The Interfacial Reactions in Ti/Si and Ni/Si Systems Observed by a Monoenergetic Positron Beam

1992 ◽  
Vol 262 ◽  
Author(s):  
S. Tanigawa ◽  
L. Wei ◽  
Y. Tabuki
Keyword(s):  
Diffusion Length ◽  
Positron Beam ◽  
Thin Film Deposition ◽  
Kirkendall Effect ◽  
Film Deposition ◽  
Si Substrate ◽  
Positron Energy ◽  
One Dimensional ◽  
Si Substrates ◽  
Dimensional Diffusion

ABSTRACTThe formation of suicides via the thin-film deposition of transition metals onto Si substrates has been investigated by a monoenergetic positron beam. The Doppler broadened spectra of annihilation radiations in the as-deposited state and the silicide-formed state of the Ti/Si and Ni/Si systems were measured as a function of the incident positron energy between 0.1 keV and 30 keV. From the depth dependence of positron annihilation characters, the diffusion length of positron was determined on the basis of one dimensional diffusion models. In the case of the Ti/Si, the formation of the suicides did not induce the shortening of positron diffusion length in Si substrate. On the contrary, the diffusion length of positrons in formed suicides was very short indicating the presence of a great number of positron traps in suicides. From this fact, the moving species during the silicidation may be Ti atoms. On the other hand, in the case of Ni/Si, the silicidation induced a very short diffusion length of positrons in the Si substrate. On the contrary, the diffusion length in the formed suicide is long to a comparable extent expected defect-free metals. From this fact, the moving species may be Si atoms. In the present parer, the first report on the microscopic observation of Kirkendall effect in metal/Si systems by means of a monoenergetic positron beam will be given.

Retarded Growth of Sputtered HfO2 Films on Germanium

2004 ◽  
Vol 811 ◽  
Author(s):  
Koji Kita ◽  
Masashi Sasagawa ◽  
Masahiro Toyama ◽  
Kentaro Kyuno ◽  
Akira Toriumi
Keyword(s):  
Film Growth ◽  
Early Stage ◽  
Gate Oxide ◽  
Interface Layer ◽  
Film Deposition ◽  
Si Substrate ◽  
Equivalent Thickness ◽  
Ternary Compounds ◽  
Si Substrates

ABSTRACTHfO2 films were deposited by reactive sputtering on Ge and Si substrates simultaneously, and we found not only the interface layer but the HfO2 film was thinner on Ge substrate compared with that on Si substrate. A metallic Hf layer has a crucial role for the thickness differences of both interface layer and HfO2 film, since those thickness differences were observed only when an ultrathin metallic Hf layer was predeposited before HfO2 film deposition. The role of metallic Hf is understandable by assuming a formation of volatile Hf-Ge-O ternary compounds at the early stage of film growth. These results show an advantage of HfO2/Ge over HfO2/Si systems from the viewpoint of further scaling of electrical equivalent thickness of the gate oxide films.

Carbon - silicon heterojunction diodes formed by CH4/ Ar rf plasma thin film deposition on Si substrates

1989 ◽  
Vol 162 ◽  
Author(s):  
G. A. J. Amaratunga ◽  
W. I. Milne ◽  
A. Putnis ◽  
K. K. Chan ◽  
K. J. Clay ◽  
...  
Keyword(s):  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Rf Plasma ◽  
Type I ◽  
Si Substrates ◽  
Semiconducting Properties ◽  
Electrical Breakdown Strength ◽  
Poly Crystalline Diamond

ABSTRACTThin C films deposited from a CH4/Ar plasma on Si substrates kept at 20C are shown to be semiconducting. The semiconducting properties are associated with the poly-crystalline diamond grains present within the films. Diode type I-V characteristics observed from AVC/Si verticle structures are explained by the action of a C-Si heterojunction. A band gap of 2eV, a resistivity of 106Ω.cm and an electrical breakdown strength of 5.106 V/cm are estimated for the C.

Reentrant Growth in Kinetic Thin-Film Deposition on Stepped Surfaces

1995 ◽  
Vol 399 ◽  
Author(s):  
Rong-Fu Xiao
Keyword(s):  
Thin Film ◽  
Monte Carlo Simulation ◽  
Deposition Temperature ◽  
Diffusion Length ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Natural Phenomenon ◽  
Two Dimensional ◽  
Stepped Surfaces ◽  
Thin Film Epitaxy

ABSTRACTWe have studied the reentrant growth in kinetic thin-film deposition on stepped surfaces using a Monte Carlo simulation. The results show that the reentrant oscillation of two dimensional nucleation growth occurs as a result of the variation of surface diffusion length with deposition temperature, and that it is a natural phenomenon in kinetic thin-film epitaxy on a substrate with a permanent step source.

