质子、中子和伽马粒子辐照对4H-SiC二极管和LGAD传感器电学性能的影响
Effects of irradiation by protons, neutrons, and gamma particles on electrical properties of 4H-SiC diodes and LGAD sensors
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中文总结 AI 辅助
研究4H-SiC二极管和LGAD传感器在质子、中子和伽马粒子辐照后的电学性能，通过IV和CV测量，发现强子辐照改变有效空间电荷，伽马辐照影响有效掺杂浓度，揭示了不同辐射对器件性能影响的机制。
中文摘要 AI 辅助
4H-SiC是一种宽带隙半导体，具有高位移阈值能量、大临界电场和低本征载流子浓度，对辐射硬探测器应用具有吸引力。本文研究了onsemi制造的4H-SiC P⁺-in-N（PN）二极管和低增益雪崩探测器（LGAD）在24 GeV/c质子、反应堆中子和⁶⁰Co伽马射线辐照前后的电学特性。在室温下对质子注量高达1×10¹⁶ 质子/cm²、中子注量高达1×10¹⁸ 1 MeV neq/cm²和总电离剂量高达300 kGy进行电流-电压（IV）和电容-电压（CV）测量。强子辐照导致漏电流和体电容发生显著变化，这与辐射诱导的深类受主缺陷形成和原始N型材料的强补偿一致。对于高质子注量，漏电流减小，体电容与偏置无关，表明外延层有效补偿。极高的中子注量导致耗尽区大幅扩展到原始高掺杂衬底中。高达300 kGy的伽马辐照导致电容行为显著改变，表明外延层和倍增层中有效掺杂浓度降低。结果表明，在高强子注量下，辐射诱导补偿强烈改变了4H-SiC器件中的有效空间电荷，而漏电流受耗尽体积增大以及场增强和表面相关产生机制的影响。相比之下，电离损伤主要影响有效掺杂和电场分布。
英文摘要
4H-SiC is a wide-bandgap semiconductor with high displacement threshold energy, large critical electric field, and low intrinsic carrier concentration, making it attractive for radiation-hard detector applications. In this work, we investigate the electrical characteristics of 4H-SiC P$^{+}$-in-N (PN) diodes and Low-Gain Avalanche Detectors (LGADs) fabricated by onsemi before and after irradiation by 24 GeV/c protons, reactor neutrons, and $^{60}$Co gamma rays. Current-voltage (IV) and capacitance-voltage (CV) measurements were performed at room temperature for proton fluences up to $1\times10^{16}\;\mathrm{protons/cm^2}$, neutron fluences up to $1\times10^{18}\;\mathrm{1\;MeV\;n_{eq}/cm^2}$, and total ionizing doses up to 300 kGy. Hadron irradiation induces pronounced changes in both leakage current and bulk capacitance, consistent with radiation-induced formation of deep acceptor-like defects and strong compensation of the originally N-type material. For high proton fluences, the leakage current decreases and the bulk capacitance becomes bias-independent, indicating effective compensation of the epitaxial layer. Extreme neutron fluences lead to a substantial expansion of the depleted region into the originally highly doped substrate, as inferred from the measured capacitance values. Gamma irradiation up to 300 kGy results in significantly modified capacitance behavior, suggesting reduction of the effective doping concentration in the epitaxial and multiplication layers. The results demonstrate that radiation-induced compensation strongly modifies the effective space charge in 4H-SiC devices at high hadron fluences, while the leakage current is influenced by the enlarged depletion volume together with field-enhanced and surface-related generation mechanisms. In contrast, ionizing damage primarily affects the effective doping and electric-field distribution.
