Semiconductor structure and forming method thereof

Abstract

The invention discloses a semiconductor structure and a forming method thereof, and the method comprises the steps: providing a substrate which comprises a substrate and a fin part protruding out of the substrate, the substrate comprises a first region used for forming a first device and a second region used for forming a second device, and the working voltage of the first device is greater than the working voltage of the second device; forming a first gate oxide layer covering the fin portions of the first region and the second region in a shape-preserving manner, the first gate oxide layer located in the second region being used for forming a gate dielectric layer of a second device; a second gate oxide layer covering the first gate oxide layer in a shape-preserving mode is formed, and the second gate oxide layer and the first gate oxide layer located in the first area are used for forming a gate dielectric layer of the first device; and carrying out gate dielectric layer thinning treatment, wherein the gate dielectric layer thinning treatment comprises the step of removing the second gate oxide layer in the second region. According to the scheme, the consumption of the fin parts in the second region in the process is reduced, and the width uniformity and height uniformity of the fin parts in the first region and the second region are further improved.

Description

technical field [0001] Embodiments of the present invention relate to the field of semiconductor manufacturing, and in particular, to a semiconductor structure and a method for forming the same. Background technique [0002] As the integration level of semiconductor devices becomes higher and higher, the voltage and current required for the operation of semiconductor devices continue to decrease, and the switching speed of transistors is also accelerated, and the requirements for all aspects of semiconductor technology are greatly increased. A gate last process is formed, that is, a dummy gate structure is formed first, source / drain implantation and high temperature annealing processes are performed, the dummy gate structure is removed, a gate oxide layer is deposited, and finally a gate structure is formed. [0003] The gate oxide layer is an important structure in a semiconductor device such as a MOSFET (Field Effect Transistor), and if there are defects on the gate oxide ...

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Problems solved by technology

[0003] The gate oxide layer is an important structure in semiconductor devices such as MOSFETs (field effect transistors). If there are defects on the gate oxide layer, the reliability of the device will be reduced.

In the I / O area, the thickness of the gate oxide layer also has different requirements, and the gate oxide layer corresponding to the thickness requirements of different processes is easy to cause a certain degree of damage to the fin portion in the process of forming the fin portion of the I / O area. damage that degrades the performance of the semiconductor structure

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