共查询到20条相似文献,搜索用时 15 毫秒
1.
Yoshifumi Ikoma Ryousuke Okuyama Makoto Arita Teruaki Motooka 《Thin solid films》2010,518(14):3759-10013
We report on the formation and the structural characterization of nanocrystalline Si/SiC (nc-Si/SiC) multilayers on Si(100) by hot filament assisted chemical vapor deposition using CH3SiH3 gas pulse jets. Si rich amorphous SiC (a-Si1 − xCx, x ~ 0.33) was initially grown at the substrate temperature (Ts) of 600 °C with heating a hot filament at ~ 2000 °C. The following crystalline SiC layers were grown at Ts = 850 °C without utilizing a hot filament. When the a-Si1 − xCx layer was ultrathin (< 2 nm) on Si(100), this a-Si1 − xCx layer was transformed to a single epitaxial SiC layer during the subsequent SiC growth process. The Si{111} faceted pits were formed at the SiC/Si(100) interface due to Si diffusion processes from the substrate. When the thickness of the initial a-Si1 − xCx layer was increased to ~ 5 nm, a double layer structure was formed in which this amorphous layer was changed to nc-Si and nc-SiC was grown on the top resulting in the considerable reduction of the {111} faceted pits. It was found that nc-SiC was formed by consuming the Si atoms uniformly diffused from the a-Si1 − xCx layer below and that Si nanocrystals were generated in the a-Si1 − xCx layers due to the annealing effect during further multilayer growths. 相似文献
2.
A.M. Hartel D. HillerS. Gutsch P. LöperS. Estradé F. PeiróB. Garrido M. Zacharias 《Thin solid films》2011,520(1):121-125
Size controlled silicon nanocrystals (SiNC) in silicon oxynitride matrix were prepared using plasma enhanced chemical vapor deposition. The as-deposited superlattices (SLs) and the corresponding bulk films were treated by thermal annealing. Hydrogen effusion was performed during the heating up by choosing a sufficiently low heating ramp. The phase separation of the layers into SiNCs and surrounding oxynitride matrix was studied at temperatures of up to 1150 °C. The influence of the annealing temperature on SiOxNy/SiO2 - SLs with varying SiOxNy layer thickness was investigated by several analytical techniques including variable angle spectroscopic ellipsometry, photoluminescence (PL) spectroscopy, x-ray photoelectron spectroscopy, Fourier transform infrared spectrometry (FTIR) and transmission electron microscopy (TEM). Before annealing FTIR investigations show in addition to the expected Si-O bonds also the formation of nitrogen and hydrogen related bonds. The shift of the Si-O-Si stretching vibration to higher wave numbers after annealing indicates phase separation. The disappearance of the hydrogen related bonds indicates the hydrogen effusion. The PL signal is rising significantly with increasing annealing temperature and the PL peak position is strongly related to the thickness of the SiOxNy sublayers due to quantum confinement effects. TEM investigations confirm the size-controlled growth of SiNCs within the oxynitride matrix. The role of incorporated nitrogen and hydrogen is discussed. 相似文献
3.
Clean oriented Al2O3 thin film with a dominant Al2O3 <1 1 3> plane was deposited on Si <1 0 0> substrate at 550 °C, by single-source chemical vapor deposition (CVD) using aluminium(III) diisopropylcarbamate, Al2(O2CNiPr2)6. This process represents a substantial reduction in typical CVD film growth temperatures which are typically > 1000 °C. Through the studies of thermal stability of this precursor, we propose a specific β-elimination decomposition pathway to account for the low temperature of the precursor decomposition at the substrate, and for the lack of carbon impurity byproducts in the resulting alumina films that are characterized using X-ray photoelectron spectroscopy and depth profiling. 相似文献
4.
Ge nanocrystals (NCs) embedded in Al2O3 were grown by RF-sputtering. X-ray diffraction, high resolution transmission electron microscopy, and Raman spectroscopy techniques were used to characterize the stresses on the NCs. While small NCs (< 10 nm) have been observed to be spherical and fully relaxed in the matrix, the larger ones (> 17 nm) demonstrated a compressive stress effect. This could be linked to the crystal structure of the adjacent Al2O3 matrix. 相似文献
5.
