Improvement of Carrier Lifetimes in Highly Al-Doped p-Type 4H-SiC Epitaxial Layers by Hydrogen Passivation
Improvement of Carrier Lifetimes in Highly Al-Doped p-Type 4H-SiC Epitaxial Layers by Hydrogen Passivation
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DOI：
10.7567/apex.6.121301
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发表时间：
2013-11
影响因子：
2.3
通讯作者：
T. Okuda;T. Kimoto;J. Suda
中科院分区：
文献类型：
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作者：
T. Okuda;T. Kimoto;J. Suda
用差示微波光导衰减法(µ-PCD)研究了高Al掺杂p型外延层(NA=1×1018 cm-3)的载流子寿命。在Ar、O2或氮气气氛(700°C)中进行热处理后，p型外延层的载流子寿命从310 ns下降到90 ns，而通过H2退火(>；750℃)，载流子寿命恢复到300 ns。在氢气退火的外延层中，氢的浓度为(2-3)×1015 cm-3。这些结果表明，p型外延层中存在寿命杀手，将载流子寿命限制在90 ns，并通过氢退火钝化，使载流子寿命提高到300 ns。
Carrier lifetimes in a highly Al-doped p-type epilayer (NA = 1×1018 cm-3) are investigated by differential microwave photoconductance decay (µ-PCD) measurements. A carrier lifetime of 310 ns in the as-grown p-type epilayer decreases to 90 ns by thermal treatment in Ar, O2, or N2 atmospheres (>700 °C), and recovers to 300 ns by H2 annealing (>750 °C). Hydrogen is detected at a concentration of (2–3)×1015 cm-3 in the H2-annealed epilayer. These results suggest that a lifetime killer exists in the p-type epilayer, limiting the carrier lifetime to 90 ns and is passivated by hydrogen annealing, resulting in the improved carrier lifetime of 300 ns.