Effects of High Resistivity Epitaxial Wafer on Pinned Photodiodes for Indirect Time-of-Flight Applications

This paper conducts analysis to examine how pinned photodiode (PPD) performance improves on high resistivity epitaxial wafers for the Time-of-Flight (ToF) applications. High epitaxial resistivity PPDs feature crucial advantages in the collection of photogenerated charges because of its wide depletion region. The comparison is made in this paper for performance analyses at a near-infrared wavelength among the pixels of identical design on epitaxial wafers under different resistivities and demodulation contrast is used as performance metrics. The effects of high resistivity epitaxial wafer with various design parameters are also discussed in the paper, and the result shows that high resistivity epitaxial wafer significantly enhances crosstalk performance, allows pixels to work at higher modulation frequencies, and equips large-size pixels with well-performed demodulation capabilities.