(1) University of Glasgow, Kelvin Building, Glasgow G12 8QQ, Scotland.
(2) Instituto de Microelectronica de Barcelona, IMB-CNM-CSIC, 08193 Bellaterra, Barcelona, Spain
(3) Diamond Light Source Ltd, Harwell Science and Innovation Campus, Oxfordshire, UK, OX11 0DE
Future high-luminosity colliders, such as the Super-LHC at CERN, will require pixel detectors capable of withstanding extremely high radiation damage. In this article, the performances of various 3D detector structures are simulated with up to $1 \times 10^{16}$ 1MeV-n$_{eq}$/cm$^{2}$ radiation damage. The simulations show that 3D detectors have higher collection efficiency and lower depletion voltages than planar detectors due to their small depletion distance. When designing a 3D detector with a large pixel size, such as an ATLAS sensor, different electrode column layouts are possible. Using a small number of n+ readout electrodes per pixel leads to higher depletion voltages and lower collection efficiency, due to the larger electrode spacing. Conversely, using more electrodes increases both the insensitive volume occupied by the electrode columns and the capacitive noise. Overall, the best performance after $1 \times 10^{16}$ 1MeV-n$_{eq}$/cm$^{2}$ damage is achieved by using 4--6 n+ electrodes per pixel.
Nuclear Instruments and Methods in Physics Research, Section A,
Vol 592 (1-2), pp16-25, 2008