G. Battistig 《Thin solid films》2012,520(6):1973-1977
Cubic SiC nanocrystals are formed epitaxially and void-free on single crystal Si substrate by reactive annealing in CO. In this study characterization of the nucleation, growth and morphology is presented on differently oriented single crystal Si substrates. It is found that SiC nanocrystals of various shape can be grown in different densities on the (100), (110) and (111) Si surfaces with an average size of 30-60 nm. Effect of annealing time, CO concentration, substrate orientation and crystal size on crystallite growth is discussed. Parameters to obtain increased SiC nucleation density are determined. 相似文献
6.
The morphology and texture of Ge films grown under oblique angle vapor deposition on native oxide covered Si(001) substrates at temperatures ranging from 230 °C to 400 °C were studied using scanning electron microscopy, X-ray diffraction and X-ray pole figure techniques. A transition from polycrystalline to {001}<110> biaxial texture was observed within this temperature range. The Ge films grown at substrate temperatures < 375 °C were polycrystalline. At substrate temperatures of 375 °C and 400 °C, a mixture of polycrystalline and biaxial texture was observed. The 230 °C sample consisted of isolated nanorods, while all other films were continuous. The observed biaxial texture is proposed to be a result of the loss of the interface oxide layer, resulting in epitaxial deposition of Ge on the Si and a texture following that of the Si(001) substrates used. The rate of oxide loss was found to increase under oblique angle vapor deposition. 相似文献
7.
Tamio Iida Yasuhiko Takamido Shunsuke Ogawa Tomoki Narita Takashi Itoh 《Thin solid films》2008,516(5):807-809
TiO2 thin films prepared by Hot-Wire CVD method have been studied as a protecting material of transparent conducting oxide (TCO) against atomic hydrogen exposures for the fabrications of Si thin film solar cells. It was found that electrical conductivity of the films at room temperature reached a value of 0.4 S/cm. This value is 2-3 orders of magnitude higher than that of TiO2 films prepared by RF magnetron sputtering and electron-beam evaporation methods in our previous works. The conductivity improvement seems to be partly due to the enlargement of TiO2 crystallites. 相似文献
8.
Su Kong Chong Boon Tong GohZarina Aspanut Muhamad Rasat MuhamadBinni Varghese Chorng Haur SowChang Fu Dee Saadah Abdul Rahman 《Thin solid films》2011,520(1):74-78
In this study, the fabrication of Si nanostructures by Au and SiH4 co-deposition technique using hot-wire chemical vapor deposition was demonstrated. A high deposition rate of 2.7 nm/s and a high density of silicon nanostructures with a diameter of about 140 nm were obtained at Ts of 250 °C. An increase in Ts led to a significant reduction in the size of the nanostructures. However, coalescence on the nanostructures was observed at Ts of 400 °C. The Si nanostructures exhibited a highly crystalline structure, which was induced by Au crystallites. The crystallite size and crystallinity of the Si nanostructures amplified with the increase in Ts. The presence of nanostructures enhanced the surface roughness of the samples and clearly reduced the reflection, especially in the visible region. 相似文献
9.
Mesoporous vanadium pentoxide (V2O5) films have been synthesized by hydrolysis of vanadium tri-isopropoxide (VO(OC3H7)3) in the presence of polyethylene glycol (PEG) as a structure-directing agent. The structure, the stoichiometry and the morphology of the films have been studied as a function of the thermal annealing by X-ray diffraction (XRD), micro-Raman spectroscopy, optical microscopy, scanning electron microscopy and atomic force microscopy. XRD patterns and Raman spectra show the presence of two previously unreported crystalline phases. The PEG:V2O5 molar ratio affects the temperature of phase formation, the amount and even the order in which the phases appear. The morphological characterization underlines the role of the surfactant to promote porous networks, formed by micrometric clusters of controlled shapes and patterns embedded in a homogeneous host matrix. 相似文献
10.
Highly (100)-oriented CeO2 films prepared on amorphous substrates by laser chemical vapor deposition
CeO2 films were prepared on amorphous silica substrates by laser chemical vapor deposition using cerium dipivaloylmethanate precursor and a semiconductor InGaAlAs (808 nm in wavelength) laser system. The laser spot size was about 20 mm, which was sufficient to cover the whole substrate. Highly (100)-oriented CeO2 films were obtained at extraordinary high deposition rates ranging from 60 to 132 μm/h. Films exhibited a columnar feather-like structure with a large number of nano-sized voids, and a surface morphology consisting of either nearly flat or pyramidal top-ending columns depending on the laser power. Nearly flat top-ending columns could be fairly (100)-oriented at the top and (111)-oriented laterally. 相似文献
11.
