Interface structure and formation between gold and trimethylcyclohexane polycarbonate
- PDF / 802,975 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 33 Downloads / 183 Views
MATERIALS RESEARCH
Welcome
Comments
Help
Interface structure and formation between gold and trimethylcyclohexane polycarbonate C.v. Bechtolsheim, V. Zaporojtchenko, and F. Faupela) Lehrstuhl fu¨r Materialverbunde, Technische Fakulta¨t der Christian-Albrechts-Universita¨t Kiel, Kaiserstraße 2, D-24143 Kiel, Germany (Received 3 November 1998; accepted 14 June 1999)
This paper presents the results of a systematic investigation of structure and formation of the interface between gold and trimethylcyclohexane polycarbonate, particularly concerning interface evolvement during gold evaporation and the influence of evaporation rate, substrate temperature, and subsequent annealing. The means of investigation were cross-sectional transmission electron microscopy, atomic force microscopy, and x-ray photoelectron spectroscopy. Extensive metal diffusion into the polymer and cluster formation near the interface were observed at deposition rates of the order of one monolayer per minute and below. The penetration depth is strongly temperature dependent. At high evaporation rates metal aggregation at the surface prevents cluster formation inside the polymer. No diffusion into the polymer was observed from metal films deposited at room temperature after extensive annealing at elevated temperatures.
I. INTRODUCTION
There is a wide range of applications for metallized polymers.1–5 Apart from the most important sector of microelectronics, metal-coated polymers are also used as reflectors, as computer housing, in data storage (compact disks) and for decorative coatings. Metals and polymers are significantly different materials. Judging especially from the cohesive energy, which for metals is typically two orders of magnitude higher than for polymers, one expects that metals will agglomerate at the polymer surface rather than diffuse into polymers. However, metal deposition generally takes place far from thermodynamic equilibrium, and it was found that metals of low reactivity may well diffuse into polymers if they are evaporated at a very low rate.6–11 With regard to applications in the packaging technology, attention has been paid mainly to the system copper onto polyimide. Based on various experimental techniques it was found that the morphology of the metal–polymer interface can be modified by variation of evaporation rate,6,7 substrate temperature during evaporation8–11 or by thermal annealing subsequent to the evaporation process.12,13 The chemical interactions at metal–polymer interfaces have also been the subject of extensive research, mainly involving photoelectron spectros-
a)
Address all correspondence to this author. e-mail: [email protected]
3538
http://journals.cambridge.org
J. Mater. Res., Vol. 14, No. 9, Sept 1999 Downloaded: 02 Apr 2015
copy.14–16 Cross-sectional transmission electron microscopy (XTEM) has been used to study the interfacial morphology and has provided direct evidence of the formation of metal clusters inside polymers. First investigations with this technique were carried out evaporating
Data Loading...
