Controlled Modifications in the Electrical Properties of Metal/GaAs Junctions

1990 ◽  
Vol 181 ◽  
Author(s):  
M. Eizenberg
Keyword(s):  
Thin Film ◽  
Solid State ◽  
Electrical Properties ◽  
Gaas Substrate ◽  
Surface Region ◽  
Solid State Reactions ◽  
Physical Processes ◽  
Compound Formation ◽  
Near Surface ◽  
Contact Metal

ABSTRACTControlled modifications in the electrical properties of metal/GaAs junctions were obtaind by a few different approaches. The first approach is based on modifications induced by solid state reactions occurring between the metal and GaAs substrate, resulting in compound formation and component redistribution. The characteristics of such contacts can further be modified when the contact metal is alloyed with another metal or with a dopant. The second approach is based on modifying the doping level of the near surface region of the GaAs. Here an enhancement of the barrier height was obtained by heavily counter doping the top GaAs region by recoil implantation of Mg from a Mg thin film irradiated by As− ions. The correlations between the electrical properties of the junctions and the physical processes taking place using the above mentioned approaches are discussed.

Correlations Between Electrical Properties and Solid-State Reactions in Co/N-GaAs Contacts: A Bulk and Thin-Film Study

1989 ◽  
Vol 148 ◽  
Author(s):  
F.-Y. Shiau ◽  
Y. A. Chang
Keyword(s):  
Thin Film ◽  
Phase Diagram ◽  
Solid State ◽  
Electrical Properties ◽  
Phase Formation ◽  
Electrical Characterization ◽  
Solid State Reactions ◽  
Film Diffusion ◽  
Film Study ◽  
Thin Film Diffusion

ABSTRACTA fundamental and comprehensive approach has been taken to study Co//GaAs interfacial reactions, using phase diagram determination, bulk and thin-film diffusion couple studies, and electrical characterization. Phase formation sequences and interfacial morphologies are found to be similar in bulk and thin-film couples. Thermodynamic and kinetic analyses are used to rationalize the contact formations. The electrical properties of the contacts are correlated to the phase formation sequences and phase diagram information.

Solid-State Reactions in Ni(10 nm)/C(2 nm)/Si(001) Thin Film System

2007 ◽  
pp. 155-158
Author(s):  
Yu.N. Makogon ◽  
O.P. Pavlova ◽  
G. Beddies ◽  
A.V. Mogilatenko ◽  
O.V. Chukhrai
Keyword(s):  
Thin Film ◽  
Solid State ◽  
Solid State Reactions ◽  
Film System ◽  
Thin Film System

Structural and Concentration Heterogeneities during Formation of Silicide Phases in the Thin Film System Ti(5nm)/Ni(24nm)/Si(001)

2013 ◽  
Vol 344 ◽  
pp. 79-84
Author(s):  
S.I. Sidorenko ◽  
S.M. Voloshko ◽  
Yu.M. Мakogon ◽  
O.P. Pavlov ◽  
I.E. Kotenko ◽  
...  
Keyword(s):  
Thin Film ◽  
Mass Spectrometry ◽  
Solid State ◽  
Auger Spectroscopy ◽  
Solid State Reactions ◽  
Layer By Layer ◽  
Film System ◽  
X Ray ◽  
Thin Film System ◽  
Secondary Ions

By the methods of Auger-spectroscopy and mass-spectrometry of secondary ions, small-angle electron diffraction, X-ray and resistometry analyses the solid-state reactions in the Ti(5 nm)/ Ni(24 nm)/Si(001) thin film system at annealing in running nitrogen in the temperature interval of 723 – 1273 К are investigated. Regularities of phase transformations, consistency of solid-state reactions, layer-by-layer redistribution of components during annealing, features of surface morphology during formation of inclusions of silicide phases are established.

Solid state interfacial reactions of Ti3Al with Si3N4 and SiC

1992 ◽  
Vol 7 (5) ◽  
pp. 1253-1265 ◽  
Author(s):  
T.C. Chou ◽  
A. Joshi
Keyword(s):  
Silicon Carbide ◽  
Solid State ◽  
Surface Region ◽  
Interfacial Reactions ◽  
Titanium Silicide ◽  
Reaction Products ◽  
Near Surface ◽  
Titanium Silicon Carbide ◽  
Titanium Silicon Nitride ◽  
Titanium Silicon

