scholarly journals Low Temperature Deposition of Metal Oxide Thin Films in Supercritical Carbon Dioxide Using Metal-organic Precursors

2007 ◽  
Vol 1007 ◽  
Author(s):  
Theodosia Gougousi ◽  
Zhiying Chen

ABSTRACTA novel chemical route in thin film formation that includes the use of inorganic and organic peroxides and metal organic complexes soluble in supercritical carbon dioxide has been investigated for the deposition of alumina, titania and zirconia thin films at low temperatures (<150°C). The metal organic precursors used include: Al(acac)3, OTi(tmhd)2, and Zr(acac)4. Tert-butyl peroxide, and a 30% aqueous solution of hydrogen peroxide were used as oxidants. Depositions were carried out in a 25 ml hot wall reactor at pressures ranging from 2100 to 3900 psi at 80-140°C. The deposited thin films were investigated by using X-ray photoelectron spectroscopy (XPS) and transmission Fourier transform infrared spectroscopy (FTIR). XPS and FTIR results indicate the formation of metal oxides thin films with some bonded carbon. The deposition temperatures achieved in this process are substantially lower than those used in conventional vacuum deposition techniques making feasible the deposition on temperature sensitive substrates and organic materials required for the development of hybrid organic/inorganic devices. Processing at low temperatures in supercritical carbon dioxide may provide the basis for the development of an alternative, environmentally friendly, thin film deposition technique for the processing of nanostructures.

2008 ◽  
Vol 388 ◽  
pp. 179-182 ◽  
Author(s):  
Rintarou Morohashi ◽  
Naoki Wakiya ◽  
Takanori Kiguchi ◽  
Tomohiko Yoshioka ◽  
M. Tanaka ◽  
...  

Lithium niobate (LiNbO3) thin films were deposited on Al2O3(001) substrates using metal-organic chemical vapor deposition (MOCVD), with Li(dpm) and Nb(C2H5)5 as precursors. By optimizing the conditions of thin film deposition, the c-axis oriented and epitaxially grown LiNbO3 thin films with stoichiometric composition were deposited on an Al2O3(001) substrate. The refractive index of the stoichiometric LiNbO3 thin film was 2.24 at = 632.8 nm, which is close to that of bulk crystal.


2006 ◽  
Vol 320 ◽  
pp. 91-94 ◽  
Author(s):  
Fuyuki Kano ◽  
Hiroshi Uchida ◽  
Kazuko Sugimoto ◽  
Seiichiro Koda

Thin films of titanium oxide (TiO2) were synthesized from Titanium diisopropoxide bis(dipivaloylmethanate) [Ti(O-i-Pr)2(dpm)2] as a source material using supercritical carbon dioxide (CO2) fluid. Flat films with a uniform microstructure were fabricated on SiO2/(100)Si substrates at a fluid pressure of 8.0 MPa, while granular particles were deposited on the film surface at a fluid pressure of 10.0 MPa. TiO2 films fabricated in supercritical CO2 atmosphere at 10.0 MPa were crystalline at the reaction temperature of 100°C, which was significantly lower than those in the conventional film-deposition techniques.


2015 ◽  
Vol 1729 ◽  
pp. 99-104 ◽  
Author(s):  
Marina Shiokawa ◽  
Katsushi Izaki ◽  
Hiroshi Funakubo ◽  
Hiroshi Uchida

ABSTRACTWe propose some chemical processing procedures for fabricating thin films in Hf-Zr-O system by a unique film deposition technique using supercritical carbon dioxide fluid (scCO2), i.e., supercritical fluid deposition (SCFD), which would be an prospective approach for fabricating metal-oxide films for integrated circuits because of its unique characteristics; e.g., extraction ability, transportation capability, and reaction equilibrium etc., are quite favorable for the film deposition from metal-complex precursors.The SCFD was accomplished in a closed batch-type reaction apparatus, consisting of two steps; (a) material deposition and (b) subsequent post-treatment under scCO2 atmosphere. Thin films of amorphous Hf-Zr-O were deposited on platinized silicon [(111)Pt/TiO2/(100)Si] substrates by SCFD using metal-complex precursors M[OCH(CH3)]2(C9H11O2)2 (M = Hf or Zr) at reaction temperature of 100 – 300 °C, significantly lower than those for MOCVD. These films possessed dielectric permittivity’s of approximately 20 – 25, comparable to those from conventional processes, although they still included residue of organic species that prompt the dielectric degradation under lower-frequency bias application.


Author(s):  
M. Grant Norton ◽  
C. Barry Carter

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.


2019 ◽  
Vol 7 (36) ◽  
pp. 20733-20741 ◽  
Author(s):  
Mehri Ghasemi ◽  
Miaoqiang Lyu ◽  
Md Roknuzzaman ◽  
Jung-Ho Yun ◽  
Mengmeng Hao ◽  
...  

The phenethylammonium cation significantly promotes the formation of fully-covered thin-films of hybrid bismuth organohalides with low surface roughness and excellent stability.


2009 ◽  
Vol 156 (6) ◽  
pp. H443 ◽  
Author(s):  
Masahiro Matsubara ◽  
Michiru Hirose ◽  
Kakeru Tamai ◽  
Yukihiro Shimogaki ◽  
Eiichi Kondoh

2013 ◽  
Vol 209 ◽  
pp. 111-115 ◽  
Author(s):  
Sandip V. Bhatt ◽  
M.P. Deshpande ◽  
Bindiya H. Soni ◽  
Nitya Garg ◽  
Sunil H. Chaki

Thin film deposition of PbS is conveniently carried out by chemical reactions of lead acetate with thiourea at room temperature. Energy dispersive analysis of X-ray (EDAX), X-ray diffraction (XRD), selected area electron diffraction patterns (SAED), UV-Vis-NIR spectrophotometer, Scanning Electron Microscopy (SEM), Atomic force microscopy (AFM), Photoluminescence (PL) and Raman spectroscopy techniques are used for characterizing thin films. EDAX spectra shows that no impurity is present and XRD pattern indicates face centered cubic structure of PbS thin films. The average crystallite size obtained using XRD is about 15nm calculated using Scherrer’s formula and that determined from Hall-Williamson plot was found to be 18nm. SAED patterns indicate that the deposited PbS thin films are polycrystalline in nature. Blue shift due to quantum confinement was seen from the UV-Vis-NIR absorption spectra of thin film in comparison with bulk PbS. The Photoluminescence spectra obtained for thin film with different excitation sources shows sharp emission peaks at 395nm and its intensity of photoluminescence increases with increasing the excitation wavelength. Raman spectroscopy of deposited thin film was used to study the optical phonon modes at an excitation wavelength of 488nm using (Ar+) laser beam.


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