This study investigates the key physical and electronic properties of Molecular Beam Epitaxy (MBE) grown silicon and germanium nanowire wafers oxidized via vapors of modified CP-4 etchant used in semiconductor microelectronics. This method leads to nanoscale surface modification with rich physical and chemical properties as evidenced from luminescence, spectroscopic ellipsometry, electron microscopy, localized vibrational modes and Raman light scattering measurements. Observed features are highly sensitive to composition, exposure duration and the nanowire structural features, offering detection of biological and chemical species related to viral and bacterial entities. Time-resolved luminescence investigations identified fast and slow recombination states spanning the nanosecond and picosecond ranges, originating from quantum confinement effects and oxidation induced structural defects. The localized vibrational modes (Si-O, Ge-O, Si-O-Ge bonds) resulting from surface modification were analyzed using Fourier transform, clarifying the chemical and structural changes occurring at nanostructures surface. A lookout is provided for potential applications in biosensors and light emitting devices with tunable properties indicating high sensitivity to external fields. By understanding the underlying mechanisms of surface engineered wafers with the light emission spanning from UV to 1800 nm, the findings establish a strategic outlook for their integration into next-generation biosensors of these CMOS compatible material.

The Si nanorods and Si/Ge nanowires grown by molecular beam epitaxy (MBE) on silicon wafers were subject to oxidation using the vapor phase form of modified CP-4 etchant. These semiconductor quantum structures offer promising application possibilities ranging from photonics to advanced electronics. Therefore, understanding of the oxidation mechanism and resulting effects would provide a valuable knowledge on physical and electrical properties of these commercially valuable materials. In this presentation, a comprehensive review of the properties is provided in order to clarify the origin of the observed oxidation based features including wafer recovery. The results have been analyzed using state-of-the-art characterization techniques and compared with the current developments in the area. At the end of the paper, a lookout is provided for possible photonic applications.

The silicon suboxide SiOx (x < 2.0) offers promising industrial application possibilities ranging from electrodes in lithium-ion batteries, which are used widely in electrical vehicles and portable devices to sensing applications. Therefore, a low cost, environmental friendly and high performance silicon oxide materials are required for an appropriate operation of any electronic gadget. In this work, we report on the physical and electrical properties of a suboxide layer of up to 1 mu m, which was grown on silicon during the formation of a dielectric layer, namely the ammonium silicon hexafluoride. It is a stable oxide exhibiting light emission from 400 to 1700 nm offering scalable and cost-effective large area processing capability. The measurement results reveal interesting properties, which are required to be understood clearly before proceeding with any suitable application. The results have been analyzed using state-of-the-art physical and electrical characterization techniques such as ellipsometry, AFM, SEM, FTIR, photoluminescence lifetime and resistive switching measurements to determine structural, optical and electrical properties. At 300 K the carrier lifetime measurements reveal the lifetime values ranging from about few tens of picosecond up to 4500 picoseconds. Scanning probe analysis indicate a surface roughness of about 30 angstrom. Resistive memory forming was observed also in these layers at relatively low power thresholds. We provide a comprehensive description of the physical and electrical properties in order to clarify the origin of the observed features. The wavelength dependent real epsilon(1)(omega) and the imaginary epsilon(2)(omega) dielectric functions provided useful insights on optical properties. A lookout is given for the possible applications of this special SiOx dielectric oxide layer.

This work looks into Iraq's best places for wind turbines, with an emphasis on economic factors. It studies wind energy conversion systems using mathematical models from Matlab and Simulink. This research aims to pinpoint areas where wind energy can produce power on its own, separate from the national grid, for a range of applications, including energy storage, water pumps, heating, and cooling. In addition, the project will use PMSG to investigate wind turbine efficiency and create vector control technique technology for permanent magnet synchronous generators. Two Iraqi cities were taken to make the calculations of wind speed and its effect on electrical generations (Nasiriyah and Basra), where wind speeds of a height of 20 and 50 m were taken at the hub level of the turbine. The mechanical, electrical, and performance characteristics of the turbine were computed during the test to achieve optimal operation cases. The development of the system was done by MATLAB SIMULINK, where the overall efficiency was enhanced to 88.22%.

