Orest Glembocki - Academia.edu (original) (raw)
Papers by Orest Glembocki
Dependence of etching roughness on molarity temperature and surface preparation for Si in aqueous... more Dependence of etching roughness on molarity temperature and surface preparation for Si in aqueous KOH
: These proceedings consist of refereed papers presented at the symposium on "Control of Sem... more : These proceedings consist of refereed papers presented at the symposium on "Control of Semiconductor Surfaces and Interfaces," held as a part of the 1996 MRS Fall Meeting in Boston, MA. Semiconductor surfaces and interfaces play a vital role in modern-day electronic devices. This is especially true as device dimensions shrink. The properties of clean surfaces and chemically processed surfaces can also have a significant impact on the properties of subsequently grown layers. These surfaces and interfaces may exhibit modified structural, electronic and optical properties, so it is important to understand their effects on subsequent growth, processing and device fabrication. In this symposium topics include the structure of surfaces, control of surface defects and properties through chemical etching and passivation, modification of surfaces for growth and processing, nucleation on semiconductor surfaces and self-assembly, the effects of surfaces and interfaces on subsequent...
Chemischer Informationsdienst, 1985
ChemInform Abstract Ellipsometrische Messungen werden gleichzeitig mit Zellstrom-und Spannungsmes... more ChemInform Abstract Ellipsometrische Messungen werden gleichzeitig mit Zellstrom-und Spannungsmessungen in 2 M KOH an Si-Proben unterschiedlicher kristallographischer Orientierung und Dotierungsart während des Siüx-Oberflächen?lmwachstums unter anodischer und kathodischer Vorspannung durchgeführt. Es wird ein Modell zur Erklärung der Orientierungsabhängigkeit derÄtzrate entwickelt.
Handbook of Optical Constants of Solids, 1997
Publisher Summary The aluminum gallium arsenide (AlxGa1-xAs) system is technologically one of the... more Publisher Summary The aluminum gallium arsenide (AlxGa1-xAs) system is technologically one of the most important alloy systems, especially when combined with GaAs. It forms the basis of quantum-well, superlattice, and single-barrier device structures, which in turn have a significant effect on high-speed electro-optics. It is noted that a fair amount of information about AlxGa1-xAs parameters—such as lattice constant, density, band gap, and phonon frequency is available. Little data for the absorption coefficient at the band edge is found, because the alloy samples are always on a GaAs substrate with a band gap smaller than the alloy film. The n and k values in the far infrared for AlxGa1-xAs are obtained by fitting the reflectivity data taken near normal incidence. The AlxGa1-xAs samples are grown by an isothermal liquid-phase-epitaxy technique for x values ranging from 0 to 0.54. The alloy compositions are evaluated by the analysis of X-ray emission produced from the layer by the electron beam of an ARL model EMX-SM electron-probe micro-analyzer.
Handbook of Optical Constants of Solids, 1997
Publisher Summary It is observed that the index of refraction of Indium Phosphide (InP) is report... more Publisher Summary It is observed that the index of refraction of Indium Phosphide (InP) is reported over a wide range of photon energies, 1.2 meV to 20 eV. Various techniques are employed in these measurements, and there is an overlap in the data obtained from different sources. Cardona measures the reflectivity of InP in the 1-20-eV range. The sample surfaces are prepared by mechanical polishing with Linde A-5175 compound. The reflection spectra are measured and the samples are etched in a 1:1 solution of HNO3 and HCl to remove any damage and to improve the reflectivity. The reflection spectra are Kramers-Kronig (KK) analyzed. The 6-eV cutoff of Cardona's values of refractive index n and extinction coefficient k results from the availability of better measurements from 1.5 to 6 eV. Aspnes and Studna have obtained the optical constants of InP and of other semiconductors, through the use of spectroscopic ellipsometry.
Physical Review B, 2005
Reflection measurements in the near-band-edge region of bulk AlN crystals have been performed as ... more Reflection measurements in the near-band-edge region of bulk AlN crystals have been performed as a function of temperature. The optical reflectance spectra of an a-face AlN sample show a feature at about 6.029 eV, which we assign to the free exciton A. The observation of the free exciton A first excited state yields the estimated values of the direct band gap and the limit of the electron effective mass. Optical reflectance measurements performed on AlN samples with two different crystallographic orientations allow the observation of transitions associated with the optical selection rules related to the so-called A , B, and C excitons. It was not possible to fully resolve the Band C-excitonic transitions, which were observed at about 6.243 and 6.268 eV, respectively. Using the measured exciton energies and a quasicubic model developed for the wurzite crystal structure we estimate the spin-orbit splitting ␦ = 36 meV and the crystal-field splitting ⌬ = −225 meV.