Low-Cost Sputtering Process for Carbon Nanotubes Synthesis

2019 ◽  
Vol 891 ◽  
pp. 195-199
Author(s):  
Theerapol Thurakitseree ◽  
Chupong Pakpum
Keyword(s):  
Carbon Nanotubes ◽  
Low Cost ◽  
Chemical Vapor ◽  
Thin Film Deposition ◽  
Deposition Process ◽  
Film Deposition ◽  
Synthesis Process ◽  
Metal Thin Films ◽  
Si Substrates ◽  
Custom Made

According to their wonderful properties, carbon nanotubes (CNTs) have been well known for decades. The synthesis process and catalyst deposition method have also drawn attention to control the nanotube structure and properties. Sputtering method is then one promising option to grow the nanotubes in mass production. This method is, however, still costly. Here, we have presented a simple low-cost custom-made DC magnetron sputtering for catalyst thin film deposition. Three different metal thin films (Fe, Ni, Cu) deposited on Si substrates have been employed to investigate nanotube production. Prior to deposition of the catalysts, Al was used as supporting layer. (Al/Fe, Al/Ni, Al/Cu). CNTs were grown by chemical vapor deposition process at 800°C. Ethanol was preliminary used as a carbon source. It was found that CNTs could be successfully grown from only Al/Ni catalysts in our system with the diameter of approximately 200 nm, where the rest of samples were not observed. In addition, vertical-aligned CNTs with the thickness of about 10 μm could be obtained when acetylene was replaced instead of ethanol with reducing partial pressure of the feedstock. A large D-band at 1338 cm-1 with broader G-band at 1582 cm-1 from Raman spectra give a rise to multi layers growth of sp2 carbon walls. Such dimension suggests that it is the characteristic of multi-walled carbon nanotubes.

Titanium Oxynitride Thin Film Deposition by Pulsed Laser Ablation of Titanium Targets in Nitrogen

1992 ◽  
Vol 285 ◽  
Author(s):  
V. Craciun ◽  
D. Craciun ◽  
S. Amirhaghi ◽  
M. Vickers ◽  
S. Tarling ◽  
...  
Keyword(s):  
Chemical Resistance ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Thin Film Deposition ◽  
Nitrogen Atmosphere ◽  
Film Deposition ◽  
Laser Deposition ◽  
High Oxygen Content ◽  
Si Substrates ◽  
High Electrical Resistivity

ABSTRACTReactive pulsed laser deposition of titanium targets in a nitrogen atmosphere has been used to deposit thin titanium oxynitride films on Si substrates. The gold coloured layers exhibited a smooth, featureless surface and good chemical resistance in HF-HNO3 mixtures. The films had a high oxygen content which was responsible for relatively high electrical resistivity, measured to be 200–600 μΩ cm. This new method can easily be applied to the growth of other important nitrides such as ZrN, WN, HfN or the deposition of multilayer structures such as TiN/Ti on a variety of substrates.

Synthesis of BiFeO3 Ceramic Targets and Thin Film Deposition by Laser Ablation

2006 ◽  
Vol 514-516 ◽  
pp. 328-332 ◽  
Author(s):  
Cezarina C. Mardare ◽  
Pedro B. Tavares ◽  
Andréi I. Mardare ◽  
Raluca Savu
Keyword(s):  
Laser Ablation ◽  
Laser Energy ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Combustion Method ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates

A dense ceramic target of BiFeO3 was synthesized by the urea combustion method. X-ray diffraction indicates that this target is composed of a mixture of phases, the main one is BiFeO3, but Bi46Fe2O72 and Bi2Fe4O9 are also present in small amounts. The BiFeO3 target was used for depositing thin films on Pt/Ti/SiO2/Si substrates by the laser ablation technique. The depositions were made in oxygen atmosphere at pressures in the range between 5x10-3 and 2x10-2mbar, using a KrF laser. The substrate temperatures were 450 or 500°C and the laser energy, the frequency and the distance between the target and the substrate were kept constant at 125mJ, 10Hz and 4cm, respectively. After a deposition time of 30minutes the thickness of the films was approximately 400nm. Some of the films were heat-treated in situ, in 100mbar O2 for 30minutes, at the same temperatures used for deposition. X-ray diffraction results show the BiFeO3 phase, as well as some Bi46Fe2O72 and Bi2Fe4O9. The films were crystallized without any preferential orientation, but the ones made at 2x10-2mbar and 450°C were partially amorphous. For measuring the ferroelectric hysteresis loops, either Al top electrodes were deposited by thermal evaporation or Pt, by sputtering. The distorted shapes of the hysteresis loops obtained indicated that the films exhibit weak ferroelectric properties and high leakage current values.

