Quasi-reversible point defect relaxation in amorphous In-Ga-Zn-O thin films by in situ electrical measurements

2013 ◽  
Vol 102 (12) ◽  
pp. 122103 ◽  
Author(s):  
Alexander U. Adler ◽  
Ted C. Yeh ◽  
D. Bruce Buchholz ◽  
Robert P. H. Chang ◽  
Thomas O. Mason
1992 ◽  
Vol 282 ◽  
Author(s):  
J. K. Truman ◽  
P. H. Ballentine ◽  
E. Terzioglu ◽  
A. M. Kadin

ABSTRACTTiN thin films were deposited by reactive sputtering onto Si substrates. TiO2 films were formed by subsequent oxidation of the TiN films, using either conventional furnace heating or rapid thermalprocessing (RTP). The materials properties of the resulting films were characterized by x-ray diffraction and Rutherford backscattering, and indicate conversion of the TiN to fully-oxidized rutile TiO2 by a diffusion-limited process. Electrical measurements of the insulating properties of the TiO2 films indicated a relative dielectric constant greater than 100, although the leakage current was greater than optimum. A fully in-situ process for the fabrication of microcapacitors is proposed, which involves the sputter deposition of TiN, the formation of TiO2 by RTP, and the deposition of a top TiN counterelectrode. This can be carried out under conditions that are compatible with Si microelectronic device processing.


1990 ◽  
Vol 201 ◽  
Author(s):  
L. Shi ◽  
Y. Hashishin ◽  
S. Y. Dong ◽  
H. S. Kwok

AbstractWe have deposited CdS thin films onto substrates such as glass, sapphire and high Tc YBCO superconducting films by Nd:YAG laser evaporation in a vacuum environment. X-ray diffraction, optical and electrical measurements were used to study the deposited CdS films. The films are highly oriented with c-axis perpendicular to the surface and are optically smooth. The effects of laser fluence, substrate temperature on the film quality will be discussed. Additionally, Indium doped CdS films were also grown on sapphire substrates by laser deposition. In-situ resistivity measurements were employed to study the film formation process during laser deposition. A simple model was given to explain the in-situ resistivity data. Finally, a deposition temperature window was found to produce good quality CdS/YBCO heterostructures. The superconducting transition temperature of the YBCO films was degraded to 68K from an original Tc of 85 K after CdS deposition. The degradation of the superconducting properties was found mainly due to the interactions in the interface region.


1998 ◽  
Vol 514 ◽  
Author(s):  
D. A. Caldwell ◽  
L.-C. Chen ◽  
A. H. Bensaoula ◽  
J. K. Farrer ◽  
C. B. Carter ◽  
...  

ABSTRACTIn-situ depositions and reactions are utilized in the study of phase formation from solid phase reactions. We report on the formation of epitaxial GaAs and the formation of NiAs or Ni2Ga3 by the exposure of Ni3GaAs to As4 or Ga fluxes. In-situ annealing of Ni on MBE-grown GaAs leads to Ni3GaAs, and subsequent reaction with As4 or Ga drives regrowth of GaAs. The structures were analyzed by RBS, XRD, TEM, and in-situ electrical measurements.


Author(s):  
Dudley M. Sherman ◽  
Thos. E. Hutchinson

The in situ electron microscope technique has been shown to be a powerful method for investigating the nucleation and growth of thin films formed by vacuum vapor deposition. The nucleation and early stages of growth of metal deposits formed by ion beam sputter-deposition are now being studied by the in situ technique.A duoplasmatron ion source and lens assembly has been attached to one side of the universal chamber of an RCA EMU-4 microscope and a sputtering target inserted into the chamber from the opposite side. The material to be deposited, in disc form, is bonded to the end of an electrically isolated copper rod that has provisions for target water cooling. The ion beam is normal to the microscope electron beam and the target is placed adjacent to the electron beam above the specimen hot stage, as shown in Figure 1.


Author(s):  
J. T. Sizemore ◽  
D. G. Schlom ◽  
Z. J. Chen ◽  
J. N. Eckstein ◽  
I. Bozovic ◽  
...  

Investigators observe large critical currents for superconducting thin films deposited epitaxially on single crystal substrates. The orientation of these films is often characterized by specifying the unit cell axis that is perpendicular to the substrate. This omits specifying the orientation of the other unit cell axes and grain boundary angles between grains of the thin film. Misorientation between grains of YBa2Cu3O7−δ decreases the critical current, even in those films that are c axis oriented. We presume that these results are similar for bismuth based superconductors and report the epitaxial orientations and textures observed in such films.Thin films of nominally Bi2Sr2CaCu2Ox were deposited on MgO using molecular beam epitaxy (MBE). These films were in situ grown (during growth oxygen was incorporated and the films were not oxygen post-annealed) and shuttering was used to encourage c axis growth. Other papers report the details of the synthesis procedure. The films were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM).


Author(s):  
K. Barmak

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.


Author(s):  
E. Holzäpfel ◽  
F. Phillipp ◽  
M. Wilkens

During in-situ radiation damage experiments aiming on the investigation of vacancy-migration properties interstitial-type dislocation loops are used as probes monitoring the development of the point defect concentrations. The temperature dependence of the loop-growth rate v is analyzed in terms of reaction-rate theory yielding information on the vacancy migration enthalpy. The relation between v and the point-defect production rate P provides a critical test of such a treatment since it is sensitive to the defect reactions which are dominant. If mutual recombination of vacancies and interstitials is the dominant reaction, vαP0.5 holds. If, however, annihilation of the defects at unsaturable sinks determines the concentrations, a linear relationship vαP is expected.Detailed studies in pure bcc-metals yielded vαPx with 0.7≾×≾1.0 showing that besides recombination of vacancies and interstitials annihilation at sinks plays an important role in the concentration development which has properly to be incorporated into the rate equations.


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