Journal of Electronic Materials, 2001
High density plasma etching of zinc selenide using CH 4 /H 2 /Ar plasma chemistries is investigat... more High density plasma etching of zinc selenide using CH 4 /H 2 /Ar plasma chemistries is investigated. Mass spectrometry, using through-the-platen sampling, is used to identify and monitor etch products evolving from the surface during etching. The identifiable primary etch products are Zn, Se, ZnH 2 , SeH 2 , Zn(CH 3) 2 , and Se(CH 3) 2. Their concentrations are monitored as ion and neutral fluxes (both in intensity and composition), ion energy, and substrate temperature are varied. General insights about the surface chemistry mechanisms of the etch process are given from these observations. Regions of process parameter space best suited for moderate rate, anisotropic, and low damage etching of ZnSe are proposed.
Journal of The Electrochemical Society, 1988
Applied Physics Letters, 1997
We present evidence that the energy introduced by a short laser pulse focused to high intensity o... more We present evidence that the energy introduced by a short laser pulse focused to high intensity on a small spot on the surface of neutron-transmutation-doped silicon electrically activates impurities far away from the focal spot. The activation of the impurities is measured by far-infrared spectroscopy of shallow donor levels and by magnetotransport characterization. Electrical activity is comparable to that obtained with conventional thermal annealing. X-ray rocking curve measurements show strain in the area of the focal spot, but none at large distances from the focal spot.
Journal of The Electrochemical Society, 1985
Mesures ellipsometriques realisees sur des pastilles de Si traitees dans une solution aqueuse de ... more Mesures ellipsometriques realisees sur des pastilles de Si traitees dans une solution aqueuse de KOH, pour differentes orientations cristallines et type de dopant, au cours de la croissance de couches de surface de SiO x . Les variations de l'epaisseur et de la stœchiometrie de la phase SiO x fournissent une base pour un modele de l'attaque de Si et pour l'influence de l'orientation sur la cinetique d'attaque
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures
ABSTRACT
AIP Conference Proceedings
We demonstrate a new mechanism for annealing silicon that does not involve the direct application... more We demonstrate a new mechanism for annealing silicon that does not involve the direct application of heat as in conventional thermal annealing or pulsed laser annealing. A laser pulse focused to high power on a small surface spot of a neutron-transmutation-doped silicon slab is shown to anneal regions far outside the illuminated spot where no heat was directly deposited. Electrical
Nanoepitaxy: Materials and Devices IV
ABSTRACT We have deposited Ag metal via plasma enhanced atomic layer deposition (PEALD) and we in... more ABSTRACT We have deposited Ag metal via plasma enhanced atomic layer deposition (PEALD) and we investigated the novel optical behavior of this material. We have found that as-deposited flat PEALD Ag films exhibit unexpected plasmonic properties and the plasmonic enhancement can differ markedly, depending on the microstructure of the Ag film. Electromagnetic field simulations indicate that this plasmonic behavior is due to air gaps that are an inherent property of the mosaiclike microstructure of the PEALD-grown Ag film. We show that this material is plasmonic by itself, and when combined with previously developed dielectric core nanowires, it can produce enhancements which are two orders of magnitude greater than those reported using electroless Ag or Ag produced by e-beam deposition. We have also investigated the effect of substrate on the plasmonic enhancement, as well deposition on fabric, which results in a flexible plasmonic material.
MRS Proceedings
ABSTRACTOptical Impedence Spectroscopy of GaN/AlGaN high electron mobility transistor structures ... more ABSTRACTOptical Impedence Spectroscopy of GaN/AlGaN high electron mobility transistor structures (HEMTs) using photoreflectance exhibit a photoreflectance lags – the component of the modulated reflectance out of phase with the chopper – ranging from 0.1 to 0.5. Photoreflectance was performed using below gap pumping on various samples. Samples that do exhibit appreciable photoreflectance lag for above gap pumping show significantly enhanced photoreflectance signals for below gap pumping. Yet, samples that do not exhibit appreciable photoreflectance lag for above gap pumping do not exhibit a signal for below gap pumping. This implies that the photoreflectance phase lag is due to mid-gap trap states. At least 2 types of traps are found, above and below about 2.5 eV. This result means that that photoreflectance can be used as a probe of HEMT device quality.
