Semiconductor structures and methods of forming them

Abstract

The invention relates to a semiconductor structure and a formation method thereof. The formation method of the semiconductor structure comprises the steps of providing a semiconductor substrate; forming a mask layer with an opening on a surface of the semiconductor substrate; etching the semiconductor substrate along the opening, and forming a groove with a side wall inclining in the semiconductor substrate; forming a doping layer on a surface of the side wall of one side of the groove, wherein the doping layer can be used for preventing doping ions from diffusing in the semiconductor substrate; and filling an isolation layer filled in the groove. By the method, the performance of semiconductor devices formed on active regions at two sides of the isolation layer can be improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a semiconductor structure and a forming method thereof. Background technique [0002] As semiconductor technology enters the deep sub-micron era, components below 0.18 microns (such as between active regions of CMOS integrated circuits) are mostly fabricated using shallow trench isolation (STI) for lateral isolation. An integrated circuit includes many transistors formed on a semiconductor substrate. Generally, the transistors are separated from each other by insulating or isolating structures. A process commonly used to form an isolation structure is a shallow trench isolation (shallow trench isolation, STI for short) process. [0003] The shallow trench isolation process usually forms a trench on a semiconductor substrate, and then fills the trench with an insulating material to form a shallow trench isolation structure. The shallow trench isolation structure surrounds...

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Problems solved by technology

[0004] The shallow trench isolation structure will exert stress on the active regions on both sides, so that the dopant ion concentration of the channel of the semiconductor device will decrease in the region far from the shallow trench isolation structure, so that the current carrying in the transistor channel region Uneven sub-distribution, leading to problems such as leakage of semiconductor devices, affecting the performance of semiconductor devices

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