Browsing by Author "Li, MF"

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3D GOI CMOSFETs with novel IrO2(Hf) dual gates and high-kappa dielectric on 1P6M-0.18 mu m-CMOS
(2004)
Yu, DS
;
Chin, A
;
Laio, CC
;
Lee, CF
;
Cheng, CF
For the first time, we demonstrate 3D integration of self-aligned IrO2(Hf)/LaAlO3/GOI CMOSFETs above 0.18 pm Si CMOSFETs. At EOT=1.4nm, the novel IrO2(Hf) dual gates (4.4 and 5.1 eV workfunction) on control 2D LaAlO3/Si devices have high electron and hole mobilities of 203 and 67 cm(2)/Vs. On the 3D structure the LaAlO3/GOI shows even higher 389 and 234 cm(2)/Vs mobilities, and process compatibility with current Si VLSI. The higher drive current, larger integration density, shorter interconnects distance, and simple process of 3D approach can help solve the AC power issue and 2D scaling limitation.
A high-density MIM capacitor (13 fF/mu m(2)) using ALD HfO2 dielectrics
(2003-02-01)
Yu, XF
;
Zhu, CX
;
Hu, H
;
Chin, A
;
Li, MF
Metal-insulator-metal (MIM) capacitors with a different thickness of HfO2 have been investigated. The results show that both the capacitance density and voltage coefficients of capacitance (VCCs) increase with decreasing the HfO2 thickness. In addition, it is also found that the VCCs decrease logarithmically with increasing the thickness Of HfO2. Furthermore, the MIM capacitor with 10-nm HfO2 shows a record high capacitance density of 13 fF/mum(2) and a VCC of 607 ppm/V, which can meet the requirement of the International Technology Roadmap for Semiconductors. It can also provide a low leakage current of 5.95 x 10-(8)A/cm(2) at room temperature at I V, low tangent values below 0.05, and a small frequency dependence as well. All these indicate that it is very suitable for use in silicon integrated circuit applications.
A novel program-erasable high-(K) A1N-Si MIS capacitor
(2005-03-01)
Lai, CH
;
Chin, A
;
Hung, BF
;
Cheng, CF
;
Yoo, WJ
We demonstrate a programmable-erasable MIS capacitor with a single layer high-kappa AIN dielectric on Si having a high capacitance density of 5 fF/mum(2). It has low program and erase voltages of +4 and -4 V, respectively. Such an erase function is not available in other single layer Al2O3, AION, or other known high-kappa dielectric capacitors, where the threshold voltage (T h) shifts continuously with voltage. This device exhibits good data retention with a V-th change of only 0.06 V after 10 000 s.
A TaN-HfO2-Ge pMOSFET with novel SiH4 surface passivation
(2004-09-01)
Wu, N
;
Zhang, QC
;
Zhu, CX
;
Chan, DSH
;
Du, AY
In this letter, we demonstrate a novel surface passivation process for HfO2 Ge pMOSFETs using SiH4 surface annealing prior to HfO2 deposition. By using SiH4 passivation, a uniform amorphous interfacial layer is formed after device fabrication. Electrical results show that the HfO2 Ge MOSFET with Si-passivation exhibits less frequency dispersion, narrower gate leakage current distribution, and a similar to 140% higher peak mobility than that of the device with surface nitridation.
A tunable and program-erasable capacitor on Si with excellent tuning memory
(2004)
Lai, CH
;
Lee, CF
;
Chin, A
;
Zhu, C
;
Li, MF
A novel tunable and program-erasable high-kappa: AIN MIS capacitor is demonstrated for the first time with excellent tuning memory, which is useful to tune the impedance mismatching and resonance frequency without always connected voltage bias circuit. Large C-max /C-min tunability of 12 is obtained due to the high-kappa AIN dielectric with high 5 muF/mum(2) capacitance density. Good tuning memory is evidenced from the small V-th variation after program or erase at +4 V or -4 V for 10,000 s and the potential of years long extrapolated memory time.
