Original Polyimide Research Articles

Ion beam treatment induced conductivity in polyimide foils

Polyimide foils were implanted with different ions (from light He + ions to heavy Ar + ions) in the energy region from 25 keV to 170 keV and ion doses from 1 x 10 15 to 2 x 10 17 ions cm −2. The electrical properties (sheet resistivity), optical properties (transmission and reflection coefficients) and tribomechanical properties (friction coefficient) were determined. Depending on the ion energy, the doses and the ion species, the conductivity of the foils can be increased by up to 10 orders of magnitudes. Sheet resistivities smaller than 100 Ω/ can be reached. The transmission coefficient of the foils can be reduced to 0.1% and the reflection coefficient of the foil surface can increase from the original 40%–60% to 90%. In the implanted region the defects relax and give temporal changes in electrical properties. With larger treatment intensity (higher energy and higher ion doses) the original polyimide structure is more strongly modified and has a better long-term stability.