Stress evolution of Ge nanocrystals in dielectric matrices

Download
2018-05-04
Bahariqushchi, Rahim
Raciti, Rosario
KASAPOGLU, Ahmet Emre
GÜR, Emre
Sezen, Meltem
Kalay, Yunus Eren
MIRABELLA, Salvatore
Aydınlı, Alptekin
Germanium nanocrystals (Ge NCs) embedded in single and multilayer silicon oxide and silicon nitride matrices have been synthesized using plasma enhanced chemical vapor deposition followed by conventional furnace annealing or rapid thermal processing in N-2 ambient. Compositions of the films were determined by Rutherford backscattering spectrometry and x-ray photoelectron spectroscopy. The formation of NCs under suitable process conditions was observed with high resolution transmission electron microscope micrographs and Raman spectroscopy. Stress measurements were done using Raman shifts of the Ge optical phonon line at 300.7 cm(-1). The effect of the embedding matrix and annealing methods on Ge NC formation were investigated. In addition to Ge NCs in single layer samples, the stress on Ge NCs in multilayer samples was also analyzed. Multilayers of Ge NCs in a silicon nitride matrix separated by dielectric buffer layers to control the size and density of NCs were fabricated. Multilayers consisted of SiNy:Ge ultrathin films sandwiched between either SiO2 or Si3N4 by the proper choice of buffer material. We demonstrated that it is possible to tune the stress state of Ge NCs from compressive to tensile, a desirable property for optoelectronic applications. We also observed that there is a correlation between the stress and the crystallization threshold in which the compressive stress enhances the crystallization, while the tensile stress suppresses the process.
NANOTECHNOLOGY

Suggestions

Optical characterization of silicon based hydrogenated amorphous thin films by un-visible and infrared measurements
Kılıç, İlker; Katırcıoğlu, Bayram; Department of Physics (2006)
Various carbon content hydrogenated amorphous silicon carbide (a-Si1ŁxCx:H) and hydrogenated amorphous silicon (a-Si:H) thin films have been deposited on various substrates by using plasma enhanced chemical vapour deposition (PECVD) technique. Transmission spectra of these films have been determined within UV-Visible region and the obtained data were analysed to find related physical constants such as; refractive indices, thicknesses, etc. Fourier transform infrared (FT-IR) spectrometry technique has been u...
Vacuum-processed polyethylene as a dielectric for low operating voltage organic field effect transistors
Kanbur, Yasin; Irimia-Vladu, Mihai; Glowacki, Eric D.; Voss, Gundula; Baumgartner, Melanie; Schwabegger, Guenther; Leonat, Lucia; Ullah, Mujeeb; Sarica, Hizir; ERTEN ELA, ŞULE; Schwoediauer, Reinhard; Sitter, Helmut; Kucukyavuz, Zuhal; Bauer, Siegfried; Sariciftci, Niyazi Serdar (2012-05-01)
We report on the fabrication and performance of vacuum-processed organic field effect transistors utilizing evaporated low-density polyethylene (LD-PE) as a dielectric layer. With C-60 as the organic semiconductor, we demonstrate low operating voltage transistors with field effect mobilities in excess of 4 cm(2)/Vs. Devices with pentacene showed a mobility of 0.16 cm(2)/Vs. Devices using tyrian Purple as semiconductor show low-voltage ambipolar operation with equal electron and hole mobilities of similar to...
Thermal characterization of composites of polyamide-6 and polypropylene involving boron compounds via direct pyrolysis mass spectrometry
İşbaşar Afacan, Güllü Ceyda; Hacaloğlu, Jale; Yılmazer, Ülkü; Department of Polymer Science and Technology (2013)
In this work, the effects of addition of boron compounds, boron phosphate (BPO4), zinc borate (ZnB), borosilicate (BSi) and lanthanum borate (LaB), on thermal degradation characteristics of composites of polyamide 6 (PA6) and polypropylene (PP) are analyzed via Direct Pyrolysis Mass Spectrometry (DP-MS) technique. The composites of PA6 involve nitrogen containing flame retardants, melamine (Me) or melamine cyanurate (MC); or phosphorus containing flame retardant, aluminum diethylphosphinate (AlPi), with or ...
Controlled assemble and microfabrication of zeolite particles on SiO2 substrates for potential biosensor applications
Öztürk, Semra; Turan, Raşit; Akata Kurç, Burcu (2008-12-04)
Zeolite nanoparticles were organized into functional entities on SiO2 substrates and microfabrication technique was tested to form patterns of zeolite nanoparticles on SiO2 using the electron beam lithography (EBL). The effect of different techniques for efficient zeolite assembly on the SiO2 substrates was investigated. For this purpose, three different assembly techniques were tested. The first two methods are spin-coating (SC) and ultrasound aided strong agitation (US) methods, which were tested using ba...
Microstructural and dielectric properties of naphthalene based polyamide/β-Ni(OH)2 nanocomposites
Sezer, Selda; Öz, Erdinc; ALTIN, SERDAR; Vural, Sema; GÜLTEK, AHMET; KÖYTEPE, SÜLEYMAN; Nilüfer Kıvılcım, F. (2018-01-01)
Background: Aromatic polyamides are important materials having outstanding thermal, electronic and mechanical properties among high performance polymers and industrial plastics. In addition, aromatic polyamides can be utilized in electronic devices with their low dielectric constant which indicates the storage capacity of these devices. Objective: Free volume is very important for dielectric materials and increase in free volume of a polymer reduces its dielectric constant. The aims of the current study are...
Citation Formats
R. Bahariqushchi et al., “Stress evolution of Ge nanocrystals in dielectric matrices,” NANOTECHNOLOGY, pp. 0–0, 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/31094.