(nano & Micro Electronics)

An ion sensitive field effect transistor can outperform conventional ion-selective electrodes. Thus, a zinc oxide (ZnO) nanowire field effect transistor (NWFET) pH sensor was fabricated and measured. The sensor contained a channel with 1.710 18 cm -3 donor concentration and 100 ZnO nanowires in parallel, each with the following dimensions: 10 µm120 nm20 nm. The active channel is passivated with an 18 nm Al2O3 layer. The device was measured under a controlled environment with and without pH solutions. The pH range was 3-9 with a sensitivity of 2.48 mV to 10.3 mV. The voltage sensitivity translates to a percentage value of 15%. The measurements obtained before and after the pH solution treatment demonstrate the possibility of re-use of the device by rinsing and brushing the sensing layer.

Amorphous lanthanum aluminate thin films were deposited by atomic layer deposition on Si(1 0 0) using La(i PrCp) 3 , Al(CH 3) 3 and O 3 species. The effects of post-deposition rapid thermal annealing on the physical and electrical properties of the films were investigated. High-temperature annealing at 900°C in N 2 atmosphere leads to the formation of amorphous La-aluminosilicate due to Si diffusion from the substrate. The annealed oxide exhibits a uniform composition through the film thickness, a large band gap of 7.0 ± 0.1 eV, and relatively high dielectric constant (j) of 18 ± 1.

Silicon Nitride (Si3N4) sacrificial replacement gate were fabricated using the nitride cast method. The purpose of the Si3N4 cast was to develop a stand-in gate, which is then replaced by metal after source/drain formation. The technique was developed by using hot phosphoric acid etch (at 160°C) to form nitride cast. The phosphoric acid has nitride etch rate of about 4nmlmin and good selectivity over oxide and good uniformity over silicon. A cross sectional analysis was done to view process steps.

The high-k oxides ZrO 2 , and LaAlO 3 can be used as dielectrics in metal-oxidesemiconductor (MOS) devices. Dielectrics are commonly grown with atomic layer deposition (ALD), often leading to unintentional incorporation of impurities such as carbon from the metal-organic precursors. Experiments indicated that carbon can be a significant cause of leakage current. We investigate this problem using density functional theory with a hybrid functional. Our results show that carbon substituting on the cation site undergoes an off-site displacement and forms close sp bonds with three oxygen atoms in ZrO 2 and LaAlO 3. We calculate the corresponding defect levels, and in order to determine the impact on MOS devices we align the band structures of the dielectrics with those of the semiconductor channel materials (including GaN, Si, and GaAs). We find that carbon incorporation leads to defect levels near the conduction-band minimum of the channel materials, proving potentially detrimental for n-type devices. Intriguingly, we find that the defect levels of these carbon centers in a variety of oxides and semiconductors are aligned at roughly-3.5 eV below the vacuum level.

The high-k oxides ZrO 2 , and LaAlO 3 can be used as dielectrics in metal-oxidesemiconductor (MOS) devices. Dielectrics are commonly grown with atomic layer deposition (ALD), often leading to unintentional incorporation of impurities such as carbon from the metal-organic precursors. Experiments indicated that carbon can be a significant cause of leakage current. We investigate this problem using density functional theory with a hybrid functional. Our results show that carbon substituting on the cation site undergoes an off-site displacement and forms close sp bonds with three oxygen atoms in ZrO 2 and LaAlO 3. We calculate the corresponding defect levels, and in order to determine the impact on MOS devices we align the band structures of the dielectrics with those of the semiconductor channel materials (including GaN, Si, and GaAs). We find that carbon incorporation leads to defect levels near the conduction-band minimum of the channel materials, proving potentially detrimental for n-type devices. Intriguingly, we find that the defect levels of these carbon centers in a variety of oxides and semiconductors are aligned at roughly-3.5 eV below the vacuum level.

