Microsystem engineering: new methods of defect diagnosis 

Every time there's a jump in microelectronics technology, new weaknesses become apparent. These problems have to be resolved by localizing, diagnosing and optimizing the corresponding processes. 

Fraunhofer IWM joins forces with the Hallebased Max Planck Institute for Microstructure Physics to use a jointly developed lock-in thermography technique to track down an interrupt in the printed conductor, a damaged diode or a short-circuited transistor in millions of components on a circuit. A leak in an integrated circuit can be detected by its heat dissipation. The infrared-based testing method makes it possible to detect temperature differences of only one fifty-thousandths of one degree, thus measuring defects of only one hundredth of a hair diameter. 

This sensitivity puts this method far beyond the methods of leakage diagnosis available on the market. It has the benefit of not only allowing defects to be detected, but also weak spots that eventually have a disastrous effect in the component’s life span.   

Detecting defects in a microelectronic circuit with lock-in thermography (© Fraunhofer IWM)

But finding the defect is just the first step. To find out where it came from, the component is opened with ion beams right down to the micrometer and the defect then analyzed in cross-section. This provides data on the production process causing the problem so that it can be repaired. This results in enhanced reliability for electronic circuits and higher production yield.