Polishing composition and method of polishing with the same

Abstract

A polishing composition comprises: at least one compound selected from tetrazole compounds and derivatives thereof and anthranilic acid compounds and derivatives thereof; abrasive particles comprising associative abrasive particles; and an oxidizing agent.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to semiconductor device production. More particularly, the invention relates to a polishing composition for use in a wiring step in semiconductor device production and to a method of polishing with the composition. [0003] 2. Description of the Related Art [0004] In the development of semiconductor devices represented by semiconductor integrated circuits (hereinafter referred to as LSIs), there recently is a desire to attain a higher density / higher degree of integration based on the scale down and multilayer arrangement of wirings so as to meet the trend toward higher degrees of integration and higher speeds. Chemical mechanical polishing (hereinafter referred to as CMP) has been used as a technique for these. This technique is used for the polishing of insulating thin films (e.g., SiO2) and thin metal films for use as wirings, and is a method for substrate planarization or the removal o...

AI Technical Summary

Benefits of technology

The invention provides a polishing composition that increases the polishing rate of wirings made from copper metal and copper alloys for faster chemical mechanical polishing (CMP) to improve productivity of LSIs. The composition includes associative abrasive particles, tetrazole compounds, anthranilic acid compounds, and an oxidizing agent. The use of this composition results in a high CMP rate and reduced dishing and scratching. The invention also provides a method of chemical mechanical polishing using the described polishing composition. The invention solves the problem of scratching while maintaining high abrading power and planarization ability by using a polishing liquid containing associative abrasive particles and tetrazole or anthranilic acid compounds. The highly associative abrasive particles have a high degree of freedom to abrade recessed parts and are less likely to damage the work surface.

Problems solved by technology

However, there are cases where CMP with such a polishing composition containing solid abrasive grains results in troubles such as polishing mars (scratches), a phenomenon in which the whole surface to be polished is excessively polished (thinning), a phenomenon in which the metal surface to be polished becomes recessed like a dish (dishing), and a phenomenon in which the insulator between metal wirings is excessively polished and the surface of the wiring metal becomes recessed like a dish (erosion).

In addition, the cleaning step which is usually conducted after the polishing in order to remove the polishing liquid remaining on the semiconductor surface is complicated because of the use of the polishing liquid containing solid abrasive grains.

Furthermore, there are problems concerning cost, for example, because the treatment of the liquid resulting from the cleaning (waste liquid) necessitates separation of the solid abrasive grains by sedimentation.

The copper wirings are apt to develop mars called scratches as compared with aluminum wirings heretofore in use and, on the other hand, have a problem that because of the ductility thereof, a high polishing rate is not attained.

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