Stress induced wavelength shift of thin film filter (TFF) were investigated. The substrate thickness of the TFF were greatly reduced by lapping to enhance the effects of stress. For CWDM TFF, no significant wavelength shift was observed by reducing their substrate thickness from 300 £gm to 70 £gm. Further, thermal stress caused by direct heating the thin TFF to 100¢J shows no effective changes of their optical characteristics. On the other hand, wavelength shifts induced by mechanical stress after reducing the substrate thickness of the DWDM TFF were observed. The maximum wavelength shift 3.8 nm was measured by lapping the substrate from 1mm to 120 £gm. Additional wavelength shifts of 3.5 nm were observed from the thin DWDM TFF if a lens fiber was brought into close contact with the thin DWDM TFF and was pushed forward for a distance of 45 £gm.

Zinc selenide is a wide bandgap II-VI semiconductor. The minimum bandgap at £F point (zone center) is direct and has a room temperature value of 2.67eV, corresponding to the blue region of the visible spectrum (464nm). Molecular beam epitaxy (MBE) is an ultra high vacuum technique used for the growth of semiconductors. The molecular beam epitaxy system used for the growth of semiconductors . The molecular beam epitaxy system used for growth of the II-VI semiconductor layers is described in detail in Chapter 2. Chapter 3 describes the substrate preparation procedure and growth of ZnSe epitaxial layers. Last, information from characterization technique has been used to analysis the quality of the layers and hence determine referred growth conditions.

Abstract Recently Cu has been used as a replacement of Al in microelectronics industry to its lower electrical resistivity and higher electromigration resistance than aluminum. It is essential to have high performance diffusion barrier to suppress the diffusion between Cu and Si . In this experiment ZrN was investigated as a possible diffusion barrier. All coatings were deposited by RF magnetron reactive sputtering system. The growth of ZrN has been evaluted at different vacuum condition¡BRF power¡Bgrowth time¡BN2 flow rate Ar flow rate and Zr or ZrN target. The thin films were then annealed at temperatures from 450 ¢J to 700 ¢J for 30 min to study its durability. In this work XRD was used to study the thin film structure, SEM and TEM study the microstructures and AFM to study the surface roughness . The film¡¦s resistivity was measured as a function of N2 flow rate and annealing temperature by four point probe . For pure Zr film Cu3Si phase has formed after annealing at 550 ¢J for 30 min . As to ZrN film, only CuZr2 is present after annealing at 650 ¢J for 30 min indicating the diffusion barrier is still effective. After annealing at 700 ¢J for 30 min, Cu3Si was detected indicating the failure of the diffusion barrier. Results up to now suggest that ZrN layer can be a successful candidate as a diffusion barrier between Cu and Si.

The thin-client/server computing model mandates applications running solely on a server and client devices connecting to the server through the Internet for carrying out works. Traditional thin-client/server computing model comprises only a single server and works only within LAN environment, which severely restrict its applicability. To meet the demand of reasonable response time over WAN, a modified thin-client/server computing model, MAS TC/S, was proposed. In MAS TC/S, multiple application servers spreading over WAN are installed, and each client device can freely connect to any application server that is close to it. However, reducing delay associated with fetching absent files, which are stored in other servers, is a challenging issue in MAS TC/S. We propose to employ data prefetching mechanisms to speed up file fetching. We use the suffix tree-like structure to store users¡¦ previous file access records and define two temporal relationships between two records: followed by or concurrent with, to decide the set of files that should be prefetched together. Each file access subsequence is associated with a set of predicted file sets, each carrying a different weight. Given a current file access session, we will first find a matching file access subsequence and then choose the predicted set that has the highest weight. Based on the chosen predicted set, suitable files are prefeteched to the connected server. We compare our method with All-Kth-Order Markov model and find our method gets higher hit ratio under various operating regions.

With the given information that dendrimers have precisely controlled their sizes and spherical structures in the molecular level, the aim of this study is to show that dendrimer particles can become ordered into a self-assembled regular structure due to the nature of their regular sizes and shapes. For this project, melamine based generation 3 dendrimer was used for solution cast of thin films from the dendrimer-chloroform solutions with different casting conditions, i.e. various solution concentrations, casting temperatures, and substrates. As a result of these experiments, unique phenomena of highly ordered uniform 2-D contraction separations were observed during the solvent evaporation from the dendrimer films. The cast films from the concentration of 0.8 wt% and higher exhibit regular 2-D separation contraction patterns and make well-developed regularly arrayed structures due to the interaction between the contraction stresses and adhesion strength between films and substrates. From the DSC tests, both powder and cast film samples of a dendrimer show similar melting behaviors with different areas under the melting peaks. The results of these tests show that dendrimers, when they are in a descent environment that provides dendrimers with molecular mobility due to surface ionic bonding strength, can make a structural order and regularity in their macroscopic structures.

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Transparent Conductive Oxide thin films (TCO) with low resistivity and high light transmission act as transparent electrode for many kinds of display panel. At present, Indium Tin Oxide (ITO) is common transparent electrode material. Because Indium is classified rare element, and it has toxicity. Moreover ITO is unstable in high temperature. Recent years many researches are searching adaptive materials to replace ITO. Al doped ZnO (AZO) has same characteristics of low resistivity and high light transmission, it is one of the adaptive materials. In this study, we choice AZO and ITO target. Sputtering is a common method to deposition TCO. We sputtered the AZO film and ITO film on glass substrate and measured the characteristics respectively. In addition, because Liquid Phase Deposition (LPD) has advantages of simple process, low cost and large amount of wafers can be used. Therefore, in this study we growth ZnO thin film on glass substrate simultaneously, and doped Aluminum to increase conductivity.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 86-92). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 164-173). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--University of Texas at Austin, 2003. / Vita. Includes bibliographical references. Available also from UMI Company.