University of Warwick

Cambridge Cmos Sensors Limited

Ams Sensors UK Limited

Julian Gardner

Florin Udrea

Syed Zeeshan Ali

Andrea De Luca

Mohamed Foysol Chowdhury

Ilie Poenaru

Richard Henry Hopper

James Anthony Covington

Marina Cole

Farah Villa Lopez

Sanju Thomas

Richard Henry Hooper

Takao Iwaki

Jan Specht

Llie Poenaru

An integrated circuit is disclosed. The integrated circuit comprises a silicon substrate, a sensor comprising a bulk acoustic wave resonator and an acoustic mirror disposed between the bulk acoustic wave resonator and the substrate, and a CMOS circuit supported by substrate and operatively connected to the sensor.

Bulk acoustic wave resonator based sensor

We disclose an array of Infra-Red (IR) detectors comprising at least one dielectric membrane formed on a semiconductor substrate comprising an etched portion; at least two IR detectors, and at least one patterned layer formed within or on one or both sides of the said dielectric membrane for controlling the IR absorption of at least one of the IR detectors. The patterned layer comprises laterally spaced structures.

IR detector array device

It is disclosed herein a semiconductor device and a method of manufacturing the semiconductor device. The semiconductor device is made using partly CMOS or CMOS based processing steps, and it includes a semiconductor substrate, a dielectric region over the semiconductor substrate, a heater within the dielectric region and a patterned layer of noble metal above the dielectric region. The method includes the deposition of a photoresist material over the dielectric region, and patterning the photo-resist material to form a patterned region over the dielectric region. The steps of depositing the photo-resist material and patterning the photo-resist material may be performed in sequence using similar photolithography and etching steps to those used in a CMOS process. The resulting semiconductor device is then subjected to further processing steps which ensure that a dielectric membrane and a metal structure within the membrane are formed in the patterned region over the dielectric region.

CMOS-based semiconductor device on micro-hotplate and method of fabrication

We disclose herein a thermal IR detector array device comprising a dielectric membrane, supported by a substrate, the membrane having an array of IR detectors, where the array size is at least 3 by 3 or larger, and there are tracks embedded within the membrane layers to separate each element of the array, the tracks also acting as heatsinks and/or cold junction regions.

An infra-red (IR) device comprising a dielectric membrane formed on a silicon substrate comprising an etched portion; and at least one patterned layer formed within or on the dielectric membrane for controlling IR emission or IR absorption of the IR device, wherein the at least one patterned layer comprises laterally spaced structures.

Plasmonic IR devices

An IR source in the form of a micro-hotplate device including a CMOS metal layer made of at least one layer of embedded on a dielectric membrane supported by a silicon substrate. The device is formed in a CMOS process followed by a back etching step. The IR source also can be in the form of an array of small membranes &#x2014;closely packed as a result of the use of the deep reactive ion etching technique and having better mechanical stability due to the small size of each membrane while maintaining the same total IR emission level. SOI technology can be used to allow high ambient temperature and allow the integration of a temperature sensor, preferably in the form of a diode or a bipolar transistor right below the IR source.

IR emitter and NDIR sensor

An IR detector in the form of a thermopile including one or more thermocouples on a dielectric membrane supported by a silicon substrate. Each thermocouple is composed of two materials, at least one of which is p-doped or n-doped single crystal silicon. The device is formed in an SOI process. The device is advantageous as the use of single crystal silicon reduces the noise in the output signal, allows higher reproducibility of the geometrical and physical properties of the layer and in addition, the use of an SOI process allows a temperature sensor, as well as circuitry to be fabricated on the same chip. The detector can also have an IR filter wafer bonded onto it and/or have arrays of thermopiles to increase the sensitivity. The devices can also be integrated with an IR source on the same silicon chip and packaged to form a complete and miniaturised NDIR sensor.

IR detector

A micro-hotplate is provided in the form of a device comprising a sensor and one or more resistive heaters within the micro-hotplate arranged to heat the sensor. Furthermore a controller is provided for applying a bidirectional drive current to at least one of the heaters to reduce electromigration. The controller also serves to drive the heater at a substantially constant temperature.

Electromigration reduction in micro-hotplates

A gas-sensing semiconductor device' is fabricated on a silicon substrate&#x2032; having a thin silicon dioxide insulating layer&#x2032; in which a resistive heatermade of doped single crystal silicon formed simultaneously with source and drain regions of CMOS circuitry is embedded. The device&#x2032; includes a sensing area provided with a gas-sensitive layer&#x2032; separated from the heater&#x2032; by an insulating layer&#x2032;. As one of the final fabrication steps, the substrate&#x2032; is back-etched so as to form a thin membrane in the sensing area. The heater&#x2032; has a generally circular-shaped structure surrounding a heat spreading plate&#x2032;, and consists of two setsof meandering resistors having arcuate portions nested within one another and interconnected in labyrinthine form. The fabrication of the heater at the same time as the source and drain regions of CMOS circuitry is particularly advantageous in that the gas-sensing semiconductor device is produced without requiring any fabrication steps in addition to those already employed in the IC processing apart from a post-CMOS back etch and deposition of the gas-sensitive layer. The circular design is advantageous in that it is the best solution to minimise the size of the membrane at fixed power loss and heated area.

Gas-sensing semiconductor devices

A gas-sensing semiconductor device is fabricated on a silicon substrate having a thin silicon oxide insulating layer in which a resistive heater made of a CMOS compatible high temperature metal is embedded. The high temperature metal is tungsten. The device includes at least one sensing area provided with a gas-sensitive layer separated from the heater by an insulating layer. As one of the final fabrication steps, the substrate is back-etched so as to form a thin membrane in the sensing area. Except for the back-etch and the gas-sensitive layer formation, that are carried out post-CMOS, all other layers, including the tungsten resistive heater, are made using a CMOS process employing tungsten metallisation. The device can be monolithically integrated with the drive, control and transducing circuitry using low cost CMOS processing. The heater, the insulating layer and other layers are made within the CMOS sequence and they do not require extra masks or processing.

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Kineton, United Kingdom

Julian Gardner