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1.
《Materials Science in Semiconductor Processing》2000,3(3):191-194
The effects of aluminum (Al) incorporation on the performance of a titanium nitride (TiN) diffusion barrier were investigated up to the temperature of 1000°C in the Cu/TixAlyNz/SiO2/Si structure. The thermal stability of the structure was evaluated by using four-point probe, X-ray diffraction, and Rutherford Backscattering Spectroscopy. The Cu/TixAlyNz/SiO2/Si system retained its structure up to 1000°C. The incorporation of Al into the TixNy film modified the microstructure of the TixNy film, especially the microstructure of grain boundaries in which oxide and nitride compounds of Al and Ti were formed during thermal annealing. As a result, the fast pathways for copper (Cu) diffusion were effectively blocked by these compounds and the stability of the barrier performance was enhanced up to 1000°C. 相似文献
2.
Titania nanoparticles (TNPs) were synthesized by a sol–gel method in our laboratory using titanium tetrachloride as the precursor and isopropanol as the solvent. The particles׳ size distribution histogram was determined using ImageJ software and the size of TNPs was obtained in the range of 7.5–10.5 nm. The nanoparticle with the average size of 8.5 nm was calculated using Scherrer׳s formula. Homogeneous and spherical nanoparticles were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM) and UV–visible spectroscopy (UV–vis). The X-ray powder diffraction analysis showed that the prepared sample (TNPs) has pure anatase phase. TNPs were deposited on porous polycrystalline silicon (PPS) substrate by electron beam evaporation. The TNPs thickness was 23±2 nm at 10−5 mbar pressure at room temperature. Porosity was performed by an anodization method. Since polycrystalline silicon wafers consist of different grains with different orientations, the pore size distribution in porous layer is non-uniform [1]. Therefore, the average diameter of pores can be reported in PPS layer analysis. Average diameter of pores was estimated in the range of 5 μm which was characterized by FESEM. The nanostructured thin films devices (Al/Si/PPS/TNPs/Al and Al/Si/PPS/Al) were fabricated in the sandwich form by aluminum (Al) electrodes which were also deposited by electron beam evaporation. Electrical measurements (I–V curves) demonstrated the semiconducting behavior of thin film devices. The gas sensitivity was studied on exposure to 10% CO2 gas. As a result, conductivity of devices increased on exposure to CO2 gas. The device with TNPs thin film (Al/Si/PPS/TNPs/Al) was more sensitive and, had better response and reversibility in comparison with the device without TNPs thin film (Al/Si/PPS/Al). 相似文献
3.
CNx:B thin films were prepared on titanium coated ceramic substrate by pulsed laser deposition technique (PLD). The microstructure of the film was examined using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The analyses indicate that the deposited samples are amorphous CNx:B thin films. Field electron emission characteristics of amorphous CNx:B thin films were measured in a vacuum chamber with a base pressure of about 3.2×10−5 Pa. The turn-on field of the film was 3.5 V/μm. The current density was 60 μA/cm2 at an electric field of 9 V/μm. The experimental results indicate that this film could be a promising material applicable to cold cathodes. 相似文献
4.
《Materials Science in Semiconductor Processing》2002,5(2-3):93-96
Thin PZT films are being developed for use in sensor and actuator application in micromechanical systems. For the use as sensor and actuator, it is desirable to combine high mechanical quality factor (Qm) with high piezoelectric constant (d) and high electro-mechanical coupling factor (kp). We fabricated PbZrxTi1−xO3-Pb(Mn,W,Sb,Nb)O3 (PZT-PMWSN) targets with variations in the Zr/Ti ratio. The dielectric and piezoelectric properties of PZT-PMWSN ceramics were investigated as a function of Zr/Ti ratio. At the Zr/Ti ratio of 0.52/0.48, the electrical coupling factor (kp) and the mechanical quality factor (Qm) showed a maximum value of 0.56 and 2344, respectively. The PZT-PMWSN thin film has been prepared on a Pt/Ti/SiO2/Si substrate using pulsed laser deposition method. The structural property was characterized with XRD, SEM and ferroelectric hysteresis loop measurement were used to characterize the electrical properties of PZT-PMWSN thin film. 相似文献
5.
