Overcoming the DX Doping Challenge in Ultra Wide Bandgap Semiconductors
Abstract
We demonstrate Si-implanted AlN with high conductivity (>1 Omega-1cm-1) and high carrier concentration (5x1018 cm-3). This was enabled by Si-implantation into AlN with low TDD (<103 cm-2), a non-equilibrium damage recovery and dopant activation annealing process, and in situ suppression of self-compensation during the annealing. Low TDD and active suppression of VAl-nSiAl complexes via defect quasi Fermi level (dQFL) control enabled low compensation, while low-temperature, non-equilibrium annealing maintained the desired shallow donor state with an ionization energy of approx.70 meV. The achieved n-type conductivity and carrier concentration are over one order of magnitude higher than reported thus far and present a major technological breakthrough in doping of AlN. Contrary to the established understanding, we find that Ge in AlGaN does not suffer from the DX transition; instead, it undergoes a shallow donor (30 meV) to deep donor (150 meV) transition at approx. 50% Al content in the alloy. This finding is of profound technological importance as it removes fundamental doping limitations in AlGaN and AlN imposed by the presumed DX-1 acceptor state.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 16, 2021
- Accession Number
- AD1155204
Entities
People
- Douglas L Irving
- James M. LeBeau
- Zlatko Sitar
Organizations
- North Carolina State University