Large-area low-noise Single-Photon Avalanche Diodes in standard CMOS

5×5 SPAD matrices for the study of the trade-offs between fill factor, dark count rate and crosstalk in the design of CMOS image sensors

“…3 shows the top view of the three different SPAD shapes that have been included in the testchip to obtain information about their relative performance in terms of DCR; namely, circular, cigar-shaped and ellipsoidal. In [11], a cigar-shaped structure is proposed as an interesting alternative to implement large-area SPADs without having restrictive increases of the DCR, due to the larger gettering efficiency of the geometry to decrease the defect density in the active region [12]. As an extension of this concept, we propose the ellipse due to its resemblance to the cigar-shape and its smoother profile.…”