Retarded Growth of Sputtered HfO2 Films on Germanium

2004 ◽  
Vol 809 ◽  
Author(s):  
Koji Kita ◽  
Masashi Sasagawa ◽  
Masahiro Toyama ◽  
Kentaro Kyuno ◽  
Akira Toriumi
Keyword(s):  
Film Growth ◽  
Early Stage ◽  
Gate Oxide ◽  
Interface Layer ◽  
Film Deposition ◽  
Si Substrate ◽  
Equivalent Thickness ◽  
Ternary Compounds ◽  
Si Substrates

ABSTRACTHfO2 films were deposited by reactive sputtering on Ge and Si substrates simultaneously, and we found not only the interface layer but the HfO2 film was thinner on Ge substrate compared with that on Si substrate. A metallic Hf layer has a crucial role for the thickness differences of both interface layer and HfO2 film, since those thickness differences were observed only when an ultrathin metallic Hf layer was predeposited before HfO2 film deposition. The role of metallic Hf is understandable by assuming a formation of volatile Hf-Ge-O ternary compounds at the early stage of film growth. These results show an advantage of HfO2/Ge over HfO2/Si systems from the viewpoint of further scaling of electrical equivalent thickness of the gate oxide films.

scholarly journals Micropits MEMS

2019 ◽  
Vol 6 (12) ◽  
Author(s):  
José Luis González-Vidal
Keyword(s):  
Thin Film ◽  
Gas Sensors ◽  
Etching Rate ◽  
Thin Film Deposition ◽  
Consumer Products ◽  
Film Deposition ◽  
Scanning Electronic Microscopy ◽  
Si Substrate ◽  
Mems Fabrication ◽  
Lift Off

Three sized Micropits were developed. Micropits were designed and fabricated using wet etching. MEMS fabrication consists of thin film deposition and patterned of several geometric structures. For Si substrate etching three layers SiO2/ Si3N4/ SiO2 were deposited and patterned. They were used as a mask. Micropit pattern was transferred by lift off technique. SiO2, Si3N4 layers and Si substrate were etched by HF, H3PO4 and KOH solutions. Si substrate has 7mm/h etching rate. Micropit micrographs were obtained by scanning electronic microscopy (SEM). Micropits are MEMS widely used in gas sensors, because they provide thermal isolation, Micropits will be used for gas microsensors, polisilicon microheater and gas sensor thin film will be deposited later. Today gas sensors have several applications in manufacturing & industry, such as, automotive, medicine/biomedical, consumer products, aerospace, chemical, optical displays, fluidics, wireless and optical communications.

Epitaxial Growth of 3C-SiC on Si Substrates by Atmospheric Hot Wall CVD Using Hexamethyledisilane[(CH3)6Si2]

2011 ◽  
Vol 679-680 ◽  
pp. 107-110
Author(s):  
Tae Woo Lee ◽  
Im Gyu Yeo ◽  
Byoung Chul Shin ◽  
Won Jae Lee ◽  
Mi Seon Park ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Epitaxial Growth ◽  
Optical Microscope ◽  
Source Material ◽  
Film Deposition ◽  
Color Patterns ◽  
Si Substrate ◽  
Si Substrates ◽  
Growth Profiles ◽  
Homogeneous Film

We adopted HMDS(Hexamethyledisilane) as a SiC(Silicon carbide) source material for epitaxial growth of 3C-SiC on Si substrate. Various growth profiles were investigated to optimize hetero-epitaxial growth of 3C-SiC layers. We also focused on the homogeneous film deposition of 3C-SiC on Si by employing two susceptor shapes, flat and tilted susceptors, to control a thickness of the boundary layer formed on the Si substrate. Fringe color patterns were observed on 3C-SiC layer on Si and hence it was easy to characterize the film uniformity by analyzing this color. 3C-SiC epitaxial layers were systematically analyzed by an optical microscope, a Raman spectroscopy, a SEM and an XRD.

Sign in / Sign up

Export Citation Format

Share Document