Enhancement of carrier lifetime in lightly Al-doped p-type 4H-SiC epitaxial layers by combination of thermal oxidation and hydrogen annealing
Enhancement of carrier lifetime in lightly Al-doped p-type 4H-SiC epitaxial layers by combination of thermal oxidation and hydrogen annealing
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DOI：
10.7567/apex.7.085501
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发表时间：
2014-08
影响因子：
2.3
通讯作者：
T. Okuda;T. Miyazawa;H. Tsuchida;T. Kimoto;J. Suda
中科院分区：
文献类型：
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作者：
T. Okuda;T. Miyazawa;H. Tsuchida;T. Kimoto;J. Suda
我们研究了通过后生长工艺提高轻掺Al的p型4 H-SiC外延层（NA = 2 × 1014 cm−3）载流子寿命。通过碳空位消除，生长态外延层中2.8 µs的载流子寿命增加到5.1 µs，即，在1400 °C下热氧化48 h。随后在1000 °C下氢退火10分钟，其达到10 µs。仅通过氢退火，生长的外延层中的载流子寿命也增加到4.0 µs。这些结果表明，除了碳空位，在p型SiC中还有另一个寿命杀手，它不能通过热氧化消除，但可以通过氢退火钝化。
We investigated the enhancement of carrier lifetime in lightly Al-doped p-type 4H-SiC epilayers (NA ≃ 2 × 1014 cm−3) by postgrowth processing. A carrier lifetime of 2.8 µs in an as-grown epilayer is increased to 5.1 µs by carbon vacancy elimination, i.e., thermal oxidation at 1400 °C for 48 h. It reaches 10 µs by subsequent hydrogen annealing at 1000 °C for 10 min. The carrier lifetime in the as-grown epilayer is also increased to 4.0 µs by only hydrogen annealing. These results suggest that, in addition to carbon vacancy, there is another lifetime killer in p-type SiC, which cannot be eliminated by thermal oxidation but can be passivated by hydrogen annealing.