Test structures for quantum efficiency characterization for silicon image sensors

To study the spectral response, test structures are specially designed. This paper presents quantum efficiency results for different kind of N-well/P-epi diodes. A comparison is made between a diode under active and under STI with or without salicidation. The impact of the design (different N-well geometries) and two reading nodes (CMOS and NMOS) are also studied. These measurements are then compared with the ISE simulation using a 2D simulation program DIOS.