Chemical vapor deposition of aluminum from a recently developed precursor, methylpyrrolidine alane complex, has been studied. Aluminum films deposited on conducting surfaces (titanium nitride, copper, gold), but not on insulating surfaces (silicon, silicon dioxide, glass) at low substrate temperatures, showing deposition selectivity, while the deposition selectivity was lost at high substrate temperatures (> 210 °C). Al deposition rates on TiN and Cu were very close, but much higher than on Au. Deposition rates on all conducting substrates increased with the temperature and reached maximum at 180 °C. Al films deposited on as-sputtered TiN or Cu have no preferred orientations. Al–Au alloys and intermetallics were observed in the films deposited on Au. Surface morphology observation revealed that the film growth on TiN or Cu is different from that on Au. The surface roughness of Al films increased with the deposition time or the film thickness. 相似文献
12.
Magnéli phases of Ti27O52 and Ti6O11 films were prepared by laser chemical vapor deposition using Ti(dpm)2(O-i-Pr)2 as a precursor. Ti6O11 film was obtained at a laser power (PL) of 200 W and a deposition temperature (Tdep) of 1270 K. Ti27O52 film was obtained at PL = 150 to 200 W and Tdep = 1120 to 1250 K. Ti6O11 and Ti27O52 films had a faceted texture about 2 μm in grain size and a columnar cross section. The deposition rate of Ti27O52 and Ti6O11 films were 90 and 70 μm h− 1, respectively. 相似文献
13.
Li-Wei Feng Chun-Yen Chang Ting-Chang Chang Chun-Hao Tu Pai-Syuan Wang Chao-Cheng LinMin-Chen Chen Hui-Chun HuangDer-Shin Gan New-Jin HoShih-Ching Chen Shih-Cheng Chen 《Thin solid films》2011,519(22):7977-7981
Formation and composition analyses of titanium oxinitride nanocrystals (NCs) fabricated via treating a magnetron co-sputtered thin film of titanium and silicon dioxide with a rapid thermal annealing in nitrogen ambient were demonstrated for nonvolatile memory applications. Phase separation characteristics with different annealing conditions were examined by transmission electron microscopy and chemical bonding characteristics were confirmed by X-ray photon emission spectra. It was observed that a blanket layer composed mainly of titanium oxide was still present as annealing temperature was increased to 700 °C, associated with the thermodynamically stable phase of titanium oxide. Furthermore, a higher thermal treatment of 900 °C induced formation of a well-separated NC structure and caused simultaneously partial nitridation of the titanium oxide, thereby forming titanium oxinitride NCs. A significant capacitance-voltage hysteresis in threshold voltage shift at 1 V was easily achieved under a small sweeping voltage range of + 2 V/−2 V, and a memory window retention of 2.2 V was obtained after 107 s by extrapolation under a 1 s initial-program/erase condition of + 5 V/−5 V, respectively. 相似文献
14.
Qing YangKaibin Tang Chunrui WangJian Zuo Daoyuan ZhangYitai Qian 《Thin solid films》2003,436(2):203-207
SnS2 films have been deposited on glass and alumina plate substrates by the reactions between an organotin precursor [tetrabuyltin, (CH2CH2CH2CH3)4Sn] and carbon disulfide in n-hexane at the temperature range 180-200 °C for 10-40 h. The reaction system was oxygen free and applied at a moderate temperature. The films so prepared were characterized by techniques of X-ray diffraction, Scanning electron microscopy, Raman and Mössbauer spectroscopies. The films deposited on glass as well as on alumina plate have an average thickness of 30 μm, but have different rose-like morphologies, which are influenced by both the anisotropic growths of crystals and the different substrate structures. Photoluminescence measurements show that the films have an emission peak at approximately 590 nm. 相似文献
15.
Wen-Bo Zhao Jun-Jie Zhu Yu Zhao Hong-Yuan Chen 《Materials Science and Engineering: B》2004,110(3):307-313
Bismuth sulfide (Bi2S3) nanofibers have been successfully prepared by a photochemical method from an aqueous solution of bismuth nitrate (Bi(NO3)3) and thioacetamide (TAA) in the presence of complexing agents of nitrilotriacetic acid (NTA) at room temperature. It was found that the irradiation time, the pH of the solution, and the species of complexing agents play important roles in the morphology control of the bismuth sulfate (Bi2S3) nanomaterials. The nanofibers were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), electron diffraction (ED), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectra (XPS), and UV-Visible absorption spectra (UV-Vis). Probable mechanisms for the photochemical formation of Bi2S3 nanofibers in aqueous solutions are proposed. The photochemical method is a convenient approach for controlling the shape for other metal sulfide semiconductor nanocrystals. 相似文献
16.
