Showing papers on "Ellipsometry published in 1987"
1,094 citations
TL;DR: In this paper, a spectroscopic study using the techniques of ellipsometry and infrared (IR) absorption spectroscopy of the chemical bonding in silicon dioxide (SiO2) films grown in dry oxygen ambients at temperatures between 550 and 1000°C was presented.
Abstract: This paper presents a spectroscopic study using the techniques of ellipsometry and infrared (IR) absorption spectroscopy of the chemical bonding in silicon dioxide (SiO2) films grown in dry oxygen ambients at temperatures between 550 and 1000 °C. We find that the index of refraction at 632.8 nm increases and the frequency of the dominant IR active bond‐stretching vibration at about 1075 cm−1 decreases as the growth temperature is decreased below 1000 °C. Comparing the properties of these films with suboxides (SiOx, x<2) grown by plasma‐enhanced chemical vapor deposition, and compacted bulk silica has lead us to conclude: (i) that films grown at temperatures at or below 1000 °C are homogeneous stoichiometric oxides (SiO2); and (ii) that the systematic and correlated variations in the index of refraction and the IR frequency result from increases in the film density with decreasing growth temperature. We present a microscopic model that accounts for (i) the increases in the density and the index of refracti...
366 citations
145 citations
TL;DR: The optical properties of liquid silicon and germanium have been determined at several laser wavelengths from 1.96 to 3.71 eV, using time-resolved ellipsometric measurements during pulsed laser melting.
Abstract: The optical properties of liquid silicon and germanium have been determined at several laser wavelengths from 1.96 to 3.71 eV, using time‐resolved ellipsometric measurements during pulsed laser melting. The results from these transient melting experiments are compared with results from the literature for materials held above their melting temperatures for long periods of time. The results for liquid germanium agree well with those of J. N. Hodgson [Philos. Mag. 6, 509 (1961)], but the results for liquid silicon disagree with the results of K. M. Shvarev, B. A. Baum, and P. V. Gel’d [High Temp. 15, 548 (1977)].
130 citations
TL;DR: The optical properties of a surface polymer formed by electropolymerization of ortoaminophenol (OAP) are studied by ellipsometry and in situ visible spectrophotometry as mentioned in this paper.
79 citations
TL;DR: In this article, the authors used the Auger electron spectroscopy (AES) to determine the O/N ratio of thin films of silicon oxynitride (SiO2)x(Si3N4)(1−x) by remote plasma enhanced chemical vapor deposition by infrared (IR) absorption and ellipsometry.
Abstract: We have deposited thin films of silicon oxynitride (SiO2)x(Si3N4)(1−x) by remote plasma enhanced chemical vapor deposition by infrared (IR) absorption, Auger electron spectroscopy (AES), and ellipsometry. The dominant IR stretching band feature shifts approximately linearly with frequency between the frequencies of the end member compounds and as such is a very good secondary standard for the determination of alloy composition. This behavior is also indicative of a homogeneous alloy, rather than a two‐phase mixture. We have used AES to determine the O/N ratio and have combined this spectroscopy with the IR to confirm that the alloy films lie on the join line between SiO2 and Si3N4. Changes in the Si LVV line shape with alloy composition in the derivative AES spectrum make it impossible to use this feature as a measure of the relative Si composition. Finally, the ellipsometry measurements are also characteristic of a homogeneous alloy material.
77 citations
TL;DR: In this article, an in situ investigation of the growth of rf glowdischarge amorphous germanium and silicon (a•Ge:H) films using fast real-time spectroscopic phase-modulated elipsometry is presented.
Abstract: An in situ investigation of the growth of rf glow‐discharge amorphous germanium (a‐Ge:H) and silicon (a‐Si:H) films using fast real‐time spectroscopic phase‐modulated elipsometry is presented. The influence of the conditions of preparation is studied in both cases. The same behavior is obtained in a‐Ge:H and a‐Si:H films deposited in similar conditions. In particular, the initial stage of the growth can be described by a nucleation process in both cases, whatever the conditions of preparation. The incomplete coalescence of the nuclei leads to the formation of a surface roughness on a ∼40‐A scale which is observed during film growth. In comparing real‐time ellipsometry measurements performed at different wavelengths, a correlation between the internuclei distance and the thickness of the surface roughness is observed. An enhancement of the surface mobility of the reactive species due to an increase of substrate temperature and/or ion‐bombardment energy results in an increase in the density of the nucleatio...
