New device to improve transistor quality
A new configurable chip which can correct faults in newly- manufactured transistors and can be implemented in mainstream devices such as mobile phones and computers, has been developed by engineers at the University of Southampton.
In a paper just published in Electronics Letters, Dr Peter Wilson with Dr Reuben Wilcock from the University's School of Electronics and Computer Science (ECS), describes the Configurable Analogue Transistor (CAT) which he and his team have developed, and for which they have a patent pending. The CAT approach can be applied to batches of transistors which in testing after manufacture prove to have an unacceptably high variability.
According to Dr Wilson, the manufacturing process for deep submicron technologies is currently very expensive, with the cost of failed devices running into huge figures. Designers create new chip designs and generally simulate how they will perform. When the silicon wafers are produced they will then undergo rigorous electrical testing to ensure that they are working. It is at this point that the designer often realises that some of the chips do not work, which creates a problem of reduced yield, i.e. a reduced number of working chips in a batch. This has been an increasing problem for Integrated Circuit designers over the last few years as process technology dimensions have become increasingly small, and the corresponding variability of devices worsened.
'One of the biggest challenges we face when shrinking devices in these new technology nodes is that there is increasing variability in the resulting devices and this is causing unacceptably poor yields in the circuits being produced - particularly in analogue and mixed signal devices where performance is at a premium,' said Dr Wilson. 'Now with CAT, we can take whole batches of chips and tighten their performance characteristics resulting in massive improvements in yield. Improvements in variability of up to 80 percent can be achieved using this approach.'
According to Dr Wilson, the CAT technique can also be applied to existing products to improve their performance and longevity.
'As technology changes over time, the CAT technique allows us to reconfigure devices so that products continue to work,' said Dr Wilson. 'For example, remote circuits in satellites and sensor devices can be "reprogrammed" and effectively recalibrated to take account of changing characteristics over time and environmental conditions.'
A copy of the paper by Dr Wilson and Dr Wilcock paper can be accessed at: http://eprints.ecs.soton.ac.uk/16667/
Notes to editors
1. Further information about Dr Wilson's work can be found at: http://www.ecs.soton.ac.uk/people/prw
2. With around 500 researchers, and 900 undergraduate students, the School of Electronics and Computer Science at Southampton is one of the world's largest and most successful integrated research groupings, covering Computer Science, Software Engineering, Electronics, and Electrical Engineering. ECS has unrivalled depth and breadth of expertise in world-leading research, new developments and their applications.
3. The University of Southampton is a leading UK teaching and research institution with a global reputation for leading-edge research and scholarship across a wide range of subjects in engineering, science, social sciences, health and humanities.
With over 22,000 students, around 5000 staff, and an annual turnover of over £350 million, the University of Southampton is acknowledged as one of the country's top institutions for engineering, computer science and medicine. We combine academic excellence with an innovative and entrepreneurial approach to research, supporting a culture that engages and challenges students and staff in their pursuit of learning.
The University is also home to a number of world-leading research centres, including the National Oceanography Centre, Southampton, the Institute of Sound and Vibration Research, the Optoelectronics Research Centre, the Centre for the Developmental Origins of Health and Disease, and the Mountbatten Centre for International Studies.