Influence of silicon-wafer loading ambients in an oxidation furnace on the gate oxide degradation due to organic contamination

Abstract

Organic contaminants adsorbed on the surface of silicon wafers do not always cause the degradation of gate-oxide integrity (GOI) degradation but very little information is available on the ambient atmosphere when wafers are loaded in an oxidation furnace. It has been found in this work that GOI is degraded when wafers having organic contamination are loaded in a nitrogen atmosphere, but that GOI degradation does not occur when the wafers are loaded in an oxygen-containing ambient. In a high-temperature nitrogen atmosphere, carbon remains in silicon dioxides, while in an oxygen-containing ambient, the organic contaminants will be oxidatively degraded and evaporated, so carbon does not remain on the surface.