Method of manufacturing dielectric film of flash memory device

Abstract

A method of manufacturing a dielectric film of a flash memory device, including the steps of providing a semiconductor substrate having floating gates formed therein, performing an oxidization process in a decompression state to form a first oxide film of a thin film on the semiconductor substrate including the floating gates, and sequentially forming a nitride film and a second oxide film on the first oxide film to form a dielectric film having the first oxide film, the nitride film and the second oxide film.

Description

technical field

[0001] The present invention relates to a method of manufacturing a flash memory device, and more particularly, to a method of forming a dielectric film formed between a floating gate and a control gate of the flash memory device. Background technique

[0002] Generally, the gate of a flash memory device has a structure including a tunnel oxide film 11, a floating gate 12, a dielectric film 13, and a control gate 14, all of which are formed on a silicon substrate 10, such as figure 1 shown. Reference numeral 15 denotes an isolation film.

[0003] The programming, erasing and reading operations of the flash memory device constructed as above are performed in such a manner that by applying an appropriate bias voltage to the control gate 14 and the silicon substrate 10, electrons are injected into or taken out from the floating gate 12 .

[0004] Dielectric film 13 has an oxide-nitride-oxide (ONO) structure in which a first oxide film 13a, a nitride film 13b,...

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