Abstract
The effect of oxygen pressure on MgO grown by RF plasma assisted gas-source molecular beam epitaxy was investigated. Increasing oxygen pressure was found to decrease the growth rate, improve the morphology and reduce the Mg/O ratio to near that obtained from bulk single crystal MgO. By contrast, the electrical characteristics of MgO/GaN diodes showed continual improvement in breakdown field and interface state density as the pressure was decreased. The lowest pressure tested, 1×10-5Torr, produced the lowest Dit, 3×1011 eV-1 cm-2, and the highest VBD, 4.4 MV/cm. Cross sectional transmission electron microscopy of the MgO grown at the lowest pressure showed the initial 40 monolayers to be epitaxial, with the remainder of the layer appearing to be fine grained poly-crystal. Comparisons with films grown using an electron cyclotron resonance (ECR) plasma suggest that higher ion energies are desirable for obtaining the best electrical characteristics.
Original language | English |
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Pages (from-to) | 285-290 |
Number of pages | 6 |
Journal | Materials Research Society Symposium - Proceedings |
Volume | 743 |
DOIs | |
Publication status | Published - 2002 |
Externally published | Yes |
Event | Gan and Related Alloys - 2002 - Boston, MA, United States Duration: 2002 Dec 2 → 2002 Dec 6 |
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering