Takai Isamu, Matsubara Hiroyuki, Soga Mineki, Ohta Mitsuhiko, Ogawa Masaru, Yamashita Tatsuya
Toyota Central R&D Labs., Inc., 41-1, Yokomichi, Nagakute, Aichi 480-1192, Japan.
Sensors (Basel). 2016 Mar 30;16(4):459. doi: 10.3390/s16040459.
A single-photon avalanche diode (SPAD) with enhanced near-infrared (NIR) sensitivity has been developed, based on 0.18 μm CMOS technology, for use in future automotive light detection and ranging (LIDAR) systems. The newly proposed SPAD operating in Geiger mode achieves a high NIR photon detection efficiency (PDE) without compromising the fill factor (FF) and a low breakdown voltage of approximately 20.5 V. These properties are obtained by employing two custom layers that are designed to provide a full-depletion layer with a high electric field profile. Experimental evaluation of the proposed SPAD reveals an FF of 33.1% and a PDE of 19.4% at 870 nm, which is the laser wavelength of our LIDAR system. The dark count rate (DCR) measurements shows that DCR levels of the proposed SPAD have a small effect on the ranging performance, even if the worst DCR (12.7 kcps) SPAD among the test samples is used. Furthermore, with an eye toward vehicle installations, the DCR is measured over a wide temperature range of 25-132 °C. The ranging experiment demonstrates that target distances are successfully measured in the distance range of 50-180 cm.
基于0.18μm CMOS技术，已开发出一种具有增强近红外（NIR）灵敏度的单光子雪崩二极管（SPAD），用于未来的汽车光探测和测距（LIDAR）系统。新提出的工作在盖革模式下的SPAD在不牺牲填充因子（FF）的情况下实现了高近红外光子探测效率（PDE），并且击穿电压低至约20.5V。这些特性是通过采用两个定制层获得的，这两个定制层旨在提供具有高电场分布的全耗尽层。对所提出的SPAD进行的实验评估显示，在870nm（即我们LIDAR系统的激光波长）处，填充因子为33.1%，光子探测效率为19.4%。暗计数率（DCR）测量表明，即使使用测试样品中最差的暗计数率（12.7kcps）的SPAD，其暗计数率水平对测距性能的影响也很小。此外，考虑到车辆安装，在25-132°C的宽温度范围内测量了暗计数率。测距实验表明，在50-180cm的距离范围内成功测量了目标距离。