MRS Proceedings
Photoreflectance has been used to characterize the etch-induced damage in GaAs processed in an Ar... more Photoreflectance has been used to characterize the etch-induced damage in GaAs processed in an Ar/Cl2 plasma generated by an electron-cyclotron resonance (ECR) source. We show that the damage is localized to the surface and that it is most influenced by the RF power, with little effect from the microwave power. The Fermi-level is observed to be unchanged in n-GaAs and remains near midgap, while for p-GaAs, the Fermi level shifts from near the valence band to midgap. Etch-induced anisite defects are proposed as a possible source of the damage.
AIP Conference Proceedings
Electric fields in the GaN underlying the 2DEG of three GaN/AlGaN field effect transistor (FET) s... more Electric fields in the GaN underlying the 2DEG of three GaN/AlGaN field effect transistor (FET) structures measured by photoreflectance (PR) using sub-gap excitation were found to be about 210-260kVcm-1, indicating the presence of traps. The sample having the lowest electric field was taken from a wafer which yielded 0.3mum gate length devices having the highest power gain performance metrics; the
Nanoepitaxy: Homo- and Heterogeneous Synthesis, Characterization, and Device Integration of Nanomaterials II
ABSTRACT Surface enhanced Raman scattering (SERS) is a powerful technique for the detection of su... more ABSTRACT Surface enhanced Raman scattering (SERS) is a powerful technique for the detection of submonolayer coverage of gold or silver surfaces. The magnitude of the effect and the spectral wavelength of the peak depend on the metal nanoparticles used and its geometry. In this paper we show that the use of chemicals that bind to gold or silver can lead to the clustering of nanoparticles. We used well defined Au nanoparticles in our experiments and add cysteamine to solutions containing the nanoparticles. The plasmonic response of the nanoparticles is measured by transmission Surface Plasmon Resonance (SPR) spectroscopy. We observed significant changes to the SPR spectra that are characteristics of close coupled nanoparticles. The time evolution of these changes indicates the formation of gold nanoparticles clusters. The SERS response of these clustered nanoparticles is observed to red shift from the designed peak wavelength in the green to the red. In addition, the placement of these clusters on dielectric surfaces shifts the SPR even more into the red. The experimental results are supported by calculations of the electromagnetic fields using finite difference methods.
![Research paper thumbnail of OPTICAL PROPERTIES OF GaAs/AlGaAs MULTIPLE QUANTUM WELLS GROWN IN THE [111] CRYSTALLOGRAPHIC DIRECTION](https://attachments.academia-assets.com/66891965/thumbnails/1.jpg)
](Le Journal de Physique Colloques
Dependence of etching roughness on molarity temperature and surface preparation for Si in aqueous... more Dependence of etching roughness on molarity temperature and surface preparation for Si in aqueous KOH
: These proceedings consist of refereed papers presented at the symposium on "Control of Sem... more : These proceedings consist of refereed papers presented at the symposium on "Control of Semiconductor Surfaces and Interfaces," held as a part of the 1996 MRS Fall Meeting in Boston, MA. Semiconductor surfaces and interfaces play a vital role in modern-day electronic devices. This is especially true as device dimensions shrink. The properties of clean surfaces and chemically processed surfaces can also have a significant impact on the properties of subsequently grown layers. These surfaces and interfaces may exhibit modified structural, electronic and optical properties, so it is important to understand their effects on subsequent growth, processing and device fabrication. In this symposium topics include the structure of surfaces, control of surface defects and properties through chemical etching and passivation, modification of surfaces for growth and processing, nucleation on semiconductor surfaces and self-assembly, the effects of surfaces and interfaces on subsequent...
Chemischer Informationsdienst, 1985
ChemInform Abstract Ellipsometrische Messungen werden gleichzeitig mit Zellstrom-und Spannungsmes... more ChemInform Abstract Ellipsometrische Messungen werden gleichzeitig mit Zellstrom-und Spannungsmessungen in 2 M KOH an Si-Proben unterschiedlicher kristallographischer Orientierung und Dotierungsart während des Siüx-Oberflächen?lmwachstums unter anodischer und kathodischer Vorspannung durchgeführt. Es wird ein Modell zur Erklärung der Orientierungsabhängigkeit derÄtzrate entwickelt.
