Investigation on the LPCVD LTO Thin Film as a New Dielectric Layer for the Future ULSI Devices

Abstract

As the design rule goes down sub-70 nm for the ULSI devices, the total thermal budget that the device can take during the fabrication is also reduced very much. Hence, in this work, we propose a novel low-temperature LPCVD process for formation of thin dielectric oxide film which does not need SiH2Cl2 gas. We have also evaluated the electrical reliability of the film by making the capacitors with oxide-nitride-oxide (ONO) structure. The leakage current of the new oxide was similar to that of the high-temperature wet oxide until the electric field is lower than 5 MV/cm. When the film was annealed by N2 gas, however, it has shown much better characteristics over the entire range.