Browsing by Author "Yu, Chia-Hui"

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3D Device Simulation of Work Function and Interface Trap Fluctuations on High-kappa/Metal Gate Devices
(2010)
Cheng, Hui-Wen
;
Li, Fu-Hai
;
Han, Ming-Hung
;
Yiu, Chun-Yen
;
Yu, Chia-Hui
This work, for the first time, examines the work function fluctuation (WKF) and interface trap fluctuation (ITF) using experimentally calibrated 3D device simulation on high-kappa / metal gate technology. The random WKs result in 36.7 mV threshold voltage fluctuation (sigma V(th)) for 16 nm N-MOSFETs with TiN gate, which is rather different from the result of averaged WKF (AWKF) method [1] due to localized random WK effect. The ITF affects the subthreshold region (the normalized sigma I(D) > 48%) and is suppressed for devices under strong inversion. Estimation of statistical covariance confirms the dependence of IT on the metal gate's WK; thus, the impacts of WKF and ITF on device and circuit variability should be considered together properly. Such variability induced static noise margin fluctuation of SRAM exceeds the influence of random dopants and cannot be ignored.
Effect of Gate Length on Device Performances of AlSb/InAs High Electron Mobility Transistors Fabricated Using BCl3 Dry Etching
(2012-06-01)
Kuo, Chien-I
;
Hsu, Heng-Tung
;
Hsu, Ching-Yi
;
Yu, Chia-Hui
;
Ho, Han-Chieh
In this paper, we present the development of a mesa isolation process for AlSb/InAs high electron mobility transistors (HEMTs) using inductively coupled plasma (ICP) etching with BCl3 gas. Devices with different gate lengths (L-g: 60, 100, and 200 nm) fabricated by this dry etching technique show good DC and RF performances. With an appropriate L-g/gate-channel distance ratio, the 200-nm-gate has very high peak transconductances of 781 mS/mm at V-DS = 0.1 V and 2000 mS/mm at V-DS = 0.5 V. Moreover, an extrinsic current gain cutoff frequency of 137 GHz and maximum oscillation frequency of 97 GHz were achieved at a drain bias voltage V-DS = 0.3 V, indicating the great potential for such a device operating at high frequency with extremely low DC power consumption. (c) 2012 The Japan Society of Applied Physics
Performance Evaluation of InGaSb/AlSb P-Channel High-Hole-Mobility Transistor Faricated Using BCl3 Dry Etching
(2013-02-01)
Yu, Chia-Hui
;
Hsu, Heng-Tung
;
Chiang, Che-Yang
;
Kuo, Chien-I
;
Miyamoto, Yasuyuki
In this study, we present the fabrication and characterization of InGaSb/AlSb p-channel high-hole-mobility-transistor devices using inductively coupled plasma (ICP) etching with BCl3 gas. Devices fabricated by the dry etching technique show good DC and RF performances. Radio-frequency (RF) performance for devices with different source-to-drain spacing (L-SD) and gate length (L-g) were investigated. The fabricated 80-nm-gate-length p-channel device with 2-mu m LSD exhibited a maximum drain current of 86.2mA/mm with peak transconductance (g(m)) of 64.5mS/mm. The current gain cutoff frequency (f(T)) was measured to be 15.8 GHz when the device was biased at V-DS = -1.2 V and V-GS = 0.4 V. (C) 2013 The Japan Society of Applied Physics
Statistical Simulation of Metal-Gate Work-function Fluctuation in High-kappa/Metal-Gate Devices
(2010)
Yu, Chia-Hui
;
Han, Ming-Hung
;
Cheng, Hui-Wen
;
Su, Zhong-Cheng
;
Li, Yiming
In this work, we statistically examine the emerging high-kappa / metal gate work-function fluctuation (WKF) induced threshold voltage (V(th)) fluctuations in 16-nm-gate MOSFET devices. Our Monte-Carlo model extensively evaluates the impact of WKF for different technology node, metal grain size, and gate material. This model provides us to identify suitable materials and fabrication processes that can significantly reduce the impact of Vth fluctuation owing to WKF. First, four kinds of gate material are examined and TiN possesses the smallest Vth fluctuation. For fabrication process, a fast deposition of metal at lower temperature prevents the metal grain not to grow to large size result in a smaller variation. In addition, an idea of modeling multilayer metal gate WKF is also presented and discussed, in which the first layer plays the most important role, compared with other layers, for the fluctuation suppression.