Electromagnetic monitoring of semiconductor ageing (EMSA)


Funder: EPSRC
Date: September 2013 - February 2014
Web pages: York Research Database
My roles: Researcher

Semiconductor devices age over time leading to a gradual degradation in their performance. Eventually these changes can lead to a malfunction in the electronics circuits in which the devices are embedded. The ability to monitor the through life ageing of semiconductor devices in a system is therefore important for providing information on the system’s “health” and thus the risk of system failure. Such monitoring can be built into the electronic circuits, but this is costly. This project demonstrated that it is feasible to monitoring age related performance effects non-invasively by measuring how the emission spectrum or re-emissions spectrum changes over time.

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A selection of images from my work on the project

This project was funded by the EPSRC Centre for Innovative Manufacturing in Through-life Engineering Services and was a collaboration between the AEG at the University of York and De Montfort University.

The characteristics of devices in a circuit determine the shape of the digital waveforms propagating along traces on PCBs and therefore the electromagnetic emission spectrum of the circuit. Furthermore, earlier work in the AEG had demonstrated that the re-emission spectrum of digital electronic system when illuminated by radio-frequency electromagetic fields carried information about the interaction of the field with the nonlinear devices in the system (Flintoft et al., 2003). We therefore postulated that ageing effects may be observed in these spectra.

To verfiy this postulate a number of simple electronic circuits were constructed, each based on a single semiconductor device. The emission and re-emission spectrum of the circuit was measured before and after the devices where aged. The image gallery above shows one of these circuits - a simple microcontroller circuit transmitting a digital signal around a loop. A number of nominally identical microcontrollers were used, some as unaged controls, while others were subjected to one or two cycles of accelerated ageing at high temperature. The graphs below show the emission spectrum of the microcontroller circuit with the same microcontrolled chip before and after ageing.

image-left Evolution of the emission spectrum near 27 MHz of a microcontroller due to two rounds of high temperature accelerated ageing

Full details of the project can be found in (Duffy et al., 2014), (Dawson et al., 2014) and (Dawson et al., 2014).


  1. Dawson, J.F., Flintoft, I.D., Duffy, A.P., Marvin, A.C. and Robinson, M.P., 2014. Effect of high temperature ageing on electromagnetic emissions from a PIC microcontroller. In: 2014 International Symposium on Electromagnetic Compatibility (EMC EUROPE 2014). Gothenburg, Sweden: IEEE, pp.1139–1143.
  2. Duffy, A.P., Dawson, J.F., Flintoft, I.D. and Marvin, A.C., 2014. Electromagnetic monitoring of semiconductor ageing. Procedia CIRP, [online] 22, pp.98–102.
  3. Dawson, J.F., Flintoft, I.D., Duffy, A.P., Marvin, A.C. and Robinson, M.P., 2014. Electromagnetic monitoring of semiconductor ageing. In: 2nd Annual Symposium on Tackling No-Fault Found in Maintenance Engineering (NFF2014). Shrivenham, UK.
  4. Flintoft, I.D., Marvin, A.C., Robinson, M.P., Fischer, K. and Rowell, A.J., 2003. The re-emission spectrum of digital hardware subjected to EMI. IEEE Transactions on Electromagnetic Compatibility, 45(4), pp.576–585.