Field effect transistor and semiconductor device, and method for manufacturing same

Abstract

Current drive efficiency is deteriorated in the conventional FET. The FET 20 includes an electrode film 24a provided over the semiconductor substrate 10 and a stressor film 24b that is provided on the electrode film 24a and constitutes a gate electrode 24 together with the electrode film 24a. Each of the electrode film 24a and the stressor film 24b is composed of a metal, a metallic nitride or a metallic silicide. The stressor film 24b is capable of exhibiting a compressive stress over the semiconductor substrate 10.

Description

[0001] This application is based on Japanese patent application No. 2006-300487, the content of which is incorporated hereinto by reference. BACKGROUND [0002] 1. Technical Field [0003] The present invention relates to a field effect transistor and a semiconductor device, and to a method for manufacturing thereof. [0004] 2. Related Art [0005] Metal insulator semiconductor field effect transistors (MISFET), which are composed of silicon and polycrystalline silicon employed as materials for semiconductor substrate and gate electrode, respectively, exhibit progressively improved performances by virtue of processing technologies for fine devices, various types of deposition technologies and impurity control technologies. Semiconductor devices having various functions are configured by combining different MISFETs that exhibits different threshold voltage properties. In particular, a considerable improvement in the current drive efficiency is obtained by a scaledown of devices. Besides, a ...

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Benefits of technology

[0012] In such n-channel FET, at least one of the first electrode film and the second electrode film is a stressor film that is capable of exhibiting a compressive stress over the semiconductor substrate. Such stressor film draws the channel region toward the outer direction, thereby providing an improved electron mobility.

[0014] In such p-channel FET, at least one of the first electrode film and the second electrode film is a stressor film that is capable of exhibiting a tensile stress for the semiconductor substrate. Such stressor film provides a compressed channel region, thereby providing an improved hole mobility.

[0017] According to the present invention, the FET that exhibits an improved mobility of charge carrier and the semiconductor device comprising thereof, and the method for manufacturing thereof are achieved.

Problems solved by technology

Nevertheless, a scaledown of devices causes a reduced channel-length of FET, causing a difficulty in controlling an electric current in the channel region by employing a gate voltage (electric charge control).

However, such process causes an increased scattering of charged carrier (electronic electron hole) by the presence of impurity, deteriorating the current drive efficiency.

For example, when a film is to be shrunk, a tensile stress exerts through the film, resulting in a compressive distortion caused in the surface of the substrate.

When a film is to be expanded, a compressive stress exerts through the film, resulting in a tensile distortion caused in the surface of the substrate.

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