Dark Current Analysis in Silicon PIN Photodetectors: TCAD, Lifetime and Statistical Process Control

Photodetectors, particularly those employing silicon PIN diodes, are critical in various applications due to their high responsivity and speed. However, minimizing dark current a primary source of noise is essential for improving performance. This study investigates the relationship between dark current and minority carrier lifetime, a key parameter influenced by material defects and process variability. A combination of experimental techniques, including microwave photoconductance decay for lifetime mapping, statistical process control (SPC), and TCAD simulations, was employed. Experimental results revealed minimal correlation between lifetime values and dark current across production phases, as indicated by statistical analyses using Spearman and Pearson correlation coefficients. Meanwhile, TCAD simulations demonstrated the dependence of dark current on Shockley-Reed-Hall (SRH) recombination, which dominated under low carrier injection conditions. These findings provide insight into dark current behavior, contributing to enhanced process control and defect analysis in photodetector manufacturing. This comprehensive approach lays the groundwork for optimizing photodetector fabrication processes while addressing variability in device performance.