A5014066453- Semiconductor Quantum Structures and Devices
- Quantum and electron transport phenomena
- Surface and Thin Film Phenomena
- Advanced Semiconductor Detectors and Materials
- Quantum Dots Synthesis And Properties
- ZnO doping and properties
- Optical Coatings and Gratings
- Integrated Circuits and Semiconductor Failure Analysis
- Advancements in Photolithography Techniques
- Semiconductor materials and devices
- Ion-surface interactions and analysis
- Semiconductor Lasers and Optical Devices
- Molecular Junctions and Nanostructures
- Electron and X-Ray Spectroscopy Techniques
- Surface Roughness and Optical Measurements
- Plasma Diagnostics and Applications
- Electrospun Nanofibers in Biomedical Applications
- Photonic and Optical Devices
- Microfluidic and Capillary Electrophoresis Applications
- Children's Physical and Motor Development
- Microfluidic and Bio-sensing Technologies
- Nanowire Synthesis and Applications
- Music Therapy and Health
- Advanced Electron Microscopy Techniques and Applications
- Optical measurement and interference techniques
ASML (Netherlands)
2013-2021
Bahçeşehir University
2021
Ankara Yıldırım Beyazıt University
2013-2019
Eindhoven University of Technology
2005-2013
RMIT University
2005-2006
The Sb-induced changes in the optical properties of GaAsSb-capped InAs/GaAs quantum dots (QDs) are shown to be strongly correlated with structural changes. observed redshift photoluminescence emission is follow two different regimes. In first regime, Sb concentrations up $\ensuremath{\sim}12\mathrm{%}$, wavelength shifts $\ensuremath{\sim}1280\text{ }\text{nm}$ a large enhancement luminescence characteristics. A analysis at atomic scale by cross-sectional scanning tunneling microscopy shows...
Structure-spectra relationship in semiconductor quantum dots (QDs) is investigated by subjecting the same QD sample to single-dot spectroscopy and cross-sectional scanning tunneling microscopy (XSTM) structural measurements. We find that conventional approach of using XSTM structure as input calculate spectra produces some notable conflicts with measured spectra. demonstrate a theoretical ``inverse approach'' which deciphers information from finds models agree both data. This effectively...
We report a combined experimental and theoretical analysis of Sb In segregation during the epitaxial growth InAs self-assembled quantum dot structures covered with GaSbAs strain-reducing capping layer. Cross-sectional scanning tunneling microscopy shows strong which extends through GaAsSb into GaAs matrix. compare various existing models used to describe exchange group III V atoms in semiconductors conclude that commonly methods only consider between two adjacent monolayers are insufficient...
The origin of the modified optical properties InAs/GaAs quantum dots (QD) capped with a thin GaAs1−xSbx layer is analyzed in terms band structure. To do so, size, shape, and composition QDs capping are determined through cross-sectional scanning tunnelling microscopy used as input parameters an 8 × k·p model. As Sb content increased, there two competing effects determining carrier confinement oscillator strength: increased QD height reduced strain on one side QD-capping valence offset other....
We investigate the exciton energy level structure of a large ensemble InAs/GaAs quantum rings by photoluminescence spectroscopy in magnetic fields up to 30 T for different excitation densities. The confinement an electron and hole these type I along with Coulomb interaction suppress excitonic Aharonov-Bohm effect. show that levels are nonequidistant split only two field, reflecting ringlike geometry. A model, based on realistic parameters self-assembled rings, allows us interpret essential...
Aggressive on-product overlay requirements in advanced nodes are setting a superior challenge for the semiconductor industry. This forces industry to look beyond traditional way-of-working and invest several new technologies. Integrated metrology<sup>2</sup>, in-chip control, sampling process correction-mechanism (using highest order of correction possible with scanner interface today), few such technologies considered this publication.
In this cross-sectional scanning tunneling microscopy study we investigated various techniques to control the shape of self-assembled quantum dots (QDs) and wetting layers (WLs). The result shows that application an indium flush during growth strained InGaAs/GaAs QD results in flattened QDs a reduced WL. height WLs could be controlled by varying thickness first capping layer. Concerning technique antimony show surfactant properties Sb preservation InAs/InP overgrowth. This achieved both...
