Patent ID: 6284580
Filing Date: 2001-09-04
Classification: H01L

Abstract:
A method for manufacturing a MOS transistor having a gate oxide film formed on an active region of a silicon semiconductor substrate, said gate oxide film consisting of a silicon nitride layer for inhibiting the penetration of oxygen into the silicon substrate and a high dielectric oxide layer with higher dielectric constant than the dielectric constant of said silicon nitride layer, comprising the steps of:pretreatment for forming a silicon oxide film with nitrogen atoms on said active region;segregation for causing a silicon nitride layer to segregate out at an interface between said silicon substrate and said silicon oxide film by heat-treating the pretreated silicon substrate in an inert gas atmosphere;forming a high dielectric film by removing the unnecessary silicon oxide film on the silicon nitride layer to expose a segregated silicon nitride layer and depositing a high dielectric oxide layer on the exposed silicon nitride layer; andforming a gate on said gate oxide film consisting of said silicon nitride layer and said high dielectric oxide layer.