Date of Award
Master of Science (MS)
Dr. William R. Harrell, Committee Chair
Dr. Yuri Freeman
Dr. Goutam Koley
Polymer Hermetic Sealed (PHS) capacitors are advanced polymer capacitors with a hermetic seal enclosing the materials inside a metal enclosure. Their primary features include leakage current stability, high volumetric efficiency, and low weight compared to both wet and solid-state polymer tantalum capacitors. However, Life Tests performed on these capacitors have revealed a failure to withstand their rated voltage in a working temperature range over the long-term. There are also other interesting properties which have been observed such as Breakdown voltage (BDV) exceeding the Formation Voltage (Vf), anomalous transient currents, and a larger than expected capacitance dependence on temperature, C(T). A primary goal in this research is to understand whether the observed characteristics of PHS capacitors are a result of their complex structure or due more to the nature of interactions between the organic and inorganic material layers present. C(T) and BDV measurements were performed on thin-film MIS capacitors representing the material layers of PHS capacitors. Measurements were performed in the voltage range (0V-100V), a temperature range (-550C to 1250C), with varying frequency (20-10kHz), under both humid and dry conditions. Furthermore, one sample went through a curing process referred to as "Heat Treatment", which is thought to improve device stability. Results from these measurements show that thin-film devices can be reasonable representatives of discrete PHS capacitors, and the properties observed in PHS capacitors are significantly dependent on the material layers in the capacitors. Thus, the thin-film MIS capacitor is shown to be a useful test structures for investigating physical phenomena observed in the more complex polymer Ta capacitor structure.
Chinnam, Shiva Kumar, "Characterization of Polymer Hermetic Sealed Tantalum Capacitors Using Thin-film Devices" (2017). All Theses. 2610.