We demonstrate the control of polarization and dipole moment in semiconductor nanostructures, through nanoscale engineering shape composition. Rodlike elongated along growth direction, are obtained by molecular beam epitaxial growth. By varying aspect ratio compositional contrast between rod surrounding matrix, we rotate dominant interband transition from transverse-electric to transverse-magnetic, modify producing a radical change voltage dependence absorption spectra. This opens way...
We present experimental evidence of Sb incorporation inside InAs/GaA(001) quantum dots exposed to an antimony flux immediately before capping with GaAs. The composition profile the nanostructures as measured by cross-sectional scanning tunneling and electron transmission microscopies show two differentiated regions within dots, rich alloy at tip dots. Atomic force microscopy micrographs increased quantum-dot height exposure. evolution reflection high-energy electron-diffraction pattern...
Several growth procedures for doping InAs/GaAs quantum dots (QDs) with manganese (Mn) have been investigated cross-sectional scanning tunneling microscopy. It is found that expulsion of Mn out the QDs and subsequent segregation makes it difficult to incorporate in even at low temperatures T=320 °C high fluxes. atoms around observed strain potential confinement changing appearance features.
We investigate the effect of an external magnetic field on physical properties acceptor hole states associated with single Mn acceptors placed near (110) surface GaAs. Cross-sectional scanning tunneling microscopy images local density (LDOS) show that strongly anisotropic wave function is not significantly affected by a up to 6 T. These experimental results are supported theoretical calculations based tight-binding model in For and subsurfaces immediately underneath, we find applied modifies...
The role of Sb atoms present on the growth front during capping InAs/InP (113)B quantum dots (QDs) is investigated by cross-sectional scanning tunnelling microscopy, atomic force and photoluminescence spectroscopy. Direct InAs QDs InP results in partial disassembly due to As/P exchange occurring at surface. However, when are supplied surface before layer overgrowth, preserve their uncapped shape, indicating that QD decomposition suppressed. When GaAs(0.51)Sb(0.49) layers deposited QDs,...
The target size reduction for overlay metrology is driven by the optimization of device area. Furthermore, future semiconductor nodes accurate on order 0.2 nm necessary locally in area, requiring small in-die targets that fit within product structures wafer. In this, diffraction-based using optical scatterometry challenged to extreme limits. grating cannot be considered as an infinitely repeating line-space structure with a sharply peaked spectrum, however continuous spectrum observed. Also,...
Theoretical analysis of the electron energy spectrum and magnetization in a strained In<sub><i>x</i></sub>Ga<sub>1-<i>x</i></sub>As/GaAs selfassembled quantum ring (SAQR) is performed using realistic parameters, determined from cross-sectional scanning-tunneling microscopy characterization. The Aharonov-Bohm oscillations persistent current have been observed low temperature measurements on these SAQRs. effect Coulomb interaction spectra SAQRs studied for rings with two electrons an exciton....
The on-product overlay roadmap demands an aggressive requirement in the advanced node. Currently is dominated by effects coming from wafer processing and target detectability. Processing such as symmetric stack variation asymmetric deformations are expected to become limiting for accurate measurements future nodes . Increased accuracy requirements overall complexity product stacks require a sensor with higher flexibility. To address this metrology system introduced fab, providing full...
The current state of the art ADI overlay metrology relies on multi-wavelength uDBO techniques. Combining wavelengths results in better robustness against process effects like induced grating asymmetries. Overlay information is extracted image plane by determining intensity asymmetry 1st order diffraction signals two pairs with an intentional shift (bias). In this paper we discuss a next evolution DBO targets where target created multiple biases. These so called cDBO (continuous bias DBO)...
(Ga${}_{1\ensuremath{-}x}$,Mn${}_{x}$)As/GaAs and (Ga${}_{1\ensuremath{-}x}$,Mn${}_{x}$)As/(Al${}_{0.2}$,Ga${}_{0.8}$)As multilayer structures grown by molecular beam epitaxy have been studied cross-sectional scanning tunneling microscopy. These dilute magnetic semiconductor predicted to a strong giant magnetoresistance effect enhanced Curie temperature. However, sharp short-period digital doping profile of the Mn acceptors is essential achieve this, therefore samples were at low growth...
Introduction: Bone marrow stimulation techniques are the most commonly preferred options in treatment of articular cartilage damage due to many features.Although nanofracture method that was developed order improve this technique has proven efficacy animal models and vitro studies, functional outcomes have not been shown actual patients.In study, our purpose compare clinical traditional microfracture knee joint.Material Methods: Patients operated using as group 1 (n=22) patients Nanofx...