GaAs nanowires were passivated by AlInP shells grown by the Au-assisted vapor-liquid-solid method in a gas source molecular beam epitaxy system. Transmission electron microscopy confirmed a core-shell GaAs-AlInP structure. Current-voltage measurements on ensemble nanowires indicated improved carrier transport properties in the passivated nanowires as compared to their unpassivated counterpart. Similarly, individual nanowires showed improved photoluminescence intensity upon passivation. A detailed model is presented to quantify the observed improvements in nanowire conduction and luminescence in terms of a reduction in surface charge trap density and surface recombination velocity upon passivation. The model includes the effects of high-level injection, bulk recombination, and surface recombination. The model can be used as a tool for assessing various passivation methods. V

Amorphous lanthanum aluminate thin films were deposited by atomic layer deposition on Si(1 0 0) using La(i PrCp) 3 , Al(CH 3) 3 and O 3 species. The effects of post-deposition rapid thermal annealing on the physical and electrical properties of the films were investigated. High-temperature annealing at 900°C in N 2 atmosphere leads to the formation of amorphous La-aluminosilicate due to Si diffusion from the substrate. The annealed oxide exhibits a uniform composition through the film thickness, a large band gap of 7.0 ± 0.1 eV, and relatively high dielectric constant (j) of 18 ± 1.

Amorphous lanthanum aluminate thin films were deposited by atomic layer deposition on Si(1 0 0) using La(i PrCp) 3 , Al(CH 3) 3 and O 3 species. The effects of post-deposition rapid thermal annealing on the physical and electrical properties of the films were investigated. High-temperature annealing at 900°C in N 2 atmosphere leads to the formation of amorphous La-aluminosilicate due to Si diffusion from the substrate. The annealed oxide exhibits a uniform composition through the film thickness, a large band gap of 7.0 ± 0.1 eV, and relatively high dielectric constant (j) of 18 ± 1.

The aim of our research project is to achieve a potentiometric multi-sensor platform, consisting of ion sensitive field effect transistors ISFET and MOSFET, which channel is a nanowire or a network of horizontal Silicon nanowires and whose gate insulator is alumina Al2O3 deposed by Atomic Layer deposition ALD. This microdevice will provide chemical and biological analyses in the liquid phase, in microfluidic channels.

Electrical power bears an important role in the production of industrial economy. During start up process in motoring Power factor might be poor due to inductive components such as welding machines, induction motors, voltage regulators power transformers, and induction furnaces, choke coils etc. it can lead to drastic loss with poor power factor for any plant due to which switch gears in thermal can face. So, it becomes necessity to somewhat improvement of power factor and it's thoroughly under control. Power factor can be improved or controlled by using capacitance as reactive power. There are capacitor banks, for reactive power to improve power factor and for their correction too which leads to plant management economically and technically too. So various aspect for improving power factor have been there in this very paper. APFC which means active power factor correction-it's basic and controlling methods have been discussed in this paper. Moreover Proteus and Multisim has been used for the simulations which are given below.

Keywords: zinc oxide, field effect transistor, nanowire, device, nanosensor, lysozyme (LYSO), phosphate buffered saline (PBS), bovine serum albumin (BSA) Abstract: A highly sensitive low-doped ZnO nanowire field effect transistor (NWFET) biosensor has been fabricated and measured. The low doped biosensor with NWFET transducer was used to sense charge of the following substances: lysozyme (LYSO), phosphate buffered saline (PBS), bovine serum albumin (BSA). It achieved maximum sensitivity of-543.2 % for the PBS-LYSO protein and 13,069 % for the PBS-BSA protein. These results were achieved because the electrical measurement and characterisation was focused on the charge effect of the LYSO and BSA acting on the ZnO nanowire subthreshold region. The nano-fabrication process is stable and reproducible. The high sensitivity of the ZnO NWFET biosensor can be exploited for selective analyte detection by functionalizing the nanowire surface with antibodies and/or other biomolecular probe molecules.