Solid state interfacial reactions of Ti3Al with Si3N4 and SiC have been studied via both bulk and thin film diffusion couples at temperatures of 1000 and 1200 °C. The nature of reactions of Ti3Al with Si3N4 and SiC was found to be similar. Only limited reactions were detected in samples reacted at 1000 °C. In the Ti3Al/Si3N4, layered reaction products consisting of mainly titanium silicide(s), titanium-silicon-aluminide, and titanium-silicon-nitride were formed; in the Ti3Al/SiC, the reaction product was primarily titanium-silicon-carbide. In both cases, silicon was enriched near the surface region, and aluminum was depleted from the reacted region. Reactions at 1200 °C resulted in a drastic change of the Si distribution profiles; the enrichment of Si in near surface regions was no longer observed, and the depletion of Al became more extensive. Titanium nitride and titanium-silicon-carbide were the major reaction products in the Ti3Al/Si3N4 and Ti3Al/SiC reactions, respectively. Mechanisms of driving the variation of Si, N, and C diffusion behavior (as a function of temperature) and the depletion of Al from the diffusion zone are suggested. It is proposed that reactions of Ti3Al with Si3N4 and SiC lead to in situ formation of a diffusion barrier, which limits the diffusion kinetics and further reaction. The thermodynamic driving force for the Ti3Al/Si3N4 reactions is discussed on the basis of Gibbs free energy.

Effect of c-Si1-xGex Thickness Grown by LPCVD on the Performance of Thin-Film a-Si/c-Si1-xGex/c-Si Heterojunction Solar Cells

2012 ◽  
Vol 1447 ◽  
Author(s):  
Sabina Abdul Hadi ◽  
Pouya Hashemi ◽  
Nicole DiLello ◽  
Ammar Nayfeh ◽  
Judy L. Hoyt
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Layer Thickness ◽  
Surface Region ◽  
Absorber Layer ◽  
Buffer Layers ◽  
Optical Carrier ◽  
Near Surface ◽  
Heterojunction Solar Cells ◽  
P Type

ABSTRACTIn this paper the effect of Si1-xGex absorber layer thickness on thin film a-Si:H/crystalline-Si1-xGex/c-Si heterojunction solar cells (HIT cells) is studied by simulation and experiment. Cells with 1, 2 and 4 μm-thick epitaxial cap layers of p-type Si0.59Ge0.41 on top of 5 μm Si1-xGex graded buffer layers are fabricated and compared to study the effect of the absorber layer thickness. The results show no change in Voc (0.41V) and that Jsc increases from 17.2 to 18.1 mA/cm2 when the Si0.59Ge0.41 absorber layer thickness is increased from 1 to 4 μm. The effect of thickness on Jsc is also observed for 2 and 4 μm-thick Si and Si0.75Ge0.25 absorber layers. Experiments and simulations show that larger Ge fractions result in a higher magnitude and smaller thickness dependence of Jsc, due to the larger absorption coefficient that increases optical carrier generation in the near surface region for larger Ge contents.

Comparison Of F2 Plasma Chemistries For Deep Etching Of SiC

2000 ◽  
Vol 640 ◽  
Author(s):  
K. P. Lee ◽  
P. Leerungnawarat ◽  
S. J. Pearton ◽  
F. Ren ◽  
S. N. G. Chu ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Etch Rate ◽  
Low Cost ◽  
Surface Region ◽  
High Rate ◽  
Near Surface ◽  
Ion Energy ◽  
Deep Etching ◽  
Process Pressure ◽  
Via Holes

ABSTRACTA number of F2-based plasma chemistries (NF3, SF6, PF5 and BF3) were investigated for high rate etching of SiC. The most advantageous of these is SF6, based on the high rate (0.6 μm · min−1) it achieves and its relatively low cost compared to NF3. The changes in electrical properties of the near-surface region are relatively minor when the incident ion energy is kept below approximately 75 eV. At a process pressure of 5 mTorr, the SiC etch rate falls-off by ∼15 % in 30 μm diameter via holes compared to larger diameter holes (> 60 μm diameter) or open areas on the mask.

Use of Pt Markers in the Study of Solid-State Reactions in the Presence of an Electric Field

1998 ◽  
Vol 4 (2) ◽  
pp. 158-163 ◽  
Author(s):  
Matthew T. Johnson ◽  
Shelley R. Gilliss ◽  
C. Barry Carter
Keyword(s):  
Thin Film ◽  
Solid State ◽  
Electric Field ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Solid State Reactions ◽  
Single Crystal Substrate ◽  
Fine Scale ◽  
Initial Location ◽  
Crystal Substrate

The use of Pt to mark the initial location of heterophase boundaries in solid-state reactions was extended to investigate the motion of interfaces during a thin-film solid-state reaction between In2O3 and MgO in the presence of an electric field. The Pt markers were prepared by sputtering a thin Pt film onto a single-crystal substrate. The resulting multilayer was then heated prior to thin-film deposition to de-wet the Pt film and thus form an array of small, isolated particles. These particles serve as fine-scale markers for tracking the motion of interfaces. However, there are certain situations in which the markers can move with the interface.

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