Al2O3-Ge-On-insulator n- and p-MOSFETs with fully NiSi and NiGe dual gates
(2004-03-01)
Yu, DS
;
Huang, CH
;
Chin, A
;
Zhu, CX
;
Li, MF
High-kappa, A1(2)O(3)/Ge-on-insulator (GOI) n- and p-MOSFETs with fully silicided NiSi and germanided NiGe dual gates were fabricated. At 1.7-nm equivalent-oxide-thickness (EOT), the A1(2)O(3)-GOI with metal-like NiSi and NiGe gates has comparable gate leakage current with A1(2)O(3)-Si MOSFETs. Additionally, A1(2) O-3-GOI C-MOSFETs with fully NiSi and NiGe gates show 1.94 and 1.98 times higher electron and hole mobility, respectively, than A1(2)O(3)-Si devices, because the electron and hole effective masses of Ge are lower than those of Si. The process with maximum 500 degreesC rapid thermal annealing (RTA) is ideal for integrating metallic gates with high-kappa to minimize interfacial reactions and crystallization of the high-kappa material, and oxygen penetration in high-kappa MOSFETs.
Alternative surface passivation on germanium for metal-oxide-semiconductor applications with high-k gate dielectric
(2004-11-01)
Wu, N
;
Zhang, QC
;
Zhu, CX
;
Chan, DSH
;
Li, MF
An alternative surface passivation process for high-k Ge metal-oxide-semiconductor (MOS) device has been studied. The surface SiH4 annealing was implemented prior to HfO2 deposition. X-ray photoelectron spectroscopy analysis results show that the SiH4 surface passivation can greatly prevent the formation of unstable germanium oxide at the surface and suppress the Ge out-diffusion after the HfO2 deposition. The electrical measurement shows that an equivalent oxide thickness of 13.5 Angstrom and a leakage current of 1.16x10(-5) A/cm(2) at 1 V gate bias was achieved for TaN/HfO2/Ge MOS capacitors with the SiH4 surface treatment. (C) 2004 American Institute of Physics.
Effect of surface NH3 anneal on the physical and electrical properties of HfO2 films on Ge substrate
(2004-05-10)
Wu, N
;
Zhang, QC
;
Zhu, CX
;
Yeo, CC
;
Whang, SJ
Metal-oxide-semiconductor capacitors were fabricated on germanium substrates by using metalorganic-chemical-vapor-deposited HfO2 as the dielectric and TaN as the metal gate electrode. It is demonstrated that a surface annealing step in NH3 ambient before the HfO2 deposition could result in significant improvement in both gate leakage current and the equivalent oxide thickness (EOT). It was possible to achieve a capacitor with an EOT of 10.5 Angstrom and a leakage current of 5.02x10(-5) A/cm(2) at 1 V gate bias. X-ray photoelectron spectroscopy analysis indicates the formation of GeON during surface NH3 anneal. The presence of Ge was also detected within the HfO2 films. This may be due to Ge diffusion at the high temperature (similar to400 degreesC) used in the chemical-vapor deposition process. (C) 2004 American Institute of Physics.
Electrical characteristics and suppressed boron penetration behavior of thermally stable HfTaO gate dielectrics with polycrystalline-silicon gate
(2004-10-04)
Yu, XF
;
Zhu, CX
;
Li, MF
;
Chin, A
;
Du, AY
The thermal stability and electrical characteristics of HfTaO gate dielectric with polycrystalline-silicon gate have been investigated. The incorporation of Ta into HfO2 enhances the crystallization temperature of film dramatically. Transmission electron microscopy micrographs confirm that HfTaO with 43% Ta film remains amorphous even after activation annealing at 950 degreesC for 30 s, and the formation of low-kappa interfacial layer is observably reduced. The capacitance-voltage curve of metal-oxide-semiconductor capacitor using HfTaO gate dielectric fits well with simulated curve, indicating good interface property between HfTaO and substrate. In addition, the boron penetration behaviors of HfTaO films are sufficiently suppressed as manifested by the narrow flat-band voltage shift. The negligible flat-band voltage shift in HfTaO with 43% Ta film is observed and attributed to its amorphous structure after device fabrication. (C) 2004 American Institute of Physics.