In this paper a new circuit for improving the input power factor is proposed. The proposed circuit is constructed based on active elements and it is called Active Impedance Power Factor Correction (AIPFC). The operation of the AIPFC is based on a PWM technique and it will be modeled and tested using a MATLAB Program (SIMULINK). In this case, the AIPFC model is installed in two different power electronics applications. The simulation results for both applications will be presented and compared with the circuit that the AIPFC is not installed. In both applications the Input Power Factor (PF in) and the Total Harmonic Distortion (THD) will be recorded. In addition, the proposed AIPFC is implemented and tested and the experimental result will be presented. KEYWORDS POWER FACTOR CORRECTION (PFC), PWM BASED INVERTER, TOTAL HARMONIC DISTORTION (THD).

The fundamental issue of oxygen stoichiometry in oxide thin film growth by subliming the source oxide is investigated by varying the additionally supplied oxygen during molecular beam epitaxy of RE 2 O 3 (RE = Gd, La, Lu) thin films on Si(111). Supplying additional oxygen throughout the entire growth was found to prevent the formation of rare earth silicides observed in films grown without an oxygen source. Postgrowth vacuum annealing of oxygen stoichiometric films did not lead to silicide formation thereby confirming that the silicides do not form as a result of an interface instability at growth temperature in vacuum but rather due to an oxygen deficiency in the source vapor. The average oxygen deficiency of the rare-earth containing species in the source vapor was quantified by the 18 O tracer technique and correlated with that of the source material, which gradually decomposed during sublimation. Therefore, any oxide growth by sublimation of the oxide source material requires additional oxygen to realize oxygen stoichiometric films.

Due to the ongoing miniaturization of semiconductor devices new gate dielectrics are required for future applications. In this work we investigated hafnium silicide as a pre-system for hafnium oxide, one of the most promising candidates. One of the major problems of HfO 2 -films on silicon is the formation of hafnium silicide at the HfO 2 =Si interface. Therefore, ultrathin films of the system HfSi on Sið1 0 0Þ with a systematic varied thickness from 3 to 30 Å were prepared. Measurements were conducted by means of X-ray photoelectron spectroscopy and low energy electron diffraction (LEED). Also full 2p X-ray photoelectron diffraction (XPD) patterns with high spectral resolution were recorded. Against other reports related to thicker films, several heating cycles showed no phase transitions of the ultrathin films. However, above temperatures of 630 C an island formation is strongly indicated. The experimental XPD patterns are compared to simulated patterns of model structures. For the first time we present a modification of the C49 structure a possible structure for ultrathin HfSi 2 -films on bulk Si. As an outlook possibilities for preparing the system HfO 2 =Sið1 0 0Þ are introduced. r

In order to increase the switching speed and the efficiency of modern semiconductor devices a further down scaling is desired. Thus, the SiO 2 gate dielectric might be replaced by layers of a material with a much higher dielectric constant like HfO 2 . A major problem of the system HfO 2 /Si(1 0 0) is the silicidation of hafnium at the interface. Therefore, ultrathin films (3-30Å) of HfSi 2 on Si(1 0 0) were investigated by photoelectron spectroscopy, low-energy electron diffraction and X-ray photoelectron diffraction. Synchrotron light with an energy of hν = 180 eV was used for excitation. First results were obtained using a Mg X-ray tube (hν = 1253.6 eV). In order to determine the structure of the films, the recorded photoelectron diffraction patterns were compared to computer simulations of model structures. The simulations for the low-energy measurements were performed using the program MSPHD. As a result a modified zirconium silicide structure is presented in order to describe the structure of ultrathin HfSi 2 films on Si(1 0 0).

In this work, we demonstrate a wafer-level zinc oxide (ZnO) nanowire fabrication process using ion beam etching and a spacer etch technique. The proposed process can accurately define nanowires without an advanced photolithography and provide a high yield over a 6-inch wafer. The fabricated nanowires are 36 nm wide and 86 nm thick and present excellent transistor characteristics. The pH sensitivity using a liquid gate was found to be 46.5 mV/pH, while the pH sensitivity using a bottom gate showed a sensitivity of 366 mV/pH, which is attributed to the capacitance coupling between the top-and bottom-gates. The maximum process temperature used in the fabrication of the nanowire sensors is optimized to be 200 °C (after wet oxidation) which makes it applicable to low-cost substrates such as glass and plastic. The Ion Beam Etching (IBE) process in this work is shown to be highly transferable and can therefore be directly used to form nanowires of different materials, such as polysilicon and molybdenum disulfide, by only an adjustment of the etch time.

