Characterization of silicon oxide films deposited using tetraethylorthosilicate

Silicon dioxide films prepared by plasma enhanced chemical vapour deposition (PECVD) from tetraethylorthosilicate (TEOS) are known to exhibit better step coverage than films prepared from silane chemistry. We have prepared TEOS oxide films under various processing conditions to investigate their electrical properties in view of their applicability to the fabrication of silicon devices. Films deposited using TEOS only and in the presence of an oxidant such as O2 or N2O were prepared. In each case we have submitted some of the samples to a rapid thermal densification cycle in N2. Metal oxide semiconductor (MOS) capacitors with oxide thickness of 50 nm were prepared for the measurements of dielectric strength, leakage current, flat-band voltage, and interface charge density. Several devices were measured to obtain significant statistical data regarding dielectric strength and uniformity of the film properties over the wafer. Thermal SiO2 films of the same thickness were used for comparison. Thicker films (~5...