Transistor structure and forming method thereof

Abstract

The invention provides a transistor structure forming method and a transistor structure. After a source and a drain are formed, the source and the drain are etched to form depth-controllable and shape-controllable source and drain extension region grooves. Meanwhile, the short channel effect of the transistor can be controlled by carrying out depth control on the junction depth of source and drain extension regions and reducing a predetermined transistor series resistance, thus achieving the purpose of effectively improving the driving performance of the transistor.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a transistor structure and a forming method thereof. Background technique [0002] With the deduction of Moore's Law, the microelectronics industry is approaching the limit of smaller scale and line width. With the continuous reduction of device feature size, conventional scaling methods have encountered a series of problems centered on the short channel effect. For example, as the transistor scales further, the parasitic series resistance of the transistor increases dramatically, reducing the response speed of the entire transistor. [0003] In recent years, strain engineering (Strain Engineering) technology has been introduced to improve transistor speed. A major technique in strain engineering is transistor source / drain selective epitaxy of substrate material alloys with different crystal lattices. Among them, the main manufacturing method of this technology is: b...

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Problems solved by technology

However, in the prior art, in order to control the short channel effect, the junction depth of the source / drain extension region is generally required to be very small, resulting in an excessively large sheet resistance of the source / drain extension region

[0005] Therefore, the use of high-mobility alloy materials to reduce the sheet resistance of the source / drain extension region has become a new method. The existing method is usually to form the source / drain extension through a special lateral etching method while forming the source / drain groove. region, this method needs to take into account the different requirements of the source / drain and the source / drain extension region, it is difficult to control the junction depth and shape of the source / drain extension region, and if the shape of the source / drain extension region is too shallow, it will lead to block If the resistance is too large, if the shape of the source / drain extension region is too deep, the short-channel effect will be serious, and the epitaxy method cannot independently optimize the balance

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