Synthesis of (Na2O,PbO)-Nb2O5, (Na2O,BaO)-Nb2O5, and (K2O,SrO)-Nb2O5 thin films using sol-gel method
Homogeneous pore-free Ba2NaNb5O15, KSr2Nb5O15, and 2·Na2O-PbO-6·Nb2O5 thin films were fabricated on sapphire substrates using the sol-gel technique. By controlling the gelation and coating process, thickness of thin films fabricated was controllable from ~ 40 nm to ~ 10 μm. Synthesized thin films possessed highly preferred orientated microstructure. Another advantage of this method is the subsequent heat treatment temperature dramatically decreased compared with other methods. This increases stoichiometry control and makes the large scale fabrication more feasible and efficient. 相似文献
17.
Ultra thin HfO2 films were grown by the atomic layer deposition (ALD) technique using tetrakismethylethylaminohafnium (Hf[N(CH)3(C2H5)]4) and ozone (O3) as the precursors and subsequently exposed to various plasma conditions, i.e., CCP (capacitively coupled plasma) and MMT (modified magnetron typed plasma) in N2 or N2/O2 ambient. The conventional CCP treatment was not effective in removing the carbon impurities, which were incorporated during the ALD process, from the HfO2 films. However, according to the X-ray photoelectron spectroscopy measurements, the MMT treated films exhibited a significant reduction in their carbon contents and the efficient incorporation of nitrogen atoms. Although the incorporated nitrogen was easily released during the post-thermal annealing of the MMT treated samples, it was more effective than the CCP treatment in removing the film impurities. Consequently, the MMT treated samples exhibited excellent electrical properties as compared to the as-deposited HfO2 films, including negligible hysteresis (flatband voltage shift), a low leakage current, and the reduced equivalent oxide thickness of the gate stack. In conclusion, MMT post treatment is more effective than conventional CCP treatment in improving the electrical properties of high-k films by reducing the carbon contamination and densifying the as-deposited defective films. 相似文献
18.
Graphene-like thin films were grown on patterned SiO2 substrates by simple thermal chemical vapor deposition using ethanol. The film growth occurred preferentially in the vicinity of pattern edges. Catalytic metal is not necessary for the substrate or the pattern. The films consist of graphitic nanocrystals of several nanometer scale. In the electric properties, the field effect is observed at room temperature. 相似文献
19.
The control of crystallographic orientation for ferroelectric oxide thin films grown on single crystal substrates has been investigated. We find that perovskite BaTiO3 has unusual orientation distributions when deposited on (100)- and (110)-oriented SrTiO3 single crystal substrates that have predeposited patterned Au regions. BTO areas deposited on gold islands were found to have a (111) orientation, whereas those deposited directly on STO had the same orientation as the substrate. Based on this method, we can select, locate, and pattern an oxide film to have different orientation distributions, and thereby engineer films with the complete property anisotropy in-plane. 相似文献
20.
Chromia (Cr2O3) has been extensively explored for the purpose of developing widespread industrial applications, owing to the convergence of a variety of mechanical, physical and chemical properties in one single oxide material. Various methods have been used for large area synthesis of Cr2O3 films. However, for selective area growth and growth on thermally sensitive materials, laser-assisted chemical vapour deposition (LCVD) can be applied advantageously.Here we report on the growth of single layers of pure Cr2O3 onto sapphire substrates at room temperature by low pressure photolytic LCVD, using UV laser radiation and Cr(CO)6 as chromium precursor. The feasibility of the LCVD technique to access selective area deposition of chromia thin films is demonstrated. Best results were obtained for a laser fluence of 120 mJ cm−2 and a partial pressure ratio of O2 to Cr(CO)6 of 1.0. Samples grown with these experimental parameters are polycrystalline and their microstructure is characterised by a high density of particles whose size follows a lognormal distribution. Deposition rates of 0.1 nm s−1 and mean particle sizes of 1.85 μm were measured for these films. 相似文献