  We present the concept of a new type of silicon tracking sensor called
Enhanced Lateral Drift (ELAD) sensor. In ELAD sensors the spatial resolution of
the impact position of ionising particles is improved by a dedicated charge
sharing mechanism, which is achieved by a non-homogeneous electric field in the
lateral direction in the sensor bulk. The non-homogeneous electric field is
created by buried doping implants with a higher concentration with respect to
the background concentration of the bulk. The resulting position-dependent
charge sharing allows for an improved interpolation of the impact position.
TCAD-based electric field simulations for 2D and 3D geometries as well as
transient simulations with a traversing particle for the 2D geometry have been
carried out. The electric field profiles have further been optimised for
position resolution. The simulations show a strong dependence of the charge
sharing mechanism on the buried implant concentration. Optimal values for the
buried implant concentration allow for nearly linear charge sharing between two
readout electrodes as a function of the impact position. Additionally, the
foreseen production technique combining silicon epitaxy and ion beam
implantation is outlined.
