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The Electric Characteristics of Thin Oxynitride Films Prepared by Liquid Phase Deposition and Quality Improvement by Biasing during the GrowthLin, Shuo-Yen 04 July 2000 (has links)
ASTRACT
Using an aqueous solution of ammonia hydroxide aqua, hydrosilicofluoric acid and boric acid, an oxynitride film can be deposited. The deposition rate and refractive index increase with the mole concentration of ammonia hydroxide aqua. However, the refractive index decreases as the mole concentration of ammonia hydroxide aqua becomes too high. The leakage current density as a function of mole concentration of ammonia hydroxide aqua was studied. The best experimental condition is found that incorporating ammonia hydroxide aqua of 0.8M will get good results.
The SIMS depth profiles shows nitrogen and hydrogen concentration accumulate at SiON/Si interface. A deposition model is proposed and LPD-SiON can be suggested that it is a combination of N-less LPD-SiON film and N-rich accumulated layer at the interface. The best characteristics of LPD-SiON film are in the range of 110Å-thick to 210Å-thick. When the thickness scales down to 110Å, all the properties become poor.
Photo-LPD-SiON process is proposed as a reference of Photo-LPD-SiO2. By mercury lamp illumination, the performances of J-E relationship and C-V characteristic become better. Nitrogen atomic concentration can increase by photo-enhancement checked by analysis of SIMS depth profile and FTIR spectrum.
A novel technique of LPD process with applying a bias during the growth is proposed and it is called Bias-LPD-SiON. A model of Bias-LPD-SiON deposition mechanism is also proposed. On the negative bias substrate, high nitrogen atomic concentration can be attained. The J-E characteristic at positive bias of 0.1V and negative bias in a range of 0.1V to 1V are better than traditional LPD-SiON film. Then, the deposition rate of positive bias and negative bias LPD-SiON films at 0.1V can reach 32Å/min and 26Å/min, respectively. Therefore, high quality and high deposition rate can be prepared by Bias-LPD-SiON.
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High Dielectric Constant and Low Leakage Current TiO2 Thin Films on SiliconWu, Tsung-Shiun 13 July 2004 (has links)
As the electronic device scale down, replacing conventional SiO2 with high dielectric constant material is very important. Due to its have high dielectric constant (£`// = 170, £`¡æ = 90), high refractive index (~2.5) and high chemical stability. TiO2 is a promising candidate for fabricating thin dielectrics in dynamic random access memory (DRAM) storage capacitors and as gate dielectrics of metal-oxide-semiconductor field effect transistor (MOSFET) without the problem of conventional SiO2 thickness scaling down in ULSI processes because of its high dielectric constant.
TiO2 thin films deposited on p-type (100) Si substrate were investigated by a cold wall horizontal MOCVD system using Ti(i-OC3H7)4, N2O as precursors in the deposition temperature range from 400 ¢J to 650 ¢J.
XRD results indicate that the structures of TiO2 films are polycrystalline and mixture of anatase and rutile phases coexist in the film at the deposition temperature of 650 ¢J. Electrical properties are strongly influenced by deposition temperature. The electrical properties of as-deposited TiO2 films can be improved by annealing treatment. The TiO2 film at the deposition temperature of 650 ¢J has the highest dielectric constant of 100.3 and at the deposition temperature of 550 oC has the lowest leakage current density of 2.07¡Ñ10-7 A/cm2 under the applied electric field of 5 MV/cm after annealing for 20 minutes at 750 ¢J in O2 ambient.
In order to obtain the better electrical properties of TiO2 films on Si substrate, LPD-SiO2 thin films were deposited on the polycrystalline MOCVD-TiO2 films. The minimum equivalent oxide thickness of LPD-SiO2/post-annealed TiO2 film is 51.13
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Study of NiO Electrochromic Films Prepared by Liquid Phase DepositionFan, Cho-Han 26 July 2005 (has links)
The electrochromic materials are capable of changing their optical properties (transmittance and/or reflectance) under applied electric potentials; when that potential is stopped or it goes on reverse, these materials keep or return to its original optical state in a reversible way. The variation of the optical properties is caused by of insertion/extraction of cations in the electrochromic film.
