Method for making semiconductor

Abstract

A method of manufacturing a semiconductor device is provided which can suppress leakage current increases by making into silicide. Impurity that suppresses silicide formation reaction (suppression impurity), such as germanium, is introduced into source / drain regions (16, 36) from their upper surfaces. In the source / drain regions (16, 36), a region shallower than a region where the suppression impurity is distributed (50) is made into silicide, so that a silicide film (51) is formed in the source / drain regions (16, 36). Thus, by making the region shallower than the region (50) into silicide, it is possible to suppress that silicide formation reaction extends to the underside of the region to be made into silicide. This enables to reduce the junction leakage between the source / drain regions (16, 36) and a well region.

Description

technical field [0001] The present invention relates to a method of manufacturing a semiconductor device having a silicide film. Background technique [0002] Semiconductor devices tend to be highly integrated in recent years, and many elements are mounted on one chip. Most of these elements are MOS transistors, and among the MOS transistors, there are nMOS transistors (negative MOS transistors) through which electrons flow and pMOS transistors (positive MOS transistors) through which holes flow. In semiconductor devices, circuits are formed by combining transistors with different polarities. [0003] In conventional MOS transistors, a silicide film is formed thereon in order to reduce the resistance of the source-drain region and the gate. In general, a silicide film is formed by directly silicided source-drain regions and gate electrodes. When the gate is silicided, since a gate insulating film is formed under it, the reaction to become silicide does not reach the semic...

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Problems solved by technology

Therefore, when the source and drain regions formed on the silicon layer of the SOI substrate are silicided, there is more silicon than the area below the silicided region, so a large amount of silicon grows toward the channel region below the gate. Silicide, which increases the leakage current between source and drain

[0016] Furthermore, even when the technique described in Patent Document 1 is applied to an SOI substrate, since atoms are suppressed from being introduced only below the exposed surface of the source and drain regions, when the source and drain regions are silicided from above , produces the same problem

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