Flash memory device and a fabrication process thereof, method of forming a dielectric film
AssigneeTadahiro Ohmi
InventorsTadahiro Ohmi, Shigetoshi Sugawa
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Abstract
A fabrication process of a flash memory device includes microwave excitation of high-density plasma in a mixed gas of Kr and an oxidizing gas or a nitriding gas. The resultant atomic state oxygen O* or hydrogen nitride radicals NH* are used for nitridation or oxidation of a polysilicon electrode surface. It is also disclosed the method of forming an oxide film and a nitride film on a polysilicon film according to such a plasma processing.
Claims16
A method of forming a silicon oxide film, characterized by the steps of:
- depositing a polysilicon film on a substrate;
- and
- forming a silicon oxide film on a surface of said polysilicon film by exposing the surface of said polysilicon film to atomic state oxygen O*, said atomic state oxygen O* being formed by exciting plasma in a mixed gas of a gas containing oxygen and an inert gas predominantly of a Kr gas by a microwave.
A method of forming a silicon nitride film, characterized by the steps of:
- depositing a polysilicon film on a substrate;
- and
- forming a nitride film on a surface of said polysilicon film by exposing the surface of said polysilicon film to hydrogen nitride radicals NH*, said hydrogen nitride radicals NH* being formed by plasma that is excited in a mixed gas of a gas containing nitrogen and hydrogen as constituent elements and an inert gas predominantly of an Ar gas or a Kr gas by a microwave.
A method of forming an oxynitride film, characterized by the steps of:
- depositing a polysilicon film on a substrate;
- and
- converting a surface of said polysilicon film to a silicon oxynitride film by exposing said polysilicon film to plasma formed by exciting a mixed gas of an inert gas predominantly of Ar or Kr and a gas containing oxygen as a constituent element and a gas containing nitrogen as a constituent element, by a microwave.
Dependencies are inferred from the claim text.