Naslov
Minimization of dark counts in PureB SPADs for NUV/VUV/EUV light detection by employing a 2D TCAD-based simulation environment

Autori
Knezevic, Tihomir ; Nanver, Lis K. ; Suligoj, Tomislav

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Proceedings of SPIE - The International Society for Optical Engineering / - San Francisco (CA) : SPIE, 2019

ISBN
9781510624665

Skup
SPIE OPTO: Physics and Simulation of Optoelectronic Devices XXVII

Mjesto i datum
San Francisco (CA), Sjedinjene Američke Države, 02.02.2019. - 07.02.2019

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Avalanche breakdown, Band-to-band tunneling, Detectors, Guard rings, Photodiode, Pure boron, Silicon, Single-photon avalanche diodes (SPADs), Trap-assisted tunneling

Sažetak
PureB single-photon avalanche diodes (SPADs) were investigated with the aid of a newly developed TCAD-based numerical modeling method with which characteristics related to the avalanching behavior can be simulated. The p + region forming the anode of the PureB p + n photodiode is extremely shallow, only a few nanometer deep, which is essential for obtaining a high photon detection efficiency (PDE) for near-, vacuum- and extreme- ultraviolet (NUV/VUV/EUV) light detection but when an implicit guard ring (GR) is implemented, the dark count rate (DCR) can, despite the GR, be deteriorated at the very sharp corners of the p + -region where there is a high concentration of the electric-field. By comparing measurements to simulations, the main mechanism dominating the DCR in the PureB SPADs was identified as band-to-band tunneling (BTBT) while trap-assisted-tunneling also plays a role when the perimeter breakdown is low. Increasing the dose of carriers in the enhancement region negatively impacts the total DCR of the device, but also shifts the origin of the dominant DCR contribution from perimeter to the active region. The simulations for optimization of the SPAD geometry predict that a modification of the n-doped epitaxial region of the PureB SPADs could decrease the DCR by almost two orders of magnitude. This is achieved by increasing the n-epi-layer thickness from 1 μm to 3 μm and lowering the doping from 10 15 cm -3 to 10 14 cm -3. A high electric field at the vertical pn junction in the active region can also be minimized by modifying the implantation parameters of the n-enhancement region thus keeping the BTBT contribution to the DCR sufficiently low.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Elektrotehnika, Interdisciplinarne tehničke znanosti

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