Quality and reliability of oxide by low thermal budget rapid thermal oxidation

Abstract

In order to meet increasing requirement for low thermal budget oxidation in memory and logic applications, RadOx™, previously known as in-situ steam generation (ISSG) oxidation, processes of low thermal budgets were developed. In this paper, oxides obtained by 700°C soak and 900–1050°C spike RadOx™ processes are presented. Sidewall growth behavior in STI-type structures were characterized and showed no bird’s beak encroachment by the developed oxidation processes. Basic bulk oxide (40Å) integrity and reliability characteristics were compared to the 1050°C soak RadOx™ reference. Using planar metal-on-semiconductor (MOS) capacitors as the test vehicles, flat-band voltage (Vfb), interface trap density (Dit), leakage current, and stress-induced leakage current (SILC) were measured. Vfb shift of less than 20mV and Dit less than 2×10¹¹/cm² were observed from the low temperature soak and spike oxides. Leakage currents from fresh devices and after high current stressing (0.1A/cm²) were comparable to the reference oxide.