The as-deposited LPD-NiO film is also uniform and transparent. The LPD-NiO film is light gray after coloring; the transparency ratio (£GT%) can reach about 48% at the wavelength of 550 nm. After annealing in 300oC, the bleached state almost approaches that of original state before colored. We expect that the electrochromic device combined LPD-TiO2 and LPD-NiO films can enhance the coloration efficiency.
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Zinc Oxide Nanostructures Prepared by Liquid Phase DepositionChen, Po-Chun 19 July 2006 (has links)
Both zinc oxide rods and zinc hydroxide slices grown on gallium arsenide in the aqueous solution of zinc nitrate and hexamethylenetetramine were studied. Zinc hydroxide is responsible for the growth of slices. Hexamethylenetetramine-zinc nitrate organometallic complex acts as the nucleus for zinc oxide rods formation. Incorporating with appropriate concentration of nitric acid in the aqueous solution, zinc oxide rods can dominate the growth at a lower temperature.
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Growth of N-F co-doped titania nanoparticle and applied on dye-sensitized solar cellChang, Hsin-chieh 12 August 2008 (has links)
Using liquid phase deposition (LPD) fluorine nitrogen altogether doping porous titanium dioxide nanoparticle, general has not doped the titanium dioxide to be able the step to be 3~3.2eV, is opposite to the absorption spectrum for ultraviolet ray 380nm about, but sunlight energy only then 6% in ultraviolet ray, but the visible light has occupied about 52% energy, because grows the titanium dioxide which comes out mainly is applies in the light catalyst and the solar cell, all hoped may enhance to the luminous energy absorption, therefore only then dopes the fluorine, the nitrogen in the titanium dioxide, the goal is in order to adjust the titanium dioxide the light to absorb the boundary (optical absorption edge), at present dopes the method can dope the impurity only then minority produces the key with the titanium dioxide to binding thus result not well, penetrates ammonium hexafluorotitanate and the boric acid by the liquid phase sedimentation mixes under 40 degrees grows ammonium oxofluorotitanate discoid crystal, in the middle of this forerunner fills the very many fluorine nitrogen, after annealing and then produces the titanium dioxide to penetrate the fluorine nitrogen which the ESCA analysis contains compared to, again applies in the solar cell when can observe the annealing temperature differently when remains the fluorine nitrogen which and the key ties to the solar cell efficiency. At present the titanium dioxide light absorbs the boundary to be possible to reach the blue light region, applies the porous titanium dioxide in the dye sensitization solar cell anode, present fill factor may reach about 29.6%.
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Titanium Oxide Prepared by Liquid Phase Deposition and Acted as Gate Oxide on Thin Film TransistorsYang, Tsai-feng 05 August 2009 (has links)
In this study, we deposit titanium dioxide (TiO2) as gate oxide on thin film transistor (TFT) by liquid phase deposition (LPD) on the amorphous silicon (a-Si) and polycrystalline silicon (poly-Si) substrates. After depositing LPD-TiO2 film, we use to fabricate TFT device.
In our experiment, we do some measurement about physical, chemical and electrical properties for LPD-TiO2 film and discussed with them. the TiO2 film morphology and thickness was characterized by scanning electron microscopy ( SEM ), structure was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and chemical properties was characterized by X-ray photoelectron spectroscopy (XPS),and electrical properties was characterized by leakage current: current-voltage (B1500A) and dielectric constant: capacitance-voltage (E4280A).
In TFT device study, we complete measurement about physical, chemical and electrical properties for LPD-TiO2 films. The LPD-TiO2 film was used as TFT device,
We complete mask manufacture, mesa structure definition, deposit TiO2 thin film, gate definition, photolithography and ICP- etching. Ion implantation is carrying out.
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Characterization of Silicon Oxide and Titanium Oxide Films Prepared on n-GaN by Liquid Phase DepositionZeng, Jia-Yi 20 July 2006 (has links)
In this study, SiO2 and TiO2 films were deposited on GaN, their physical and chemical properties were measured. An Al/SiO2/GaN and Al/TiO2/GaN MOS structures were used for the electrical measurements. To improve the electrical properties, we investigated the characteristics of SiO2 and TiO2 films after annealing in nitrogen, oxygen, and nitrous oxide ambient.
The highest dielectric constant of 3.91 and 28.68, and lowest leakage current density of 8.97¡Ñ10-5 A/cm2 at 2 MV/cm and 2¡Ñ10-2 A/cm2 at 1 MV/cm for the N2O-annealed SiO2 film and TiO2 film can be obtained.
