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PhD Thesis Proposal: Wei Deng

Thursday, October 22, 2020, 3:00pm

Videoconference

For info on how to attend this videoconference, please email wei.deng.TH@dartmouth.edu

“Noise Performance of Quanta Image Sensors”

Abstract

Quanta Image Sensor (QIS), invented and under development at Dartmouth, is a next-generation solid-state image sensor technology after charge-coupled device (CCD) and CMOS image sensor (CIS). QIS features high temporal-spatial resolution and has a deep sub-electron read noise that allows photon counting. For accurate photon counting, the QIS read noise target is below 0.15 e− rms although single electron quantization becomes apparent below about 0.45 e− rms. Currently, it is believed that noise from the in-pixel source-follower (SF) transistor dominates the read noise of QIS. SF noise is composed of several different types of noise, mainly 1/f noise or flicker noise, random telegraph noise (RTN), and thermal noise. The origin of RTN is usually attributed to conduction carrier trapping and re-emission, while the theory of thermal noise is well-established. Nevertheless, the physical origin of 1/f noise has not been well established.

To further reduce QIS read noise and enable accurate single-photon counting, the origins of all different noise sources need to be identified, especially 1/f noise. This dissertation looks to model the 1/f noise of QIS, along with other noises such as RTN. The physical origin of 1/f noise will be investigated and comparison between the modeling and experimental results will be discussed. Different approaches, including bandpass filtering, SF sizing, and further cooling, to achieve even lower read noise will be explored. To better understand the noise origin, a QIS prototype chip consisting of different design variations and novel structures was designed, fabricated and the characterization is underway. The performance of QIS at low temperature will also be investigated for future space missions.

Thesis Committee

For more information, contact Daryl Laware at daryl.a.laware@dartmouth.edu.