver is for communication with other nodes in a network, the wireless transceiver switching a channel frequency upon detection of interference.
3. The integrated sensor device of claim 2 , wherein the transceiver is initialized to a first predetermined channel.
4. The integrated sensor device of claim 2 , wherein the transceiver may enter a sleep mode after channel frequency initialization.
5. The integrated sensor device of claim 2 , further comprising a low noise amplifier formed in the MOS circuits, the low noise amplifier comprising a strained silicon device.
6. The integrated sensor device of claim 1 , further comprising a low noise amplifier formed in the MOS circuit.
7. The integrated sensor device of claim 6 , wherein the low noise amplifier comprises a strained silicon device.
8. The integrated sensor device of claim 7 , wherein the low noise amplifier utilizes copper interconnect levels.
9. The integrated sensor device of claim 7 , wherein the strained silicon device comprises a strained silicon layer over a silicon germanium layer.
10. An integrated sensor device comprising:
MOS circuits in a semiconductor substrate;
a wireless transceiver formed in the MOS circuits;
a sensor comprising sensor electrodes and a porous sensor material for ingress of gas or humidity to be sensed wherein at least some of the MOS circuits are directly beneath the sensor in a vertical dimension;
an interconnect stack comprising a plurality of interconnect levels, the interconnect stack comprising interconnect conductors and insulating dielectrics, said interconnect stack being over the substrate and forming interconnect levels interconnecting the MOS circuits; and
a processor circuit formed within the MOS circuits, the processor circuit coupled to sensor signals from the sensor circuit to process the sensor signals,
wherein the sensor electrodes are embedded in at least one of the insulating dielectrics and are integrally formed within at least one of the interconnect conductors.
11. The integrated sensor device of claim 10 , wherein the porous sensor material is a porous oxide.
12. The integrated sensor device of claim 11 , wherein the porous sensor material forms at least a portion of one of the insulating dielectrics.
13. The integrated sensor device of claim 11 , wherein the wireless transceiver is for communication with other nodes in a network, the wireless transceiver utilizing channel hopping.
14. The integrated sensor device of claim 13 , the wireless transceiver including a low noise amplifier formed in the MOS circuits, the low noise amplifier comprising a strained silicon device.
15. The integrated sensor device of claim 11 , the wireless transceiver including a low noise amplifier formed in the MOS circuits, the low noise amplifier comprising a strained silicon device.
16. The integrated sensor device of claim 10 , wherein the wireless transceiver is for communication with other nodes in a network, the wireless transceiver utilizing channel hopping.
17. The integrated sensor device of claim 16 , the wireless transceiver including a low noise amplifier formed in the MOS circuits, the low noise amplifier comprising a strained silicon device.
18. The integrated sensor device of claim 10 , the wireless transceiver including a low noise amplifier formed in the MOS circuits, the low noise amplifier comprising a strained silicon device.