Handbook of Optical Constants of Solids, 1997
Publisher Summary The aluminum gallium arsenide (AlxGa1-xAs) system is technologically one of the... more Publisher Summary The aluminum gallium arsenide (AlxGa1-xAs) system is technologically one of the most important alloy systems, especially when combined with GaAs. It forms the basis of quantum-well, superlattice, and single-barrier device structures, which in turn have a significant effect on high-speed electro-optics. It is noted that a fair amount of information about AlxGa1-xAs parameters—such as lattice constant, density, band gap, and phonon frequency is available. Little data for the absorption coefficient at the band edge is found, because the alloy samples are always on a GaAs substrate with a band gap smaller than the alloy film. The n and k values in the far infrared for AlxGa1-xAs are obtained by fitting the reflectivity data taken near normal incidence. The AlxGa1-xAs samples are grown by an isothermal liquid-phase-epitaxy technique for x values ranging from 0 to 0.54. The alloy compositions are evaluated by the analysis of X-ray emission produced from the layer by the electron beam of an ARL model EMX-SM electron-probe micro-analyzer.
Handbook of Optical Constants of Solids, 1997
Publisher Summary It is observed that the index of refraction of Indium Phosphide (InP) is report... more Publisher Summary It is observed that the index of refraction of Indium Phosphide (InP) is reported over a wide range of photon energies, 1.2 meV to 20 eV. Various techniques are employed in these measurements, and there is an overlap in the data obtained from different sources. Cardona measures the reflectivity of InP in the 1-20-eV range. The sample surfaces are prepared by mechanical polishing with Linde A-5175 compound. The reflection spectra are measured and the samples are etched in a 1:1 solution of HNO3 and HCl to remove any damage and to improve the reflectivity. The reflection spectra are Kramers-Kronig (KK) analyzed. The 6-eV cutoff of Cardona's values of refractive index n and extinction coefficient k results from the availability of better measurements from 1.5 to 6 eV. Aspnes and Studna have obtained the optical constants of InP and of other semiconductors, through the use of spectroscopic ellipsometry.
Physical Review B, 2005
Reflection measurements in the near-band-edge region of bulk AlN crystals have been performed as ... more Reflection measurements in the near-band-edge region of bulk AlN crystals have been performed as a function of temperature. The optical reflectance spectra of an a-face AlN sample show a feature at about 6.029 eV, which we assign to the free exciton A. The observation of the free exciton A first excited state yields the estimated values of the direct band gap and the limit of the electron effective mass. Optical reflectance measurements performed on AlN samples with two different crystallographic orientations allow the observation of transitions associated with the optical selection rules related to the so-called A , B, and C excitons. It was not possible to fully resolve the Band C-excitonic transitions, which were observed at about 6.243 and 6.268 eV, respectively. Using the measured exciton energies and a quasicubic model developed for the wurzite crystal structure we estimate the spin-orbit splitting ␦ = 36 meV and the crystal-field splitting ⌬ = −225 meV.
Journal of Electronic Materials, 2001
High density plasma etching of zinc selenide using CH 4 /H 2 /Ar plasma chemistries is investigat... more High density plasma etching of zinc selenide using CH 4 /H 2 /Ar plasma chemistries is investigated. Mass spectrometry, using through-the-platen sampling, is used to identify and monitor etch products evolving from the surface during etching. The identifiable primary etch products are Zn, Se, ZnH 2 , SeH 2 , Zn(CH 3) 2 , and Se(CH 3) 2. Their concentrations are monitored as ion and neutral fluxes (both in intensity and composition), ion energy, and substrate temperature are varied. General insights about the surface chemistry mechanisms of the etch process are given from these observations. Regions of process parameter space best suited for moderate rate, anisotropic, and low damage etching of ZnSe are proposed.
Journal of The Electrochemical Society, 1988
Applied Physics Letters, 1997
We present evidence that the energy introduced by a short laser pulse focused to high intensity o... more We present evidence that the energy introduced by a short laser pulse focused to high intensity on a small spot on the surface of neutron-transmutation-doped silicon electrically activates impurities far away from the focal spot. The activation of the impurities is measured by far-infrared spectroscopy of shallow donor levels and by magnetotransport characterization. Electrical activity is comparable to that obtained with conventional thermal annealing. X-ray rocking curve measurements show strain in the area of the focal spot, but none at large distances from the focal spot.