A simple method for fabricating methane gas sensor of indium oxide (In2O3) transparent film was presented. Indium of 3 mg as a raw material was used to direct deposition of In2O3 film through a simplified thermal evaporation method. X-ray diffraction confirmed the cubic polycrystalline structure of the as prepared In2O3 film. The transmittance (T) of the film was recorded as high as 96%. The optical band gap (Eg) of the deposited film was found of 3.68 eV. The sensing properties of In2O3 film toward methane gas (CH4) were investigated at various operating temperatures and various gas concentrations. The prepared film highly detected CH4 gas at concentrations much lower than the explosive limit. Good performance (sensor response and stability) of the film for CH4 gas was exhibited. The film exhibited a good repeatability with repeating the gas sensing measurements towards CH4. 相似文献
6.
The study concerns the CNx thin films deposited by Low Pressure Hot Target Reactive Magnetron Sputtering (LP-HTRMS). The thin film resistance changes with relative humidity (RH) and optical properties have been studied in the range of 300-653 K. The temperature coefficients of resistivity changes were −2.5%/K at 300 K and −0.5%/K at 500 K. The activation energy of conductivity Eρ was found to be 0.21 eV in the case of unannealed sample and 0.44 eV when the sample was annealed at 653 K. The CNx thin films fastness to light was tested in the range of 200-2500 nm by measuring their transmittance. The calculations of absorption carrying out with Tauc formula proved the dominance of indirect optical transitions with Eg energy of 1.04 eV and direct transitions of Eg 2.05 eV. The UV radiation was fully absorbed and light transmission was ca. 90% in the range from visible radiation to far infrared of 1000-2500 nm. The CNx thin films showed the high resistance sensitivity to RH changes. At T = 300 K resistance changed from 882 M Ω for 36% RH to 386 k Ω for 85% RH. The CNx thin films susceptibility to humidity was observed in case of both DC and AC current (100 Hz to 10 kHz) measurements. The Si3N4 or SiC buffer adhesive layer was incorporated between CNx film and substrate and its influence on CNx electrical properties was observed. 相似文献
7.
《Applied Superconductivity》1999,6(10-12):483-489
We systematically investigated the characteristics of Nb/Al/AlOx/Al/AlOx/Nb junctions having a structure in which Al/AlOx films are placed in a Nb/Al/AlOx/Nb trilayer junction. The junction characteristics reflect superconductivity in the second Al film due to the proximity effect. As a result, the critical current density Jc and the hysteresis on its current–voltage (I–V) curve strongly depend on the transparencies of the AlOx barriers. The hystereses of the junctions are smaller than those of Nb/Al/AlOx/Nb junctions at the same Jc. Intrinsically overdamped junctions are also realized. The intrinsically overdamped junctions can considerably reduce an area occupied by a single gate. Furthermore, the spread of critical current Ic for the junctions, which have hystereses, connected in series, is ±1.2%. This shows that the junctions with additional Al/AlOx have uniform enough characteristics to be used in integrated circuits. 相似文献
8.
Jun Xiang Xing Huang Gengqi Lin Jiang Tang Chen Ju Xiangshui Miao 《Journal of Electronic Materials》2014,43(7):2658-2666
Cu(In1?x Ga x )Se2 (CIGS) thin films were deposited by a one-step radio frequency (RF) magnetron sputtering process using a quaternary CIGS target. The influence of substrate temperature on the composition, structure, and optical properties of the CIGS films was investigated. All the CIGS films exhibited the chalcopyrite structure with a preferential orientation along the (112) direction. The CIGS film deposited at 623 K showed significant improvement in film crystallinity and surface morphology compared to films deposited at 523 and 573 K. To simplify the manufacturing procedure of solar cells and avoid the use of the toxic element Cd, the properties of ZnS films prepared by RF sputtering were also investigated. The results revealed that the sputtered ZnS film exhibits good lattice matching with the sputtered CIGS film with significantly lower optical absorption loss. Finally, all-sputtered Cd-free CIGS-based heterojunction solar cells with the structure SLG/Mo/CIGS/ZnS/AZO/Al grids were fabricated without post-selenization. Furthermore, the results demonstrated the feasibility of using a full sputtering process for the fabrication of Cd-free CIGS-based solar cell. 相似文献
9.
