发表机构
Lawrence Berkeley National Laboratory; North Carolina State University; NRL/National Research Council; University of California, Berkeley; Brookhaven National Laboratory（劳伦斯伯克利国家实验室; 北卡罗来纳州立大学; 海军研究实验室/国家研究委员会; 加州大学伯克利分校; 布鲁克海文国家实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文通过UV-TCT和β源实验，研究了4H-SiC LGAD增益层掺杂浓度（4×10¹⁷与5×10¹⁷ cm⁻³）对电荷收集和计时性能的影响，发现25%掺杂差异导致增益范围3.7–216，并确定了最佳计时窗口，为增益层设计优化提供了实验依据。
AI 中文摘要
增益层掺杂浓度决定了低增益雪崩探测器（LGAD）中的电场分布，因此是主要的设计参数。本工作报道了其对4H-SiC LGAD电荷收集和计时行为的影响。两个具有冷氦离子注入终端、台面隔离的器件仅增益层掺杂不同，分别为4×10¹⁷ cm⁻³和5×10¹⁷ cm⁻³，并与同一晶圆上的PIN二极管一起使用紫外瞬态电流技术（UV-TCT）进行表征。25%的掺杂差异在相同偏压下产生了约两个数量级的增益差异，代表增益范围为3.7至216。在UV-TCT激发下，较高掺杂器件在所研究的激光强度下，在约20–80的增益范围内表现出时间分辨率最小值，这与从电子噪声主导的抖动到倍增散粒噪声的转变一致。非单调的计时响应也在使用Si LGAD作为参考的⁹⁰Sr β源下观察到：较高掺杂器件在280 V时达到51.7 ps，随后退化，而较低掺杂器件需要超过450 V。这一实测增益窗口为增益层设计的进一步优化提供了实验参考。
英文摘要
Gain layer doping concentration determines the electric field profile in a low gain avalanche detector (LGAD) and is therefore the primary design parameter. This work reports its influence on the charge collection and timing behavior of 4H-SiC LGADs. Two mesa-isolated devices with cold He ion implanted termination differ only in gain layer doping, $4\times10^{17}$~$cm^{-3}$ and $5\times10^{17}$~$cm^{-3}$, and are characterized together with a PIN diode from the same wafer using the ultraviolet transient current technique (UV-TCT). The 25\% doping difference produces a gain difference of about two orders of magnitude at the same applied bias, representing a gain range of 3.7 to 216. Under UV-TCT excitation, the higher-doped device exhibits time-resolution minima within a gain range of about 20--80 across the investigated laser intensities, consistent with the transition from electronic-noise-dominated jitter to multiplication shot noise. The non-monotonic timing response is also observed under a $^{90}Sr$ beta source with a Si LGAD reference: the higher-doped device reaches 51.7 ps at 280 V and then degrades, while the lower-doped device requires more than 450 V. This measured gain window provides an experimental reference for further optimization of the gain-layer design.
