Semiconductor device and forming method thereof

Abstract

A semiconductor device and a forming method thereof are provided. The forming method of the semiconductor device comprises the following steps: providing a substrate; forming a lamination structure covering the surface of the substrate, wherein the lamination structure includes a first stress layer disposed on the surface of the substrate, an intrinsic layer disposed on the surface of the first stress layer and a second stress layer disposed on the surface of the intrinsic layer, the lattice constant of the first stress layer is smaller than the lattice constant of the intrinsic layer, and the lattice constant of the intrinsic layer is smaller than the lattice constant of the second stress layer; forming a gate structure on the surface of the second stress layer; etching the lamination structure on the two sides of the gate structure to form grooves; and forming a third stress layer filling the grooves, wherein the lattice constant of the third stress layer is greater than the lattice constant of the first stress layer. The leakage current in the semiconductor device is reduced and the source-to-drain punch-through problem of the semiconductor device is inhibited while the carrier mobility of the semiconductor device is improved.

Description

technical field [0001] The invention relates to the technology in the field of semiconductor manufacturing, in particular to a semiconductor device and a forming method thereof. Background technique [0002] With the continuous development of semiconductor technology, carrier mobility enhancement technology has been widely studied and applied. Improving the carrier mobility in the channel region can increase the driving current of semiconductor devices and improve the performance of devices. [0003] In the existing manufacturing process of semiconductor devices, since stress can change the energy gap and carrier mobility of silicon materials, it has become more and more common means to improve the performance of semiconductor devices through stress. Specifically, by properly controlling the stress, the mobility of carriers (electrons in NMOS devices, holes in PMOS devices) can be increased, thereby increasing the driving current, thereby greatly improving the performance of...

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Problems solved by technology

[0005] However, in practical applications, it is found that the degree of carrier mobility improvement of semiconductor devices formed by the prior art is limited, which is not enough to meet the needs of increasing the operating speed of semiconductor devices, and there are problems such as Source to Drain PunchThrough and leakage current.

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