Journal of The Electrochemical Society, 1985
Mesures ellipsometriques realisees sur des pastilles de Si traitees dans une solution aqueuse de ... more Mesures ellipsometriques realisees sur des pastilles de Si traitees dans une solution aqueuse de KOH, pour differentes orientations cristallines et type de dopant, au cours de la croissance de couches de surface de SiO x . Les variations de l'epaisseur et de la stœchiometrie de la phase SiO x fournissent une base pour un modele de l'attaque de Si et pour l'influence de l'orientation sur la cinetique d'attaque
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures
ABSTRACT
AIP Conference Proceedings
We demonstrate a new mechanism for annealing silicon that does not involve the direct application... more We demonstrate a new mechanism for annealing silicon that does not involve the direct application of heat as in conventional thermal annealing or pulsed laser annealing. A laser pulse focused to high power on a small surface spot of a neutron-transmutation-doped silicon slab is shown to anneal regions far outside the illuminated spot where no heat was directly deposited. Electrical
Nanoepitaxy: Materials and Devices IV
ABSTRACT We have deposited Ag metal via plasma enhanced atomic layer deposition (PEALD) and we in... more ABSTRACT We have deposited Ag metal via plasma enhanced atomic layer deposition (PEALD) and we investigated the novel optical behavior of this material. We have found that as-deposited flat PEALD Ag films exhibit unexpected plasmonic properties and the plasmonic enhancement can differ markedly, depending on the microstructure of the Ag film. Electromagnetic field simulations indicate that this plasmonic behavior is due to air gaps that are an inherent property of the mosaiclike microstructure of the PEALD-grown Ag film. We show that this material is plasmonic by itself, and when combined with previously developed dielectric core nanowires, it can produce enhancements which are two orders of magnitude greater than those reported using electroless Ag or Ag produced by e-beam deposition. We have also investigated the effect of substrate on the plasmonic enhancement, as well deposition on fabric, which results in a flexible plasmonic material.
MRS Proceedings
ABSTRACTOptical Impedence Spectroscopy of GaN/AlGaN high electron mobility transistor structures ... more ABSTRACTOptical Impedence Spectroscopy of GaN/AlGaN high electron mobility transistor structures (HEMTs) using photoreflectance exhibit a photoreflectance lags – the component of the modulated reflectance out of phase with the chopper – ranging from 0.1 to 0.5. Photoreflectance was performed using below gap pumping on various samples. Samples that do exhibit appreciable photoreflectance lag for above gap pumping show significantly enhanced photoreflectance signals for below gap pumping. Yet, samples that do not exhibit appreciable photoreflectance lag for above gap pumping do not exhibit a signal for below gap pumping. This implies that the photoreflectance phase lag is due to mid-gap trap states. At least 2 types of traps are found, above and below about 2.5 eV. This result means that that photoreflectance can be used as a probe of HEMT device quality.
MRS Proceedings
Photoreflectance has been used to characterize the etch-induced damage in GaAs processed in an Ar... more Photoreflectance has been used to characterize the etch-induced damage in GaAs processed in an Ar/Cl2 plasma generated by an electron-cyclotron resonance (ECR) source. We show that the damage is localized to the surface and that it is most influenced by the RF power, with little effect from the microwave power. The Fermi-level is observed to be unchanged in n-GaAs and remains near midgap, while for p-GaAs, the Fermi level shifts from near the valence band to midgap. Etch-induced anisite defects are proposed as a possible source of the damage.
AIP Conference Proceedings
Electric fields in the GaN underlying the 2DEG of three GaN/AlGaN field effect transistor (FET) s... more Electric fields in the GaN underlying the 2DEG of three GaN/AlGaN field effect transistor (FET) structures measured by photoreflectance (PR) using sub-gap excitation were found to be about 210-260kVcm-1, indicating the presence of traps. The sample having the lowest electric field was taken from a wafer which yielded 0.3mum gate length devices having the highest power gain performance metrics; the
Nanoepitaxy: Homo- and Heterogeneous Synthesis, Characterization, and Device Integration of Nanomaterials II
ABSTRACT Surface enhanced Raman scattering (SERS) is a powerful technique for the detection of su... more ABSTRACT Surface enhanced Raman scattering (SERS) is a powerful technique for the detection of submonolayer coverage of gold or silver surfaces. The magnitude of the effect and the spectral wavelength of the peak depend on the metal nanoparticles used and its geometry. In this paper we show that the use of chemicals that bind to gold or silver can lead to the clustering of nanoparticles. We used well defined Au nanoparticles in our experiments and add cysteamine to solutions containing the nanoparticles. The plasmonic response of the nanoparticles is measured by transmission Surface Plasmon Resonance (SPR) spectroscopy. We observed significant changes to the SPR spectra that are characteristics of close coupled nanoparticles. The time evolution of these changes indicates the formation of gold nanoparticles clusters. The SERS response of these clustered nanoparticles is observed to red shift from the designed peak wavelength in the green to the red. In addition, the placement of these clusters on dielectric surfaces shifts the SPR even more into the red. The experimental results are supported by calculations of the electromagnetic fields using finite difference methods.
Le Journal de Physique Colloques