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in creator/contributor: "Jellison, G.E."

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The calculation of thin film parameters from spectroscopic ellipsometry data

Spectroscopic ellipsometry (SE) has proven to be a very powerful diagnostic for thin film characterization, but the results of SE experiments must first be compared with calculations to determine thin film parameters such as film thickness and optical functions. This process requires 4 steps: (1) The quantities measured must be specified and the equivalent calculated parameters identified. (2) The film structure must be modeled, where the number of films is specified and certain characteristics… more

Date: February 1996

Creator: Jellison, G. E., Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Fundamental aspects of pulsed-laser irradiation of semiconductors

Fundamental aspects of pulsed laser melting and solidification of crystalline silicon and germanium are reviewed. The discussion concentrates on time-resolved experiments performed with nanosecond pulsed lasers, although some picosecond and femtosecond experiments are also considered. The creation of amorphous material from crystalline material induced by ultrarapid melting and resolidification using either nanosecond or picosecond lasers is surveyed and the inverse process of recrystallization… more

Date: August 1, 1986

Creator: Jellison, G. E., Jr.; Lowndes, D. H. & Wood, R. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Spectroscopic ellipsometry data analysis: Measured vs. calculated quantities

Spectroscopic ellipsometry is a very powerful technique for optical characterization of thin-film and bulk materials, but the technique measures functions of complex reflection coefficients, which are usually not of interest per se. The interesting characteristics such as film thickness, surface roughness thickness, and optical functions can be determined only by modeling the near-surface region of the sample. However, the measured quantities are not equivalent to those determined from the mode… more

Date: May 1, 1997

Creator: Jellison, G. E., Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Molecular-jet chemical vapor deposition of SiC

SiC films have been deposited by molecular-jet chemical vapor deposition (MJCVD) on Si(001) substrates. Methylsilane (MS) diluted in He was used as a precursor for deposition under conditions which produced a MS molecular beam with 0.365 eV translational energy. Films grown at temperatures between 1000 and 1150 C and above {approx}1200 C were single crystal as judged by electron channeling, while those grown at intermediate temperatures were polycrystalline. Films grown at lower temperatures ge… more

Date: September 1, 1995

Creator: Lubben, D.; Jellison, G.E. & Modine, F.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Time-resolved studies of ultrarapid solidification of highly undercooled molten silicon formed by pulsed laser irradiation

This paper reports new results of nanosecond-resolution time-resolved optical reflectivity measurements, during pulsed excimer (KrF, 248 nm) laser irradiation of Si-implanted amorphous (a) silicon layers, which, together with model calculations and post-irradiation TEM measurements, have allowed us to study both the transformation of a-Si to a highly undercooled liquid (l) phase and the subsequent ultrarapid solidification process.

Date: July 20, 1984

Creator: Lowndes, D. H.; Jellison, G. E., Jr.; Wood, R. F. & Carpenter, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Time-resolved reflectivity measurements of silicon and germanium pulsed excimer laser irradiation

Time-resolved reflectivity measurements of silicon and germanium have been made during pulsed KrF excimer laser irradiation. The reflectivity was measured simultaneously at both 1152 and 632.8 nm wavelengths, and the energy density of each laser pulse was monitored. The melt duration and the time of the onset of melting were measured and compared with the results of melting model calculations. For energy densities just above the melting threshold, it was found that the melt duration was never l… more

Date: November 1, 1985

Creator: Jellison, G. E., Jr.; Lowndes, D. H.; Mashburn, D. N. & Wood, R. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The optical functions of silicon at elevated temperatures and their application to pulsed laser annealing

The results of measurements of the optical functions of silicon at elevated temperatures are reviewed and the results applied to pulsed laser annealing of silicon. Several optical experiments which were performed to understand the physics of pulsed laser annealing are described, and related to detailed thermal modeling. The fabrication of silicon solar cells using both thermal and laser processing is described, both of which give very goods results.

Date: June 1, 1993

Creator: Jellison, G. E., Jr.; Lowndes, D. H. & Wood, R. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Amorphous diamond-like carbon film growth by KrF- and ArF- excimer laser PLD: Correlation with plume properties

A comparative study of ArF- and KrF-laser deposition of amorphous diamond-like carbon (DLC) films and relevant carbon plasmas has been performed. Spectroscopic ellipsometry and EELS analysis of the DLC films deposited on Si <100> and NaCl substrates were utilized to characterize the high quality ArF- and KrF-laser deposited films (up to 84% of sp{sup 3} bonded carbon in 7 J/cm{sup 2} -ArF-laser DLC film). Gated ICCD imaging, luminescence and ion current probe diagnostics of the carbon plume hav… more

Date: April 1, 1995

Creator: Puretzky, A.A.; Geohegan, D.B. & Jellison, G. E., Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Calibration Procedures for a Two-Modulator Generalized Ellipsometer

A Two-Modulator Generalized Ellipsometer (2-MGE) has been extremely useful in characterizing optical properties of uniaxial bulk materials, thin films and diffraction gratings. The instrument consists of two polarizer-photoelastic modulator pairs, one operating as the polarization state generator and the other as the polarization state detector. Each photoelastic modulator operates at a different remnant frequency (such as 50 kHz and 60 kHz), making it possible to measure eight elements of the … more

Date: July 18, 1999

Creator: Chen, C.; Jellison, G. E., Jr. & Modine, F.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Development of the Two-Modulator Generalized Ellipsometer (2-MGE) for Commercial Application

The two-modulator generalized ellipsometer (2-MGE) is an instrument that measures the change of light polarization upon interacting with a sample. The 2-MGE can operate in either reflection or transmission. In reflection, it acts as a generalized ellipsometer, measuring the standard ellipsometry parameters, as well as the cross-polarization parameters. In transmission, it measures all parameters associated with a general diattenuation and retarder. In this CRADA, Hinds and ORNL have explored th… more

Date: June 1, 2003

Creator: Jellison, G. E., Jr. & Griffiths, C.O. (Hinds Instruments, Inc.)

