Vertical transport in isotype InAlN/GaN dipole induced diodes grown by molecular beam epitaxy
Abstract
InAlN dipole diodes were developed and fabricated on both (0001) Ga-Face and 0001¯ N-face oriented GaN on sapphire templates by molecular beam epitaxy. The orientation and direction of the InAlN polarization dipole are functions of the substrate orientation and composition, respectively. Special consideration was taken to minimize growth differences and impurity uptake during growth on these orientations of opposite polarity. Comparison of devices on similarly grown structures with In compositions in excess of 50% reveals that dipole diodes shows poorer forward bias performance and exhibited an increase in reverse bias leakage, regardless of orientation. Similarly, (0001) Ga-face oriented InAlN at a lowered 40% In composition had poor device characteristics, namely, the absence of expected exponential turn on in forward bias. By contrast, at In compositions close to 40%, 0001¯ N-face oriented InAlN devices had excellent performance, with over five orders of magnitude of rectification and extracted barrier heights of 0.53– 0.62 eV; these values are in close agreement with simulation. Extracted ideality factors ranging from 1.08 to 1.38 on these devices are further evidence of their optimal performance. Further discussion focuses on the growth and orientation conditions that may lead to this discrepancy yet emphasizes that with proper design and growth strategy, the rectifying dipole diodes can be achieved with InAlN nitride dipole layers.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 24, 2017
- Source ID
- 10.1063/1.4983767
Entities
People
- Haoran Li
- James S. Speck
- Micha N. Fireman
- S. Keller
- Umesh Mishra
Organizations
- Office of Naval Research