73 citations
Book•
01 Jan 1987
TL;DR: In this paper, the authors proposed a method for applying ellipsometry to polymers at interfaces and in thin films, and showed the properties of polymers from surface quasi-Elastic Light Scattering.
Abstract: Application of Ellipsometry to Polymers at Interfaces and in Thin Films (D. Styrkas, et al.). MeV Ion Beam Profiling of Polymer Surfaces and Interfaces (M. Geoghegan). Phase Separation in Thin Films of Strongly Incompatible Polymer Blends (S. Walheim, et al.). Mechanical Properties of Polymer Interfaces (C. Creton). Neutron Reflectivity for the Study of Polymer Interfaces (R. Jones). Modification of Electrode Surfaces with Electroactive Polymers (A. Hillman, et al.). Interactions of Tethered Polyelectrolytes in Poor Solvents (C. Singh, et al.). Viscoelastic Properties of Polymer Films from Surface Quasi--Elastic Light Scattering (S. Peace & M. Taylor). Magnetic Resonance Relaxation and Imaging (P. McDonald & D. Lane). Surface Modification for Adhesion Minimization in Aqueous Environments (W.--L. Chen & K. Shull). Atmospheric versus Low--Pressure Plasma Oxidation of Rubber Surfaces (S. Wheale, et al.). Index.
64 citations
Book•
14 Dec 1987
TL;DR: In this paper, the authors present design rules for high speed rotating analyzer ellipsometers and their effect on the ellipsometric angles and the sample structure, as well as the effect of error effects on the Ellipsometric angle.
Abstract: 1. Basics of Ellipsometry.- 1.1 Physics.- 1.2 Instrumentation.- 1.2.1 Null Ellipsometry.- 1.2.2 Photometric Ellipsometry.- 1.3 Developments in Ellipsometry.- 1.4 Static and Dynamic Ellipsometry.- 2. Ellipsometry in Microelectronic Technology.- 2.1 Semiconductor Substrates and Films.- 2.2 Insulating Films.- 2.3 Etching Processes.- 3. Error Effects in Ellipsometric Investigations.- 3.1 Random Measurement Errors.- 3.2 Instrumentation Error Effects.- 3.2.1 Null Ellipsometers.- 3.2.1.1 Error Sources.- 3.2.1.2 Numerical Alignment.- 3.2.2 Rotating Analyzer Ellipsometers.- 3.2.2.1 Intrinsic Accuracy.- 3.2.2.2 Angular Encoder Orbiting.- 3.2.2.3 Periodic and Random Noise.- 3.2.2.4 The Influence of the Error Effects Discussed on the Ellipsometric Angles ? and ?.- 3.2.2.5 Design Rules for Rotating Analyzer Ellipsometers.- 3.3 Effects of the Sample Structure.- 3.3.1 Substrate Refractive Index.- 3.3.2 Interface Layer Between Substrate and Film.- Appendix A: Design Considerations for a High-Speed Rotating.- Analyzer Ellipsometer.- Al The Optical Assembly.- A2 Electronic Interface Circuitry.- A3 The Microcomputer System.- A3.1 Hardware.- A3.2 Software.- References.
52 citations
TL;DR: In this article, high-resolution transmission electron microscopy (HRTEM) and ellipsometry techniques have been employed to measure thicknesses of silicon oxide, grown at 800°C in dry oxygen, in the thickness range of 2-20 nm.
