Method for manufacturing a MOS transistor having multi-layered gate oxide
AssigneeOki Electric Industry Co., Ltd.
InventorShinobu Takehiro
Life of this patent
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Abstract
In a pretreatment process, a silicon oxide film (13) with nitrogen content is formed on a semiconductor substrate (10). In a segregation process executing heat treatment in an inert gas atmosphere, a silicon nitride layer (14) segregates out at the interface of the silicon substrate (10) and the silicon oxide film (13). In a high dielectric film forming process, the unnecessary silicon oxide film (13) on the silicon nitride layer (14) is removed, a high dielectric oxide layer (15) is formed on the exposed silicon nitride layer (14). Whereby, a gate electrode (16) consisting of the silicon nitride layer (14) and the high dielectric oxide layer (15) is formed.
Claims5
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;
- and
- forming a gate on said gate oxide film consisting of said silicon nitride layer and said high dielectric oxide layer.
Dependencies are inferred from the claim text.