As a result of the high luminosity phase of the SLHC, for CMS a tracking system with very high granularity is mandatory and the sensors will have to withstand an extreme radiation environment of up to 1016 part/2. On this basis, a new geometry with silicon short strip sensors (strixels) is proposed. To understand their performances, test geometries are developed whose parameters can be verified and optimized using simulation of semiconductor structures. We have used the TCAD-ISE (SYNOPSYS package) software in order to simulate the main electrical parameters of different strip geometries, for p-in-n-type wafers.