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Characterization of SrTiO3 Films by Liquid Phase DepositionLee, Zhen-Hui 25 July 2006 (has links)
The area of advanced gate dielectrics has gained considerable attention recently, and there are significant leakage current and reliability concerns for oxy-nitride in this regime. So it¡¦s an important business to use alternate high-k dielectrics instead of oxy-nitride.
Titanium dieoxide shows a high dielectric constant for dielectric applications. Besides, strontium can create additional oxygen vacancies that can enhance dielectric constant. In this study, we prepared SrTiO3 film by liquid phase deposition which is a novel material considered to have high dielectric constant. From several characteristic measurements, we found that SrTiO3 with exhibiting higher dielectric constant and well interface state which is very promising candidates to instead of titanium dieoxide.
The physical and chemical properties of SrTiO3 films by means of several measuring instruments, including Fourier transform infrared spectrometer (FTIR), secondary ion spectrometer (SIMS), and X-Ray diffractometer (XRD). An Al / SrTiO3 / Si metal-oxide-semiconductor (MOS) capacitor structure was used for the electrical measurements. To improve the electrical properties, we investigated the characteristics of SrTiO3 films after annealing in oxygen, nitrous oxide, and nitrogen ambient. Including the variations of thickness, structure, dielectric constant, and leakage current were discussed in this work.
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Characterization of Zinc Oxide Thin Films Prepared by Liquid Phase Deposition and RF SputteringLee, Jung-Chun 12 August 2008 (has links)
Transparent Conductive Oxide thin films (TCO) with low resistivity and high light transmission act as transparent electrode for many kinds of display panel. At present, Indium Tin Oxide (ITO) is common transparent electrode material. Because Indium is classified rare element, and it has toxicity. Moreover ITO is unstable in high temperature. Recent years many researches are searching adaptive materials to replace ITO. Al doped ZnO (AZO) has same characteristics of low resistivity and high light transmission, it is one of the adaptive materials.
In this study, we choice AZO and ITO target. Sputtering is a common method to deposition TCO. We sputtered the AZO film and ITO film on glass substrate and measured the characteristics respectively. In addition, because Liquid Phase Deposition (LPD) has advantages of simple process, low cost and large amount of wafers can be used. Therefore, in this study we growth ZnO thin film on glass substrate simultaneously, and doped Aluminum to increase conductivity.
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Electrochromic Properties of Tungsten Oxide Films Prepared by RF Sputtering and Liquid Phase DepositionChang, Che-Yang 05 August 2009 (has links)
Tungsten trioxide (WO3) films are important for various optical devices and
especially for electrochromic materials. Sputtered WO3 thin films were deposited on
conductive glass substrate (ITO/glass) by RF sputtering from a WO3 target(diameter
2¡¨x 6 mm) in a reactive atmosphere of oxygen and argon flow ratio(0 to 1) mixture in
a total gas pressure of 10m Torr. The RF power was 100W operating at 13.56MHz.We
will improve the WO3 films by post-annealing in different atmosphere ambient.
In addition, to prepare treatment solution of growing WO3 films were dissolved
tungsten to aqueous which mixed hydrofluoric acid and nitric acid until it
supersaturate. This solution was then diluted to 0.02 M of tungsten ions with distilled
water. And we can get the treatment solution (WO3-HF aqueous). The WO3 thin films
have been deposited at 40oC with the treatment solution (WO3-HF aqueous) which
full of W ions, the 0.1M boric acid (H3BO3) solution and added aluminium metal by
liquid phase deposition (LPD) technique. The deposition rate could be controlled to
45 nm/h.
In our experiment, the WO3 films morphology and thickness was characterized
by scanning electron microscopy(SEM), structure was characterized by X-ray
diffraction(XRD), chemical properties was characterized by X-ray photoelectron
spectroscopy(XPS) and Fourier transform infrared spectroscopy(FT-IR), optical
properties was characterized by spectrophotometer(MP-100M), and electrochromic
characterized by cyclic voltammetry(CHI627C).
In our results, it will be improved the optical and electrochromic properties of
sputtered-WO3 films by post-annealing in O2 ambient. we also have try a novel and
very simple process for the thin films of WO3 by the LPD process. Adherent and
conformal WO3 electrochromic films were prepared on ITO/glass from aqueous
fluoride solution.
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