Moisture-induced material instability of porous organosilicate glass

Abstract

The mechanism of leakage current of porous organosilicate glass (POSG) with O-2 plasma ashing is investigated. The O-2 plasma ashing often deteriorates the POSG film, causing moisture uptake. We find that the leakage-current mechanism of POSG transforms from Schottky emission into ionic conduction after O-2 plasma treatment. The mobile ions (H+,OH-) supported by absorbing moisture move easily when an external electric field is applied to POSG film, which leads to the ionic conduction leakage current across the moisture-absorbing POSG film. Hence, the leakage current density is drastically increased about four to five orders of magnitude compared with untreated POSG film. (C) 2003 The Electrochemical Society.