International audienceA 3D technology is used to design ESD protection devices. These planar bidirectional components, based on back-to-back diodes, are dedicated to first stage, external ESD protection. The main feature consists in using deep micro-holes, usually dedicated to the manufacturing of high-value capacitors, to design 3D diode. These devices present an unexpected behaviour when they are submitted to cumulative ESD stress. Finally, we propose an optimized configuration based on deep trenches that improves cumulative ESD stress robustness