Method for cleaning surface after chemically mechanical polishing of tungsten-molybdenum alloy

Abstract

The invention discloses a method for cleaning surface after chemically mechanical polishing of a tungsten-molybdenum alloy, aiming to provide a cleaning method which has the beneficial effects of improving the wafer surface quality and reducing the subsequent processing cost of alkaline chemically mechanical polishing of a tungsten-molybdenum alloy material and is convenient to use, simple and practical. The method comprises the following steps: taking ultrapure water with resistance being more than 18MOmega and adding a surfactant and an FA / OII chelating agent while stirring; adopting the ultrapure water with resistance being more than 18MOmega to dilute a corrosion inhibitor; adding the diluted corrosion inhibitor to obtained liquid while stirring and preparing alkaline water polishing liquid with pH value of 7.5-8.5 after uniform stirring; immediately using the alkaline water polishing liquid to carry out water polishing under the conditions of high flow of 1000-5000ml / min and low pressure of 0-0.01 atmosphere after chemically mechanical polishing of the tungsten-molybdenum alloy material; and later using the ultrapure water with resistance being more than 18MOmega to wash the surface under the conditions of zero pressure and flow of 1000-5000ml / min.

Description

technical field [0001] The invention belongs to the cleaning technology of the wafer surface after CMP, in particular to the cleaning technology for controlling the surface cleaning of the tungsten-molybdenum alloy alkaline chemical mechanical polishing. Background technique [0002] With the rapid development of computer technology, network and communication technology, the requirements for integrated circuits (IC) are getting higher and higher, and the feature size is gradually reduced to meet the requirements of high-speed, high-integration, high-density and high-performance integrated circuits. direction development requirements. W, Mo and their alloy materials are refractory metals, widely used in national defense, aerospace, high energy physics, electronic information, energy, metallurgy, chemical industry, nuclear industry and other fields, and have always been valued by countries all over the world. At the same time, due to its low resistance, high heat resistance, ...

AI Technical Summary

Problems solved by technology

[0004] At present, the new surface is exposed after the batch polishing process of tungsten-molybdenum alloy, which destroys the original lattice structure and produces a large number of dangling bonds. The surface energy is high and the surface tension is high. Although the polishing stops, the reaction on the wafer surface has a In the lagging process, simple water washing cannot avoid the phenomenon of uneven distribution of polishing liquid and contamination of metal ions, etc., resulting in uneven fog, high roughness, uneven corrosion, etc. on the surface of the wafer after cleaning, which seriously affects the quality of the wafer surface. As a result, the cost in subsequent processing is increased and the device yield is reduced.

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