The Importance of Self-Sputtering by Low Energy Ions in Partially Ionized Beam Deposition

1989 ◽  
Vol 157 ◽  
Author(s):  
P. Bai ◽  
CH. SteinbrÜChel ◽  
T.-M. Lu

ABSTRACTIn ion-assisted deposition techniques such as partially ionized beam deposition, ions derived from the depositing material itself concurrently bombard the surface during thin film growth. The ion percentage in the deposition beam ranges from less than 0.1% to 100% (Ion Beam Deposition) with the ion energy varying between a few eV and several keV. When the sputtering yield of the self-sputtering is greater than one, there is a critical ion percentage, for a given ion energy, above which no net deposition can be obtained. The self-sputtering yield is shown to have a square root dependence on the ion energy above the threshold energy by fitting the experimental data obtained from the literature. The critical ion percentage for Al, Cu, Au, Ag, and C is then calculated and plotted as a function of the ion energy so that deposition and no-deposition regions are illustrated in terms of the ion energy and ion percentage.

1991 ◽  
Vol 236 ◽  
Author(s):  
Nicole Herbots ◽  
O.C. Hellman ◽  
O. Vancauwenberghe

AbstractThree important effects of low energy direct Ion Beam Deposition (IBD) are the athermal incorporation of material into a substrate, the enhancement of atomic mobility in the subsurface, and the modification of growth kinetics it creates. All lead to a significant lowering of the temperature necessary to induce epitaxial growth and chemical reactions. The fundamental understanding and new applications of low temperature kinetics induced by low energy ions in thin film growth and surface processing of semiconductors are reviewed. It is shown that the mechanism of IBD growth can be understood and computed quantitatively using a simple model including ion induced defect generation and sputtering, elastic recombination, thermal diffusion, chemical reactivity, and desorption The energy, temperature and dose dependence of growth rate, epitaxy, and chemical reaction during IBD is found to be controlled by the net recombination rate of interstitials at the surface in the case of epitaxy and unreacted films, and by the balance between ion beam decomposition and phase formation induced by ion beam generated defects in the case of compound thin films. Recent systematic experiments on the formation of oxides and nitrides on Si, Ge/Si(100), heteroepitaxial SixGe1−x/Si(100) and GaAs(100) illustrate applications of this mechanism using IBD in the form of Ion Beam Nitridation (IBN), Ion Beam Oxidation (IBO) and Combined Ion and Molecular beam Deposition (CIMD). It is shown that these techniques enable (1) the formation of conventional phases in conditions never used before, (2) the control and creation of properties via new degrees of freedom such as ion energy and lowered substrate temperatures, and (3) the formation of new metastable heterostructures that cannot be grown by pure thermal means.


1991 ◽  
Vol 235 ◽  
Author(s):  
Nicole Herbots ◽  
O. C. Hellman ◽  
O. Vancauwenberghe

ABSTRACTThree important effects of low energy direct Ion Beam Deposition (IBD) are the athermal incorporation of material into a substrate, the enhancement of atomic mobility in the subsurface, and the modification of growth kinetics it creates. All lead to a significant lowering of the temperature necessary to induce epitaxial growth and chemical reactions. The fundamental understanding and new applications of low temperature kinetics induced by low energy ions in thin film growth and surface processing of semiconductors are reviewed. It is shown that the mechanism of IBD growth can be understood and computed quantitatively using a simple model including ion induced defect generation and sputtering, elastic recombination, thermal diffusion, chemical reactivity, and desorption. The energy, temperature and dose dependence of growth rate, epitaxy, and chemical reaction during IBD is found to be controlled by the net recombination rate of interstitials at the surface in the case of epitaxy and unreacted films, and by the balance between ion beam decomposition and phase formation induced by ion beam generated defects in the case of compound thin films. Recent systematic experiments on the formation of oxides and nitrides on Si, Ge/Si(100), heteroepitaxial SixGe1−x/Si(100) and GaAs(lOO) illustrate applications of this mechanism using IBD in the form of Ion Beam Nitridation (IBN), Ion Beam Oxidation (IBO) and Combined Ion and Molecular beam Deposition (CIMD). It is shown that these techniques enable (1) the formation of conventional phases in conditions never used before, (2) the control and creation of properties via new degrees of freedom such as ion energy and lowered substrate temperatures, and (3) the formation of new metastable heterostructures that cannot be grown by pure thermal means.


1991 ◽  
Vol 223 ◽  
Author(s):  
Qin Fuguang ◽  
Yao Zhenyu ◽  
Ren Zhizhang ◽  
S.-T. Lee ◽  
I. Bello ◽  
...  

ABSTRACTDirect ion beam deposition of carbon films on silicon in the ion energy range of 15–500eV and temperature range of 25–800°C has been studied using mass selected C+ ions under ultrahigh vacuum. The films were characterized with X-ray photoelectron spectroscopy, Raman spectroscopy, and transmission electron microscopy and diffraction analysis. Films deposited at room temperature consist mainly of amorphous carbon. Deposition at a higher temperature, or post-implantation annealing leads to formation of microcrystalline graphite. A deposition temperature above 800°C favors the formation of microcrystalline graphite with a preferred orientation in the (0001) direction. No evidence of diamond formation was observed in these films.


1997 ◽  
Vol 485 ◽  
Author(s):  
H. R. Khan ◽  
H. Frey

AbstractSilicon films of thicknesses (100 – 800 nm) are deposited on Si[111] substrate at 490°C using Si+ ions of energies (20 – 70 eV) from Silane plasma. The structure of the films depends on the energy of Si+ ions and the film grows epitaxially for ion energy <20 eV. Si films are analyzed by X-ray diffraction technique.


1991 ◽  
Vol 70 (10) ◽  
pp. 5623-5628 ◽  
Author(s):  
W. M. Lau ◽  
I. Bello ◽  
X. Feng ◽  
L. J. Huang ◽  
Qin Fuguang ◽  
...  

1988 ◽  
Vol 64 (4) ◽  
pp. 2206-2208 ◽  
Author(s):  
W. I. Lee ◽  
J. Wong ◽  
J. M. Borrego ◽  
T.‐M. Lu

1991 ◽  
Vol 223 ◽  
Author(s):  
I. Kataoka ◽  
K. Ito ◽  
N. Hoshi ◽  
T. Yonemitsu ◽  
K. Etoh ◽  
...  

ABSTRACTThe x-ray reflectivity and surface morphology of C/W multilayers fabricated by ion beam sputtering (IBS) method was evaluated. Also the surface roughness and amorphous structure of C and W films fabricated by direct ion beam deposition (DIBD) method were evaluated as a function of ion energy. The reflectivity was measured by the C-K line (4.47nm) and STM was used for surface roughness measurement and root-mean-square value of correlation function of the RHEED pattern was used for evaluation of amorphous structure. The reflectivity of C/W multilayer was about 69% of the theoretical one, and micro-columnar structures were observed from STM images. The film structure and surface roughness of DIBD film were changed with the depositing ion energy. The surface roughness of films becomes smaller as the depositing energy becomes higher in the energy range from 20 to 140eV.


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