DID YOU KNOW? DTIC has over 3.5 million final reports on DoD funded research, development, test, and evaluation activities available to our registered users. Click HERE
to register or log in.
Overcoming the DX Doping Challenge in Ultra Wide Bandgap Semiconductors
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.
Approved For Public Release