Date of Award
Master of Science
Department of Electrical and Computer Engineering
James Fellows, PhD
This thesis investigated the thermal phase-change properties in Ge2Sb2Te5 (GST) chalcogenide-based films and determined the feasibility of coupling the GST with photosensitive DNA material for novel optical device applications. Modeling and testing of GST were researched with the approach that GST would react as a resistive mechanism through thermal manipulation. A test structure was fabricated with a 2-micronmeter MEMS fabrication process. GST material was deposited (by RF sputtering) on the surface of the test structures. The GST was analyzed primarily in the amorphous to crystalline transition states due to more distinct changes in the resistance between partial states. Using both filtered light (via a monochromator), and non-filtered white light, light was incident on the GST for photo response testing. A biased voltage was applied to the device and the current change was measured. The GST was tested electrically, applying a current sweep across the device and measuring change in resistance as the GST changed states. Data recorded on the thermal properties of GST leading to resistive changes from both optical and electrical sources was analyzed. The results of this research indicate how future optical and electrical testing of the GST can be improved. The data measured by testing the GST electrically was compared to other research data (following similar testing procedures), revealing that optimal designs need sub-micro layers of GST with electrodes places above and below the GST. It was concluded that higher power light sources will be needed to continue exploring the optical reaction of GST in future research.
DTIC Accession Number
Chezem, John R. V., "Analysis of Photoconductive Properties in Ge2Sb2Te5 (GST) Chalcogenide Films for Applications in Novel Electronics" (2006). Theses and Dissertations. 3314.