Single-Electron Quantization of Dark Current in Quanta Image Sensors

We present a first experimental study of dark current in a quanta image sensor (QIS) based on complementary metal-oxide-semiconductor (CMOS) technology. With the extremely low noise levels of this sensor it is possible to observe spatial and temporal dark current quantization. Analysis of dark carrier emission timing confirms that carrier generation behaves as a Poisson process. The mean of this Poisson distribution is the only parameter needed to characterize a sensor, thus greatly reducing the required measurement and computational resources typically employed in device noise analysis. The impact of this new characterization method will be useful to a range of industrial and scientific applications requiring high accuracy in photoelectron counting, such as in particle detection or quantum sensing. The ability to observe single carrier emission in a QIS leads to a deeper understanding of the mechanism of dark current generation in state-of-the-art semiconductors, thereby promoting improvements in the development of device design and process technology.