Abstract: High-resolution transmission electron microscopy (HRTEM) and ellipsometry techniques have been employed to measure thicknesses of silicon oxide, grown at 800°C in dry oxygen, in the thickness range of 2–20 nm. While the oxide growth data measured from TEM obey a nearly linear behavior, those obtained from ellipsometry are seen to vary nonlinearly. The interface structure as function of the increasing oxide thickness was studied using HRTEM. At these oxidation temperatures, the earlier reported variations of roughness at the interface on the oxide thickness for oxides grown at 900°C are not seen. Attempts aimed at correlating the high-resolution transmission electron micrographs with some physical parameters like the refractive index and the dielectric breakdown lead to considerations of the importance of the effect of protrusions of silicon atoms of 1 mm size into SiO2 layers on the interface properties. These findings lead to explanations of some key features concerning the refractive index and density of thin SiO2.
37 citations
TL;DR: In this article, high temperature oxygen ion implantation has been used to form buried oxide layers in silicon single crystals, which were subsequently annealed at high temperatures to form a buried SiO2 layer with sharp interfaces and to minimize dislocation densities in the top silicon layers.
Abstract: High‐temperature oxygen ion implantation has been used to form buried oxide layers in silicon single crystals. The ion implantation and substrate variables, particularly the substrate temperature, were optimized to obtain silicon layers with controlled microstructures near the surface. The as‐implanted specimens were subsequently annealed at high temperatures to form a buried SiO2 layer with sharp interfaces and to minimize dislocation densities in the top silicon layers. The specimens were characterized by cross‐section transmission electron microscopy and these results were compared with those obtained using spectroscopic ellipsometry. We discuss the application of the nondestructive scanning ellipsometry technique in the characterization of silicon‐on‐insulator materials.
TL;DR: In this article, the growth and ion-beam etching of dielectric zirconium oxide films have been deduced from in situ measurements by ellipsometry, photometry, and ion scattering spectroscopy for the cases of vapor-deposited films produced with or without ion assistance.
Abstract: Some aspects of the dynamics of growth and ion-beam etching of dielectric zirconium oxide films have been deduced from in situ measurements by ellipsometry, photometry, and ion scattering spectroscopy for the cases of vapor-deposited films produced with or without ion assistance. These measurements confirm that the porous microstructure exhibited by an evaporated film can be modified significantly by ion bombardment during growth, since ion and surface-atom recoil implantation lead to film densification. The ellipsometric data for ion-beam etching have been compared with a dynamical collision cascade model which has been used recently to describe ion-assisted thin-film densification. The model predicts the time evolution of the atomic densities and stoichiometry near the surface and considers the diffusion of atoms from overdensified and nonstoichiometric regions in terms of random-walk theory. The measured growth of the surface damage layer, which is formed during etching of a porous film, as well as the surface recession rate, can be explained quantitatively by the model.
TL;DR: In this paper, variable angle of incidence spectroscopic ellipsometry, cross-sectional transmission electron microscopy, and Rutherford backscattering are used to measure heterojunction layer thicknesses in the same AlGaAs/GaAs sample.
Abstract: Variable angle of incidence spectroscopic ellipsometry, cross‐sectional transmission electron microscopy, and Rutherford backscattering are used to measure heterojunction layer thicknesses in the same AlGaAs/GaAs sample. All three techniques yield the same thickness values within error limits. Two additional samples were implanted with 750‐keV Ga ions to fluences of 5×1015 and 1016 cm−2, respectively, and results of diagnostics measurements by the three techniques compared. The three techniques are found to complement each other in providing useful information.
TL;DR: Mesure de l'adsorption et de la desorption de triglycerides adsorbes sur une surface de polychlorure de vinyle as mentioned in this paper, where the surface is covered by polyvinyl chloride.
Abstract: Mesure de l'adsorption et de la desorption de triglycerides adsorbes sur une surface de polychlorure de vinyle
TL;DR: In this paper, in situ ellipsometry experiments have been used to study the initial nucleation and growth of glowdischarge hydrogenated amorphous silicon (a•Si:H) deposited on c•Si substrates under different conditions.
