Characterization of Low-Frequency Noise in Etched GaAs Nanowire Field-Effect Transistors Having SiNx Gate Insulator

• Published in: Jpn J Appl Phys 2012-06, Vol.51 (6), p.06FE18-06FE18-5
• Main Authors: Muramatsu, Toru, Miura, Kensuke, Shiratori, Yuta, Yatabe, Zenji, Kasai, Seiya
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.51.06FE18

Low-frequency noise in SiN x insulator--gate GaAs-based etched nanowire field-effect transistors (FETs) is investigated, focusing on the device size dependence and the effect of electron traps in the insulator. Intensity of the drain current noise is found to systematically increase when the nanowire width and gate length decrease, as indicated by the conventional FET noise model. Noise spectrum also changes continuously from $1/f$ to $1/f^{2}$ with the decrease of the device size, which is not observed in Schottky-gate nanowire FETs. Theoretical analysis shows that traps having short time constants mainly affect on the spectrum slope, whereas those having long time constants only shift the spectrum and do not affect on the slope. Observed size dependence of the spectrum slope is explained by broadening of the distribution of the time constant rather than the change in the combination of discrete traps having different time constants.