Study of the Silicon/?-APS/Pyralin Assembly Interfaces by X-ray Photoelectron Spectroscopy

✍ Scribed by George, I.; Viel, P.; Bureau, C.; Suski, J.; L�cayon, G.

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 740 KB
• Volume: 24
• Category: Article
• ISSN: 0142-2421
• DOI: 10.1002/(sici)1096-9918(199610)24:11<774::aid-sia180>3.0.co;2-x

✦ Synopsis

Polyimides have been extensively studied in view of their wide industrial applications. Adhesion to a substrate is essential for normal operation of devices. This problem is often solved by the use of an adhesion promoter on the surface of interest. A surface-sensitive technique such as XPS has proved to be a powerful analytical tool for the analysis of the polymer/substrate interface.

In the present paper, the interfaces of the SiO,/y-aminopropyltriethoxysilane (7-APS)/Pyralin system have been investigated at a precured stage. A detailed analysis of the molecular structures formed at the interface is carried out using XPS spectroscopy. An attribution of the various peak components is made with the help of accurate calculations of presumed core-electron binding energies using a recent procedure based on the Density Functional Theory.

Two acid-base mechanisms are described. The first one occurs between the ammonium end of the y-APS molecule and the silicon surface hydroxyl (NH,+SiO-), whereas the second one is formed between the ammonium end of the y A P S and the polymer carboxylic function (NH,+COO-). The results at the first interface are in contradiction with the expected stable oxygen-bridged bond (siloxane), thus the rearrangement of the yAPS molecule upon heating, as suggested by Linde in a dynamic 'Flip model,' has been studied.