Semiconductor device and manufacturing method thereof

Abstract

The invention provides a semiconductor device and a manufacture method thereof. The manufacture method includes the steps of: providing a semiconductor substrate; producing a shallow channel isolation structure and a gate structure on the semiconductor substrate; performing light dope drain injection and pocket injection are performed on the semiconductor substrate on two sides of the gate structure, wherein the pocket injection are performed for two times, one time of pocket injection is the injection of light atomic weight impurities while the other time of pocket injection is the injection of heavy atomic weight impurities, and the dosage ratio of the heavy atomic weight impurities to the light atomic weight impurities is more than 1:1; producing the side wall of the gate structure; performing source injection and drain injection on the semiconductor substrate on two sides of the side wall. The injected impurities with heavy atom weights diffuse slowly on the semiconductor substrate, and few impurities diffuse to the silicon / silicon dioxide interface formed by the isolation of the semiconductor substrate and the shallow channel, so that the threshold voltage of a narrow channel MOS tube can be effectively maintained or promoted; requirements on different threshold voltages can be met by variation of dosage ratio of the impurities with light and heavy atom weights.

Description

technical field [0001] The present application relates to the technical field of semiconductor manufacturing, and in particular, to a semiconductor device and a manufacturing method thereof. Background technique [0002] With the development of the semiconductor industry, the feature lateral size and depth of semiconductor devices are gradually reduced, and changes in device size will lead to changes in device performance, which in turn will affect the design and use of small-size devices. [0003] In a platform using a shallow trench isolation (STI) process, an active region is isolated from a field region by a shallow trench isolation structure, and a source region and a drain region are provided in the active region. On the two-dimensional plane of the top view of the semiconductor device, the current direction from the source region to the drain region is the length direction of the channel, and the direction perpendicular to the length direction is the width direction o...

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Problems solved by technology

[0005] The purpose of this application is to provide a method for manufacturing a semiconductor device to solve the problem of threshold voltage roll-off due to the narrowing of the channel region in the prior art

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