Semiconductor structure and formation method thereof

Abstract

The invention provides a semiconductor structure and a formation method thereof. The formation method of the semiconductor structure comprises steps that, a semiconductor substrate is provided; a fin portion is formed on the semiconductor substrate; an epitaxial layer is formed at the surface of the fin portion, and the hole mobility of the epitaxial layer is greater than the hole mobility of the fin portion. Through the method, performance of a P-type tin type field effect transistor formed on the basis of the semiconductor structure can be improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a semiconductor structure and a forming method thereof. Background technique [0002] With the continuous development of semiconductor process technology, process nodes are gradually reduced, and gate-last (gate-last) process has been widely used to obtain an ideal threshold voltage and improve device performance. However, when the feature size 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 (FinFET) has been obtained as a multi-gate device. Widespread concern. The fin field effect transistor can effectively improve the short channel effect of the transistor and improve the performance of the device. [0003] The adjacent fins of existing fin field effect transistors are generally silicon...

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Problems solved by technology

[0003] The adjacent fins of existing fin field effect transistors are generally silicon. For N type fin field effect transistors, the carriers are electrons, and the mobility in silicon is relatively large, so that the N type fin field effect transistor has a relatively high mobility. High saturation current; for P-type fin field effect transistors, the carriers are holes, and the mobility of holes in silicon is low, resulting in a low saturation current of P-type fin field effect transistors. The above N A Type FinFET and a P-Type FinFET constitute a Complementary FinFET, which causes a saturation current of the N-Type FinFET and the P-Type FinFET within the Complementary FinFET Mismatch, which leads to performance degradation of complementary FinFETs, which in turn affects the performance of the entire integrated circuit

[0004] Therefore, the performance of the P-type fin field effect transistor needs to be further improved

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