Detrimental effect of impact ionization in the absorption region on the frequency response and excess noise performance of InGaAs-InAlAs SACM avalanche photodiodes

2005 ◽  
Vol 41 (4) ◽  
pp. 568-572 ◽  
Author(s):  
Ning Duan ◽  
S. Wang ◽  
X.G. Zheng ◽  
X. Li ◽  
Ning Li ◽  
...  
2020 ◽  
Vol 92 (1) ◽  
pp. 10301
Author(s):  
Tat Lung Wesley Ooi ◽  
Pei Ling Cheang ◽  
Ah Heng You ◽  
Yee Kit Chan

In this work, Monte Carlo model is developed to investigate the avalanche characteristics of GaN and Al0.45Ga0.55N avalanche photodiodes (APDs) using random ionization path lengths incorporating dead space effect. The simulation includes the impact ionization coefficients, multiplication gain and excess noise factor for electron- and hole-initiated multiplication with a range of thin multiplication widths. The impact ionization coefficient for GaN is higher than that of Al0.45Ga0.55N. For GaN, electron dominates the impact ionization at high electric field while hole dominate at low electric field whereas Al0.45Ga0.55N has hole dominate the impact ionization at higher field while electron dominate the lower field. In GaN APDs, electron-initiated multiplication is leading the multiplication gain at thinner multiplication widths while hole-initiated multiplication leads for longer widths. However for Al0.45Ga0.55N APDs, hole-initiated multiplication leads the multiplication gain for all multiplication widths simulated. The excess noise of electron-initiated multiplication in GaN APDs increases as multiplication widths increases while the excess noise decreases as the multiplication widths increases for hole-initiated multiplication. As for Al0.45Ga0.55N APDs, the excess noise for hole-initiated multiplication increases when multiplication width increases while the electron-initiated multiplication increases with the same gradient at all multiplication widths.


2000 ◽  
Vol 10 (01) ◽  
pp. 327-337
Author(s):  
J. C. CAMPBELL ◽  
H. NIE ◽  
C. LENOX ◽  
G. KINSEY ◽  
P. YUAN ◽  
...  

The evolution of long-haul optical fiber telecommunications systems to bit rates greater than 10 GB/s has created a need for avalanche photodiodes (APDs) with higher bandwidths and higher gain-bandwidth products than are currently available. It is also desirable to maintain good quantum efficiency and low excess noise. At present, the best performance (f3dB ~ 15 GHz at low gain and gain-bandwidth product ~ 150 GHz) has been achieved by AlInAs/InGaAs(P) multiple quantum well (MQW) APDs. In this paper we report a resonant-cavity InAlAs/InGaAs APD that operates near 1.55 μm. These APDs have achieved very low noise (k equivalent to 0.18) as a result of the very thin multiplication regions that were utilized. The low noise is explained in terms of a new model that accounts for the non-local nature of impact ionization. A unity-gain bandwith of 24 GHz and a gain-bandwidth-product of 290 GHz were achieved.


2002 ◽  
Vol 742 ◽  
Author(s):  
Kent Burr ◽  
Peter Sandvik ◽  
Stephen Arthur ◽  
Dale Brown ◽  
Kevin Matocha

ABSTRACTAvalanche photodiodes (APDs) that are sensitive in the ultraviolet (UV) from approximately 250 – 350 nm have been fabricated from 4H-SiC. The SiC APDs, which use hole-initiated avalanche multiplication, were produced using n-type SiC epitaxial layers grown on a p-type substrate. In order to achieve avalanche breakdown in the bulk of the material, a dry ion-based etching technique was used to form sloped sidewalls on the devices. The devices had an area of approximately 1 mm2, and they had maximum breakdown voltages of approximately 500 V. The APDs had a positive temperature coefficient for avalanche breakdown voltage and showed excellent stability for multiplication factors in excess of several hundred. Dark current, photo responsivity, and multiplication measurements from room temperature to 150°C will be presented. The dark noise performance of the APDs has also been characterized using a standard nuclear spectroscopy system consisting of a charge sensitive preamplifier, a shaping amplifier, and a multichannel analyzer. The input equivalent dark noise charge and excess noise factor for the dark current was measured over a range of shaping times, temperatures, and bias voltages. The noise performance of SiC APDs in applications such as gamma ray or x-ray spectroscopy will be highly dependent on the achievement of low bulk leakage current at the operating point. Here, an ionization coefficient ratio (k=α/β) of 0.078 was found.