Black silicon (b-Si) has been receiving a great deal of interest for its potential to be used in applications ranging from sensors to solar cells and electrodes in batteries due to its promising optical, electronic and structural properties. Several approaches have been used to demonstrate the possibility of producing application quality b-Si, which also exhibits light emission properties. The photoluminescence is a useful technique to identify recombination pathways and thus, enable us to optimize device quality. In this work, we report the results of the radiative recombination dynamics in b-Si produced by a technique involving thermal oxidation, photoresist coating and chlorine plasma etching. An ultrafast blue luminescence component competing with non-radiative recombination at surface defects was identified as no-phonon radiative recombination. This component involves two decay processes with a peak energy at around 480 nm, which have the fast component of about 15 ps followed by a component of around 50 ps lifetime. The emission exhibits a slow process in red spectral region with time constant of 1500 ps. When the surface is smoothed, the lifetime of carriers increased up to 4500 ps and the emission peak blue shifted indicating downsizing in dimensions. The results are correlated with transmission electron microscopy, localized vibrational modes and spectroscopic ellipsometry and interpreted through the presence of quantum confinement at the tip regions of the wires, surface defects and oxide environment surrounding the nanoscale wires.

This paper explores the suitability of atomic layer deposited hafnium oxide (HfO2) based resistive oxide memories for their integration into advanced embedded non-volatile memory technology nodes at 28 nm and below. Downscaling trends in advanced CMOS semiconductor technology and novel user needs require high packing density, lower power consumption, faster read-write with enhanced reliability features. Two terminal resistive memory layers, which were produced under optimized atomic layer deposition conditions have been investigated in terms of these features in addition of downscaling and cost-effective production. The experimental results are focused on downscaling issue of HfO2 based oxide RAMs with an emphasis on structure and electrode metallization dependent resistive switching of Metal/HfO2/Metal memory stacks and associated physical and electrical characteristics. The role of the metallization, microstructure and dielectric properties were determined to have better insight into the switching performance. Finally, a memory cell array test platform was set up using a 4k 1T1R cell array architecture and its suitability was demonstrated for testing the performance of resistive memory cells for advanced technology nodes.

The silicon suboxide SiOx (x<2.0) offers promising application possibilities ranging from electrodes in lithium-ion batteries used widely in electrical vehicles and portable devices to sensing applications. Therefore, a low cost, environmental friendly and high performance oxide materials are required for an appropriate operation of any electronic gadget. In this work, we report on the physical and electrical properties of a suboxide formed as a seed layer during the formation of a dielectric layer, namely the ammonium silicon hexafluoride. The measurement results reveal interesting properties, which are required to be understood clearly before any application. The results have been analyzed using state-of-the-art techniques and compared with the developments of SiOx obtained by related techniques. In this presentation, a comprehensive review of the physical and electrical properties is given in order to clarify the origin of the observed features. At the end of the paper, a lookout is provided for the possible applications of this special SiOx dielectric seed layer.

Surface functionalization of silicon wafers using nanoscale fabrication techniques has attracted a great deal of interest for its promising photonic applications ranging from energy harvesting to sensing and imaging. The surfaces so produced offer also exciting physical properties particularly optical emission and light trapping in a broad spectral range. Several approaches have been used to demonstrate the possibility of producing such functional surfaces using plasma processing, pulsed laser ablation, etc. However, the investigation of a detailed radiative dynamical properties of the recombination processes is still lacking a detailed knowledge. Here, we present the results of the investigation of optical properties of nano sized silicon quantum pillar arrays using advanced characterization techniques.

This paper presents recent progress in resistive oxide memories and their integration into advanced embedded nonvolatile memory technology nodes. With the downscaling trends in emerging semiconductor manufacturing and novel user needs such as higher density, low power consumption, high speed and reliable memories are needed by manufacturers. Two terminal memory cells based on resistive devices as oxides, phase change materials or magnetism are discussed in terms of power consumption, read/write speeds, scalability and effective cost. The experimental results are focused on oxide RRAMs with an emphasis on resistive switching of Metal/HfO2/Metal memory stacks and associated physical and electrical characteristics.

