FAILURE MECHANISMS AT METAL-DIELECTRIC INTERFACES.
Abstract
Thin film capacitors have been used as a means of studying the changes induced at a metal dielectric interface by electrical and thermal stress. Long term stress testing indicates that a capacitor's stability may be grossly affected by surface contamination with water vapor prior to electroding. The nature of the electrode material also plays an important role in capacitor stability. The more active electroding metal, aluminum, produces capacitors considerably more stable than the capacitors using gold electrodes. It was found that the capacitance and dissipation factor of gold electroded capacitors exhibited greatest changes at lower frequencies. During stress test the capacitance and dissipation factor decreased during 1200 hours of accumulated test time, and then increased. DC measurements indicated that leakage through the dielectric film could not account for the changes observed. Thin film anodized Ta2O5 capacitors prepared for radioactive tracer studies have been placed on stress test. One group of units has now accumulated 12 weeks of stress time with a maximum increase of capacitance of 3.45 percent. A second group stressed at a higher level have shown capacitance changes of from +6.7 percent to -4.5 percent. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1964
- Accession Number
- AD0609995
Entities
People
- David J. Peterson
Organizations
- Motorola Mobility