Manufacturing method of metal gate electrode

Abstract

The invention discloses a manufacturing method of a metal gate electrode, which comprises the steps of: forming side wall layers at both sides of a substitution gate electrode after forming a gate oxide layer and the substitution gate electrode on a provided semiconductor substrate; taking the side wall layers and the substitution gate electrode as masking membranes to carry out ion implantation to the semiconductor substrate to form a source leakage area; depositing contact etching stop layers on the semiconductor substrate, the side wall layers and the surface of the substitution gate electrode; after depositing an interlayer medium layer on the contact etching stop layer, polishing the deposited interlayer medium layer of which the height exceeds the surface of the substitution gate electrode to the etching stop layer; after depositing a stretching layer which ensures the pressure of each part of the side wall layers identical in follow-up substitution gate electrode etching on the interlayer medium layer, polishing the stretching layer to the interlayer medium layer; and etching away the substitution gate electrode to obtain a substitution gate electrode groove, and filling a metal gate electrode in the substitution gate electrode groove. The method makes the shape of the manufactured metal gate electrode be the shape of the substitution gate electrode.

Description

technical field [0001] The invention relates to detection technology in the field of semiconductors, in particular to a method for manufacturing a metal gate. Background technique [0002] Currently, high dielectric constant insulating materials and metal gates will be used to manufacture logic circuit devices in semiconductor devices. [0003] In order to control the short channel effect, semiconductor devices with smaller feature sizes require a further increase in gate electrode capacitance. This can be achieved by continuously reducing the thickness of the gate oxide layer, but this is accompanied by an increase in gate electrode leakage current. When silicon dioxide is used as the gate oxide layer and the thickness is below 3.0nm, the leakage current becomes unbearable. The way to solve the above problems is to use high dielectric constant insulating materials to replace silicon dioxide. High dielectric constant insulating materials can be hafnium silicate, hafnium si...

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Problems solved by technology

[0023] In the above process, if Figure 7 As shown in , the shape of the fabricated metal gate is not the shape of the replacement gate because, in Image 6 In the process of etching the replacement gate, the pressure applied to the upper half of the sidewall layer is different from the pressure applied to the lower half of the sidewall layer, and the pressure applied to the upper half of the sidewall layer There is no interlayer dielectric layer, so the pressure is relatively large, and the lower half of the side wall layer has an interlayer dielectric layer, so the pressure is relatively small. Due to the unbalanced pressure, the side wall layer will collapse, thereby Changes the shape of the replacement gate trench formed by the sidewall layer, which ultimately affects the shape of the metal gate

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