Method for removing polymer stacked on a lower electrode within an etching reaction chamber

Abstract

An object of the invention is to provide a preventive maintenance for effectively removing polymer stacked on a lower electrode within a reaction chamber of etching equipment during the process of dry etching of a silicon oxide layer. First, the lower electrode is preferably set at 0° C., and then the reaction chamber is pre-cleaned preferably 20 times by a pump/purge cleaning manner. After the pre-cleaning, nitrogen or inert gas is supplied into the reaction chamber such that the internal pressure is equal to atmospheric pressure. Subsequently, the reaction chamber is opened preferably for 10 minutes, and the lower electrode is kept at 0° C. during this moment. Afterwards, the surface of the lower electrode is wiped by a piece of clean cloth to peel off the polymer. Finally, the lower electrode is preferably set at 25° C. and is wiped several times by using de-ionized water, isopropanol (IPA), ethanol, a solution of hydrogen peroxide in water, or Cleaner 5060 produced by the 3M corporation. According to the invention, the surface of the lower electrode does not suffer scratches and damage caused by a scraper. Therefore, the lifespan of the lower electrode is increased and the stability of the etching process is successfully enhanced.