Comparison for 1/ Noise Characteristics of AlGaN/GaN FinFET and Planar MISHFET

• Published in: IEEE transactions on electron devices Vol. 64; no. 9; pp. 3634 - 3638
• Main Authors: Vodapally, Sindhuri, Theodorou, Christoforos G., Youngho Bae, Ghibaudo, Gerard, Cristoloveanu, Sorin, Ki-Sik Im, Jung-Hee Lee
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: 1/<italic xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">f noise; 2-D electron gas (2-DEG); AlGaN/GaN; Aluminum gallium nitride; Aluminum gallium nitrides; Buffer layers; Buffers; Current carriers; Electric potential; Electron gas; Electron traps; Field effect transistors; fin-shaped field-effect transistor (FinFET); FinFETs; G-R noise; Gallium nitride; Gallium nitrides; Insulators; Logic gates; metal-insulator-semiconductor heterostructure field-effect-transistor (MISHFET); MIS (semiconductors); Noise; Transconductance; Transistors; Trapping; Variation; Wide band gap semiconductors
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2017.2730919

DC and 1/f noise performances of the AlGaN/GaN fin-shaped field-effect transistor (FinFET) with fin width of 50 nm were analyzed. The FinFET exhibited approximately six times larger normalized drain current and transconductance, compared to those of the AlGaN/GaN planar metal-insulator-semiconductor heterostructure field-effect-transistor (MISHFET) fabricated on the same wafer. It was also observed that the FinFET exhibited improved noise performance with lower noise magnitude of 8.5×10 -15 A 2 /Hz when compared to the value of 8.7×10 -14 A 2 /Hz for the planar MISHFET. An intensive analysis indicated that both devices follow the carrier number fluctuation model, but the FinFET suffers much less charge trapping effect compared to the MISHFET (two orders lower charge trapping was observed). Moreover, the FinFET did not exhibit the Lorentz-like components, which explains that the depleted fin structure effectively prevents the carriers from being trapped into the underlying thick GaN buffer layer. On the other hand, the slope of the noise is 2 irrespective of drain voltage and apparently showed the Lorentz-like components, especially at high drain voltage in MISHFET device. This explains that the carrier trapping/detrapping between the 2-D electron gas channel and the GaN buffer layer is significant in MISHFET.