STRIP DETECTOR DESIGN FOR ATLAS AND HERA-B USING 2-DIMENSIONAL DEVICESIMULATION

Irradiation scenarios were simulated in order to evaluate different te chnology and design options for silicon strip detectors exposed to a h igh luminosity environment. Two-dimensional. process and device simula tions were performed to get an insight into the device behaviour. The boundary condition of the free oxide regions between the strips was ev aluated thoroughly to obtain correct field distributions. Using these results the formation of electron accumulation layers on the surface o f the p-side and the depletion voltage dependence on the strip geometr y can be explained. We investigated the ''blocking implant'' and the ' 'spray implant'' techniques as promising candidates for the n-side iso lation of irradiated detectors. The main drawback of the ''blocking im planted'' devices is the increase of the electric field with increasin g oxide charges. This implies the danger of impact ionization in irrad iated devices. A ''spray implanted'' isolation layer leads to the high est electric field in the non-irradiated state which has the advantage of a better testability. Small gaps between strips as used in charge division readout reduce electric fields and leakage currents.