| About this Abstract |
| Meeting |
2011 Electronic Materials Conference
|
| Symposium
|
2011 Electronic Materials Conference
|
| Presentation Title |
S3, Dynamic Control of Growth Kinetics for Three-Dimensional Semiconductor Nano-Heterostructures |
| Author(s) |
Santino D. Carnevale, Jing Yang, Patrick J. Phillips, Michael J. Mills, Roberto C. Myers |
| On-Site Speaker (Planned) |
Santino D. Carnevale |
| Abstract Scope |
The geometry of semiconductor nanowires (NWs) allows for both vertical and coaxial heterostructures, while only vertical heterostructures can be formed using planar structures. This is especially important for III-nitride NWs because crystallographic directions in which heterostructures are formed largely determine the magnitude of internal electric fields due to polarization. Here we describe a method to control the relative vertical and coaxial growth rates in catalyst-free GaN/AlN NW heterostructures grown on Si(111) substrates by plasma-assisted molecular beam epitaxy*. A growth phase diagram is established relating NW density to substrate temperature and III/V ratio. This diagram reveals a reduction in effective growth rate and an increase in nucleation time caused by GaN decomposition. A two-step growth method using dynamic conditions (determined by growth phase diagram) is developed to control NW density independently from deposition time. This method also allows for active tailoring of growth kinetics which is shown to tune the ratio of vertical to coaxial rates. We demonstrate the effectiveness of this method by forming multiple period GaN/AlN (2 nm / 2 nm) superlattices along either the vertical or coaxial NW axis that exhibit atomically sharp compositional profiles. This work is supported by the ONR under grant N00014-09-1-1153. * S.D. Carnevale, J. Yang, P.J. Phillips, M.J. Mills, and R.C. Myers. <I>Nano Lett</I>. (Article ASAP, 2011) |
| Proceedings Inclusion? |
Undecided |