Guard-Ring-Free InGaAs/InP Single-Photon Avalanche Diode Based on a Novel One-Step Zn-Diffusion Technique
Ekin Kizilkan, Utku Karaca, Vladimir Pešić, Myung-Jae Lee, Claudio Bruschini, A. J. SpringThorpe, Alexandre W. Walker, Costel Flueraru, O. J. Pitts, Edoardo Charbon
Abstract
This work presents a novel InGaAs/InP SPAD structure fabricated using a selective area growth (SAG) method. The surface topography of the selectively grown film deposited within the 70 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mu$</tex-math></inline-formula> m diffusion apertures is used to engineer the Zn diffusion profile to suppress premature edge breakdown. The device achieves a highly uniform active area without the need for shallow diffused guard ring (GR) regions that are inherent in standard InGaAs/InP SPADs. We have obtained 33% and 43% photon detection probability (PDP) at 1550 nm, with 5 V and 7 V excess bias, respectively. These measurements were performed at 300 K and 225 K. The dark count rate (DCR) per unit area at room temperature and at 5 V excess bias is 430 cps/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mu$</tex-math></inline-formula> m <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{2}$</tex-math></inline-formula> and it decreases to 5 cps/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mu$</tex-math></inline-formula> m <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{2}$</tex-math></inline-formula> at 225 K. Timing jitter is measured with passive quenching at 1550 nm as 149 ps at full-width-at-half-maximum (FWHM), (300 K, 5 V excess bias). The proposed technology is suitable for a number of applications, including optical time-domain reflectometry (OTDR), quantum information, and light detection and ranging (LiDAR).