Abstract: In situ ellipsometry experiments have been used to study the initial nucleation and growth of glow‐discharge hydrogenated amorphous silicon (a‐Si:H) deposited on c‐Si substrates under different conditions. The substrate temperature (Ts), dc bias, and silane concentration in both hydrogen and inert gas diluents were varied. In the first ∼30–60 A of film growth, deviations of the in situ ellipsometry data from models assuming thickness independent dielectric functions are observed for a‐Si:H prepared under conditions that lead to a low density of electronic defects. The form of the deviations in the in situ data appear to be consistent with the development and convergence of densely packed clusters with a lateral extent of ∼20–30 A, not with a well‐dispersed distribution. The deviations disappear for Ts less than ∼200 °C and for flow ratios less than 1:20 (SiH4):(diluent). The low Ts effect is attributed to the lack of development of the initial growth microstructure caused by (1) the low mobility and desor...
13 Jul 1987
TL;DR: In situ spectroscopic ellipsometry is used to reveal the structural changes that occur in the initial stages of the growth of microcrystalline silicon (μc•Si) deposited by glow discharge decomposition of a (SiH4,H2) mixture on silica substrates as discussed by the authors.
Abstract: In situ spectroscopic ellipsometry is used to reveal the structural changes that occur in the initial stages of the growth of microcrystalline silicon (μc‐Si) deposited by glow discharge decomposition of a (SiH4,H2) mixture on silica substrates. In a first step, the real time measurements can be described by the following nucleation model: stable nuclei are created, with an average distance between them estimated to be ∼100 A, followed by the growth of three‐dimensional crystalline islands. In a second step an interfacial component composed of amorphous silicon and voids is produced as a consequence of the incomplete coalescence of the crystalline islands.
TL;DR: In this article, a vertical null-type ellipsometer was used with a homemade aluminum Teflon-coated Langmuir trough, to study thin films at gas-water interface.
Abstract: Ellipsometry is a sensitive nondestructive optical technique which can be successfully used for determining the thickness of an optically transparent thin film deposited on a dielectric substrate. In this laboratory we have constructed a vertical null‐type ellipsometer which has been used with a homemade aluminum Teflon‐coated Langmuir trough, to study thin films at gas–water interface. Surface pressure, surface potential, and ellipsometric measurements have been performed simultaneously. Ellipsometric measurements have been done directly on the aqueous substrate contained in the trough, with and without the film, with reproducibility (±0.02°) and good signal stability (±0.1 mV) on the 10‐mV scale. The performance of the homemade instrument had been checked against the known ellipsometric properties of spread arachidic acid on acidic water solution. In this paper, details of construction and performance of the ellipsometer as well as characteristics of the trough and ellipsometric study of β‐palmitoyl‐α‐o...
TL;DR: In this paper, the authors used spectroscopic ellipsometry to characterize high-dose oxygen implanted and 1350°C annealed silicon-on-insulator structures.
Abstract: Nondestructive characterization of high‐dose oxygen implanted and 1350 °C annealed silicon‐on‐insulator structures has been performed by spectroscopic ellipsometry. This method provides a fully in‐depth profiling (thickness and nature) of the structure including interfaces. Results have been confirmed by other techniques such as cross‐sectional transmission electron microscopy and high‐resolution Rutherford backscattering spectroscopy.
TL;DR: In this paper, the Drude parameters of liquid silicon at the melting temperature have been obtained from time-resolved reflectivity measurements at 1064, 532, and 355 nm following melting of an optically thick layer by a picosecond visible laser pulse.
Abstract: The Drude parameters of liquid silicon at the melting temperature have been obtained from time‐resolved reflectivity measurements at 1064, 532, and 355 nm following melting of an optically thick layer by a picosecond visible laser pulse. The ratio of the electron density N to the electron mass m is found to be equal to 2.17×1059 m−3 kg−1 and the relaxation time τ to be equal to 212 as. These values are compared to previous results obtained by cw ellipsometry between 1 and 0.4 μm and by nanosecond time‐resolved ellipsometry of 632.8 nm.
