Semiconductor structure and forming method thereof

Abstract

The invention provides a semiconductor structure and a forming method thereof. The forming method comprises the steps: forming a base, wherein the base comprises a substrate, a fin part protruding outof the substrate and a gate structure stretching across the fin part, the gate structure covers part of the top and part of the side wall of the fin part, and a gate mask layer is formed at the top of the gate structure; forming an isolation layer on the substrate exposed out of the fin part, wherein the isolation layer covers part of the side wall of the gate structure; after the isolation layeris formed, removing part of the width of the gate mask layer on the two sides of the gate structure, and etching the gate structure exposed by the gate mask layer by taking the residual gate mask layer as a mask and the isolation layer as an etching stop layer to form a beam-shaped gate structure, which comprises a gate structure first part located below the gate mask layer and gate structure second parts located on two sides of the gate structure first part and protruding out of the gate structure first part. According to the embodiment of the invention, the height consistency and the film quality of the second part of the gate structure can be improved, and the process difficulty of forming the beam-shaped gate structure can be reduced.

Description

technical field [0001] Embodiments of the present invention relate to the field of semiconductor manufacturing, and in particular, to a semiconductor structure and a method for forming the same. Background technique [0002] In semiconductor manufacturing, with the development trend of ultra-large-scale integrated circuits, the feature size of integrated circuits continues to decrease. In order to adapt to smaller feature sizes, metal-oxide-semiconductor field-effect transistors (Metal-Oxide-Semiconductor Field-Effect Transistor , MOSFET) channel length has been shortened accordingly. However, as the channel length of the device is shortened, the distance between the source and the drain of the device is also shortened, so the ability of the gate structure to control the channel becomes worse, and the gate voltage pinches off the channel. The channel becomes more and more difficult, making subthreshold leakage (subthreshold leakage), the so-called short-channel effect (shor...

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Problems solved by technology

However, as the channel length of the device is shortened, the distance between the source and the drain of the device is also shortened, so the ability of the gate structure to control the channel becomes worse, and the gate voltage pinches off the channel. The difficulty of the channel is also increasing, making the phenomenon of subthreshold leakage (subthreshold leakage), the so-called short-channel effect (short-channel effects, SCE) more prone to occur

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