Properties of a radiation-induced charge multiplication region in epitaxial silicon diodes ☆
Properties of a radiation-induced charge multiplication region in epitaxial silicon diodes ☆
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外延硅二极管辐射感应电荷倍增区的特性☆
DOI：
10.1016/j.nima.2010.07.036
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发表时间：
2010
影响因子：
1.4
通讯作者：
G. Lindstrom
中科院分区：
文献类型：
--
作者：
J. Lange;J. Becker;E. Fretwurst;R. Klanner;G. Lindstrom
为了克服未来超级大型强子对撞机（Super-LHC）探测器最内层追踪区载流子的强烈俘获，研究了在1 MeV中子当量注量为1016 cm − 2的质子辐照后，高电压下75、100和150μm厚的p+n外延硅垫二极管中的电荷倍增（CM）。采用瞬态电流技术（TCT）测量了不同穿透率（670、830、1060 nm激光和α粒子）的电荷收集效率（CCE），以确定靠近p+注入的CM区。研究了材料、外延层厚度、退火和温度对CM的影响。发现在CM制度中收集的电荷与沉积的电荷成比例，在二极管区域上均匀，并且在几天的时间内稳定。在高电压下随机发生的微放电被证明是CM机制中二极管操作的最大挑战。虽然在高电压下观察到TCT基线噪声的增加，但发现由于激光的CM，信噪比得到改善。没有观察到由于CM过程中的统计波动而对用激光测量的电荷谱可能产生的影响。相反，α粒子的光谱相对宽度增加，可能是由于CM区域中沉积的电荷不同。
Charge multiplication (CM) in p+n epitaxial silicon pad diodes of 75, 100 and 150μm thickness at high voltages after proton irradiation with 1MeV neutron equivalent fluences in the order of 1016cm−2was studied as an option to overcome the strong trapping of charge carriers in the innermost tracking region of future Super-LHC detectors. Charge collection efficiency (CCE) measurements using the Transient Current Technique (TCT) with radiation of different penetration (670, 830, 1060nm laser light and α-particles with optional absorbers) were used to locate the CM region close to the p+-implantation. The dependence of CM on material, thickness of the epitaxial layer, annealing and temperature was studied. The collected charge in the CM regime was found to be proportional to the deposited charge, uniform over the diode area and stable over a period of several days. Randomly occurring micro-discharges at high voltages turned out to be the largest challenge for operation of the diodes in the CM regime. Although at high voltages an increase of the TCT baseline noise was observed, the signal-to-noise ratio was found to improve due to CM for laser light. Possible effects on the charge spectra measured with laser light due to statistical fluctuations in the CM process were not observed. In contrast, the relative width of the spectra increased in the case of α-particles, probably due to varying charge deposited in the CM region.