Degradation of polyimide by implantation with Ar+ ions

✍ Scribed by V. Svorcík; V. Rybka; V. Hnatowicz; I. Miček; O. Jankovskij; R. Öchsner; H. Ryssel

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 198 KB
• Volume: 64
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19970425)64:4<723::aid-app12>3.0.co;2-v

✦ Synopsis

Polyimide (PI) samples were irradiated with 200 keV Ar / ions to fluences from 5 1 10 13 -1 1 10 17 cm 02 and the concentration depth profiles of implanted Ar atoms as well as of carbon and oxygen atoms of the polymer matrix were determined using the Rutherford backscattering technique. The surface polarity, sheet resistivity, and thermoelectric power of PI samples were also determined as a function of the ion fluence and temperature. As a result of the ion irradiation, the polyimide surface layer is depleted of oxygen and enriched by carbon. The sheet resistivity exhibits a minimum at the ion fluence of 5 1 10 16 cm 02 and the temperature dependence of the sheet resistivity indicates the semiconducting character of irradiated PI and the variable range hopping mechanism of charge transport. The thermoelectric power of the PI samples irradiated to high fluences is small, of the order of mV/K, and independent of temperature. This behavior is typical for metals. The simultaneous appearance of metal and semiconducting properties is probably due to the complex structure of the PI surface layer modified by the ion irradiation.