Formation method of MOS transistor

Abstract

The invention discloses a formation method of a MOS transistor. The method comprises the following steps: providing a silicon substrate; forming multiple split shallow trenches in the silicon substrate, the region between adjacent shallow trenches being an active region; after the shallow trenches are formed, carrying out silicon ion implantation on the silicon substrate until a silicon-enriched layer at least disposed at the corners of the shallow trenches is formed; after the silicon ion implantation, filling the shallow trenches by use of an insulation material to form a shallow trench isolation structure; forming a gate medium layer on the silicon substrate of the active region; and forming a grid electrode on the gate medium layer. By using the formation method of the MOS transistor, the reliability of the formed MOS transistor can be improved.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method for forming a MOS transistor. Background technique [0002] In the manufacture of integrated circuits, the isolation structure is an important technology, and the components formed on the semiconductor substrate must be isolated from other components. With the advancement of semiconductor manufacturing technology, shallow trench isolation (Shallow Trench Isolation, STI) technology has gradually replaced traditional semiconductor device isolation methods such as local oxidation of silicon (LOCOS). [0003] The formation method of the existing shallow trench isolation structure generally includes: oxidizing the wafer (the wafer is the semiconductor substrate) in a high-temperature oxidation furnace tube, forming a pad oxide layer (PadOxide) and a hard mask layer on the semiconductor substrate, and then etching A plurality of discrete shallow trenches are formed ...

AI Technical Summary

Problems solved by technology

And once said problem occurs, it will cause unstable performance of the semiconductor device, such as causing time-dependent breakdown (TimeDependentDielectricBreakdown, TDDB) of the gate dielectric layer, especially for non-volatile semiconductor devices, if said problem occurs, it will seriously affect Reliability of Non-Volatile Semiconductor Devices

[0006] For this reason, a new method of forming MOS transistors is needed to prevent the problem that the thickness of the gate dielectric layer is reduced at the corners on the shallow trenches.

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