S. Battiston S. Fiameni M. Saleemi S. Boldrini A. Famengo F. Agresti M. Stingaciu M.S. Toprak M. Fabrizio S. Barison 《Journal of Electronic Materials》2013,42(7):1956-1959
Magnesium silicide (Mg2Si)-based alloys are promising candidates for thermoelectric (TE) energy conversion for the middle to high range of temperature. These materials are very attractive for TE research because of the abundance of their constituent elements in the Earth’s crust. Mg2Si could replace lead-based TE materials, due to its low cost, nontoxicity, and low density. In this work, the role of aluminum doping (Mg2Si:Al = 1:x for x = 0.005, 0.01, 0.02, and 0.04 molar ratio) in dense Mg2Si materials was investigated. The synthesis process was performed by planetary milling under inert atmosphere starting from commercial Mg2Si pieces and Al powder. After ball milling, the samples were sintered by means of spark plasma sintering to density >95%. The morphology, composition, and crystal structure of the samples were characterized by field-emission scanning electron microscopy, energy-dispersive spectroscopy, and x-ray diffraction analyses. Moreover, Seebeck coefficient analyses, as well as electrical and thermal conductivity measurements were performed for all samples up to 600°C. The resultant estimated ZT values are comparable to those reported in the literature for these materials. In particular, the maximum ZT achieved was 0.50 for the x = 0.01 Al-doped sample at 600°C. 相似文献
10.
A. V. Zenkevich Y. Y. Lebedinskii N. S. Barantsev V. N. Nevolin V. S. Kulikauskas G. Scarel M. Fanciulli 《Russian Microelectronics》2006,35(4):210-215
The evolution of microstructure and phase structure of ultrathin HfO2 films on Si(100) under ultrahigh-vacuum annealing is investigated in situ by x-ray photoelectron spectroscopy (XPS) and low-energy ion scattering (LEIS). The onset temperature of degradation is found to depend on film thickness. It is established that, for HfO2 (4 nm)/SiO2 (1 nm)/Si(100) specimens, 5-min annealing at about 900°C causes silicon (LEIS evidence) to appear on the surface, the silicon being uncombined with oxygen or the metal (XPS evidence). A longer annealing at the same temperature produces HfSix; annealing at 950°C converts the entire HfO2 film into polycrystalline silicide whose grains are partly oriented as the Si substrate. With respect to annealing in a low-oxygen environment, the experimental results support a model whereby the degradation of an ultrathin HfO2 film starts with the formation of nanopores by clustering of oxygen vacancies, whose density increases sharply due to partial desorption of oxygen; HfOx with x < 2 then forms in the vicinity of vacancy clusters. It is concluded that the formation of hafnium silicide, the end product of HfO2 degradation, starts in Si surface areas at the bottom of nanopores. 相似文献
11.
《Materials Science in Semiconductor Processing》2012,15(1):6-10
Aluminum nitride (AlN) film, which is being investigated as a possible passivation layer in inkjet printheads, was deposited on a Si (1 0 0) substrate at 400 °C by radio frequency (RF) magnetron sputtering using an AlN ceramic target. Dependence on various reactive gas compositions (Ar, Ar:H2, Ar:N2) during sputtering was investigated to determine thermal conductivity. The crystallinity, grain size, and Al–N bonding changes by the gas compositions were examined and are discussed in relation to thermal conductivity. Using an Ar and 4% H2, the deposited AlN films were crystalline with larger grains. Using a higher nitrogen concentration of 10%, a near amorphous phase, finer morphology, and an enhanced Al–N bonding ratio were achieved. A high thermal conductivity of 134 W/mk, which is nine times higher than that of the conventional Si3N4 passivation film, was obtained with a 10% N2 reactive gas mixture. A high Al–N bonding ratio in AlN film is considered the most important factor for higher thermal conductivity. 相似文献
12.
