Defect spectroscopy of sidewall interfaces in gate-all-around silicon nanosheet FET

Kookjin Lee, Yeonsu Kim, Hyebin Lee, Sojeong Park, Yongwoo Lee, Min Kyu Joo, Hyunjin Ji, Jaewoo Lee, Jungu Chun, Moonsoo Sung, Young Hoon Cho, Doyoon Kim, Junhee Choi, Jae Woo Lee, Dae Young Jeon, Sung Jin Choi, Gyu Tae Kim

Research output: Contribution to journalArticlepeer-review

Abstract

Through time-dependent defect spectroscopy and low-frequency noise measurements, we investigate and characterize the differences of carrier trapping processes occurred by different interfaces (top/ sidewall) of the gate-all-around silicon nanosheet field-effect transistor (GAA SiNS FET). In a GAA SiNS FET fabricated by the top-down process, the traps at the sidewall interface significantly affect the device performance as the width decreases. Compare to expectations, as the width of the device decreases, the subthreshold swing (SS) increases from 120 to 230 mV/dec, resulting in less gate controllability. In narrow-width devices, the effect of traps located at the sidewall interface is significantly dominant, and the 1/f 2 noise, also known as generation-recombination (G-R) noise, is clearly appeared with an increased time constant (τi). In addition, the probability density distributions for the normalized current fluctuations (ΔID) show only one Gaussian in wide-width devices, whereas they are separated into four Gaussians with increased in narrow-width devices. Therefore, fitting is performed through the carrier number fluctuation-correlated with mobility fluctuations model that separately considered the effects of sidewall. In narrow-width GAA SiNS FETs, consequently, the extracted interface trap densities (NT) distribution becomes more dominant, and the scattering parameter (aSC) distribution increases by more than double.

Original languageEnglish
Article number165202
JournalNanotechnology
Volume32
Issue number16
DOIs
Publication statusPublished - 2021 Apr 16

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Electrical and Electronic Engineering

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