Abstract
We have fabricated AlxGa1-xN/GaN heterostructures with high two-dimensional electron gas (2DEG) mobilities and high sheet carrier densities by metalorganic vapor phase epitaxy (MOVPE). The 2DEG sheet density and mobility exhibit a compositional dependence on the Al fraction of the electron donor layer. The highest mobility (5750 cm2/Vs at 16K) was measured in a sample with x=0.15 that had a sheet carrier density of 8.5×1012 cm-2. The undoped AlxGa1-xN layers have low background carrier concentrations and can be intentionally doped n-type using SiH4. The effect of intentional n-type doping of the AlxGa1-xN donor layer on the electrical properties of the 2DEG was studied in structures that included an undoped AlxGa1-xN spacer layer of varying thickness. Higher 2DEG mobilities were obtained when a 100 angstrom thick undoped layer was included in the structure due to spatial separation of the 2DEG from ionized impurities in the doped AlxGa1-xN. These initial results demonstrate that the electrical properties of AlxGa1-xN/GaN heterostructures can be controlled by intentional doping and appropriate layer design.
Original language | English (US) |
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Pages (from-to) | 201-206 |
Number of pages | 6 |
Journal | Materials Research Society Symposium - Proceedings |
Volume | 395 |
State | Published - Jan 1 1996 |
Event | Proceedings of the 1995 MRS Fall Meeting - Boston, MA, USA Duration: Nov 26 1995 → Dec 1 1995 |
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering