Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1830045 | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | 2007 | 6 Pages |
Abstract
Direct-detection CMOS image sensors optimized for charged-particle imaging applications, such as electron microscopy and particle physics, have been designed, fabricated and characterized. These devices directly image charged particles without reliance on image-degrading hybrid technologies such as the use of scintillating materials. Based on standard CMOS Active Pixel Sensor (APS) technology, the sensor arrays use an 8-20 μm thick epitaxial layer that acts as a sensitive region for the generation and collection of ionization electrons resulting from impinging high-energy particles. A range of optimizations to this technology have been developed via simulation and experimental device design. These include the simulation and measurement of charge-collection efficiency vs. recombination, effect of diode area and stray capacitance vs. signal gain and noise, and the effect of different epitaxial silicon depths. Several experimental devices and full-scale prototypes are presented, including two prototypes that systematically and independently vary pixel pitch and diode area, and a complete high-resolution camera for electron microscopy optimized through experiment and simulation. The electron microscope camera has 1Ã1 k2 pixels with a 5 μm pixel pitch and an 8 μm epitaxial silicon thickness.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Instrumentation
Authors
Stuart Kleinfelder, Shengdong Li, Yandong Chen,