Importance of shallow hydrogenic dopants and material purity of ultra-wide bandgap semiconductors for vertical power electron devices
Importance of shallow hydrogenic dopants and material purity of ultra-wide bandgap semiconductors for vertical power electron devices
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浅氢掺杂剂和超宽带隙半导体材料纯度对垂直电力电子器件的重要性
DOI：
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发表时间：
2020
影响因子：
1.9
通讯作者：
J. Speck
中科院分区：
文献类型：
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作者：
Yuewei Zhang;J. Speck
超宽带隙（UWBG）半导体在功率器件应用中吸引了越来越多的研究兴趣。虽然已经报道了各种材料的有希望的结果，但仍不清楚哪种材料和技术将取得成功。功率器件应用中的许多品质因数（FOM）被用来指导材料选择，包括广泛使用的Baliga的FOM（BFOM）来描述功率器件的电阻损耗，以及Baliga的高频FOM（BHFFOM）来进一步考虑开关损耗。然而，那些被广泛引用的FOM的关键基础假设，包括浅类氢掺杂剂的假设，往往会失败的UWBG半导体。在这项工作中，我们重新审视了几个重要的FOM在描述垂直电力电子，以正确地考虑不完全电离和背景补偿效应。我们建议，有必要包括掺杂剂电离项（例如，在n-漂移层中的n/Nd）的BFOM和BHFFOM，以充分捕捉功率器件应用的UWBG半导体的潜力。金刚石和AlN等材料中的不完全掺杂离子化大大降低了它们用于功率开关的FOM，导致高导电和开关损耗。由于浅施主、低背景杂质补偿和体衬底的可用性，β-Ga 2 O3有望在所研究的材料中获得最佳性能。修正后的FOM为功率器件应用的材料选择提供了有价值的指导。
Ultra-wide bandgap (UWBG) semiconductors are attracting increasing research interest for power device applications. While promising results have been reported for various materials, it remains unclear which material and technology will succeed. Many figure of merits (FOMs) were derived for power device applications to guide material choices, including the widely used Baliga’s FOM (BFOM) to describe the resistive loss of power devices, and Baliga’s high-frequency FOM (BHFFOM) to further consider the switching loss. However, key underlying assumptions for those widely cited FOMs, including the assumption of shallow hydrogenic dopants, tend to fail for UWBG semiconductors. In this work, we revisit several important FOMs in describing vertical power electronics to properly account for both incomplete ionization and background compensation effects. We suggest that it is necessary to include the dopant ionization term (for example n/Nd in an n-drift layer) for both BFOM and BHFFOM to fully capture the potential of the UWBG semiconductors for power device applications. Incomplete dopant ionization in materials like diamond and AlN substantially lowers their FOMs for power switching, leading to high conductive and switching losses. Due to the availability of shallow donors, low background impurity compensation, and bulk substrates, β-Ga2O3 promises the best performance among the investigated materials. The modified FOMs offer a valuable guidance in material choices for power device applications.