Semiconductor memory device and method of manufacturing the same

Abstract

A semiconductor memory device manufacturing method includes forming a floating gate electrode above a semiconductor substrate, forming an interelectrode insulating film above the floating gate electrode, forming a first radical nitride film on a surface of the interelectrode insulating film by first radical nitriding, and forming a control gate electrode on the first radical nitride film.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2005-128232, filed Apr. 26, 2005, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a semiconductor memory device including a floating gate electrode and control gate electrode, and a method of manufacturing the same. [0004] 2. Description of the Related Art [0005] Conventionally, a nonvolatile semiconductor memory device including a floating gate electrode FG and control gate electrode CG has been proposed as a semiconductor memory. [0006] In this nonvolatile semiconductor memory device, as shown in FIG. 19, a floating gate electrode FG, interelectrode insulating film 208, and control gate electrode CG are processed into a desired shape, and a gate sidewall oxide film 212 is formed on the entire surface by oxidat...

AI Technical Summary

Benefits of technology

[0011] A semiconductor memory device according to a first aspect of the present invention comprises a semiconductor substrate, a tunnel insulating film formed on the semiconductor substrate, a floating gate electrode formed on the tunnel insulating film, and having a first side-surface portion positioned in an upper portion and a second side-surface portion positioned below the first side-surface portion, an element isolation trench formed in the semiconductor substrate to be adjacent to the floating gate electrode, a first element isolation insulating film formed along a side surface and bottom surface of the element isolation trench from the second side-surface portion of the floating gate electrode, a second element

Problems solved by technology

This decreases the electric capacitance of the interelectrode insulating film 208, and causes faulty operations of the memory device.

However, the following problems arise if the silicon nitride layers 231 and 232 are formed by using CVD or thermal nitriding.

This decreases the capacitance of the interelectrode insulating film 208 and increases the parasitic capacitance between the adjacent cells, so the memory device suffers faulty operation.

Since this depletes the buried portion of the control gate electrode CG, the memory device suffers faulty operation.

This decreases the breakdown voltage between the substrate 201 and control gate electrode CG, so the memory device suffers faulty operation.

These problems are significant when the depth P, width Q, and distance R are approximately 100 nm or less.

Since this degrades the quality of a tunnel oxide film 202, the reliability of the memory device is also degraded.

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