Effect of surface modification on the properties of plasma‐polymerized hexamethyldisiloxane thin films

Plasma‐polymerized hexamethyldisiloxane (pp‐HMDSO) thin films have been deposited in a radiofrequency (RF) remote plasma‐enhanced chemical vapor deposition (PECVD) system, on different types of substrates: silicon wafers, glass, quartz crystals, and chemiresistor structure. The as‐grown thin films have been post treated in two types of reactive plasmas produced in SF 6 and O 2 gases. The effect of this surface modification on different properties of the as‐grown pp‐HMDSO thin film (chemical structure, elemental composition, surface morphology, film density and thickness, optical bandgap, and electrical resistivity) has been investigated. It is found that SF 6 plasma and O 2 plasma surface modifications of the as‐grown pp‐HMDSO thin film induce property changes different from each other. SF 6 plasma converted the as‐grown pp‐HMDSO film to a more porous material and caused a narrowing of its optical band gap of about 33%, while O 2 plasma induced a lowering of film electrical resistivity of about two orders of magnitude.