TY - JOUR
T1 - Noise characteristics of stacked CMOS active pixel sensor for charged particles
AU - Kunihiro, Takuya
AU - Nagashima, Kazuhide
AU - Takayanagi, Isao
AU - Nakamura, Junichi
AU - Kosaka, Koji
AU - Yurimoto, Hisayoshi
N1 - Funding Information:
We are grateful to H. Emori for helpful comments. This study was partly supported by Monbu-Kagaku-sho and Gakushin-fellowship.
PY - 2001/9/11
Y1 - 2001/9/11
N2 - The noise characteristics of a stacked CMOS active pixel sensor (SCAPS) for incident charged particles have been analyzed under 4.5 keV Si+ ion irradiation. The source of SCAPS dark current was found to change from thermal to electron leakage with decreasing device temperature. Leakage current at charge integration part in a pixel has been reduced to 0.1electronss-1 at 77K. The incident ion signals are computed by subtracting reset frame values from each frame using a non-destructive readout operation. With increase of irradiated ions, the dominant noise source changed from read noise, and shot noise from the incident ions, to signal frame fixed-pattern noise from variations in sensitivity between pixels. Pixel read noise is equivalent to ten incident ions. The charge of an incident ion is converted to 1.5electrons in the pixel capacitor. Shot noise corresponds to the statistical fluctuation of incident ions. Signal frame fixed-pattern noise is 0.7% of the signal. By comparing full well conditions to noise floor, a dynamic range of 80dB is achieved. SCPAS is useful as a two-dimensional detector for microanalyses such as stigmatic secondary ion mass spectrometry.
AB - The noise characteristics of a stacked CMOS active pixel sensor (SCAPS) for incident charged particles have been analyzed under 4.5 keV Si+ ion irradiation. The source of SCAPS dark current was found to change from thermal to electron leakage with decreasing device temperature. Leakage current at charge integration part in a pixel has been reduced to 0.1electronss-1 at 77K. The incident ion signals are computed by subtracting reset frame values from each frame using a non-destructive readout operation. With increase of irradiated ions, the dominant noise source changed from read noise, and shot noise from the incident ions, to signal frame fixed-pattern noise from variations in sensitivity between pixels. Pixel read noise is equivalent to ten incident ions. The charge of an incident ion is converted to 1.5electrons in the pixel capacitor. Shot noise corresponds to the statistical fluctuation of incident ions. Signal frame fixed-pattern noise is 0.7% of the signal. By comparing full well conditions to noise floor, a dynamic range of 80dB is achieved. SCPAS is useful as a two-dimensional detector for microanalyses such as stigmatic secondary ion mass spectrometry.
KW - Charged particle
KW - Detector
KW - Noise
KW - SIMS
KW - Solid-state image sensor
UR - http://www.scopus.com/inward/record.url?scp=0035845597&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035845597&partnerID=8YFLogxK
U2 - 10.1016/S0168-9002(01)00795-1
DO - 10.1016/S0168-9002(01)00795-1
M3 - Article
AN - SCOPUS:0035845597
VL - 470
SP - 512
EP - 519
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
SN - 0168-9002
IS - 3
ER -