Semiconductor structure and formation method thereof

Abstract

The invention relates to a semiconductor structure and a formation method thereof. The method comprises the steps of providing a base, wherein the base includes a substrate, discrete fins protruding out of the substrate and channel laminations on the fins, wherein each channel lamination include a sacrificial layer and a channel layer located on the sacrificial layer, the number of the channel laminations is one or more, and the fins and the channel layers are made from SiGe; forming a pseudo gate layer which crosses the channel laminations and covers the top and part of the side walls of the channel laminations; sequentially etching the channel laminations and the fin at two sides of the pseudo gate layer, forming a top groove inside the channel laminations, and forming a bottom groove, which exposes the substrate and is communicated with the top groove, inside the fin; forming a semiconductor layer in the bottom groove, wherein the heat conductivity coefficient of the semiconductor layer is greater than that of SiGe; and forming a doped epitaxial layer in the top groove after forming the semiconductor layer. The semiconductor layer with a higher heat conductivity coefficient is adopted to replace the SiGe fin at both sides of the pseudo gate layer, thereby improving the spontaneous heating effect, and thus improving the performance of PMOS (P-channel Metal Oxide Semiconductor) transistors.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a semiconductor structure and a forming method thereof. Background technique [0002] In semiconductor manufacturing, with the development trend of VLSI, the feature size of integrated circuits continues to decrease. In order to adapt to the reduction of feature size, the channel length of MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET) is also shortened correspondingly. 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 control ability of the gate to the channel becomes worse, and the gate voltage pinches off the channel. The difficulty is also increasing, making the phenomenon of subthreshold leakage (subthreshold leakage), the so-called short-channel effect (SCE: short-channel effects) more likely to occur. [0003] Therefore, in order to better meet the...

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Problems solved by technology

[0005] However, after the introduction of SiGe channel technology, it is easy to cause the degradation of device performance

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