A process in plastics (thermal decomposition) in opposite direction of polymerisation, caused by temperature increase. During decomposition, the various polymers on the surface either form their original monomers or other decomposition products. Depolymerisation down to the monomer state also takes place during plasma cleaning and etching. erfolgt eine Depolymerisation bis zum monomeren Zustand. The decomposition products react with the active species of the process gas to form volatile molecules.the substrates to remove contaminations.