We fabricated unpassivated and passivated zinc oxide (ZnO) nanowire field effect transistors (NWFETs) using conventional top-down method of remote plasma atomic layer deposition and anisotropic dry etch. This paper investigates the effect of Al2O3 passivation on the electrical characteristics of the ZnO NWFETs. Measured unpassivated ZnO NWFETs show a threshold voltage of 6.5 V, drain current on/off ratio of 106 and field effect mobility of 31.4 cm2/V s. Passivated ZnO NWFETs demonstrate threshold voltage shift to −10 V, drain current on/off ratio of 104 and improvement of mobility of 35.5 cm2/V s. The passivated device results indicate suitability for biosensing applications.

We report on growth behavior, structure, thermal stability and electrical properties of ultrathin (,10 nm) hafnium oxide films deposited by atomic layer deposition using sequential exposures of HfCl and H O at 300 8C on a bare silicon surface 4 2 or a thin thermally grown SiO -based interlayer. Compared to good quality continuous films deposited on SiO surfaces, 2 2

Rare earth oxides (REOs) have lately received extensive attention in relation to the continuous scaling down of non-volatile memories (NVMs). In particular, La 2 O 3 films are promising for integration into future NVMs because they are expected to crystallize above 400°C in the hexagonal phase (h-La 2 O 3 ) which has a higher j value than the cubic phase (c-La 2 O 3 ) in which most of REOs crystallize. In this work, La 2 O 3 films are grown on Si by atomic layer deposition using La(C 5 H 5 ) 3 and H 2 O. Within the framework of the h-La 2 O 3 formation, we systematically study the crystallographic evolution of La 2 O 3 films versus annealing temperature (200-600°C) by Fourier transform infrared spectroscopy (FTIR) and grazing incidence X-ray diffraction (GIXRD). As-grown films are chemically unstable in air since a rapid transformation into monoclinic LaO(OH) and hexagonal La(OH) 3 occurs. Vacuum annealing of sufficiently thick (>100 nm) La(OH) 3 layers induces clear changes in FTIR and GIXRD spectra: c-La 2 O 3 gradually forms in the 300-500°C range while annealing at 600°C generates h-La 2 O 3 which exhibits, as inferred from our electrical data, a desirable j $ 27. A quick transformation from h-La 2 O 3 into La(OH) 3 occurs due to H 2 O absorption, indicating that the annealed films are chemically unstable. This study extends our recent work on the h-La 2 O 3 formation.

Micro-flexography printing was developed in patterning technique from micron to nano scale range to be used for graphic, electronic and bio-medical device on variable substrates. In this work, lanthanum oxide (La 2O3) has been used as a rare earth metal candidate as depositing agent. This metal deposit was embedded on Carbon (C) and Silica (Si) wafer substrate using Magnetron Sputtering technique. The choose of Lanthanum as a target is due to its wide application in producing electronic devices such as thin film battery and printed circuit board. The La 2O3 deposited on the surface of Si wafer substrate was then analyzed using Angle Resolve X-Ray Photoelectron Spectroscopy (ARXPS). The position for each synthetic component in the narrow scan of Lanthanum (La) 3d and O 1s are referred to the electron binding energy (eV). From the La 3d narrow scan, it revealed that the oxide species of this particular metal is mainly contributed by La2O3 and La(OH)3. The information of oxygen species, O 2component from O 1s narrow scan indicated that there are four types of species which are contributed from the bulk (O 2-), two chemisorb component (La2O3) and La(OH)3 and physisorp component (OH) -. Here, it is proposed that from the adhesive and surface chemical properties of La is suitable as an alternative medium for micro-flexography printing technique in printing multiple fine solid lines at nano scale. Hence, this paper will describe the capability of this particular metal as rare earth metal in a practice of microflexography printing. The review of other parameters contributing to print fine lines will also be described later.

