Lateral Charge Transport in the Carbon-Doped Buffer in AlGaN/GaN-on-Si HEMTs
Lateral Charge Transport in the Carbon-Doped Buffer in AlGaN/GaN-on-Si HEMTs
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DOI：
10.1109/ted.2016.2645279
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发表时间：
2017-03-01
影响因子：
3.1
通讯作者：
Kuball, Martin
中科院分区：
文献类型：
--
作者：
Chatterjee, Indranil;Uren, Michael J.;Kuball, Martin
使用动态R-ON和倾斜衬底偏压测量来验证功率晶体管中与尺寸和几何有关的色散。这是由于AlGaN/GaN高电子迁移率晶体管中半绝缘碳掺杂GaN缓冲器中的一种新的横向输运机制。我们认为，垂直场在GaN：C层底部产生二维空穴气体(2DHG)，空穴流延伸到隔离区之外。器件到器件的差异是由于穿过结构的大间距优先泄漏路径和从这些路径到陷阱位置的横向传输的组合。2DHG在器件有源区之外的扩散强烈影响衬底斜率测量的结果，从而导致单指和多指器件之间的重大差异。在动态RON恢复测量中，单指器件表现出较大的器件间差异，多指器件表现出较小的变化，其瞬变由多个小型单指器件的恢复瞬变叠加而成。
Dynamic R-ON and ramped substrate bias measurements are used to demonstrate size-and geometry-dependent dispersion in power transistors. This is due to a novel lateral transport mechanism in the semi-insulating carbon-doped GaN buffer in AlGaN/GaN high-electron-mobility transistors. We propose that the vertical field generates a 2-D hole gas (2DHG) at the bottom of the GaN:C layer, with hole flowextending outside the isolated area. The device-to-device variation is due to a combination of widely spaced preferential leakage paths through the structure and lateral transport from those paths to trapping sites. The spread of the 2DHG outside the active area of the device strongly affects the result of substrate ramp measurements producing major differences between single and multifinger devices. In dynamic RON recovery measurements, single-finger devices show large device-to-device variation, with multifinger devices showing a small variation with the transient comprising the superpositionof the recovery transient of multiple small single-finger devices.