scholarly journals Development of in-situ Depth Profiling for Extraterrestrial Materials with Isotope Nanoscope

2021 ◽  
Vol 69 (6) ◽  
pp. 197-201
Author(s):  
Yuta Otsuki ◽  
Ken-ichi Bajo ◽  
Hisayoshi Yurimoto
Keyword(s):  
Depth Profiling ◽  
Extraterrestrial Materials

Fim/Iap/Tem Studies of Ion Implanted Nickel Emitters

1984 ◽  
Vol 41 ◽  
Author(s):  
S. D. Walck ◽  
J. J. Hren
Keyword(s):  
Electric Fields ◽  
Depth Profiling ◽  
Atom Probe ◽  
Hydrogen Trapping ◽  
Transmission Electron ◽  
Microscope Imaging ◽  
Important Field ◽  
High Electric Fields ◽  
Field Ion Microscope

AbstractAccurate depth profiling of implanted hydrogen and its isotopes in metals is extremely important. Field ion microscopy and atom-probe techniques provide the most accurate depth profiling analytical method of any available. In addition, they are extremely sensitive to hydrogen. This paper reports our early work on hydrogen trapping at defects in metals using the Field Ion Microscope/Imaging Atom Probe (FIM/IAP). Our results deal primarily with the control experiments required to overcome instrumental difficulties associated with in situ implantation and the influence of a high electric field. Transmission Electron Microscopy (TEM) has been used extensively to independently examine the influence of high electric fields on emitters.

In-Situ, Time Resolved, Kinetics of Reactions in Co-Ge thin Films

1991 ◽  
Vol 237 ◽  
Author(s):  
R. M. Walser ◽  
Byung-Hak Lee ◽  
Alaka Valanju ◽  
Winston Win ◽  
M. F. Becker
Keyword(s):  
Depth Profiling ◽  
Laser Interferometry ◽  
Semiconductor Interface ◽  
Time Resolved ◽  
Interface Reactions ◽  
Valuable Adjunct ◽  
Diffusion Controlled ◽  
Sputter Deposited ◽  
Time Required

ABSTRACTWe report the first kinetic study of metal-semiconductor interface reactions using in-situ, time resolved, laser interferometry. Diffusion couples with Co/Ge thicknesses of 1500 Å/1500 Å were sputter deposited on silicon wafers, and vacuum-annealed at temperatures between 300°C-400°C. Under these conditions polycrystalline CoGe was expected to form [1]. Real time laser (HeNe 6328 Å) interferograms for each anneal were recorded in-situ. These data were supplemented by information from AES and X-ray.For temperatures below 400°C the diffusion controlled formation of CoGe was observed. The composition was confirmed by Auger depth profiling that showed uniform Co and Ge concentrations when the reaction went to completion. The well defined interferences fringes were formed by the dissolution of amorphous Ge. The activation energy = 1.6 eV for the formation of CoGe were determined with precision from the temperature dependence of the time required to anneal the fixed λ/4 distance between adjacent minima and maxima of the interferogram. We discuss the evidence for formation of an intermediate Co-rich compound following the initial diffusion of Co into Ge. The results of these experiments indicate that optical interferometry will be a valuable adjunct to other techniques used to study metal-semiconductor interface reactions.

More Insights Into the ZnO/a-SiC:H(B) Interface - An Improved TCO/p Contact

1996 ◽  
Vol 426 ◽  
Author(s):  
E. Böhmer ◽  
F. Siebke ◽  
B. Rech ◽  
C. Beneking ◽  
H. Wagner
Keyword(s):  
Fill Factor ◽  
Series Resistance ◽  
Depth Profiling ◽  
Binding Energies ◽  
Level Shift ◽  
Accumulation Layer ◽  
Front Electrode ◽  
P Type ◽  
Deposition Conditions

AbstractSolar cells based on amorphous silicon (a-Si:H) exhibit a decreased fill factor if ZnO is used as front electrode instead of SnO2. This is due to a poor electric contact between the ZnO and the p-type a-SiC:H(B) layer. To gain a deeper understanding of the chemical and electronic properties of the ZnO/p interface, in-situ XPS measurements were applied to thin a-SiC:H(B) films deposited on ZnO. The effects of CO2 and H2 plasma pretreatments on clean ZnO surfaces and the influence of deposition conditions on the ZnO/a-SiC:H interface were investigated. Upon H2 plasma treatment the formation of SiOx by chemical transport of Si from the reactor walls is observed. Furthermore, a shift of all core levels towards higher binding energies indicates the formation of an accumulation layer. CO2 plasma treatments show no effects on ZnO. Depth profiling across the ZnO/a-SiC:H interface indicates SiO2 formation on ZnO. The depth profile of ZnO related core levels exhibits two features: a reduction of the ZnO at the interface, and, after longer sputter times, a core level shift towards higher binding energy due to an hydrogen induced accumulation layer in the n-type ZnO. The latter causes a depletion of the p-layer resulting in an enhanced series resistance and diminished fill factor. To reduce the depletion layer thin highly conductive microcrystalline layers were introduced, increasing the fill factor up to 74%.

Characterization and Optimization of The Tco/a-Si:H(,B) Interface for Solar Cells by In-Situ Ellipsometry and Sims/XPS Depth Profiling

1994 ◽  
Vol 336 ◽  
Author(s):  
H.N. Wanka ◽  
E. Lotter ◽  
M.B. Schubert
Keyword(s):  
Solar Cells ◽  
Light Trapping ◽  
Hydrogen Plasma ◽  
Depth Profiling ◽  
Trapping Efficiency ◽  
Force Microscopy ◽  
Hydrogen Plasmas ◽  
Atomic Force ◽  
20 Nm

ABSTRACTThe chemical reactions at the surface of transparent conductive oxides (SnO2, ITO and ZnO) have been studied in silane and hydrogen plasmas by in-situ ellipsometry and by SIMS as well as XPS depth profiling. SIMS and XPS of the interface reveal an increasing amount of metallic phases upon lowering a-Si:H growth rates (controlled by plasma power), indicating that the ion and radical impact is more than compensated by protecting the surface by a rapidly growing a-Si:H film. Hence, optical transmission of TCO films as well as the efficiency of solar cells can be improved if the first few nanometers of the p-layer are grown at higher rates. Comparing a-Si:H deposition on top of different TCOs, reduction effects on ITO and SnO2 have been detected whereas ZnO appeared to be chemically stable. Therefore an additional shielding of the SnO2 surface by a thin ZnO layer has been investigated in greater detail. Small amounts of H are detected close to the ZnO surface by SIMS after hydrogen plasma treatment, but no significant changes occur to the optical and electrical properties. In-situ ellipsometry indicates that a ZnO layer as thin as 20 nm completely protects SnO2 from being reduced to metallic phases. This provides for shielding of textured TCOs, and hence rising solar cell efficiencies, too. Regarding light trapping efficiency we additionally investigated the smoothing of initial TCO texture when growing a-Si:H on top by combining atomic force microscopy and spectroscopie ellipsometry.

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