Mechanical Properties of Organosilicon Thin Films Deposited from Cyclic and Acyclic Precursors using Water as an Oxidant.

Abstract

AbstractPulsed-plasma chemical vapor deposition was used to deposit thin films from four different organosilicon (OSG) precursors, using water as the oxidant. The OSG precursors varied in structure (cyclic or acyclic), chemical composition (siloxane or silane), and type of organic substituent. Significant differences in final film structure were observed based on precursor identity, with the primary result being that cyclic siloxane precursors yielded films with a greater degree of crosslinking. The identity of the organic substituents was shown to affect the crosslinking potential, in that more reactive side groups, such as vinyl groups, facilitated the formation of crosslinking groups. At low power (200 W), film structure was dictated by precursor identity, whereas at high power (400 W), film structure became more uniform and precursor identity was less important. Mechanical properties tracked with plasma power, with low power samples being relatively soft, with hardness values between 0.126 GPa and 0.536 GPa. Samples produced at higher powers are more extensively crosslinked, resulting in enhanced mechanical properties. Samples produced at high powers had hardness values between 0.679 and 3.22 GPa, depending upon precursor identity. Dielectric constants ranged between 2.3 and 4.0.