title: Enhanced plasmonic resonant excitation in a grating gated field-effect transistor with supplemental gates.
abstract: An alternative-grating gated AlGaN/GaN field-effect transistor (FET) is proposed by considering the slit regions to be covered by a highly doped semiconductor acting as supplemental gates. The plasmonic resonant absorption spectra are studied at THz frequencies using the FDTD method. The 2DEGs, under supplemental gates, modulated by a positive voltage, can make the excitation of the higher order plasmon modes under metallic fingers more efficient in comparison to ungated regions in common slit-grating gate transistors. Moreover, the supplemental gates can confine the electric field of dipole oscillation between metallic gate fingers under THz radiation. The competition of the near-field enhancement and screening effect of the supplemental gate fingers results in the intensity of the higher order plasmon resonances being maximized at increased doping concentration. Our results demonstrate the possibility of significant improvement in the excitation of plasmon resonances in FETs for THz detection.
authors: National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China.
authors: Nan
authors: N
authors: Guo
authors: Wei-Da
authors: WD
authors: Hu
authors: Xiao-Shuang
authors: XS
authors: Chen
authors: Lin
authors: L
authors: Wang
authors: Wei
authors: W
authors: Lu
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D055053:Terahertz Radiation; D014173:Transistors, Electronic