Fin field effect transistor and forming method thereof

Abstract

The invention discloses a fin field effect transistor and a forming method thereof. The fin field effect transistor comprises a semiconductor substrate, a first doping layer, an isolating layer, a gate structure, a dielectric layer, a through hole and a conductive plug, wherein first fin parts and a second fin part which are discrete are formed on the semiconductor substrate; the first doping layer covers the first fin parts, the second fin part and the surface of the semiconductor substrate; the isolating layer is located on the semiconductor substrate; the surface of the isolating layer is lower than the surface of the first doping layer at the top ends of the first fin parts and the second fin part; the gate structure crosses side wall and top end surfaces of the first fin parts; the dielectric layer is located on the isolating layer, and covers the gate structure and the second fin part; the through hole is located in the dielectric layer, and exposed out of the first doping layer at the top end of the second fin part; and the conductive plug fills the through hole, and is connected with bias control voltage. Regulation of threshold voltage can be conveniently achieved by the conductive plug and the first doping layer.

Description

Technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a fin field effect transistor and a method for forming the same. Background technique [0002] With the continuous development of semiconductor process technology, process nodes are gradually reduced, and the gate-last process has been widely used to obtain ideal threshold voltage and improve device performance. However, when the feature size (CD, Critical Dimension) of the device is further reduced, even if the gate-last process is adopted, the structure of the conventional MOS field effect transistor can no longer meet the requirements for device performance, and the fin field effect transistor (Fin FET) is used as The replacement of conventional devices has received extensive attention. [0003] figure 1 The structure diagram of a fin field effect transistor in the prior art is shown. Such as figure 1 As shown, it includes: a semiconductor substrate 10 on which a protrudi...

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Problems solved by technology

[0004] When the existing fin field effect transistors are in use, the bias control voltage is usually connected to the semiconductor substrate 10 to adjust the threshold voltage of the fin field effect transistors, but the existing adjustment methods have no effect on the fin field effect transistors. It is difficult to adjust the threshold voltage of the transistor

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