Browsing by Author "Yeh, M. -S."

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A Comprehensive Study of Polymorphic Phase Distribution of Ferroelectric-Dielectrics and Interfacial Layer Effects on Negative Capacitance FETs for Sub-5 nm Node
(2018-01-01)
Tang, Y. -T
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Su, C. -J.
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Wang, Y. -S.
;
Kao, K. -H.
;
Wu, T. -L.
The impact of a realistic representation of gate-oxide granularity on negative-capacitance (NC) FETs at sub-5nm node is studied by a newly developed thermodynamic energy model based on the first principle calculation (FPC). For the first time, the calculation fully couples the Landau-Khalatnikov (L-K) equation with grain-size effect equation in NC-FETs. It explains the experimental results in phase transition and reveals excellent immunity against depolarization in ferroelectric (FE) layer owing to dopant concentration and stress in thin films. A sub-5nm node (L-G=10nm) NC-FET with thin FE layer (T-FE similar to 2nm) is integrated to achieve low subthreshold slope (SS) of 52mV/dec via a 1.9GPa-tensor stressed interfacial layer (IL) and 12% Zr-doped HfO2.
Ge FinFET CMOS Inverters With Improved Channel Surface Roughness by Using In-Situ ALD Digital O-3 Treatment
(2018-01-01)
Yeh, M. -S.
;
Luo, G. -L.
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Hou, F. -J.
;
Sung, P. -J.
;
Wang, C. -J.
Improved electrical characteristics of CMOS inverters composed of Ge n- and p-finFETs were demonstrated by utilizing newly introduced Ge surface treatments. In-situ digital O-3 treatment in ALD chamber was adopted on the surface of Ge fin sidewall in order to reduce the roughness and etching damages through the GeO desorption mechanism. The treatment effects were checked by AFM and C-V measurements. By combining this treatment with optimized microwave annealing, sub-threshold slope and the I-ON/I-OFF ratio were remarkably improved in both n-finFET and p-finFET, and Ge CMOS inverters with high voltage gain of 50.3 V/V at low V-D = 0.6 V was realized. Finally, simulations on an ideal Ge CMOS inverter were presented.
Ge Nanowire FETs with HfZrOx Ferroelectric Gate Stack Exhibiting SS of Sub-60 mV/dec and Biasing Effects on Ferroelectric Reliability
(2017-01-01)
Su, C. -J.
;
Hong, T. -C.
;
Tsou, Y. -C.
;
Hou, F. -J.
;
Sung, P. -J.
Ge nanowire (NW) FETs exhibiting subthreshold swing (SS) of 54 mV/dec at room temperature are demonstrated with ferroelectric HfZrOx (FE-HZO) gate stack for the first time. I-ON/I-OFF ratios higher than 10(7) and 10(6) for p- and n-NWFETs, respectively, have been achieved by adopting the gate-all-around (GAA) configuration. Electrical biasing effects on the HZO ferroelectric reliability have been systematically investigated in this work. It is found that the polarization behavior will degrade with electrical stress time and can be recovered. The Ge HZO FinFET CMOS inverter shows experimentally voltage gain of 24.8 V/V.