Title :
Design of bipolar imaging devices (BASIS): analysis of random noise
Author :
Nakamura, Yoshio ; Ohzu, Hayao ; Miyawaki, Mamoru ; Ishizaki, Akira ; Kochi, Tetsunobu ; Ohmi, Tadahiro
Author_Institution :
Canon Inc., Kanagawa, Japan
fDate :
6/1/1992 12:00:00 AM
Abstract :
A design methodology for a bipolar imaging device, the base-stored image sensor (BASIS), has been established by theoretical analysis and experimental verification for random noise. The random noise in BASIS is dominated by the shot noise in readout and transient reset operation. The theoretical analysis has been carried out by introducing the probability density functions for these operations. The readout noise depends on the base-to-collector junction capacitance Cbc , the emitter common current gain hFE, the storage capacitor CT, and the emitter voltage V E. The reset noise has been confirmed to be given by thermal noise. The theoretical results coincide well with the experimental results obtained by TEG devices. An expression for the S/N ratio has been derived theoretically. It is found that hFE should be made as large as possible and ( Cbc+Cbe) as small as possible to improve the S/N ratio for random noise, where C be is the base-to-emitter junction capacitance
Keywords :
electron device noise; image sensors; semiconductor device models; BASIS; S/N ratio; TEG devices; base-stored image sensor; base-to-collector junction capacitance; base-to-emitter junction capacitance; bipolar imaging devices; design methodology; emitter common current gain; emitter voltage; experimental results; probability density functions; random noise; readout noise; reset noise; shot noise; storage capacitor; theoretical results; thermal noise; transient reset operation; Capacitance; Capacitors; Circuit noise; Computed tomography; Design methodology; Image analysis; Semiconductor device noise; Signal to noise ratio; Silicon compounds; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