TL;DR: In this article, a combined system of Raman spectroscopy and ellipsometry is developed for the study of catalyst surfaces on which a chemical reaction is taking place, and the dielectric function and the thickness of a surface layer or a surface compound produced in the reaction are analyzed by ellipsometrics.
TL;DR: In this article, Sb layers, prepared under UHV conditions by thermal evaporation onto cleaved surfaces of GaAs and InP, were investigated by Raman scattering and ellipsometry.
TL;DR: Spectroscopic ellipsometric measurements followed by linear-regression analysis of the SE data obtained on ZnS and MgO films on vitreous silica substrates reveal the distribution of voids in these transparent thin films.
Abstract: Spectroscopic ellipsometric (SE) measurements followed by linear-regression analysis of the SE data obtained on ZnS and MgO films on vitreous silica substrates reveal the distribution of voids (or low-density regions) in these transparent thin films.
TL;DR: In this article, thin films of suboxides of silicon (SiOx, 1.4
Abstract: Thin films of suboxides of silicon (SiOx, 1.4
TL;DR: The low-energy optical data are interpreted in terms of intraband transitions, which allows us to calculate the dc conductivity as well as other electronic transport parameters, and these parameters agree well with the electrical conductivities and the Hall coefficients obtained by the van der Pauw technique.
Abstract: The optical and electrical properties were measured for single crystals of ${\mathrm{NbC}}_{\mathrm{x}}$ for x=0.98, 0.87, and 0.76, and for one hot-isostatically-pressed sample of ${\mathrm{NbC}}_{0.88}$. Specular reflectance was measured between 0.025 and 11 eV, and ellipsometry measurements were made at 1.96 eV. By using the phase obtained from ellipsometry data to correct the Kramers-Kronig analyses of the reflectances, we were able to improve the accuracy of the resulting optical functions. For energies below 6.5 eV, there are differences in the reflectance and optical functions of the samples which are due to differences in x. We interpret the low-energy optical data in terms of intraband transitions, which allows us to calculate the dc conductivity as well as other electronic transport parameters. These parameters agree well with the electrical conductivities and the Hall coefficients obtained by the van der Pauw technique. The higher-energy optical data are interpreted in light of recent electronic-structure calculations, which suggest that most interband transitions occur near the square face of the Brillouin zone.
TL;DR: In this paper, the optical properties of the buried oxide in silicon-on-insulator films synthesized by oxygen implantation are investigated by ellipsometry performed during progressive etching of the structure.
TL;DR: With a transmission ellipsometer working automatically on the basis of an eight-zone measuring method, resolution and reproducibility are attained which are 1-2 decades better than that of commercial research reflection ellipsometers.
Abstract: A new transmission ellipsometric method—based on an eight-zone measurement—allows determination of birefringent properties of transparent systems and samples. In addition to well-known magnitudes (relative retardation Δ and polarization-dependent loss ψ) of reflection ellipsometry, two additional magnitudes—orientation of the optical axis φ and pseudoactivity angle ρ—have to be ascertained. With a transmission ellipsometer working automatically on the basis of an eight-zone measuring method we attained resolution and reproducibility which is 1–2 decades better than that of commercial research reflection ellipsometers.
TL;DR: In this article, a multipolar plasma passivation scheme controlled by in-situ ellipsometry has been developed to produce a high electrical quality InGaAs/Si3N4 interface.
TL;DR: Improved numerical techniques for the calculation of the reflection of electromagnetic waves by an arbitrary stratified inhomogeneity are derived and assessed in this paper, where the inhomogeneous is sectioned into thin layers, in each of which the dielectric function is taken to vary linearly, or cubically, with depth.
Abstract: Improved numerical techniques for the calculation of the reflection of electromagnetic waves by an arbitrary stratified inhomogeneity are derived and assessed. The inhomogeneity is sectioned into thin layers, in each of which the dielectric function is taken to vary linearly, or cubically, with depth. The matrices representing each layer are calculated to third order in layer thickness. Some general properties of the matrices used in these calculations are also presented.