The role of plasma etching in the semiconductor technology upon switching from the microscale to the nanoscale dimensions is discussed. The continuing miniaturization has led to impossibility of simple scaling and further use of the conventional materials of silicon microelectronics. New materials and functional elements of integrated circuits call for revision of the existing plasma etching processes and development of novel processes. This situation brings plasma etching along with photolithography to the forefront of nanoelectronics technology.

Рассматриваются особенности динамических эффектов в электронных волнах потока, движущегося в периодическом волноводе. С помощью эквивалентного описания полей волновода показывается, что в зависимости от вида резонанса поля между периодическими неоднородностями характерные частоты электронного потока могут увеличиваться или уменьшаться под воздействием несинхронных высокочастотных полей.

The authors describe a technique of numerical simulation for pulsed unsteady low-frequency microwave processes in periodic transmission lines and a periodic waveguide with electron flux. An opportunity for pulsed microwave generation is shown and the transition from one or a few generation pulses (spikes) to a mode of long microwave pulses is considered.

A novel explanation of the low values of work function in case of activated (partly deoxidized) polycrystalline oxides of alkali and alkaline earth metals is offered. Use of the metallic plasma model to the conducting oxides leads to the following values (in eV): 1.00, 1.67, 1.50, 1.44, 1.46 and 1.59 for activated Cs 2 O, CaO, SrO, BaO, Y 2 O 3 and La 2 O 3 , respectively. The main reason of low work function of the oxide cathodes is very low density of free electrons in the emitting surface layer. #

Ultrathin amorphous Hf-aluminate ͑Hf-Al-O͒ films have been deposited on p-type ͑100͒ Si substrates by pulsed-laser deposition using a composite target containing HfO 2 and Al 2 O 3 plates. Transmission electron microscopy observation of Hf-Al-O films showed that the amorphous structure of Hf-Al-O films was stable under rapid thermal annealing at temperatures up to at least 1000°C. Capacitance-voltage measurement of a 38 Å Hf-Al-O film revealed that the relative permittivity of the film was about 16. Such a film showed very low leakage current density of 4.6ϫ10 Ϫ3 A/cm 2 at 1 V gate bias. The Hf-Al-O film under optimized condition did not show any significant interfacial layer at the interface and an equivalent oxide thickness of less than 10 Å has been achieved. The formation of Hf-O and Al-O bonds in the film was revealed by x-ray photoelectron spectroscopy.

Ultrathin amorphous Hf-aluminate ͑Hf-Al-O͒ films have been deposited on p-type ͑100͒ Si substrates by pulsed-laser deposition using a composite target containing HfO 2 and Al 2 O 3 plates. Transmission electron microscopy observation of Hf-Al-O films showed that the amorphous structure of Hf-Al-O films was stable under rapid thermal annealing at temperatures up to at least 1000°C. Capacitance-voltage measurement of a 38 Å Hf-Al-O film revealed that the relative permittivity of the film was about 16. Such a film showed very low leakage current density of 4.6ϫ10 Ϫ3 A/cm 2 at 1 V gate bias. The Hf-Al-O film under optimized condition did not show any significant interfacial layer at the interface and an equivalent oxide thickness of less than 10 Å has been achieved. The formation of Hf-O and Al-O bonds in the film was revealed by x-ray photoelectron spectroscopy.

Due to the ongoing miniaturization of semiconductor devices new gate dielectrics are required for future applications. In this work we investigated hafnium silicide as a pre-system for hafnium oxide, one of the most promising candidates. One of the major problems of HfO 2 -films on silicon is the formation of hafnium silicide at the HfO 2 =Si interface. Therefore, ultrathin films of the system HfSi on Sið1 0 0Þ with a systematic varied thickness from 3 to 30 Å were prepared. Measurements were conducted by means of X-ray photoelectron spectroscopy and low energy electron diffraction (LEED). Also full 2p X-ray photoelectron diffraction (XPD) patterns with high spectral resolution were recorded. Against other reports related to thicker films, several heating cycles showed no phase transitions of the ultrathin films. However, above temperatures of 630 C an island formation is strongly indicated. The experimental XPD patterns are compared to simulated patterns of model structures. For the first time we present a modification of the C49 structure a possible structure for ultrathin HfSi 2 -films on bulk Si. As an outlook possibilities for preparing the system HfO 2 =Sið1 0 0Þ are introduced. r

