Growth, physical properties, and adhesion of copper-polyphenylquinoxaline interfaces

Abstract

Monochromatized x-ray photoelectron spectroscopy, contact angle measurements, and peeling tests have been used to investigate the physicochemical surface properties of polyphenylquinoxaline (PPQ) and of copper-PPQ interfaces. The surface composition and oxygen content of a polymer that was deliberately oxidized by ultraviolet exposure in air were determined, and monitored during the anneal (up to 400 °C) of this thermostable polymer. Subsequent copper deposition in the monolayer range and film growth is characterized by small cluster formation, before percolation into a conducting metallic layer. Further anneal of the Cu-PPQ interface is seen to promote diffusion of Cu into the polymer, and to catalytically degrade the interface by oxidizing the polymer. These observations are correlated with peeling test measurements on the same Cu-PPQ interfaces: UV treatment combined with an anneal process are shown to be deleterious to the mechanical properties of the interface.

Physical and chemical properties of the chromium/polyphenylquinoxaline interface

“…The main one, centered at 399.3 eV, is characteristic of nitrogen in the quinoxaline rings. 3,16 The peak localized at 406.3 eV is a shake-up satellite attributed to -* transitions in the quinoxaline rings, in good accordance with previous reported values for polymers containing nitrogenous heterocycles. 17,18 The N 1s level is strongly modified upon metallization, as shown in Fig.…”

“…Rods of chromium are first cut in a 99.99% pure chromium slab. The angles are then ground down before chemical cleaning in a solution of HCl and HNO 3 . The chromium rod is then introduced in the electron-beam evaporator and polarized at 3 kV.…”

“…1͒ is a thermostable polymer presenting suitable properties to be used as an insulator for such applications. 1 Previous studies 2, 3 have already shown that copper does not adhere well to the polymer. Plasma treatments of the polymer have been realized to improve the adhesion properties of the interface.…”

Surface characterization of a low dielectric constant polymer–SiLK* polymer, and investigation of its interface with Cu

“…SiLK* semiconductor dielectric is one of these new materials, which is principally characterized by the fact it is an aromatic hydrocarbon containing no silicon or fluorine, with a dielectric constant of 2.65, a cure temperature between 400 and 450°C, and a glass transition temperature T g of 490°C. 11 This XPS analysis was performed on annealed ͑up to 300°C, for 1 h͒ PPQ, and ultraviolet ͑UV͒-treated PPQ surfaces. It blossomed approximately 12 yr ago with studies of polyimide ͑PMDA-ODA͒, 4 and extended to analysis of copper interaction with, for example, Teflon, 5-7 polyethyleneterephthalate, 8 polyetherimide, 9 and Flare 1.0 10 ͑this last polymer is a fluorinated poly ͑arylene ether͒ recently developed by Allied Signal͒.…”