Electron mobility in Ge and strained-Si channel ultrathin-body metal-oxide semi conductor field-effect transistors
(2004-09-20)
Low, T
;
Li, MF
;
Shen, C
;
Yeo, YC
;
Hou, YT
Electron mobility in strained silicon and various surface oriented germanium ultrathin-body (UTB) metal-oxide semiconductor field-effect transistors (MOSFETs) with sub-10-nm-body thickness are systematically studied. For biaxial tensile strained-Si UTB MOSFETs, strain effects offer mobility enhancement down to a body thickness of 3 nm, below which strong quantum confinement effect renders further valley splitting via application of strain redundant. For Ge channel UTB MOSFETs, electron mobility is found to be highly dependent on surface orientation. Ge<100> and Ge<110> surfaces have low quantization mass that leads to a lower mobility than that of Si in aggressively scaled UTB MOSFETs. (C) 2004 American Institute of Physics.
Fully silicided NiSi and germanided NiGe dual gates on SiO2 n- and p-MOSFETs
(2003-12-01)
Yu, DS
;
Wu, CH
;
Huang, CH
;
Chin, A
;
Chen, WJ
We have fabricated the fully silicided NiSi and germanided NiGe dual gates n- and p-MOSFETs on 1.9 nm thick SiO2 gate dielectric. The extracted work functions of fully NiSi and NiGe gates from thickness-dependent flat band voltage were 4.55 and 5.2 eV respectively, which may provide possible wide work function tuning using NiSi1-xGex. In additional to the lower gate current than Al gate n- and p-MOSFETs, the fully silicided NiSi and germanided NiGe gates MOSFETs show electron and hole mobilities close to universal mobility values with special advantage of process compatible to current VLSI fabrication line.
Fully silicided NiSi and germanided NiGe dual gates on SiO2/Si and Al2O3/Ge-on-insulator MOSFETs
(2003)
Huang, CH
;
Yu, DS
;
Chin, A
;
Wu, CH
;
Chen, WJ
We demonstrate for the first time fully silicided NiSi (4.55eV) and germanided NiGe (5.2eV) dual gates on 1.9nm-SiO2/Si and Al2O3/Ge-On-Insulator (GOI) MOSFETs (EOT = 1.7nm). In additional to the comparable gate current and time-to-breakdown with AI gate C-MOSFETs, the fully NiSi and NiGe gates on SiO2/Si show mobility close to universal mobility while on Al2O3/GOI show similar to2.0X higher peak electron and hole mobility than Al on Al2O3/Si with special advantage of NiSi and NiGe compatible to current VLSI process line.
Fully silicided NiSi gate on La2O3 MOSFETs
(2003-05-01)
Lin, CY
;
Ma, MW
;
Chin, A
;
Yeo, YC
;
Zhu, CX
We have fabricated the fully silicided NiSi on La2O3 for n- and p-MOSFETs. For 900 degreesC fully silicided CoSi2 on La2O3 gate dielectric with 1.5 mn EOT, the, gate dielectric has large leakage current by possible excess Co diffusion at high silicidation temperature. In sharp contrast, very low gat e leakage current density of 2 x 10(-4) A/cm(2) at 1 V is measured for 400 degreesC formed fully silicided NiSi and comparable with Al gate. The extracted work function of NiSi was 4.42 eV, and the corresponding threshold voltages are 0.12 and -0.70 V for respective n- and p-MOSFETs. Electron and hole mobilities of 156 and 44 cm(2)/V-s are obtained for respective n- and p-MOSFETs, which are comparable with the HfO2 MOSFETs without using H-2 annealing.
Germanium pMOSFETs with Schottky-barrier germanide S/D, high-kappa gate dielectric and metal gate
(2005-02-01)
Zhu, SY
;
Li, R
;
Lee, SJ
;
Li, MF
;
Du, AY
Schottky-barrier source/drain (S/D) germanium p-channel MOSFETs are demonstrated for the first time with HfAlO gate dielectric, HfN-TaN metal gate and self-aligned NiGe S/D. The drain drivability is improved over the silicon counterpart with PtSi S/D by as much as similar to5 times due to the lower hole Schottky barrier of the NiGe-Ge contact than that of PtSi-Si contact as well as the higher mobility of Ge channel than that of Si.
High density RF MIM capacitors using high-kappa AlTaOx dielectrics
(2003)
Huang, CH
;
Yang, MY
;
Chin, A
;
Zhu, CX
;
Li, MF
Very high capacitance density of 10 fF/mum(2) is measured using high-kappa AlTaOx, with small capacitance reduction of 5% from 10 KHz to 30 GHz, low loss tangent < 0.03, and process compatible with existing VLSI back-end integration. Small voltage dependence of capacitance < 600 ppm, mathematical derived from S-parameters, is obtained at 1 GHz, which ensures this MIM capacitor useful for high precision circuits operated at RF regime.
