Electric field mapping of wide-bandgap semiconductor devices at a submicrometre resolution
Electric field mapping of wide-bandgap semiconductor devices at a submicrometre resolution
复制标题
DOI：
10.1038/s41928-021-00599-5
复制
发表时间：
2021-06-21
影响因子：
34.3
通讯作者：
Kuball, Martin
中科院分区：
文献类型：
--
作者：
Cao, Yuke;Pomeroy, James W.;Kuball, Martin
电场感应二次谐波可以用来测量氮化镓高电子迁移率晶体管的面内电场，并探讨掺杂物对电场分布的影响。电场驱动宽带隙半导体器件的退化。然而，直接绘制有源器件区域内的电场仍然具有挑战性。本文表明，电场诱导的二次谐波可以用于绘制基于氮化镓的高电子迁移率晶体管器件通道中的电场，分辨率为亚微米。为了说明该方法的能力，我们使用它来检查碳杂质在器件外延缓冲层中的影响。碳是氮化镓中的p掺杂剂，其浓度的微小变化会极大地改变体费米能级，有时会导致浮动缓冲器通过位错“短路”到器件通道。我们的测量表明，尽管具有相似的设备终端特性，但不同碳浓度的设备中可能出现非常不同的电场分布。我们还表明，位错相关的泄漏路径会导致电场中的不均匀性。
Electric-field-induced second harmonic generation can be used to measure the in-plane electric field in gallium nitride high-electron-mobility transistors and probe how dopants influence the electric field distribution.Electric fields drive the degradation of wide-bandgap semiconductor devices. However, directly mapping the electric field inside an active device region remains challenging. Here we show that electric-field-induced second harmonic generation can be used to map the electric field in the device channel of GaN-based high-electron-mobility transistors at submicrometre resolution. To illustrate the capabilities of the approach, we use it to examine the impact of carbon impurities in the epitaxial buffer layer of a device. Carbon is a p dopant in GaN, and small changes in its concentration can dramatically change the bulk Fermi level, sometimes resulting in a floating buffer that is 'short-circuited' to the device channel via dislocations. Our measurements show that very different electric field distributions can occur in devices with different carbon concentrations, despite them having similar device terminal characteristics. We also show that dislocation-related leakage paths can lead to inhomogeneity in the electric field.