화학공학소재연구정보센터
Plasma Chemistry and Plasma Processing, Vol.17, No.2, 123-154, 1997
DC Plasma Polymerization of Hexamethyldisiloxane
Hexamethyldisiloxane (HMDS) was polymerized onto metallic and insulating substrates in a parallel-plate DC reactor. The limits of the DC reactor with respect to pressure and power were determined for deposition of PP-HMDS films. In all conditions ranging from 5 Pa/0.03 W to 100 Pa/50 W, solid films were deposited. No powders or oily films were obtained under any condition in the operating range. The films were polymeric in nature, i.e., they were neither carbon-like nor SiOx-like films. The structures and crosslink densities of the plasma films depended strongly on the deposition conditions. The highest deposition rates, up to 2 mu m per minute (or 0.3 mg/cm(2) min), were obtained at high power, pressure, and flow rate conditions. An efficiency epsilon is introduced, defined as the fraction of the monomer that is retained in the form of a polymer deposited on the substrate. Efficiencies as high as 25% could be obtained in certain conditions. Pulsing the discharge power increased the conversion efficiency markedly, but the effect depended strongly on the monomer used. In addition to HMDS, plasma polymers were also deposited from pyrrole in pulsed conditions for comparison. A method is described for depositing films on insulators from a DC glow discharge using two wire meshes held at a negative potential.