In this work, we have investigated the structural properties of Germanium (Ge)-Antimony (Sb)-Tellurium (Te) (GST) and Ge-rich GST thin film samples. The structural properties of the films are studied after annealing temperatures from room temperature to 450 degrees C. We performed the annealing procedure using a heat rate of 10 degrees C/min to achieve the target temperature for a duration of 10 min under N2 flow. After heat treatment, we carried out X-Ray Diffraction (XRD), Fourier Infra-Red Spectroscopy (FTIR), Raman Spectroscopy and Scanning Electron Microscopy (SEM) equipped with Energy-dispersive X-ray spectroscopy (EDS) to investigate the evolution of the structure in the samples.

This paper explores the possible use of silicon nanopillars as electronic devices. The silicon nanopillars studied in this work were fabricated by electron beam lithography and by plasma ion etching of silicon wafers. The electrical and physical properties of these pillars with full width at half maximum ranging from few nanometers to 100 nm and length of few hundreds of nanometer have been investigated by time-resolwed photoluminescence, infrared spectroscopy and current-voltage characteristics. An ultrafast blue luminescence component competing with non-radiative recombination at surface defects was quantified as originating from the no-phonon recombination. This component involved two decay processes with a peak energy at around 500 nm, which have the fast component close to femtosecond time scale. The emission exhibits also a slow component in the red spectral region with a time constant in the nanosecond regime. The nanopillars have been smoothened in an attempt to passivate surface defects. The results are indicative of an increase in the lifetimes-of carriers and an enhancement in the red component of the emission with much slower sates. The presence of ultrafast decay at blue-green spectral region is suggestive of the possibility of using the silicon nanopillars as ultrafast switching devices. Silicon nanopillar arrays can also be an ideal platform in trapping and sensing chemical or biological species using diamond NV centers.

Black silicon has attracted a great deal of interest for its promising photonic applications and exciting physical properties. Several approaches have been used to demonstrate the possibility of producing black silicon with CW light emission, but the investigation of a detailed radiative dynamical properties of the recombination process is still lacking. Here, we present ultrafast radiative recombination phenomena from black silicon consisting of quantum pillars produced by plasma ion etching. An ultrafast blue luminescence component competing with non-radiative recombination at surface defects was identified as no-phonon recombination process. This component involves two decay processes with a peak energy at around 480 nm, which have the fast component of about 10 ps followed by a component of around 50 ps decay time constant. The emission exhibits slow component in red spectral region with time constant ranging from 1.5 to 2.5 ns. When the surface of nano pillars is smoothed, the slow component at around 600 nm is enhanced to the detriment of blue-green emission, increasing the lifetime of carriers within the Si core of the quantum pillars. This process results in a slower sates assuming a 3-component exponential decay as measured by Streak camera. The ultrafast PL decay leads to a transfer of carriers to long-lived defect states as evidenced by a red emission at around 2 eV. The results are interpreted through the presence of quantum confinement at the tip regions of the pillars and surface defects originating from the oxide environment surrounding the nanometer size pillars.

In the present study the structural properties of Germanium (Ge)-Antimony (Sb)-Tellurium (Te) (GST) and Ge-rich GST thin film samples are investigated after annealing temperatures ranging from room temperature up to 450°C. We performed the annealing procedure using a heat rate of 10 °C/s to achieve the target temperature for a duration of 10 minutes under N2 flow. After heat treatment, we carried out X-Ray Diffraction (XRD), Fourier Infra-Red Spectroscopy (FTIR) and Raman Spectroscopy measurements to investigate the evolution of the structure in the samples. We confirm the delayed crystallization and structure evolution at higher temperatures of Ge-rich samples with respect to standard GST.

