Vacuum-plasma deposition of resist film on substrate by means of copolymerization of monomers in the afterglow zone of rf discharge

摘要

Abstract: The plasma polymerization is one of the methods of resist film coating. It is known that polymer deposition rate has maximum value in the glow zone of discharge (GZD). But the activation of monomer molecules in GZD may lead to their considerable destruction. To keep the initial molecular structure of at least one monomer, the following experiment on copolymerization of two monomers was carried out. Inside the flowing tube reactor, the vapor of one monomer (for example, xylene) was filled in the glow zone of argon plasma, and the vapor of another monomer, (methyl methacrylate) was filled outside this zone in the lower part of the gas flow. The silicon substrate was placed perpendicularly to the reactor axis under GZD. The thickness of the polymer film was controlled by means of a laser interferometer. The experiment revealed that the film deposition rate is significantly greater for copolymerization of two monomers than for polymerization of each monomer separately when another one is not filled. Thus, the principal possibility of copolymerization of monomers in the after glow zone of discharge (AGZD) has been demonstrated. Moreover, only one monomer is activated in the plasma during this process, while the structure of another one is preserved. !6