Semiconductor structure and forming method thereof

Abstract

The invention relates to a semiconductor structure and a forming method thereof. The forming method comprises the following steps: forming at least one metal gate structure, source and drain doped layers located in fin parts at two sides of the metal gate structure, and a dielectric layer located between the metal gate structures and covering the source and drain doped layers, wherein the metal gate structure stretches across a plurality of fin parts; forming a mask layer exposing the junction of a first region and a second region on the metal gate structure and the dielectric layer; taking the mask layer as a mask, and performing multiple deposition etching steps to form an opening penetrating through the metal gate structure, wherein the deposition etching steps comprising: a depositionprocess of depositing a protective layer on the surface of the dielectric layer at the junction of the first region and the second region, ; and performing an etching process after the protective layer is formed, wherein the etching process etches the metal gate structure at the junction of the first region and the second region. In the process of multiple deposition etching steps, a protective layer is always arranged on the dielectric layer, so that the source-drain doped layer can provide enough pressure stress or tensile stress for a channel, and the electrical property of the semiconductor structure is improved.

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 channel becomes more and more difficult, making subthreshold leakage (subthreshold leakage), the so-called short channel effect (Short Channel Effects, SCE) more likely to occur

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