Integrated Sensor Technology Research Articles

ISFET integrated sensor technology

ISFETs have been fabricated using a modified CMOS silicon-gate 5 μm P-well process. The technology flow and ISFET cross sections are designed with a view to achieving as low a light sensitivity as possible. Three different ISFET structures are suggested; they are simulated using SUPREM4 and PISCES2B to determinate influence of the channel and drain-source areas on the light sensitivity of ISFETs and these structures have been fabricated. The light response of one structure (MOSFET type) is measured at a probe station. The ISFET is fabricated with an operational amplifier connected as a follower, a bias (band-gap based) generator and a temperature sensor based on the temperature-dependent current source. The whole circuit needs only four wires, e.g., VCC, GND, OUT and TEMP.

Electronic odour sensing systems

An odour sensing instrument has been developed and used to classify many different materials, including beers, spirits and alcohols. The next stage in development is to begin to relate subjective odour descriptors (e.g. fruity, minty) to quantitative sensor array measurements. This task is being approached using both neural network and multivariate statistical techniques. The ultimate goal is to provide a measurement standard for odours. This exciting prospect requires the integration of sensor technology, signal conditioning, data acquisition and pattern recognition.

Annealing-related electrical and piezoresistive properties of Band As-implanted LPCVD silicon films

We investigate the electrical properties of polycrystalline silicon thin films implanted with arsenic or boron ions. Two types of post-implantation annealing have been performed on the samples: a conventional thermal annealing (CTA) and a rapid thermal annealing (RTA). We find that RTA improves the electrical properties. Measurements of gauge factors have been carried out on both films. We conclude that RTA can be applied successfully in thin film silicon integrated sensor technology

An electronic nose: a sensitive and discriminating substitute for a mammalian olfactory system

The dream of a direct electronic analogue for a biological nose may still be some way from realisation, but considerable progress can be reported towards prototype computerised instruments capable of equivalent, or even better, performance in certain applications. The achievements are partly attributable to success in new circuit and systems approaches, as well as in developing sensing devices, with the prospect of further rapid progress based on the exploitation of materials and integrated sensor technology. Other important advances are being created in information processing, particularly in relation to pattern recognition.