A compact pixel for single-photon detection in the analog domain is presented. The pixel integrates a single-photon avalanche diode(SPAD), a passive quenching & active recharging circuit(PQARC), and an analog coun...A compact pixel for single-photon detection in the analog domain is presented. The pixel integrates a single-photon avalanche diode(SPAD), a passive quenching & active recharging circuit(PQARC), and an analog counter for fast and accurate sensing and counting of photons. Fabricated in a standard 0.18 μm CMOS technology, the simulated and experimental results reveal that the dead time of the PQARC is about 8 ns and the maximum photon-counting rate can reach 125 Mcps(counting per second). The analog counter can achieve an 8-bit counting range with a voltage step of 6.9 mV. The differential nonlinearity(DNL) and integral nonlinearity(INL) of the analog counter are within the ± 0.6 and ± 1.2 LSB, respectively, indicating high linearity of photon counting. Due to its simple circuit structure and compact layout configuration, the total area occupation of the presented pixel is about 1500 μm^(2), leading to a high fill factor of 9.2%. The presented in-pixel front-end circuit is very suitable for the high-density array integration of SPAD sensors.展开更多
The influence of the virtual guard ring width(GRW)on the performance of the p-well/deep n-well single-photon avalanche diode(SPAD)in a 180 nm standard CMOS process was investigated.TCAD simulation demonstrates that th...The influence of the virtual guard ring width(GRW)on the performance of the p-well/deep n-well single-photon avalanche diode(SPAD)in a 180 nm standard CMOS process was investigated.TCAD simulation demonstrates that the electric field strength and current density in the guard ring are obviously enhanced when GRW is decreased to 1μm.It is experimentally found that,compared with an SPAD with GRW=2μm,the dark count rate(DCR)and afterpulsing probability(AP)of the SPAD with GRW=1μm is significantly increased by 2.7 times and twofold,respectively,meanwhile,its photon detection probability(PDP)is saturated and hard to be promoted at over 2 V excess bias voltage.Although the fill factor(FF)can be enlarged by reducing GRW,the dark noise of devices is negatively affected due to the enhanced trap-assisted tunneling(TAT)effect in the 1μm guard ring region.By comparison,the SPAD with GRW=2μm can achieve a better trade-off between the FF and noise performance.Our study provides a design guideline for guard rings to realize a low-noise SPAD for large-array applications.展开更多
We present a novel gated operation active quenching circuit （AQC）. In order to simulate the quenching circuit a complete SPICE model of a InGaAs SPAD is set up according to the I-V characteristic measurement resuits...We present a novel gated operation active quenching circuit （AQC）. In order to simulate the quenching circuit a complete SPICE model of a InGaAs SPAD is set up according to the I-V characteristic measurement resuits of the detector. The circuit integrated with a ROIC （readout integrated circuit） is fabricated in an CSMC 0.5 μm CMOS process and then hybrid packed with the detector. Chip measurement results show that the functionality of the circuit is correct and the performance is suitable for practical system applications.展开更多
基金supported by the National Natural Science Foundation of China (No. 61571235, 61871231)the Key Research&Development Plan of Jiangsu Province+2 种基金China(No. BE2019741)the Natural Science Foundation of Jiangsu ProvinceChina (No. BK20181390)。
文摘A compact pixel for single-photon detection in the analog domain is presented. The pixel integrates a single-photon avalanche diode(SPAD), a passive quenching & active recharging circuit(PQARC), and an analog counter for fast and accurate sensing and counting of photons. Fabricated in a standard 0.18 μm CMOS technology, the simulated and experimental results reveal that the dead time of the PQARC is about 8 ns and the maximum photon-counting rate can reach 125 Mcps(counting per second). The analog counter can achieve an 8-bit counting range with a voltage step of 6.9 mV. The differential nonlinearity(DNL) and integral nonlinearity(INL) of the analog counter are within the ± 0.6 and ± 1.2 LSB, respectively, indicating high linearity of photon counting. Due to its simple circuit structure and compact layout configuration, the total area occupation of the presented pixel is about 1500 μm^(2), leading to a high fill factor of 9.2%. The presented in-pixel front-end circuit is very suitable for the high-density array integration of SPAD sensors.
基金supported by the Jiangsu Agricultural Science and Technology Innovation Fund of China(No.CX(21)3062)the National Natural Science Foundation of China(No.62171233).
文摘The influence of the virtual guard ring width(GRW)on the performance of the p-well/deep n-well single-photon avalanche diode(SPAD)in a 180 nm standard CMOS process was investigated.TCAD simulation demonstrates that the electric field strength and current density in the guard ring are obviously enhanced when GRW is decreased to 1μm.It is experimentally found that,compared with an SPAD with GRW=2μm,the dark count rate(DCR)and afterpulsing probability(AP)of the SPAD with GRW=1μm is significantly increased by 2.7 times and twofold,respectively,meanwhile,its photon detection probability(PDP)is saturated and hard to be promoted at over 2 V excess bias voltage.Although the fill factor(FF)can be enlarged by reducing GRW,the dark noise of devices is negatively affected due to the enhanced trap-assisted tunneling(TAT)effect in the 1μm guard ring region.By comparison,the SPAD with GRW=2μm can achieve a better trade-off between the FF and noise performance.Our study provides a design guideline for guard rings to realize a low-noise SPAD for large-array applications.
基金Supported by National Natural Science Foundation of China(61233010,61274043)Hunan Provincial Natural Science Fund for Distinguished Young Scholars(2015JJ1014)
基金supported by the Jiangsu Provincial Natural Science Fund(No.BK2012559)
文摘We present a novel gated operation active quenching circuit （AQC）. In order to simulate the quenching circuit a complete SPICE model of a InGaAs SPAD is set up according to the I-V characteristic measurement resuits of the detector. The circuit integrated with a ROIC （readout integrated circuit） is fabricated in an CSMC 0.5 μm CMOS process and then hybrid packed with the detector. Chip measurement results show that the functionality of the circuit is correct and the performance is suitable for practical system applications.
基金Supported by State Key Program of National Natural Science of China(61233010)National Natural Science Foundation of China(61774129,61704145)Hunan Provincial Natural Science Fund for Distinguished Young Scholars(2015JJ1014)
基金Supported by the Key Program of National Natural Science of China(61233010)by the National Natural Science Foundation of China(61774129,61704145)by Hunan Provincial Natural Science Fund for Distinguished Young Scholars(2015JJ1014)
基金Supported by National Natural Science Foundation of China(61774129,61704145,61525305,61827812)Hunan Provincial Natural Science Fund for Distinguished Young Scholars(2015JJ1014)