We report an efficient room temperature photon source at 1320 nm telecommunication wavelength from nanostructured silicon surface. The activation of this light source was realized by treating the surface of Si wafer by vapor of heavy water (D2O) containing a mixture of hydrofluoric and nitric acids. Treatment without deuterium generates an intense light emission band at the band-edge of Si, while the deuterium treatment alone creates a strong emission band at 1320 nm in the near infrared. It was found that the deuterium is actively involved in the formation of a nanostructured Si surface as evidenced from relative strength of the Si-O vibrational modes and presence of N-D bondings. The origin of this photon source was discussed in terms of oxygen related defect states and dislocations. The Si surface treated by Deuterium containing mixture exhibits a strong rectifying electrical activity as it is demonstrated by Schottky diodes fabricated on these wafers. Being compatible with mature silicon circuitry, the source may find applications in photonics and optoelectronics.

This presentation is on ultrafast photoluminescence recombination phenomena from black silicon consisting of quantum pillars produced by plasma ion etching. An ultrafast blue luminescence component competing with non-radiative recombination at surface defects was quantified as originating from the no-phonon recombination. This component involves two decay processes with a peak energy at around 480 nm, which have the fast component of about 10 ps followed by a component of about 50 ps decay time constant. The emission exhibits also a slow component in the red spectral region with a time constant of about 1.5-2.5 ns. When black Si is oxidized, the slow band at around 600 nm is enhanced in intensity to the detriment of blue-green emission band. This process results in a much slower sates assuming a 3-component exponential decay as measured by Streak camera. The ultrafast PL decay leads to a transfer of carriers to long-lived defect states as evidenced by a red emission at around 2 eV. Time-correlated single photon counting revealed a life-time of about few ns for these states. The results are discussed in terms of band structure modification at reduced sizes and defects at surfaces.

Today, users of existing commercial products expect longer battery life from the electronic products that they use in their daily activities. In addition to this, emerging technologies, especially in the Internet-of-Things domain require very long battery life time to be regarded as useful by their potential users. Energy harvesting methods which are used for extending the battery life or battery-free operation have been long studied by researchers. With the utilization of FD-SOI technology which can significantly reduce the leakage current in the stand-by mode of the electronic devices, more efficient energy harvesting power management integrated circuits can be designed. In this work, we present the design of an energy harvesting circuit which is optimized to benefit from the low leakage current characteristics of FD-SOI transistor.

Flash memory has been the dominant technology in non-volatile memory market for the last couple of decades. Along with down-scaling in the CMOS manufacturing process, industry and academia started to evaluate the use of alternative memory cell architectures so that the integration problems and the performance degradation seen in Flash memories can be overcome. Resistive Random-Access Memory (RRAM) technology has emerged as a promising option for manufacturing larger memory arrays in a smaller area and with higher performance. There are multiple types of RRAM memory cell architectures. HfO 2 -based memory cells are a type of oxide based RRAM memory cell architectures which rely on the resistance change of a dielectric material. In this work, an FPGA-based test platform which is designed to test 4Kbit RRAM samples is presented. The proposed system differs from other RRAM measurement platforms by its simplicity and the independency from a more sophisticated carrier module. The platform also allows development of security primitives which can benefit from the intrinsic characteristics of HfO 2 -based RRAM arrays.

HfO 2 based resistive RAM devices as the important candidates of future embedded non-volatile memory technology were investigated using state of art physical and electrical characterization methods. Memory stacks used for measurements, named MARS, having four different bottom electrode materials fabricated by CEA-LETI and ASM cooperation. The effects of bottom electrode metallization on Forming, switching and capacitive characteristics were studied and most efficient combinations were determined among these structures. It was observed that devices having atomic layer deposited (ALD) bottom electrode have some capacitive properties. Also TiN and TiWN bottom electrodes indicate promising switching characteristics and low operation voltages among others.

We review the results of silicon measurements, which we have performed on suboxide SiO x formed on n and p type Si wafers with different surface textures. Localized vibrational modes through Raman and FTIR, light emission properties by photoluminescence (PL), energy critical points for optical transitions, excited state dynamics and non-linear electrical properties can be used as effective methods in investigating thin oxide layers on Si. Infrared vibrational spectrum of Si-O-Si bondings in terms of transverse-optic (TO) and longitudinal-optic (LO) phonons indicating that disorder induced LO-TO optical mode coupling can be an effective tool in assessing the structural quality of the SiOx. Excited carrier dynamics and switching mechanisms can provide critical information about electronic quality of sub oxides for applications in CMOS circuits.