The ability to produce atomically precise, artificial oxide heterostructures allows for the possibility of producing exotic phases and enhanced susceptibilities not found in parent materials. Typical ferroelectric materials either exhibit large saturation polarization away from a phase boundary or large dielectric susceptibility near a phase boundary. Both large ferroelectric polarization and dielectric permittivity are attained wherein fully epitaxial (PbZr0.8Ti0.2O3)
Epitaxial ScxAl1−xN thin films of ∼100 nm thickness grown on metal polar GaN substrates are found to exhibit significantly enhanced relative dielectric permittivity (εr) values relative to AlN. εrvalues of ∼17–21 for Sc mole fractions of 17%–25% ( x = 0.17–0.25) measured electrically by capacitance–voltage measurements indicate that ScxAl1−xN has the largest relative dielectric permittivity of any existing nitride material. Since epitaxial ScxAl1−xN layers deposited on GaN also exhibit large polarization discontinuity, the heterojunction can exploit the in situ high-K dielectric property to extend transistor operation for power electronics and high-speed microwave applications.
more » « less- Award ID(s):
- 1719875
- NSF-PAR ID:
- 10366316
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- Applied Physics Letters
- Volume:
- 120
- Issue:
- 15
- ISSN:
- 0003-6951
- Page Range / eLocation ID:
- Article No. 152901
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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