TY - CHAP

T1 - Random nanosized metal grains and interface-trap fluctuations in emerging CMOS technologies

AU - Li, Yiming

PY - 2019/1/1

Y1 - 2019/1/1

N2 - 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, WKs+σ2Vth, 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.

AB - 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, WKs+σ2Vth, 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.

KW - 3D device simulation

KW - Coupled device-circuit simulation

KW - Gate capacitance

KW - High-κ/metal gate

KW - Interface trap fluctuation

KW - Nanosized metal grain

KW - On-/Off-state current

KW - SRAM circuit

KW - Static noise margin

KW - Threshold voltage

KW - Work-function fluctuation

UR - http://www.scopus.com/inward/record.url?scp=85078649754&partnerID=8YFLogxK

U2 - 10.1016/B978-0-12-803581-8.00633-0

DO - 10.1016/B978-0-12-803581-8.00633-0

M3 - Chapter

AN - SCOPUS:85078649754

SN - 9780128122969

VL - 1-5

SP - 123

EP - 134

BT - Comprehensive Nanoscience and Nanotechnology

PB - Elsevier

ER -