Youhei Sugimoto Hideto Adachi Keisuke Yamamoto Dong Wang Hideharu Nakashima Hiroshi Nakashima 《Materials Science in Semiconductor Processing》2006,9(6):1031
High permittivity (high-k) gate dielectrics were fabricated using the plasma oxidation of Hf metal/SiO2/Si followed by the post-deposition annealing (PDA), which induced a solid-phase reaction between HfOx and SiO2. The oxidation time and PDA temperature affected the equivalent oxide thickness (EOT) and the leakage current density of the high-k dielectric films. The interfacial structure of the high-k dielectric film/Si was transformed from HfOx/SiO2/Si to HfSixOy/Si after the PDA, which led to a reduction in EOT to 1.15 nm due to a decrease in the thickness of SiO2. These high-k dielectric film structures were investigated by X-ray photoelectron spectroscopy. The leakage current density of high-k dielectric film was approximately four orders of magnitude lower than that of SiO2. 相似文献
13.
Backscattering spectrometry with 2.3 and 2.0 MeV 4He+ have been used to study the role of Cr as a barrier in the interaction of Pd2Si with Al. Samples of palladium silicide (Pd2Si) grown on Si 〈100〉 single crystal and Al evaporated on top, in that order, showed a substantial intermixture of Pd2Si and Al, and a non-uniform erosion of the Pd2SiSi interface when heated between 300 and 450°C. With a thin layer of Cr(300–1500 Å) interposed between Pd and Al intermixing of Pd2Si and Al was suppressed for temperatures up to 500°C and times up to 2 hr. In these samples distinct sublayers of Pd2Si, CrSi2 and CrAlx (where the values of x depends on the relative thicknesses of Al and Cr) are formed. We have noted that whenever there is a thin unreached Cr layer the spectra of the distinct sublayers show sharp boundaries. 相似文献
14.
0.25 μm CdxZn1−xS thin films were deposited on Si and glass substrates by using a chemical Spray Pyrolysis technique (CSP). Measurements of the absorption spectrum of the film were carried out. The values of band gaps (Eg) are calculated from the absorption spectrum. X-ray diffraction (XRD) of the CdxZn1−xS thin films on Si and glass substrates was carried out. The full width at half-maximum (FWHM)) of diffraction peak was calculated to be about 0.640, which showed that it is a polycrystalline thin film. A CdxZn1−xS Metal–Semiconductor–Metal (MSM) photodetector with nickel (Ni) contact electrodes was then fabricated. The electrical property of the Ni/CdxZn1−xS/Si and Ni/CdxZn1−xS/glass detectors was investigated using the current–voltage (I–V) measurements. The barrier heights ϕΒ of Ni/CdxZn1−xS/Ni MSM on Si and glass substrates were 0.551 eV and 0.593 eV, respectively with an applied bias voltage of 3 V. 相似文献
15.
Effect of annealing temperature on the characteristics of sol–gel-driven Ta ax La(1?a)x O y thin film spin-coated on Si substrate as a high-k gate dielectric was studied. Ta ax La(1?a)x O y thin films with different amounts of a were prepared (as-prepared samples). X-ray diffraction measurements of the as-prepared samples indicated that Ta0.3x La0.7x Oy film had an amorphous structure. Therefore, Ta0.3x La0.7x O y film was chosen to continue the present studies. The morphology of Ta0.3x La0.7x O y films was studied using scanning electron microscopy and atomic force microscopy techniques. The obtained results showed that the size of grain boundaries on Ta0.3x La0.7x O y film surfaces was increased with increasing annealing temperature. Electrical and optical characterizations of the as-prepared and annealed films were investigated as a function of annealing temperature using capacitance–voltage (C–V) and current density–voltage (J–V) measurements and the Tauc method. The obtained results demonstrated that Ta0.3x La0.7x O y films had high dielectric constant (≈27), wide band gap (≈4.5 eV), and low leakage current density (≈10?6 A/cm2 at 1 V). 相似文献
16.
