Chemical mechanical polishing agent kit and chemical mechanical polishing method using the same

Abstract

A chemical mechanical polishing method of the present invention comprises conducting polishing by the use of a chemical mechanical polishing aqueous dispersion (A) containing abrasive grains and then conducting polishing by the use of a chemical mechanical polishing aqueous composition (B) containing at least one organic compound having a heterocyclic ring in addition to the chemical mechanical polishing aqueous dispersion (A). Also A chemical mechanical polishing agent kit of the present invention comprises the chemical mechanical polishing aqueous dispersion (A) and the chemical mechanical polishing aqueous composition (B). The polishing method and the polishing agent kit can prevent an increase of dishing and corrosion of wiring portion to enhance the yield.

Description

[0001] The present invention relates to a chemical mechanical polishing agent kit comprising a chemical mechanical polishing aqueous dispersion containing abrasive grains and a chemical mechanical polishing aqueous composition containing an organic compound having a heterocyclic ring.[0002] With densification of semiconductor devices, wirings formable in the devices have been made finer recently. Exemplary technologies capable of attaining much finer wirings include the damascene method. This method comprises steps of filling a trench or the like formed in an insulating substrate with a wiring material, and then removing an excess wiring material by chemical mechanical polishing to form desired wiring.[0003] In the conventional chemical mechanical polishing, if wiring is formed by, for example, copper as a wiring material, the copper wiring portion is excessively polished and hence the copper wiring portion sometimes becomes concave. Such concave curve of the wiring is called "dishi...

AI Technical Summary

Benefits of technology

[0018] The chemical mechanical polishing agent kit of the present invention and the chemical mechanical polishing method using the kit can inhibit increase of dishing and occurrence of corrosion during the over-polishing and can prevent lowering of the yield.[0019] FIG. 1 is a group of views showing exemplary steps of a chemical mechanical polishing method according to the present invention.[0020] FIG. 2 is a group of views showing exemplary steps of a chemical mechanical polishing method according to the present invention.[0021] FIG. 3 is a graph showing a relationship between a ratio of the over-polishing time to the polishing time until endpoint and dishing.[0022] Here are symbols in the Figures.[0023] 1: metal material (metal wiring portion)[0024] 2: substrate[0025] 2a: non-wiring portion[0026] 3a: barrier metal layer in a trench of the substrate[0027] 3b: barrier metal layer on the non-wiring area[0028] 4: metal layer

Problems solved by technology

In the conventional chemical mechanical polishing, if wiring is formed by, for example, copper as a wiring material, the copper wiring portion is excessively polished and hence the copper wiring portion sometimes becomes concave.

Such concave curve of the wiring is called "dishing" or "erosion", and this causes the yield loss of semiconductor devices.

If such a remainder is present, copper sometimes remains on the surface of the insulating substrate even after the barrier metal polishing, and this causes great lowering of the yield.

Moreover, there is another problem that occurrence of scratches on the wiring or the insulating substrate or occurrence of "corrosion" that is a phenomenon that the copper wiring portion is corroded during the polishing has a great influence on the yield.

In this case, there resides a problem that dishing of a wide wiring portion is increased or corrosion of a copper wiring portion occurs during the over-polishing.

Such a problem has caused great lowering of the yield.

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