A kind of semiconductor structure and its forming method

Abstract

The invention discloses a semi-conductor structure and a forming method thereof. Shallow channel isolation is processed in an ultraviolet irradiating method, so that the concentration of free oxygen in the shallow channel isolation is greatly reduced, a blocking layer is formed, diffusion of the free oxygen is further prevented, a high K dielectric layer cannot be eroded by the free oxygen, large leak currents are avoided, shift of a threshold voltage Vt can be effectively controlled, and performance of a component is improved.

Description

technical field [0001] The invention relates to the field of integrated circuit manufacturing, in particular to a semiconductor structure capable of avoiding damage to a high-K dielectric layer and a forming method thereof. Background technique [0002] As the size of transistors continues to shrink, HKMG (high-K dielectric layer + metal gate) technology has almost become an essential technology for processes below 45nm. Due to its large dielectric constant, the high-K dielectric layer can achieve the same equivalent oxide thickness (EOT: equivalent oxide thickness) as silicon dioxide, and its actual thickness is much larger than silicon dioxide, so it is deeply loved Industry welcome. [0003] However, most high-K materials are ionic metal oxides. This basic material characteristic may cause many unreliable problems when high-K materials are used as dielectric layers. [0004] In the actual production process, due to the etching process, etc., there will be more free oxyg...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a semiconductor structure and its formation method to solve the situation in the prior art that the high-K dielectric layer is adversely affected and affects the performance of the device

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