The low-temperature electrical and magnetotransport characteristics of partially relaxed Si/Si1 ? x Ge x heterostructures with an electron conduction channel in an elastically strained nanoscale silicon layer are investigated. It is demonstrated that the electron gas in the system exhibits 2D properties. A dependence of the conductivity along layers in the system on the degree of elastic-stress relaxation in it is observed. To understand the observed regularities, the potential and the electron distribution over the structure layers are calculated in detail for samples with different layer strains and doping levels. For the structure with x = 0.25, the parameters of the potential barrier and characteristics of the quantum well formed in the Si layer are estimated. It is established that the characteristics of the potential formed near interfaces strongly depend on the initial parameters of the system, in particular, on the degree of the plastic relaxation of elastic stresses and on the doping level. The formation of a thin tunneling-transparent barrier near the upper interface can lead to the redistribution of electrons between the 2D and 3D conduction channels in the structure, which ensures the spread of the measured transport characteristics of the samples during the measurements. The interlayer tunneling transitions of carriers from the 2D state in the Si transport channel to the 3D state of the Si1 ? x Ge x crystal matrix, which are separated by a tunneling-transparent potential barrier near the heterointerface, were observed for the first time during transport in the direction transverse to the layer plane. 相似文献
17.
It is investigated for the effect of a ferroelectric Si:HfO2 thin film on the resistive switching in a stacked Pt/Si:HfO2/highly-oxygen-deficient HfO2-x/Pt structure. Improved resistance performance was observed. It was concluded that the observed resistive switching behavior was related to the modulation of the width and height of a depletion barrier in the HfO2-x layer, which was caused by the Si:HfO2 ferroelectric polarization field effect. Reliable switching reproducibility and long data retention were observed in these memory cells, suggesting their great potential in non-volatile memories applications with full compatibility and simplicity. 相似文献
18.
M.A. PampillónP.C. Feijoo E. San Andrés M. Toledano-LuqueA. del Prado A.J. BlázquezM.L. Lucía 《Microelectronic Engineering》2011,88(7):1357-1360
Amorphous Gd2O3 and Sc2O3 thin films were deposited on Si by high-pressure sputtering (HPS). In order to reduce the uncontrolled interfacial SiOx growth, firstly a metallic film of Gd or Sc was sputtered in pure Ar plasma. Subsequently, they were in situ plasma oxidized in an Ar/O2 atmosphere. For post-processing interfacial SiOx thickness reduction, three different top metal electrodes were studied: platinum, aluminum and titanium. For both dielectrics, it was found that Pt did not react with the films, while Al reacted with them forming an aluminate-like interface and, finally, Ti was effective in scavenging the SiO2 interface thickness without severely compromising gate dielectric leakage. 相似文献
19.
《Organic Electronics》2008,9(5):916-920
Organic bistable devices with an Al/Alq3/n-type Si structure are investigated at different deposition rates of Alq3 thin film. We can obtain current–voltage characteristics of these devices similar to those of metal/organic semiconductor/metal structures that are widely used for organic bistable devices. The bistable effect of the Al/Alq3/n-type Si structure is primarily caused by the interface defects at the Al/Alq3 junction. Moreover, the electrical properties of these devices can be modified and controlled by utilizing the appropriate deposition rates of the Alq3 thin film by thermal deposition. XPS, AFM, and GIXRD measurements are performed to characterize the properties of Alq3 thin film and Alq3/Al interface. This type of devices involves an extremely simple fabrication process and offers great potential in future advanced organic electronics. 相似文献
20.
Yota Takamura Kengo Hayashi Yusuke Shuto Satoshi Sugahara 《Journal of Electronic Materials》2012,41(5):954-958
A high-quality Co2FeSi (CFS)/SiO
x
N
y
/Si tunnel junction was fabricated, in which the SiO
x
N
y
barrier layer was formed by radical oxynitridation of an Si(100) substrate and the CFS electrode was formed by silicidation
of an Fe/Co/amorphous-Si multilayer deposited on the barrier layer. The ultrathin SiO
x
N
y
barrier layer completely blocked diffusion of Co and Fe atoms into the Si substrate during rapid thermal annealing (RTA)
for the silicidation. X-ray diffraction investigations clarified that the CFS film on the ultrathin SiO
x
N
y
barrier layer exhibited a highly (110)-oriented texture structure and that the film had the L21 structure with a high degree of L21 order. High resolution cross-sectional transmission electron microscopy investigations revealed that the CFS/SiO
x
N
y
interface was atomically flat and that the crystal lattice of the CFS film was directly grown on the SiO
x
N
y
surface without degradation of the crystallinity at the interface. 相似文献