2D Dark-Count-Rate Modeling of PureB Single-Photon Avalanche Diodes in a TCAD Environment

Tihomir Knežević, Lis K. Nanver, Tomislav Suligoj

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

Abstract

PureB silicon photodiodes have nm-shallow p+n junctions with which photons/electrons with penetration-depths of a few nanometer can be detected. PureB Single-Photon Avalanche Diodes (SPADs) were fabricated and analysed by 2D numerical modeling as an extension to TCAD software. The very shallow p+-anode has high perimeter curvature that enhances the electric field. In SPADs, noise is quantified by the dark count rate (DCR) that is a measure for the number of false counts triggered by unwanted processes in the non-illuminated device. Just like for desired events, the probability a dark count increases with increasing electric field and the perimeter conditions are critical. In this work, the DCR was studied by two 2D methods of analysis: the “quasi-2D” (Q-2D) method where vertical 1D cross-sections were assumed for calculating the electron/hole avalanche-probabilities, and the “ionization-integral 2D” (II-2D) method where cross sections were placed where the maximum ionization-integrals were calculated. The Q-2D method gave satisfactory results in structures where the peripheral regions had a small contribution to the DCR, such as in devices with conventional deepjunction guard rings (GRs). Otherwise, the II-2D method proved to be much more precise. The results show that the DCR simulation methods are useful for optimizing the compromise between fill-factor and p-/n-doping profile design in SPAD devices. For the experimentally investigated PureB SPADs, excellent agreement of the measured and simulated DCR was achieved. This shows that although an implicit GR is attractively compact, the very shallow pn-junction gives a risk of having such a low breakdown voltage at the perimeter that the DCR of the device may be negatively impacted.
LanguageEnglish
Title of host publicationPhysics and Simulation of Optoelectronic Devices XXVI
Subtitle of host publicationSPIE OPTO, 27 January - 1 February 2018, San Francisco, California, United States
EditorsBernd Witzigmann , Marek Osiński , Yasuhiko Arakawa
Place of PublicationBellingham, WA
PublisherSPIE
Number of pages10
DOIs
Publication statusPublished - 23 Feb 2018
EventSPIE Optoelectronics and Photonic Materials and Devices Conference, OPTO 2018 - The Moscone Center, San Francisco, United States
Duration: 28 Jan 20172 Feb 2017

Publication series

NameProceedings of SPIE
PublisherSPIE
Volume10526
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Conference

ConferenceSPIE Optoelectronics and Photonic Materials and Devices Conference, OPTO 2018
Abbreviated titleOPTO
CountryUnited States
CitySan Francisco
Period28/01/172/02/17

Fingerprint

avalanche diodes
photons
ionization
electric fields
rings
cross sections
p-n junctions
electrical faults
avalanches
photodiodes
anodes
penetration
curvature
computer programs
silicon
profiles
electrons
simulation

Keywords

  • photodiode
  • single-photon avalanche diodes (SPADs)
  • detectors
  • silicon
  • pure boron
  • guard rings

Cite this

Knežević, T., Nanver, L. K., & Suligoj, T. (2018). 2D Dark-Count-Rate Modeling of PureB Single-Photon Avalanche Diodes in a TCAD Environment. In B. Witzigmann , M. Osiński , & Y. Arakawa (Eds.), Physics and Simulation of Optoelectronic Devices XXVI: SPIE OPTO, 27 January - 1 February 2018, San Francisco, California, United States [105261K] (Proceedings of SPIE; Vol. 10526). Bellingham, WA: SPIE. https://doi.org/10.1117/12.2290757
Knežević, Tihomir ; Nanver, Lis K. ; Suligoj, Tomislav. / 2D Dark-Count-Rate Modeling of PureB Single-Photon Avalanche Diodes in a TCAD Environment. Physics and Simulation of Optoelectronic Devices XXVI: SPIE OPTO, 27 January - 1 February 2018, San Francisco, California, United States. editor / Bernd Witzigmann ; Marek Osiński ; Yasuhiko Arakawa. Bellingham, WA : SPIE, 2018. (Proceedings of SPIE).
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title = "2D Dark-Count-Rate Modeling of PureB Single-Photon Avalanche Diodes in a TCAD Environment",
abstract = "PureB silicon photodiodes have nm-shallow p+n junctions with which photons/electrons with penetration-depths of a few nanometer can be detected. PureB Single-Photon Avalanche Diodes (SPADs) were fabricated and analysed by 2D numerical modeling as an extension to TCAD software. The very shallow p+-anode has high perimeter curvature that enhances the electric field. In SPADs, noise is quantified by the dark count rate (DCR) that is a measure for the number of false counts triggered by unwanted processes in the non-illuminated device. Just like for desired events, the probability a dark count increases with increasing electric field and the perimeter conditions are critical. In this work, the DCR was studied by two 2D methods of analysis: the “quasi-2D” (Q-2D) method where vertical 1D cross-sections were assumed for calculating the electron/hole avalanche-probabilities, and the “ionization-integral 2D” (II-2D) method where cross sections were placed where the maximum ionization-integrals were calculated. The Q-2D method gave satisfactory results in structures where the peripheral regions had a small contribution to the DCR, such as in devices with conventional deepjunction guard rings (GRs). Otherwise, the II-2D method proved to be much more precise. The results show that the DCR simulation methods are useful for optimizing the compromise between fill-factor and p-/n-doping profile design in SPAD devices. For the experimentally investigated PureB SPADs, excellent agreement of the measured and simulated DCR was achieved. This shows that although an implicit GR is attractively compact, the very shallow pn-junction gives a risk of having such a low breakdown voltage at the perimeter that the DCR of the device may be negatively impacted.",
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}

