A novel cathode structure for a self-biased linear Silicon Drift Detector

A novel cathode structure for a self-biased linear Silicon Drift Detector (SDD) is presented. The proper potential profile inside the fully depleted substrate is established by the voltage drop along a single cathode implanted across each external surface and arranged as a zigzag. Compared to other self-biased linear SDDs, the proposed structure features a uniform thermal distribution and optimizes the sensitive area. The Poissonʹs equation together with the proper boundary conditions has been analytically solved in the 3D domain, and the solution has been validated by means of 3D simulation. A prototype based on this geometrical configuration has been manufactured at Canberra Semiconductor. The resistance spread of each portion which constitutes the implanted cathode has been measured and results within 2%.