Performance improvement of Si-CCD detector based backside reflected light and photon emission microscopy by FIB ultimate substrate thinning

In FA laboratories a significant number of photon emission microscopy (PEM) systems are equipped with the most common detector, namely cooled Si-CCD camera. Backside reflected light microscopy (RLM) and photon emission microscopy (PEM) using this detector are possible but strongly limited by the interaction of light with silicon substrate. In this work, we show the improvement of the RLM and PEM performed from the chip backside using standard cooled Si-CCD camera by localized focused-ion-beam (FIB) assisted silicon substrate removal. Thinning down the silicon substrate significantly improves signal-to-noise ratio of the techniques as well as their resolving properties. It also enables extended spectral analysis, also in the visible regime of the light spectrum. This study has been done using 120 nm technology process test structures.