Single photon avalanche diode for millimeter level object recognition using KIST

LiDAR sensors are crucial for implementing modern technologies such as autonomous driving, AR/VR, and advanced driving assistance systems. For example, more accurate shape detection in AR/VR devices and smartphones depends on the improved range resolution of medium and short range LiDAR. This requires a single photon detector with improved timing jitter performance.

LiDAR calculates the distance and generates a three-dimensional image by measuring the time it takes for photons released by the transmitter to impact an object, reflect and return to the receiver. The higher the accuracy of object recognition, the smaller the value of "timing jitter", which is a small change in detection time when a single photon detector on the receiver converts an optical signal into an electrical signal.

According to the Korean Academy of Science and Technology, under the guidance of Dr. Myung Jae Lee, a team from the Institute of Postsilicon Semiconductors has created a "single photon avalanche diode" that can recognize millimeter level objects using 40nm backlit CMOS image sensor technology.

The development of SPAD is extremely difficult, and currently only Sony in Japan has successfully commercialized LiDAR based on SPAD and supplied it to Apple products based on its 90nm backlit CMOS image sensor technology.

Although the timing jitter performance of Sony SPAD is about 137-222 ps, it is not yet sufficient to achieve the user recognition, gesture recognition, and precise shape recognition of objects required for medium and short distance LiDAR applications. Sony's SPAD is more effective than the backlit SPAD reported in the literature.

The single photon sensor element developed by KIST has more than twice the jitter performance at 56 ps, with a distance resolution of about 8 mm, and has great potential as a medium to short range LiDAR sensor element.

Specifically, SPAD was created based on 40nm backlit CMOS image sensor technology through collaborative research with SK Hynix, and is expected to be immediately localized and commercialized.

This study was funded by the Korea Institute of Science and Technology and the Korea National Research Foundation, and was highlighted at the 2023 International Conference on Electronic Devices held in San Francisco, USA on December 12, 2023, from December 9 to 13.

IEDM is one of the most important conferences for semiconductor industry and research professionals, attended by major global semiconductor companies such as SK Hynix, Samsung Electronics, and Intel.

Source: Laser Net