High performance metal-gate/high-kappa, MOSFETs and GaAs compatible RF passive devices on Ge-on-Insulator tlechnology
(2004)
Chin, A
;
Kao, HL
;
Yu, DS
;
Liao, CC
;
Zhu, C
We propose and demonstrate a new VLSI structure using high performance metal-gate/high-kappa MOSFETs and high-Q RF passive devices on Ge-on- Insulator (GOI) platform. In additional to high RF performance passive devices on insulating Si formed by ion implantation. the metal-gate/(La)AiO(3)/GOI MOSFETs have 1.7-2.0X improved electron and hole mobility with the merits of minimizing interfacial reaction., high-kappa crystallization, Fermi-level pinning, and impurity diffusion due to low thermal budget of 500 degrees C RTA.
High work function IrxSi gates on HfAlON p-MOSFETs
(2006-02-01)
Wu, CH
;
Yu, DS
;
Chin, A
;
Wang, SJ
;
Li, MF
We have fabricated the fully silicided IrxSi-gated p-MOSFETs on HfAlON gate dielectric with 1.7-mn equivalent oxide thickness. After 950 degrees C rapid thermal annealing, the fully IrxSi/HfAlON device has high effective work function of 4.9 eV, high peak hole mobility of 80 cm(2)/V.s, and the advantage of being process compatible to the current VLSI fabrication line.
High-density MIM canpacitors using AlTaOx dielectrics
(2003-05-01)
Yang, MY
;
Huang, CH
;
Chin, A
;
Zhu, CX
;
Li, MF
The authors have obtained good MIM capacitor integrity of high-capacitance density of 10 fF/mum(2) using high-k AlTaOx fabricated at 400degreesC. In addition, small voltage dependence of capacitance of < 600, ppm (quadratic voltage coefficient of only 130 ppm/V-2). is obtained at 1 GHz using their mathematical derivation from measured high-frequency S parameters. These good results ensure the high-k AlTaOx. MIM capacitor technology is useful for high-precision circuits operated at the RF frequency regime.
High-performance microwave coplanar bandpass and bandstop filters on Si substrates
(2003-09-01)
Chan, KT
;
Chin, A
;
Li, MF
;
Kwong, DL
;
McAlister, SP
High-performance bandpass and bandstop microwave coplanar filters, which operate from 22 to 91 GHz, have been fabricated on Si substrates. This was achieved using an optimized proton implantation process that converts the standard low-resistivity (similar to10 Omega (.) cm) Si to a semi-insulating state. The bandpass filters consist of coupled lines to form a series resonator, while the bandstop filter was designed in a double-folded short-end stub structure. For the bandpass filters at 40 and 91 GHz, low insertion loss was measured, close to electromagnetic simulation values. We also fabricated excellent bandstop filters with very low transmission loss of similar to1 dB and deep band rejection at both 22 and 50 GHz. The good filter performance was confirmed by the higher substrate impedance to ground, which was extracted from the well-matched S-parameter equivalent-circuit data.
High-performance MIM capacitor using ALD high-k HfO2-Al2O3 laminate dielectrics
(2003-12-01)
Ding, SJ
;
Hu, H
;
Lim, HF
;
Kim, SJ
;
Yu, XF
For the first time, we successfully fabricated and demonstrated high performance metal-insulator-metal (MIM) capacitors with HfO2-Al2O3 laminate dielectric' using atomic im layer deposition (ALD) technique. Our data indicates that the laminate NUM capacitor can provide high capacitance density of 12.8 fF/ mum(2) from 10 kHz up to 20 GHz, very low leakage current of 3.2 x 10(-8) A/cm(2) at 3.3 V, small linear voltage coefficient of capacitance of 240 ppm/V together with quadratic. one of 1830 PPM/V-2, temperature coefficient of capacitance of 182 ppm/degreesC, and high breakdown field of similar to6 MV/cm as well as promising reliability. As a result, the HfO2-Al2O3 laminate is a very promising candidate for next generation MINI capacitor for radio frequency and mixed signal integrated circuit applications.