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Comparative diagnostics of ArF- and KrF-laser generated carbon plumes used for amorphous diamond-like carbon film deposition

A comparative study of ArF- and KrF-laser generated carbon plasmas has been performed under pulsed laser deposition conditions of amorphous diamond-like carbon (DLC) films. Gated-ICCD species-resolved imaging, luminescence spectroscopy and ion probe diagnostics have revealed distinct differences between the carbon plumes generated by ArF- and KrF-lasers. KrF-laser (6.7 J/cm{sup 2}) irradiation produces a less energetic carbon plasma containing larger amounts of luminescent C{sub 2} compared wit… more

Date: May 1, 1995

Creator: Puretzky, A.A.; Geohegan, D.B.; Jellison, G. E., Jr. & McGibbon, M.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Characterization of lithium phosphorous oxynitride thin films

Electrical and electrochemical properties of an amorphous thin-film lithium electrolyte, lithium phosphorous oxynitride (Lipon), have been studied with emphasis on the stability window vs Li metal and the behavior of the Li/Lipon interface. Ion conductivity of Lipon exhibits Arrhenius behavior at {minus}26 to +140 C, with a conductivity of 1.7 {times} 10{sup {minus}6}S/cm at 25 C and an activity energy of 0.50 {plus_minus} 0.01 eV. A stability window of 5.5 V was observed with respect to a Li{s… more

Date: January 1, 1996

Creator: Yu, Xiaohua; Bates, J. B. & Jellison, G. E., Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Spectroscopic ellipsometry characterization of thin-film silicon nitride

We have measured and analyzed the optical characteristics of a series of silicon nitride thin films prepared by plasma-enhanced chemical vapor deposition on silicon substrates for photovoltaic applications. Spectroscopic ellipsometry measurements were made by using a two-channel spectroscopic polarization modulator ellipsometer that measures N, S, and C data simultaneously. The data were fit to a model consisting of air / roughness / SiN / crystalline silicon. The roughness was modeled using th… more

Date: May 1, 1997

Creator: Jellison, G. E., Jr.; Modine, F.A.; Doshi, P. & Rohatgi, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Pulsed-Laser Deposited Amorphous Diamond and Related Materials: Synthesis, Characterization, and Field Emission Properties

Amorphous carbon films with variable sp{sup 3} content were produced by ArF (193nm) pulsed laser deposition. An in-situ ion probe was used to measure kinetic energy of C{sup +} ions. In contrast to measurements made as a function of laser fluence, ion probe measurements of kinetic energy are a convenient as well as more accurate and fundamental method for monitoring deposition conditions, with the advantage of being readily transferable for inter-laboratory comparisons. Electron energy loss spe… more

Date: January 23, 1999

Creator: Baylor, L. R.; Geohegan, D. B.; Jellison, G. E., Jr.; Lowndes, D. H.; Merkulov, V. I. & Puretzky, A. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Surface Engineering of Silicon and Carbon by Pulsed-Laser Ablation

Experiments are described in which a focused pulsed-excimer laser beam is used either to ablate a graphite target and deposit hydrogen-free amorphous carbon films, or to directly texture a silicon surface and produce arrays of high-aspect-ratio silicon microcolumns. In the first case, diamond-like carbon (or tetrahedral amorphous carbon, ta-C) films were deposited with the experimental conditions selected so that the masses and kinetic energies of incident carbon species were reasonably well co… more

Date: February 28, 1999

Creator: Fowlkes, J.D.; Geohegan, D.B.; Jellison, G. E., Jr.; Lowndes, D.H.; Merkulov, V.I.; Pedraza, A.J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Field Emission from Carbon Films Deposited by Controlled-Low-Energy Beams and CVD Sources

The principal interests in this work are energetic-beam control of carbon-film properties and the roles of doping and surface morphology in field emission.

Date: November 29, 1999

Creator: Lowndes, D. H.; Merkulov, V.I.; Baylor, L.R.; Jellison, G. E., Jr.; Poker, D. B.; Kim, S. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Photovoltaic Materials

The goal of the current project was to help make the US solar industry a world leader in the manufacture of thin film photovoltaics. The overall approach was to leverage ORNL’s unique characterization and processing technologies to gain a better understanding of the fundamental challenges for solar cell processing and apply that knowledge to targeted projects with industry members. ORNL has the capabilities in place and the expertise required to understand how basic material properties includin… more

Date: October 15, 2012

Creator: Duty, C.; Angelini, J.; Armstrong, B.; Bennett, C.; Evans, B.; Jellison, G. E. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department