Morphological changes of poly(tetrafluoroethylene) surface due to low current density proton irradiation
Abstract
The changes of the surface morphology of poly(tetrafluoroethylene) due to proton irradiation was investigated. 1 MeV proton beam was used for the irradiations with relatively low current densities, in the range of 10-100,000 pA/mm2. The applied ion fluences ranged from 0.1 to 2500 nC/mm2 (6.24 * 1010-1.56 * 1015 ion/cm2). The surface was characterized by interference contrast microscopy, surface profilometry and scanning electron microscopy. The results show that at each current density the surface can be machined, and the etching depth is increasing with increasing ion fluence, up to a certain point. However, in each case there is a threshold value, between 50 and 100 nC/mm2, where the process turns back. First, the etching depth starts to decrease. Later, by further increasing the delivered ion fluence, an opposite process begins and the surface becomes protruding.
- Publication:
-
Nuclear Instruments and Methods in Physics Research B
- Pub Date:
- June 2019
- DOI:
- 10.1016/j.nimb.2019.04.050
- Bibcode:
- 2019NIMPB.449...71N
- Keywords:
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- Poly(tetrafluoroethylene);
- PTFE;
- Material modification;
- Scanning nuclear microprobe;
- Proton beam writing