SK Hynix Develops 40nm SPAD For Proximity Laser Sensing

Recently, a research team from the Korea Institute of Science and Technology (KIST) and SK Hynix joined hands to successfully develop a short-range single photon avalanche diode (SPAD) based on a commercial 40nm backlit CMOS image sensor process for the first time. This high-performance sensor has an excellent ability to detect single photons and can be applied in user programs to achieve accurate recognition of millimeter-level objects.
The SPAD, an advanced sensor capable of detecting single photons, was extremely difficult to develop. Previously, only Sony of Japan successfully commercialized SPAD LIDAR and provided Apple with a product based on a 90nm back-illuminated CMOS image sensor process. Although Sony's SPAD design outperforms backlit devices reported in the literature in terms of efficiency, its timing jitter performance of 137~222 ps fails to meet the needs of short- and medium-range LiDAR applications in user identification, gesture recognition, and precise shape recognition.
To address this issue, a team led by Dr. Myung-Jae Lee of the Post-Silicon Semiconductor Institute (the Post-Silicon Semiconductor Institute) has developed a new single-photon sensor element in close collaboration with SK Hynix. This element significantly improves timing jitter performance to 56 ps, while increasing the distance resolution to approximately 8 millimeters. This breakthrough shows great potential in the field of short- and medium-range LiDAR sensor elements.
It is noteworthy that the product was developed based on a mass-produced semiconductor process, the 40nm backlit CMOS image sensor process, and is therefore expected to be rapidly localized and commercialized. This achievement not only demonstrates Korea's innovative strength in the field of semiconductor technology, but also supports the competitiveness of next-generation system semiconductors, a strategic industry for Korea.
Myung-Jae Lee, Principal Researcher at KIST, commented, "If we commercialize this semiconductor LiDAR and 3D image sensor as core technologies, Korea's competitiveness in the global semiconductor market will be greatly enhanced." This important R&D achievement has reinvigorated Korea's leadership in the global semiconductor industry.