Abstract
Off-axis electron holography has been used to measure the built-in potential profile across an Al0.85 In0.15 N/AlN/GaN high electron mobility transistor heterostructure. Profile measurements indicated a polarization-induced electric field of 6.9 MV/cm within the AlN layer. A two-dimensional electron gas with a density of ∼2.1× 1013 cm-2 was located in the GaN layer at ∼0.8 nm away from the AlN/GaN interface in reasonable agreement with the reported simulations. Electron microscopy confirmed that the Al0.85 In0.15 N layer was uniform and that Al0.85 In0.15 N/AlN and AlN/GaN interfaces were abrupt and well defined.
Original language | English |
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Article number | 121909 |
Journal | Applied Physics Letters |
Volume | 94 |
Issue number | 12 |
DOIs | |
State | Published - 2009 |
Externally published | Yes |
Funding
This work was supported by a contract from Wright Patterson Air Force Base (Monitor: C. Bozada) and the Swiss National Science Foundation (Contract No. 200021-107642/1). We acknowledge the use of facilities at John M. Cowley Center for High Resolution Electron Microscopy at Arizona State University.