The Compact Linear Collider CLIC, a multi-TeV linear electron-positron collider, aims at precision measurements of the Standard Model, as well as direct and indirect searches of physics beyond the Standard Model. These aims translate into challenging requirements imposed on the detector. To reach these requirements, a silicon tracking system is envisaged, being composed of a low-mass vertex detector and a large scale tracker. While the requirements on the tracker are mainly driven by the need for a precise momentum resolution, the requirements on the vertex detector are mainly motivated by the demand on reconstructing secondary vertices from heavy-flavour quarks. A single point spatial resolution of a few micrometres is required for the tracking system together with a material budget of 0.2% of a radiation length per detection layer in the innermost layers. To mitigate hit rates from beam-induced background particles, a timing resolution in the order of a few nanoseconds is needed and the cell sizes are restricted down to 25 μm x 25 μm in the vertex detector and 25 μm − 10 mm in the tracker. To evaluate which technology can meet these requirements, a broad silicon detector R&D is performed for a selected choice of technologies.