Integrated Design of a Scalable SPAD-array for On-Chip Magnetometers
Analyzing and designing an on-chip SPAD-array for bio-sensing applications fabricated with 40-nm CMOS technology
F.J. Barzilaij (TU Delft - Electrical Engineering, Mathematics and Computer Science)
Z. Jin (TU Delft - Electrical Engineering, Mathematics and Computer Science)
Salahuddin Nur – Mentor (TU Delft - Quantum Circuit Architectures and Technology)
Michiel Pertijs – Graduation committee member (TU Delft - Electronic Instrumentation)
Seyedmahdi Izadkhast – Graduation committee member (TU Delft - Electrical Engineering Education)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
The biomedical world is seeking imaging devices that are compact, operative at room-temperature and of high spatial resolution to enhance the localization and detection of living cells. This includes applications such as the detection of cancer cells among healthy tissue. To this end, CMOS chips containing arrays of single-photon avalanche diodes (SPADs) are a promising subject with excellent potential to drive advancements in the field of bio-sensing. In this work, we present a 1.32 x 1.32 mm imaging chip consisting of a 16 x 16 SPAD-pixel array and a 32 pin I/O ring. The SPAD-pixels are organized into rows, with each SPAD-row connected to a single I/O pin. To output all the data from each SPAD-pixel in a row serially, a parallel in, serial out (PISO) shift register is integrated into the SPAD-row. Each SPAD-pixel consists of a photon-detecting SPAD-cell, a voltage controlled resistor (VCR) and its complementary circuit. This circuitry includes an active quenching and recharge circuit, a counter-based externally configurable hold-off mechanism and a count register with a Schmitt-trigger capable of counting up to 1.0·10⁶ detected photons over an 1-s integration time. In addition, the SPAD-array architecture is scalable, requiring minimal adjustments to expand to a larger format. The chip is developed for applications in quantum diamond sensing, a promising method for high-resolution magnetic field imaging. This work was conducted in the context of the Bachelor Graduation Project at the TU Delft Faculty of Electrical Engineering, Mathematics and Computer Science, in collaboration with the Quantum Integration Technology (QIT) group.