2005 ◽  
Vol 41 (8) ◽  
pp. 1092-1096 ◽  
Author(s):  
J.S. Ng ◽  
C.H. Tan ◽  
J.P.R. David ◽  
G.J. Rees

Author(s):  
Heng Ah You ◽  
Che Cha Sun

This work simulated the avalanche characteristics of 4H- and 6H-SiC avalanche photodiodes (APDs) at 0.1 µm, 0.2 µm and 0.3 µm avalanche widths. A Monte Carlo model with random ionization path length techniques is developed to simulate mean multiplication gain and excess noise factor in thin SiC APDs. Mean multiplication gain, breakdown voltage and excess noise factor are simulated based on the electric field dependent impact ionization coefficients with the inclusion of dead space effect. Our results show that hole-initiated impact ionization gives high multiplication gain with low excess noise factor in both devices. We observed that dead space effect is more pronounce in thin structure since it covers a significant portion of the avalanche region. In thick device structure, a high breakdown voltage is observed. A comparison between these two polytypes shows that 4H-SiC provides high multiplication gain with low excess noise factor than 6H-SiC.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuchen Liu ◽  
Xin Yi ◽  
Nicholas J. Bailey ◽  
Zhize Zhou ◽  
Thomas B. O. Rockett ◽  
...  

AbstractAvalanche Photodiodes (APDs) are key semiconductor components that amplify weak optical signals via the impact ionization process, but this process’ stochastic nature introduces ‘excess’ noise, limiting the useful signal to noise ratio (or sensitivity) that is practically achievable. The APD material’s electron and hole ionization coefficients (α and β respectively) are critical parameters in this regard, with very disparate values of α and β necessary to minimize this excess noise. Here, the analysis of thirteen complementary p-i-n/n-i-p diodes shows that alloying GaAs with ≤ 5.1 % Bi dramatically reduces β while leaving α virtually unchanged—enabling a 2 to 100-fold enhancement of the GaAs α/β ratio while extending the wavelength beyond 1.1 µm. Such a dramatic change in only β is unseen in any other dilute alloy and is attributed to the Bi-induced increase of the spin-orbit splitting energy (∆so). Valence band engineering in this way offers an attractive route to enable low noise semiconductor APDs to be developed.


2019 ◽  
Vol 9 (2) ◽  
pp. 185-191
Author(s):  
Somrita Ghosh ◽  
Aritra Acharyya

Background: Excess noise characteristics of Multiple Quantum Barrier (MQB) nanoscale avalanche photodiodes (APDs) based on Si~3C-SiC heterostructures have been studied in this part of the paper. The multiplication gain and Excess Noise Factor (ENF) of the MQB APDs have been calculated by varying the number of Quantum Barriers (QBs). Methods: The numerically calculated ENF values of MQB APDs have been compared with the ENF of Si flat conventional APDs of similar dimensions and it is observed that the use of QBs leads to significant reduction in ENF of the APDs under similar biasing and illumination conditions. Results: The enhanced ratio of hole to electron ionization rates in MQB structures as compared to the bulk Si APD structure has been found to be the primary cause of improvement in the noise performance of the MQB nano-APDs. Conclusion: Finally, the numerically calculated ENF of Si flat APD has been compared with the experimentally measured ENF of a commercially available Si APD and those are found to be in good agreement; this comparison validates the simulation methodology adopted by the authors in this paper.


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