scholarly journals Current-Assisted SPAD with Improved p-n Junction and Enhanced NIR Performance

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7105
Author(s):  
Gobinath Jegannathan ◽  
Thomas Van den Dries ◽  
Maarten Kuijk

Single-photon avalanche diodes (SPADs) fabricated in conventional CMOS processes typically have limited near infra-red (NIR) sensitivity. This is the consequence of isolating the SPADs in a lowly-doped deep N-type well. In this work, we present a second improved version of the “current-assisted” single-photon avalanche diode, fabricated in a conventional 350 nm CMOS process, having good NIR sensitivity owing to 14 μm thick epilayer for photon absorption. The presented device has a photon absorption area of 30 × 30 µm2, with a much smaller central active area for avalanche multiplication. The photo-electrons generated in the absorption area are guided swiftly towards the central area with a drift field created by the “current-assistance” principle. The central active avalanche area has a cylindrical p-n junction as opposed to the square geometry from the previous iteration. The presented device shows improved performance in all aspects, most notably in photon detection probability. The p-n junction capacitance is estimated to be ~1 fF and on-chip passive quenching with source followers is employed to conserve the small capacitance for bringing monitoring signals off-chip. Device physics simulations are presented along with measured dark count rate (DCR), timing jitter, after-pulsing probability (APP) and photon detection probability (PDP). The presented device has a peak PDP of 22.2% at a wavelength of 600 nm and a timing jitter of 220 ps at a wavelength of 750 nm.

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 436 ◽  
Author(s):  
Chin-An Hsieh ◽  
Chia-Ming Tsai ◽  
Bing-Yue Tsui ◽  
Bo-Jen Hsiao ◽  
Sheng-Di Lin

Single-photon avalanche diodes (SPADs) in complementary metal-oxide-semiconductor (CMOS) technology have excellent timing resolution and are capable to detect single photons. The most important indicator for its sensitivity, photon-detection probability (PDP), defines the probability of a successful detection for a single incident photon. To optimize PDP is a cost- and time-consuming task due to the complicated and expensive CMOS process. In this work, we have developed a simulation procedure to predict the PDP without any fitting parameter. With the given process parameters, our method combines the process, the electrical, and the optical simulations in commercially available software and the calculation of breakdown trigger probability. The simulation results have been compared with the experimental data conducted in an 800-nm CMOS technology and obtained a good consistence at the wavelength longer than 600 nm. The possible reasons for the disagreement at the short wavelength have been discussed. Our work provides an effective way to optimize the PDP of a SPAD prior to its fabrication.


Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5860
Author(s):  
Aymeric Panglosse ◽  
Philippe Martin-Gonthier ◽  
Olivier Marcelot ◽  
Cédric Virmontois ◽  
Olivier Saint-Pé ◽  
...  

Single-Photon Avalanche Diodes (SPAD) in Complementary Metal-Oxide Semiconductor (CMOS) technology are potential candidates for future “Light Detection and Ranging” (Lidar) space systems. Among the SPAD performance parameters, the Photon Detection Probability (PDP) is one of the principal parameters. Indeed, this parameter is used to evaluate the SPAD sensitivity, which directly affects the laser power or the telescope diameter of space-borne Lidars. In this work, we developed a model and a simulation method to predict accurately the PDP of CMOS SPAD, based on a combination of measurements to acquire the CMOS process doping profile, Technology Computer-Aided Design (TCAD) simulations, and a Matlab routine. We compare our simulation results with a SPAD designed and processed in CMOS 180 nm technology. Our results show good agreement between PDP predictions and measurements, with a mean error around 18.5%, for wavelength between 450 and 950 nm and for a typical range of excess voltages between 15 and 30% of the breakdown voltage. Due to our SPAD architecture, the high field region is not entirely insulated from the substrate, a comparison between simulations performed with and without the substrate contribution indicates that PDP can be simulated without this latter with a moderate loss of precision, around 4.5 percentage points.


2017 ◽  
Vol 31 (17) ◽  
pp. 1750193 ◽  
Author(s):  
Wei Wang ◽  
Xiaoyuan Bao ◽  
Li Chen ◽  
Ting Chen ◽  
Guanyu Wang ◽  
...  

This paper proposed a single photon avalanche diodes (SPADs) designed with 0.18 [Formula: see text] standard CMOS process. One of the major challenges in CMOS SPADs is how to raise the low photon detection efficiency (PDE). In this paper, the device structure and process parameters of the CMOS SPAD are optimized so as to improve PDE properties which have been investigated in detail. The CMOS SPADs are designed in p+/n-well/deep n-well (DNW) structure with the p-sub and the p-well guard ring (GR). The simulation results show that with the p-well GR, the quantum efficiency (QE) is about 80% with the breakdown voltage of 12.7 V, the unit responsivity is as high as 0.38 A/W and the PDE of 51% and 53% is obtained when the excess bias is at 1 V and 2 V, respectively. The dark count rate (DCR) is 6.2 kHz when bias voltage is 14 V. With the p-sub GR, the breakdown voltage is 13 V, the unit responsivity is up to 0.26 A/W, the QE is 58%, the PDE is 33% and 37% at excess bias of 1 V and 2 V, respectively. The DCR is 3.4 kHz at reverse bias voltage of 14 V.


2017 ◽  
Vol 56 (8) ◽  
pp. 2195 ◽  
Author(s):  
Junjie Wu ◽  
Lixing You ◽  
Sijing Chen ◽  
Hao Li ◽  
Yuhao He ◽  
...  

2011 ◽  
Vol 23 (13) ◽  
pp. 887-889 ◽  
Author(s):  
Yan Liang ◽  
E Wu ◽  
Xiuliang Chen ◽  
Min Ren ◽  
Yi Jian ◽  
...  

2020 ◽  
Vol 11 ◽  
pp. 960-965 ◽  
Author(s):  
Leonid S Revin ◽  
Andrey L Pankratov ◽  
Anna V Gordeeva ◽  
Anton A Yablokov ◽  
Igor V Rakut ◽  
...  

An aluminium Josephson junction (JJ), with a critical current suppressed by a factor of three compared with the maximal value calculated from the gap, is experimentally investigated for application as a threshold detector for microwave photons. We present the preliminary results of measurements of the lifetime of the superconducting state and the probability of switching by a 9 GHz external signal. We found an anomalously large lifetime, not described by the Kramers’ theory for the escape time over a barrier under the influence of fluctuations. We explain it by the phase diffusion regime, which is evident from the temperature dependence of the switching current histograms. Therefore, phase diffusion allows for a significant improvement of the noise immunity of a device, radically decreasing the dark count rate, but it will also decrease the single-photon sensitivity of the considered threshold detector. Quantization of the switching probability tilt as a function of the signal attenuation for various bias currents through the JJ is observed, which resembles the differentiation between N and N + 1 photon absorption.


2021 ◽  
Vol 482 ◽  
pp. 126588
Author(s):  
Yang Wang ◽  
Xiangliang Jin ◽  
Shengguo Cao ◽  
Yan Peng ◽  
Jun Luo

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