Semiconductor structure and forming method thereof

Abstract

The invention provides a semiconductor structure and a forming method thereof. The forming method comprises the steps of providing a base, wherein the base comprises a substrate and fin parts locatedon the substrate, the base comprises an isolation region and a device region which are adjacent, the fin parts located in the device region are device fin parts, and the fin parts located in the isolation region are pseudo fin parts; forming a pseudo gate structure stretching across the fin parts; forming source and drain doped regions in the fin parts on the two sides of the pseudo gate structure; removing the pseudo gate structure to form a gate opening; and removing the pseudo fin parts in the gate opening. According to the embodiment of the invention, in the process of forming the pseudo gate structure, the sparsity degree consistency of the fin parts in the isolation region and the device region is good, so that the pseudo gate structure in the device region and the isolation region is good in height uniformity, and the distance between the top of the gate opening and the top of the device fins is equal to the distance between the top of the gate opening and the top of the pseudofins; a gate structure is subsequently formed in the gate opening, the height consistency of the gate structure in the isolation region and the device region is good, and the electrical performance ofthe semiconductor structure is optimized.

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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