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Suppression of surface-originated gate lag by a dual-channel AlN/GaN high electron mobility transistor architecture

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.4961009· OSTI ID:22594315
; ; ;  [1]
  1. Naval Research Laboratory, Electronics Science and Technology Division, Washington, DC 20375 (United States)

A dual-channel AlN/GaN high electron mobility transistor (HEMT) architecture is demonstrated that leverages ultra-thin epitaxial layers to suppress surface-related gate lag. Two high-density two-dimensional electron gas (2DEG) channels are utilized in an AlN/GaN/AlN/GaN heterostructure wherein the top 2DEG serves as a quasi-equipotential that screens potential fluctuations resulting from distributed surface and interface states. The bottom channel serves as the transistor's modulated channel. Dual-channel AlN/GaN heterostructures were grown by molecular beam epitaxy on free-standing hydride vapor phase epitaxy GaN substrates. HEMTs fabricated with 300 nm long recessed gates demonstrated a gate lag ratio (GLR) of 0.88 with no degradation in drain current after bias stressed in subthreshold. These structures additionally achieved small signal metrics f{sub t}/f{sub max} of 27/46 GHz. These performance results are contrasted with the non-recessed gate dual-channel HEMT with a GLR of 0.74 and 82 mA/mm current collapse with f{sub t}/f{sub max} of 48/60 GHz.

OSTI ID:
22594315
Journal Information:
Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 6 Vol. 109; ISSN APPLAB; ISSN 0003-6951
Country of Publication:
United States
Language:
English