A new polymer, poly(3,4-bis(phenylethynyl)styrene), has been synthesized that undergoes a Bergman reaction upon heating to yield a highly aromatic material. The occurrence of the cycloaromatization reaction is characterized through thermal analysis and absorption spectroscopy. The plasma etch resistance of the polymer has been measured by reactive ion etching (RIE) in sulfur hexafluoride and oxygen plasmas and is shown to be superior to other conventional organic plasma etch barriers.