Knežević, T, Nanver, LK & Suligoj, T 2018, 2D Dark-Count-Rate Modeling of PureB Single-Photon Avalanche Diodes in a TCAD Environment. in B Witzigmann , M Osiński & Y Arakawa (eds), Physics and Simulation of Optoelectronic Devices XXVI: SPIE OPTO, 27 January - 1 February 2018, San Francisco, California, United States., 105261K, Proceedings of SPIE, vol. 10526, SPIE, Bellingham, WA, SPIE Optoelectronics and Photonic Materials and Devices Conference, OPTO 2018, San Francisco, United States, 28/01/17. https://doi.org/10.1117/12.2290757

2D Dark-Count-Rate Modeling of PureB Single-Photon Avalanche Diodes in a TCAD Environment. / Knežević, Tihomir; Nanver, Lis K.; Suligoj, Tomislav.

Physics and Simulation of Optoelectronic Devices XXVI: SPIE OPTO, 27 January - 1 February 2018, San Francisco, California, United States. ed. / Bernd Witzigmann ; Marek Osiński ; Yasuhiko Arakawa. Bellingham, WA : SPIE, 2018. 105261K (Proceedings of SPIE; Vol. 10526).

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

TY - GEN

T1 - 2D Dark-Count-Rate Modeling of PureB Single-Photon Avalanche Diodes in a TCAD Environment

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AU - Nanver, Lis K.

AU - Suligoj, Tomislav

PY - 2018/2/23

Y1 - 2018/2/23

N2 - PureB silicon photodiodes have nm-shallow p+n junctions with which photons/electrons with penetration-depths of a few nanometer can be detected. PureB Single-Photon Avalanche Diodes (SPADs) were fabricated and analysed by 2D numerical modeling as an extension to TCAD software. The very shallow p+-anode has high perimeter curvature that enhances the electric field. In SPADs, noise is quantified by the dark count rate (DCR) that is a measure for the number of false counts triggered by unwanted processes in the non-illuminated device. Just like for desired events, the probability a dark count increases with increasing electric field and the perimeter conditions are critical. In this work, the DCR was studied by two 2D methods of analysis: the “quasi-2D” (Q-2D) method where vertical 1D cross-sections were assumed for calculating the electron/hole avalanche-probabilities, and the “ionization-integral 2D” (II-2D) method where cross sections were placed where the maximum ionization-integrals were calculated. The Q-2D method gave satisfactory results in structures where the peripheral regions had a small contribution to the DCR, such as in devices with conventional deepjunction guard rings (GRs). Otherwise, the II-2D method proved to be much more precise. The results show that the DCR simulation methods are useful for optimizing the compromise between fill-factor and p-/n-doping profile design in SPAD devices. For the experimentally investigated PureB SPADs, excellent agreement of the measured and simulated DCR was achieved. This shows that although an implicit GR is attractively compact, the very shallow pn-junction gives a risk of having such a low breakdown voltage at the perimeter that the DCR of the device may be negatively impacted.

AB - PureB silicon photodiodes have nm-shallow p+n junctions with which photons/electrons with penetration-depths of a few nanometer can be detected. PureB Single-Photon Avalanche Diodes (SPADs) were fabricated and analysed by 2D numerical modeling as an extension to TCAD software. The very shallow p+-anode has high perimeter curvature that enhances the electric field. In SPADs, noise is quantified by the dark count rate (DCR) that is a measure for the number of false counts triggered by unwanted processes in the non-illuminated device. Just like for desired events, the probability a dark count increases with increasing electric field and the perimeter conditions are critical. In this work, the DCR was studied by two 2D methods of analysis: the “quasi-2D” (Q-2D) method where vertical 1D cross-sections were assumed for calculating the electron/hole avalanche-probabilities, and the “ionization-integral 2D” (II-2D) method where cross sections were placed where the maximum ionization-integrals were calculated. The Q-2D method gave satisfactory results in structures where the peripheral regions had a small contribution to the DCR, such as in devices with conventional deepjunction guard rings (GRs). Otherwise, the II-2D method proved to be much more precise. The results show that the DCR simulation methods are useful for optimizing the compromise between fill-factor and p-/n-doping profile design in SPAD devices. For the experimentally investigated PureB SPADs, excellent agreement of the measured and simulated DCR was achieved. This shows that although an implicit GR is attractively compact, the very shallow pn-junction gives a risk of having such a low breakdown voltage at the perimeter that the DCR of the device may be negatively impacted.

KW - photodiode

KW - single-photon avalanche diodes (SPADs)

KW - detectors

KW - silicon

KW - pure boron

KW - guard rings

U2 - 10.1117/12.2290757

DO - 10.1117/12.2290757

M3 - Conference contribution

T3 - Proceedings of SPIE

BT - Physics and Simulation of Optoelectronic Devices XXVI

A2 - Witzigmann , Bernd

A2 - Osiński , Marek

A2 - Arakawa, Yasuhiko

PB - SPIE

CY - Bellingham, WA

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Knežević T, Nanver LK, Suligoj T. 2D Dark-Count-Rate Modeling of PureB Single-Photon Avalanche Diodes in a TCAD Environment. In Witzigmann B, Osiński M, Arakawa Y, editors, Physics and Simulation of Optoelectronic Devices XXVI: SPIE OPTO, 27 January - 1 February 2018, San Francisco, California, United States. Bellingham, WA: SPIE. 2018. 105261K. (Proceedings of SPIE). https://doi.org/10.1117/12.2290757