Pulsed laser for radiation sensitivity evaluation has become a common tool used in research and industrial laboratory. This paper aims to highlight an approach to understand weaknesses of a component under radiation environment using a short pulsed width laser beam coupled to thermography technique, heavy ions test inputs and physical analysis. This paper is based on a study of a PWM device embedded on voltage converter.

To debug ASIC we likely use accurate tools such as an electron beam tester (Ebeam tester) and a Focused Ion Beam (FIB). Interactions between ions or electrons and the target device build charge up on its upper glassivation layer. This charge up could trigger several problems. With Ebeam testing, it sharply decreases voltage contrast during Image Fault Analysis and hide static voltage contrast. During ASIC reconfiguration with FIB, it could induce damages in the glassivation layer. Sample preparation is getting a key issue and we show how we can deal with it by optimizing carbon coating of the devices. Coating is done by an evaporator. For focused ion beam reconfiguration, we need a very thick coating. Otherwise the coating could be sputtered away due to imaging. This coating is use either to avoid charge-up on glassivated devices or as a sacrificial layer to avoid short circuits on unglassivated devices. For electron beam Testing, we need a very thin coating, we are now using an electrical characterization method with an insitu control system to obtain the right thin thickness. Carbon coating is a very cheap and useful method for sample preparation. It needs to be tuned according to the tool used.