The paper describes the application of X-ray photoelectron spectroscopy (XPS) based method to quantify changes in the electric dipole formed at the metal/dielectric interface following heat treatments of metaloxide-semiconductor (MOS) stack in different environments. The presented results on Me (Me = Au, Ni)/ dielectric (dielectric = HfO 2 , LaAlO 3 ) evidence the oxygen vacancies generated in dielectric contribute to the effective work function changes.

Amorphous lanthanum aluminate thin films were deposited by atomic layer deposition on Si(1 0 0) using La( i PrCp) 3 , Al(CH 3 ) 3 and O 3 species. The effects of post-deposition rapid thermal annealing on the physical and electrical properties of the films were investigated. High-temperature annealing at 900°C in N 2 atmosphere leads to the formation of amorphous La-aluminosilicate due to Si diffusion from the substrate. The annealed oxide exhibits a uniform composition through the film thickness, a large band gap of 7.0 ± 0.1 eV, and relatively high dielectric constant (j) of 18 ± 1.

Certain results of experimental investigations of recent years devoted to new materials of under gate dielectrics and gates for field effect MOS transistors based on high k metal oxides and metal layers, respectively, are presented. The laboratory technology of fabrication of a functional field effect transistor based on the TaN/LaAlO 3 /Si structure is described briefly.

Ülkelerin gücü 17. -18. yüzyıl: Bilimsel geliĢme  Teknoloji Teknolojiyi kullanan ülkeler güçlendi ve ön plana çıktılar ÜRETĠM TEKNOLOJĠLERĠ  Makroskopik teknolojiler (tarım, metalurji, gemi inşat, makina imalat, otomotiv.. tekstil) katma değer=1  Mikroteknolojiler (mikroelektronik, bilgisayar..) katma değer=100  Nanoteknoloji katma değer=10.000 Türkiye her yıl 15 gram DNA bazlı kimyasal ilaç ithal etmek için 400 Milyon Dolar ödüyor.

"A method and apparatus is described for combined deposition of thin films of materials from an ion beam source and a molecular beam source in a single reactor.

SUMMARY OF THE INVENTION

The method and apparatus of the invention comprise the combination of MBE and IBD, in a unique and novel way, to create a new materials processing system, i.e., Combined Ion and Molecular Beam Deposition (CIMD). CIMD allows the growth of novel artificially structured materials and the study of thin films in processing conditions that neither MBE nor IBD, used independently, presently permit. The general concept of CIMD is to simultaneously use a neutral molecular beam and a focused low energy ion beam to form layered films, such as epitaxial heterostructures. Simultaneous use of both types of beams allows the fabrication of structures and epitaxial and/or compound films at lower temperatures, or higher rates, than obtainable when MBE is used alone. The CIMD technique thus combines the main attraction of IBD, i.e., the enhancement of kinetic processes in the rate of formation of a thin film phase at a given temperature, while retaining important advantageous features of MBE.

For the growth of elemental films, CIMD provides a unique process for the formation of epitaxial heterostructures at low temperatures. The molecular beam provides a high flux of the desired material, while an ion beam of the same species is used to enhance atomic mobilities at or near the growing interface. This enhancement occurs through exchange of the kinetic energy of the ions with the substrate atoms and the deposited atoms, during collisional processes. The kinetic energy of ions is used to reduce the temperature needed for epitaxial growth, effectively reducing undesirable thermal diffusion, de-adsorption and thermal decomposition effects. These temperature dependent effects constitute a heretofore unresolved problem in the formation of sharp modulation doping profiles on Si and compound semiconductor."