Semiconductor device and method for manufacturing semiconductor device

Abstract

A semiconductor device is provided which has insulating film side wall spacers having a barrier function. The semiconductor device comprises: a gate oxide film and a gate electrode formed on and above a semiconductor substrate; source / drain regions formed in the semiconductor substrate; and first laminated side wall spacers having two or more layers and formed on side walls of the gate electrode, the first laminated side wall spacers including a nitride film as a layer other than an outermost layer, the outermost layer being made of an oxide film or an oxynitride film and having a bottom surface contacting the semiconductor substrate, the gate oxide film or a side wall spacer layer other than the nitride film.

Description

CROSS REFERENCE TO RELATED APPLICATION [0001] This application is based on and claims priority of PCT / JP2003 / 013582 filed on Oct. 23, 2003, the entire contents of which are incorporated herein by reference.TECHNICAL FIELD [0002] The present invention relates to a semiconductor device and a method for manufacturing the semiconductor device, and more particularly to a highly integrated semiconductor device having side wall spacers with a barrier function and a method of manufacturing the semiconductor device. BACKGROUND ART [0003] Since self-aligned contacts (SAC) are used recent years because of micro patterning requirements, side wall spacers of silicon nitride film are used. A silicon nitride film is an insulating film with a barrier function capable of functioning as an etching stopper having etching selectivity relative to an interlayer insulating film made of a silicon oxide film. [0004] Device sizes are reduced due to high integration and miniaturization of MOSFETs. As the pn j...

AI Technical Summary

Benefits of technology

[0035] An object of the present invention is to provide a semiconductor device having side wall spacers made of insulating films having a barrier function and being free of disadvantages to be caused by forming the side wall spacers.

[0036] Another object of the present invention is to provide a semiconductor device integrating flash memory cells, low voltage operation transistors and high voltage operation transistors and being free of disadvantages to be caused by mixedly forming different types of transistors.

Problems solved by technology

As the pn junction depth of source / drain regions becomes shallow, resistance values have a tendency of becoming large.

Damages are therefore hard to be formed in the surface layer of the active regions.

If metal enters the undercuts in a later process and left unremoved, the remaining metal may cause a short circuit.

However, since the nitride film side wall spacers contact the substrate surfaces, it is inevitable that the nitride film side wall spacers impart stresses to the substrate.

While the gate electrode pattern is dry-etched, if the gate insulating film is also removed, the substrate surface is exposed to etching and may be damaged.

As the extension regions are subjected to the heat treatment at 700° C. or higher, impurities are thermally diffused so that there is a possibility that the extension regions cannot retain a desired shape.

As the overhangs are formed, the overhangs may cause a short circuit and the like.

As above, as semiconductor elements of a plurality of types are formed on the same semiconductor substrate and the characteristics of each semiconductor element are to be optimized, unexpected disadvantages may be given to other semiconductor devices.

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