Infrared and X-Ray Photoelectron Spectroscopy Studies of the Polyimide/Metal Interface
Abstract
This thesis considers the chemical interactions which occur at the interface of a polymer and a metal. Polyimides were chosen for this study because of their application in microelectronic devices, flexible interconnects, solar cells, and printed circuit boards. In these applications polyimide typically forms an interface with chromium, aluminum, copper, or gold. Numerous results have been published on the processes which occur when metals are deposited on cured polyimide. Less attention has been given to the equally important sequence of polyimide curing on a metal. The interfaces studied for this thesis were those formed by imidization of polyamic acid on gold, chromium, and copper. Infrared spectroscopy (IR) and x-ray photoelectron spectroscopy (XPS) were used to study these interfaces. Polyimide films as thin as 34 A were prepared on metallized silicon wafers for these analyses. The IR and XPS results indicated the gold interacted very little with the polyimide, while copper produced significant changes in the IR and XPS spectra. At elevated cure temperatures chromium also reacted with the polyimide. In the structures with chromium and copper, the thermal stability of the polyimide at the interface was reduced from that of bulk polyimide. The data showed that the metals interact with the polymer structure at the point where ring closure occurs to form the polyimide from polyamic acid.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1989
- Accession Number
- ADA218249
Entities
People
- William C. Stewart
Organizations
- Air Force Institute of Technology