Characteristics and Reliability of Hafnium Oxide Dielectric Stacks With Room Temperature Grown Interfacial Anodic Oxide
TL;DR: In this article, a tilted-substrate sputtering technique, which provides various film thicknesses in one processing step, was proposed and useful for the characterization of charge distribution in low-temperature dielectric stacks with anodic oxide interfacial layer (ANO-IL).
Abstract: Hafnium oxide dielectric stacks with anodic oxide interfacial layer (ANO-IL) were investigated under low-temperature consideration. A tilted-substrate sputtering technique, which provides various film thicknesses in one processing step, was proposed and useful for the characterization of charge distribution. It was found that charges existed in the HfO2/ANO-IL were smaller than that in HfO2/rapid-thermal-oxidation IL. The prepared samples exhibit good electrical characteristics, including small electrical hysteresis (< 10 mV), low leakage current, high effective dielectric breakdown field of 12.7 MV/cm, and maximum operating voltages of -2.74 V at 25degC and -2.32 V at 125degC for EOT = 2.3 nm stacks under a ten-year lifetime evaluation. The results suggest that the quality of IL in the dielectric stack is a critical reliability issue and that ANO is provided as a candidate for IL consideration of low-temperature dielectric stacks.
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TL;DR: In this paper, a novel approach for efficient SPP amplification under electrical pumping in a deep-subwavelength metal-insulator-semiconductor waveguiding geometry was proposed.
Abstract: Surface plasmon polaritons (SPPs) give an opportunity to break the diffraction limit and design nanoscale optical components, however their practical implementation is hindered by high ohmic losses in a metal. Here, we propose a novel approach for efficient SPP amplification under electrical pumping in a deep-subwavelength metal-insulator-semiconductor waveguiding geometry and numerically demonstrate full compensation for the SPP propagation losses in the infrared at an exceptionally low pump current density of 0.8 kA/cm2. This value is an order of magnitude lower than in the previous studies owing to the thin insulator layer between a metal and a semiconductor, which allows injection of minority carriers and blocks majority carriers reducing the leakage current to nearly zero. The presented results provide insight into lossless SPP guiding and development of future high dense nanophotonic and optoelectronic circuits.
24 citations
TL;DR: A novel approach for efficient SPP amplification under electrical pumping in a deep-subwavelength metal-insulator-semiconductor waveguiding geometry is proposed and full compensation for the SPP propagation losses in the infrared at an exceptionally low pump current density of 0.8 kA/cm2 is demonstrated.
Abstract: Surface plasmon polaritons (SPPs) give an opportunity to break the diffraction limit and design nanoscale optical components, however their practical implementation is hindered by high ohmic losses in a metal Here, we propose a novel approach for efficient SPP amplification under electrical pumping in a deep-subwavelength metal-insulator-semiconductor waveguiding geometry and numerically demonstrate full compensation for the SPP propagation losses in the infrared at an exceptionally low pump current density of 08 kA/cm$^2$ This value is an order of magnitude lower than in the previous studies owing to the thin insulator layer between a metal and a semiconductor, which allows injection of minority carriers and blocks majority carriers reducing the leakage current to nearly zero The presented results provide insight into lossless SPP guiding and development of future high dense nanophotonic and optoelectronic circuits
22 citations
Journal Article•
Abstract: The quality of low-temperature (/spl ap/400/spl deg/C) atmospheric pressure chemical vapor deposited (APCVD) silicon dioxide (SiO/sub 2/) films has been improved by a short time rapid thermal annealing (RTA) step. The RTA step followed by a low temperature (400/spl deg/C) forming gas anneal (FGA) results in a well-passivated Si-SiO/sub 2/ interface, comparable to thermally grown conventional oxides. Efficient and stable surface passivation is obtained by this technique on virgin silicon as well as on photovoltaic devices with diffused (n/sup +/p) emitter surface while maintaining a very low thermal budget. Device parameters are improved by this APCVD/RTA/FGA passivation process.
12 citations
TL;DR: In this paper, the electrical characteristics and reliability of the aluminum oxide (Al2O3) metal-oxide-semiconductor (MOS) capacitors were investigated under low-temperature process consideration.
Abstract: The electrical characteristics and reliability of the aluminum oxide (Al2O3) metal-oxide-semiconductor (MOS) capacitors were investigated under low-temperature process consideration. The simple cost-effective technique in preparing the Al2O3/SiO2 bilayer structure as the high-k gate dielectrics was demonstrated in this paper. SiO2 was prepared by room-temperature anodic oxidation, and Al2O3 was fabricated by room-temperature in situ natural oxidation during the dc sputtering of aluminum in Ar/O2 ambient. Compared to the Al2O3 MOS capacitors without nitric acid (HNO3) compensation, significant improvements in electrical characteristics, reliability, and uniformity were achieved by utilizing HNO3 to moderately oxidize the existing Al2O3 layer. In addition, the charge trapping behaviors of our samples were also studied by time-dependent dielectric breakdown under the 1000-s constant voltage stress and constant current stress tests. It was found that the electron trapping is dominant under a low negative bias stress. However, under a high negative bias stress, the Al2O3 MOS capacitors show hole trapping due to the impact ionization near the SiO2/Si interface. The in situ oxidation in sputtering with HNO3 compensation is suitable for future low-temperature dielectric applications.
