Semiconductor trackers for future particle physics detectors

Plans to use solid state sensors in high-energy particle trackers at upcoming experiments are reviewed. This will include a description of the detector layouts being considered as well as the main experimental challenge in these applications: radiation hardness. Our understanding of the phenomena that limit silicon sensor lifetime will be summarised. After listing the compromises inherent with the use of silicon I describe an alternative: diamond. The properties of diamond make it an ideal material for tracking detectors especially in the high rate and radiation environments near the collision point in future colliders. Micro-strip tracker and pixel detectors have been constructed using high-quality Chemical Vapour Deposited (CVD) diamond. While this is an important first step a number of issues remain: ensuring the radiation hardness of the material is sufficient to survive in regions where silicon cannot and maximising the charge observed when a charged particle traverses the material. Work in these directions is described.