Enhancement-mode AlGaN/GaN HEMTs fabricated by standard fluorine ion implantation with a Si_3N_4 energy-absorbing layer

摘要

This paper presents a fabrication technology of enhancement-mode AlGaN/GaN high electron mobility transistors (HEMTs) using standard fluorine ion implantation. An 80 nm silicon nitride layer was deposited on the AlGaN as an energy-absorbing layer that slows down the high energy (～25 keV) fluorine ions so that majority of the fluorine ions are incorporated in the AlGaN barrier. The threshold voltage was successfully shifted from -1.9 to 1.8 V, converting depletion mode HEMTs to enhancement-mode ones. The fluorine ion distribution profile was confirmed by Secondary Ion Mass Spectrometry (SIMS).