Design of an Ultrasensitive Active Pixel Sensor Taking into Account Charging Effects in a Nanoscale Transistor

Active pixel sensors (APS), essential components in commercial digital cameras and medical instruments, are currently under consideration as direct-conversion particle detectors for nuclear physics research.  Across many fields, there is increasing demand for more sensitive detectors. This project will utilize the novel features of charging effects in nanoscale silicon transistors to obtain dramatic improvement in the sensitivity of APS. In Phase I, the differences between the standard APS (where charge transport is based on the usual principles of drift and diffusion) and the new device (in which tunneling and charging effects of ultrasmall capacitances play an important role) will be clarified. The design of the device, as well as the steps in the fabrication process, will be specified. Noise characteristics and sensitivity for various designs also will be specified. In Phase II, the device will be fabricated and tested. Commercial Applications And Other Benefits as described by the Applicant: High sensitivity APS should find use in a variety of commercial imaging instruments, from cameras for high definition images to robotic manufacturing systems. In nuclear physics research, the device would be useful for charged-particle tracking.