Abstract: A method for manufacturing a radiation hardened semiconductor device, having defined active region and isolation region. The isolation region containing an isolation material and active region containing a transition region between active and isolation region, sometimes denoted a bird's beak region. Wherein the transition region is implanted with germanium and boron, to prevent formation of leakage paths between active devices, or within an active device. The implanted area can be further limited to that area of the transition region that is adapted to be covered by a gate material, such as polysilicon.