Materials Science and Engineering Commons^™

Design Of Gradient Index Optical Thin Films, Jeffrey J. Druessel

Theses and Dissertations

Gradient index thin films provide greater flexibility for the design of optical coatings than the more conventional 'layer' films. In addition, gradient index films have higher damage thresholds and better adhesion properties. This dissertation presents an enhancement to the existing inverse Fourier transform gradient index design method, and develops a new optimal design method for gradient index films using a generalized Fourier series approach. The inverse Fourier transform method is modified to include use of the phase of the index profile as a variable in rugate filter design. Use of an optimal phase function in Fourier-based filter designs reduces the …

Synthesis And Characterization Of Silicon Nitride Films Deposited By Plasma Enhanced Chemical Vapor Deposition Using Diethylsilane, Yanyao Yu

Theses

Silicon nitride thin films were deposited on silicon substrates using Diethylsilane (DES) and ammonia by Plasma Enhanced Chemical Vapor Deposition (PECVD) over a temperature range of 100 - 300°C, a pressure range of 0.2 - 0.6 torr, and a ratio of NH₃/DES was varied from 6 - 26. The R.F. power and frequency were kept at 0.15 watts/cm^{2 and 100 KHz respectively. DES flow rate was set at 15 sccm for all experiments in this study. One set of experiments were performed at different values of one parameter while the other parameters were kept constant.}

The deposition …

Design And Performance Evaluation Of A Gas Chromatograph Micromachined In A Single Crystal Silicon Substrate, Rocky R. Reston

Theses and Dissertations

This investigation designed and developed a miniature gas chromatograph (GC) using silicon micromachining techniques. The GC is composed of a miniature sample injector (10 µl sample loop); a 0.9 m long, rectangular-shaped (300 µm width and 10 micrometers height) capillary column coated with a 0.2 µm thick copper phthalocyanine (CuPc) stationary phase; and a dual-detector scheme incorporating a CuPc-coated chemiresistor and a 125 µm diameter thermal conductivity detector bead. Micromachining was employed to fabricate the sample injector interface, the GC column, and the dual-detector cavity. A novel processing technique was developed to sublime the CuPc stationary phase coating on the …

Synthesis And Characterization Of Lpcvd Boron Nitride Films For X-Ray Lithography, Wen-Pin Kuo

Theses

Boron nitride thin films were deposited on silicon and fused quartz substrates using ammonia and the liquid precursor borane-triethylamine complex (TEAB) by low pressure chemical vapor deposition over a temperature range of 300-850°C, a pressure range of 0.21-0.6 torr, and an ammonia flow rate range of 0-740 sccm. An increased in the nitrogen content in the film due to the addition of ammonia flow resulted in a pronounced improvement in the optical transmission, an increase in the film uniformity and a decrease in the depletion effect. IR spectra of the films showed an asymmetrical wide band centered around 1400 cm …

Intermetallic Reactions In Vacuum-Deposited Nickel And Gold Films On (111) Silicon Single Crystals, K. H. Yoon, Gordon Lewis, L. L. Levenson

Materials Science and Engineering Faculty Research & Creative Works

Pure nickel and gold thin films were vacuum-deposited on (111) silicon single crystals. When Ni/Au/Si or Au/Ni/Si samples were heated to about 550° in situ, hexagonal or deformed hexagonal shaped crystallites were formed on the silicon substrates. The composition of these crystallites was determined by using x-ray diffraction, scanning electron microscopy and scanning Auger microprobe methods. The crystallites were identified as NiSi2. The crystal-lites on the (111) silicon plane parallel to the surface appeared as regular hexagons while the inclined crystal-lites resembled trapezia. The results of Auger spectra and in-depth composition profiles for Ni, Au, and Si showed that the …

A Study Of Thin-Film Superconducting Junctions, William P. Korink

Electrical & Computer Engineering Theses & Dissertations

The information presented in this paper is the result of research conducted toward the development. of a reproducible thin-film superconducting junction. The results of this experimentation and the equipment and procedures used are provided.

A qualitative explanation is given for the theory used in the derivation of the volt-ampere characteristics of thin-film superconducting junctions of metal-insulator- metal construction. This explanation entails the electron flow through the insulating layer through the use of the Fermi-Dirac and density of states functions.

The theoretical investigation is based on the BCS Theory and results in volt-ampere characteristics that agree very well with published experimental …