Random nanosized metal grains and interface-trap fluctuations in emerging CMOS technologies

Yiming Li*

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingChapterpeer-review

1 Scopus citations


This article estimates the influences of work-function fluctuation (WKF) and interface-trap fluctuation (ITF) on emerging high-κ/metal gate complementary metal-oxide-semiconductor (CMOS) devices using an experimentally validated three-dimensional (3D) device simulation. Randomness of nanosized metal grains on a device’s gate is simulated using localized WKF (LWKF) technqiue and 2D random ITs at the HfO2/silicon interface are considered in contrast with 1D ITF simulation. Proportional to minimal grain size, fluctuation of threshold voltage (σVth, WKs) induced by random WKs is 36.7 and 42.5 mV for 16-nm-gate (width: 16 nm) N- (with TiN gate) and P-MOSFETs (with TiN+Al gate), respectively. Random WKs perturb local potential barrier and result in rather different Vth even when a device has the same number of metal grains owing to random position effect which is beyond the averaged WK method. For devices with random IT’s density Dit varying from 1.51×1011 to 6.32×1012 eV-1 cm-2, the random ITs-induced Vth fluctuations (σVth, ITs) is up to 39 mV and it is reduced to 25 mV around for devices with a tenth of Dit. Statistical sum of WKF and ITF: (σ2Vth, WKs2Vth, ITs)0.5=53.7 mV overestimates σVth,“WKs+ITs”=46.8 mV (>14% overestimation) of combined random WKs and ITs because assumption of identical independent distribution may not hold owing to their interaction of surface potentials. Fluctuation resulting from the combined random WKs and ITs could be comparable to the random dopant fluctuation.

Original languageEnglish
Title of host publicationComprehensive Nanoscience and Nanotechnology
Number of pages12
ISBN (Electronic)9780128122952
ISBN (Print)9780128122969
StatePublished - 1 Jan 2019


  • 3D device simulation
  • Coupled device-circuit simulation
  • Gate capacitance
  • High-κ/metal gate
  • Interface trap fluctuation
  • Nanosized metal grain
  • On-/Off-state current
  • SRAM circuit
  • Static noise margin
  • Threshold voltage
  • Work-function fluctuation

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