Abstract
Charging effects in an AlxGa1-xN/GaN heterostructure field-effect transistor epitaxial layer structure have been studied using scanning capacitance microscopy. Voltages of ≤6 V applied between an AlxGa1-xN/GaN sample structure and a conducting proximal probe tip are found to create trapped charge in both doped and undoped heterostructures. Scanning capacitance measurements obtained over a wide range of bias voltages allow the charge distribution to be mapped both laterally and in depth with submicron to nanometer scale spatial resolution. Scanning capacitance imaging as a function of bias voltage performed in conjunction with numerical capacitance-voltage simulations suggests that positive charge can be trapped at the AlxGa1-xN surface and within the GaN layer and negative charge can be trapped at or near the AlxGa1-xN/GaN interface.
Original language | English (US) |
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Pages (from-to) | 2304-2308 |
Number of pages | 5 |
Journal | Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures |
Volume | 18 |
Issue number | 4 |
State | Published - 2000 |
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Electrical and Electronic Engineering