Silicon Germanium
Mostrando 1-12 de 12 artigos, teses e dissertações.
-
1. Estudo experimental do sistema Ta-Ge e da região rica em Ta do ternário Ta-Ge-B / Experimental Investigation of the Ta-Ge System and of the Ta Rich Region of Ta-Ge-B Ternary System.
Jet engines are important and complex engineering devices, whose efficiency and performance are directly related to the operating temperature of the combustion chamber, the higher the gas temperature in this region, the greater the overall efficiency of the process, resulting in economy of fuel and more efficiency. Ni-based superalloys are currently used in
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 22/05/2011
-
2. A comparison between channel selections in heavy ion reactions
The gamma rays de-exciting the yrast and near yrast states in neutron deficient as well as neutron rich nuclei from fusion-evaporation and deep-inelastic reactions and other emission particles have been recorded using an array of escape suppressed germanium detectors, a BGO ball, a recoil separator, silicon charge particle detectors and an ionization chamber
Brazilian Journal of Physics. Publicado em: 2009-03
-
3. Cristalização do germanio amorfo pelo aluminio : caracterização por espectroscopia Raman / Aluminium induced crystallization of the amorphous germanium : characterization for Raman spectroscopy
This research work studies the microscopic mechanisms leading to the low-temperature crystallization of amorphous germanium (a-Ge) films induced by aluminum. The crystallization process was studied in Al-doped samples and also in multi-layer structures possessing an Al layer sandwiched between the substrate and the a-Ge film. In the case of Al-doped samples,
Publicado em: 2007
-
4. Development of silicon-germanium films for MOS / Desenvolvimento de filmes de silicio-germanio para aplicações em dispositivos MOS
Conforme os dispositivos eletrônicos atingem dimensões nanométricas, surgem limitações que não podem ser solucionadas com os materiais empregados atualmente, como efeito de canal curto, depleção de porta, corrente de fuga e variação do Vt devido à variação estatística da dopagem. Dessa forma, novos materiais devem ser introduzidos no processo d
Publicado em: 2006
-
5. Synthesis and characterization of Ge nanocrystal by LPCVD / Sintese e caracterização de nanocristais de Ge por LPCVD
In this thesis we studied the synthesis of Ge nanocrystals (NCs) by the LPCVD technique (Low Pressure Chemical Vapor Deposition). We looked for NCs with characteristics of sizes, density and uniformity of sizes that are necessary for applications in floating gate memory devices. To reach those characteristics we have optimized the process conditions. The NCs
Publicado em: 2006
-
6. First-principles study of the adsorption of PH3 on Ge(001) and Si(001) surfaces
Using a first-principles pseudopotential method we have compared the adsorption and dissociation of the common n-type dopant molecule PH3 on the Si(001)-(21) and Ge(001){(21) surfaces. We find that the dissociated state is energetically more favourable than the molecular state by 1.70(0.81) eV, whereas the latter is 0.58(0.25) eV more stable than the system
Brazilian Journal of Physics. Publicado em: 2002-06
-
7. Tensores polares atomicos e energias das camadas internas
Atomic polar tensors were calculated for the group IV hydrides: CH4, SiH4, GeH4 and SnH4 based on the resolution of the sign ambiguities in the dipole moment derivatives using principal component analysis and ab initio calculations. The proposed tensors result from the analysis of different sets of experimental intensity values of gas phase infrared fundamen
Publicado em: 1999
-
8. Cristalização uniforme e seletiva de materiais semicondutores amorfos utilizando pulsos curtos de uma fonte de luz laser
We have investigated the laser induced crystallization of amorphous semiconductors using short-pulses (5-7 ns wide) from the second harmonic (l = 532 nm) of a Nd:Yag laser source. The main studied material was the amorphous germanium (a-Ge), while some alloys like its hydrogenated counterpart (a-Ge:H), silicon-germanium (a-SiGe) and germanium nitride (a-GeN)
Publicado em: 1998
-
9. Caracterização de filmes finos por difração de raios-X com baixo angulo de incidencia
In this work we present a study of thin and ultrathin3 films by X-Ray diffraction with asymmetric ref1ection and small incidence angle using a Guinier goniometer. The main purpose of this work was to study, in general, the properties of the diffraction by asymmetric ref1ection showing alI the possibilities of this technique when applied to the study of thin
Publicado em: 1995
-
10. Nitrogenio em semicondutores amorfos
This work presents experimental data referring to the effects resulting from the introduction of nitrogen into amorphous silicon and germanium. AlI the samples studied in this work were deposited as thin films using the rf reactive sputtering technique in highly controlled Ar+(H2)+N2 gaseous atmospheres. It is shown that either the nitrogen presence and its
Publicado em: 1995
-
11. ENHANCED DIFFUSION AND ELECTRICAL BEHAVIOR OF MISFIT DISLOCATIONS IN EPITAXIAL Si/Si(Ge)
This dissertation addresses enhanced or \"pipe\" diffusion of dopants along localized misfit dislocations (MD) using a \"model\" misfit dislocation structure at epitaxial Si/Si(Ge) interfaces and provides basic information on the merits of applicability of novel bandgap engineered devices. Pipe diffusion is modeled and explored to create pipe-like one dimens
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 1994
-
12. Tunneling microscopy of silicon and germanium