Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
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- Creators: Crozier, Peter
- Creators: Jiang, Hanqing
Description
Ball Grid Array (BGA) using lead-free or lead-rich solder materials are widely used as Second Level Interconnects (SLI) in mounting packaged components to the printed circuit board (PCB). The reliability of these solder joints is of significant importance to the performance of microelectronics components and systems. Product design/form-factor, solder material, manufacturing process, use condition, as well as, the inherent variabilities present in the system, greatly influence product reliability. Accurate reliability analysis requires an integrated approach to concurrently account for all these factors and their synergistic effects. Such an integrated and robust methodology can be used in design and development of new and advanced microelectronics systems and can provide significant improvement in cycle-time, cost, and reliability. IMPRPK approach is based on a probabilistic methodology, focusing on three major tasks of (1) Characterization of BGA solder joints to identify failure mechanisms and obtain statistical data, (2) Finite Element analysis (FEM) to predict system response needed for life prediction, and (3) development of a probabilistic methodology to predict the reliability, as well as, the sensitivity of the system to various parameters and the variabilities. These tasks and the predictive capabilities of IMPRPK in microelectronic reliability analysis are discussed.
ContributorsFallah-Adl, Ali (Author) / Tasooji, Amaneh (Thesis advisor) / Krause, Stephen (Committee member) / Alford, Terry (Committee member) / Jiang, Hanqing (Committee member) / Mahajan, Ravi (Committee member) / Arizona State University (Publisher)
Created2013
Description
Two dimensional (2D) Janus Transition Metal Dichalcogenides (TMDs) are a new class of atomically thin polar materials. In these materials, the top and the bottom atomic layer are made of different chalcogen atoms. To date, several theoretical studies have shown that a broken mirror symmetry induces a colossal electrical field in these materials, which leads to unusual quantum properties. Despite these new properties, the current knowledge in their synthesis is limited only through two independent studies; both works rely on high-temperature processing techniques and are specific to only one type of 2D Janus material - MoSSe. Therefore, there is an urgent need for the development of a new synthesis method to (1) Extend the library of Janus class materials. (2) Improve the quality of 2D crystals. (3) Enable the synthesis of Janus heterostructures. The central hypothesis in this work is that the processing temperature of 2D Janus synthesis can be significantly lowered down to room temperatures by using reactive hydrogen and sulfur radicals while stripping off selenium atoms from the 2D surface. To test this hypothesis, a series of controlled growth studies were performed, and several complementary characterization techniques were used to establish a process–structure-property relationship. The results show that the newly proposed approach, namely Selective Epitaxy and Atomic Replacement (SEAR), is effective in reducing the growth temperature down to ambient conditions. The proposed technique benefits in achieving highly crystalline 2D Janus layers with an excellent optical response. Further studies herein show that this technique can form highly sophisticated lateral and vertical heterostructures of 2D Janus layers. Overall results establish an entirely new growth technique for 2D Janus.layers, which pave ways for the realization of exciting quantum effects in these materials such as Fulde–Ferrell–Larkin–Ovchinnikov (FFLO) state, Majorana fermions, and topological p-wave superconductors.
ContributorsSayyad, Mohammed Yasir (Author) / Tongay, Sefaattin (Thesis advisor) / Crozier, Peter (Committee member) / Alford, Terry (Committee member) / Arizona State University (Publisher)
Created2020