Semiconductor structure and forming method thereof

Abstract

The invention provides a semiconductor structure, which comprises a semiconductor substrate, an interface layer, a first dielectric layer and a second dielectric layer, wherein the interface layer is formed on the semiconductor substrate; the first dielectric layer is formed on the interface layer; the second dielectric layer is formed on the first dielectric layer; and the phase-transition temperature of the second dielectric layer is lower than that of the first dielectric layer. By the semiconductor structure and the forming method thereof provided by the invention, the condition that external oxygen diffuses and passes through the second dielectric layer and enters the first dielectric layer is facilitated when dielectric constants of the dielectric layers are improved; and oxygen vacancies in the first dielectric layer are reduced, so that a gate leakage current is reduced.

Description

technical field [0001] The invention relates to the field of integrated circuit manufacturing, more specifically, to a semiconductor structure with a high dielectric constant gate dielectric and a forming method thereof. Background technique [0002] As the feature size of metal-oxide-semiconductor field-effect transistors (MOSFETs) continues to shrink according to Moore's Law, the gate dielectric layer (usually SiO 2 or SiON) is also scaled down to the nanometer level. When the thickness of the gate dielectric layer is thinned to a certain extent, due to the influence of quantum tunneling effect and the diffusion of impurities in the gate electrode to the substrate, the gate leakage current will increase significantly, which will increase the power consumption of the device and seriously affect the performance of the device. stability and reliability. High-k materials have been used instead of SiO in the prior art 2 Form the gate dielectric. Using a high-k material as t...

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And the traditional rapid thermal anneal (rapidthermal anneal) process time is 15-60 seconds

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