11 citations
TL;DR: In this paper , a high performance electro-optic Mach-Zehnder modulator (MZM) with outstanding characteristics is proposed, which is in a push-pull configuration that is constructed using an ITO/graphene-based silicon waveguide.
Abstract: A high-performance electro-optic Mach-Zehnder modulator (MZM) with outstanding characteristics is proposed. The MZM is in a push-pull configuration that is constructed using an ITO/graphene-based silicon waveguide. A novel idea for engineering of the plasma dispersion effect in an ITO/graphene-based waveguide is proposed so that the modulation characteristics of the MZM are highly improved. Plasma dispersion effects of ITO and graphene layers are tailored in such a way that a large difference between real parts of guided mode effective index of the two arms is achieved while their corresponding imaginary parts are equal. As a result, a very low [Formula: see text] of [Formula: see text] is achieved. To the best of our knowledge, this is one of the lowest [Formula: see text] reported for an electro-optic modulator. In addition, the proposed modulator exhibits a very high extinction ratio of more than 30 dB, low insertion loss of 2.8 dB and energy consumption of as low as 10 fJ/bit, which are all promising for optical communication and processing systems.
6 citations
References
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01 Jan 2005
150 citations
Additional excerpts
...in low-temperature process conditions [8], [9]....
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TL;DR: In this paper, the defect properties of undoped low-pressure chemical-vapor-deposited (LPCVD) polysilicon films have been investigated by capacitance techniques on a simple metal-oxide-semiconductor (MOS) capacitor structure.
Abstract: Defect properties of undoped low-pressure chemical-vapor-deposited (LPCVD) polysilicon films have been investigated by capacitance techniques on a simple metal-oxide-semiconductor (MOS) capacitor structure. The results show that the effective density of bulk and interface trap states is almost independent of the deposition pressure. After reducing the polysilicon film thickness by etching, although the grain size decreases due to the columnar mode of growth at low pressures, the trap states density reduces significantly. This finding could be explained by the hypothesis that, during the growth of the material, impurities are segregated at the film surface by fast diffusion through the grain boundaries. The transport properties of 0.5- mu m-thick polysilicon films deposited at a pressure ranging from 100 to 0.5 mtorr were evaluated from measurements on thin-film transistors (TFTs). The results demonstrate that at high pressures the grain boundaries and at low pressures the polysilicon-SiO/sub 2/ interface roughness scattering are the main factors in determining the transistor performance. >
109 citations
Additional excerpts
...in low-temperature process conditions [8], [9]....
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TL;DR: In this article, the work function of metal electrodes on high/spl kappa/ dielectrics with various charge distributions was derived and a mathematical analysis including sources of errors was used to study the effect of charge distribution in gate dielectric stacks on the flatband voltage.
Abstract: This letter presents a methodology to accurately extract the work function of metal electrodes on high-/spl kappa/ dielectrics with various charge distributions. A mathematical analysis including sources of errors was used to study the effect of charge distribution in gate dielectric stacks on the flatband voltage of the device. The calculations are verified by experimental results obtained for Ru-Ta alloys on HfO/sub 2/ and SiO/sub 2/ gate dielectric stacks. It is shown that accounting for the appropriate charge model is imperative for accurate calculation of workfunction on high-/spl kappa//SiO/sub 2/ gate dielectric stacks.
108 citations
"Characteristics and Reliability of ..." refers methods in this paper
...To study the charge distributions in the HfO2/SiO2 stacks, the relation of VFB values versus EOT in the bilayer stacks structure with a fixed SiO2 thickness and varied HfO2 thicknesses is adopted [16]....
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...From the slope of the VFB versus EOT curve, the interfacial charges QHI can be extracted as follows [16]:...
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IBM1
TL;DR: In this paper, the authors discuss several important aspects of reliability projections, especially for ultra-thin oxides in a direct tunneling regime such as stress methodologies, the determination of projection parameters, and their dependence on stress conditions as well as their impact on reliability projection.
Abstract: In this work, we discuss several important aspects of reliability projections, especially for ultra-thin oxides in a direct tunneling regime such as stress methodologies, the determination of projection parameters, and their dependence on stress conditions as well as their impact on reliability projection. Most importantly, we found that the Weibull shape factors and area dependence are key to understanding of the reliability limitations for ultra-thin oxides.
98 citations
TL;DR: In this article, a methodology to analyze charge pumping (CP) data, which allows positions of probing traps in the dielectric to be identified, was applied to extract the spatial profile of traps in SiO2∕HfO2 gate stacks.
Abstract: A methodology to analyze charge pumping (CP) data, which allows positions of probing traps in the dielectric to be identified, was applied to extract the spatial profile of traps in SiO2∕HfO2 gate stacks. The results suggest that traps accessible by CP measurements in a wide frequency range, down to few kilohertz, are located within or near the interfacial SiO2 layer rather than in the bulk of the high-k film.
87 citations