Abrasive tool and method of making the same

Abstract

An abrasive tool includes a substrate, a plurality of abrasive particle groups, and a bonding layer. The abrasive particle group consists of a plurality of abrasive particles grouped together. The abrasive particle groups are disposed in a regular pattern on the surface of the substrate and fixed on the surface by the bonding layer. To control the disposition of the abrasive particle groups, an abrasive particle template is used to form the required pattern. The size of the abrasive particle positioning holes on the template is used to adjust the number of particles in an abrasive particle group.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of Invention [0002] The invention relates to an abrasive tool and the method of making the same. In particular, the invention relates to a diamond abrasive tool and the method of making the same. [0003] 2. Related Art [0004] In the manufacturing process of deep sub-micro semiconductor devices, the planarization technique for the oxide layer and the metal layer on the surface of wafer becomes important along with the development in the wire miniaturization and the multiple metal connection technique. In order to have a dense circuit in a small area, the thickness and flatness in each layer of the wafer are strictly demanded. [0005] The chemical mechanical polishing (CMP) technique employs slurry and polish pad, along with mechanical polishing, to planarize the oxide layer and the metal layer of a wafer. This method can remove limitations in the layout design, increase the pattern density, reduce the defect density, and promote the yield. In...

AI Technical Summary

Benefits of technology

[0010] In view of the foregoing, an object of the invention is to provide an abrasive tool and the method of making the same. It combines the features of regular and random abrasive particle dispositions. The surface of the abrasive tool is provided with a plurality of abrasive particle groups to increase the abrasive particle density and to maintain the uniform pressures on the abrasive particles. Therefore, the invention can increase the cutting rate and lifetime of the abrasive tool.

[0012] The bonding layer can be a metal solder and / or polymer bonding layer to provide the necessary combining force for the abrasive particle. The bonding layer may use a low-temperature brazing material to avoid the problem of substrate deformation and diamond deterioration because of high-temperature brazing processes. A polymer bonding layer can completely free from the soldering process and problems derived from it.

[0014] In particular, the abrasive positioning holes are designed to have an appropriate size so that a single hole can accommodate a plurality of abrasive particles to form an abrasive particle group. The abrasive positioning holes may have different patterns according to the abrasive tool that one wants to form. The abrasive positioning holes are preferably disposed in a shape of the donut type or the segment type. The pitch between the abrasive positioning holes is preferably to be greater than the diameter of the abrasive particle positioning holes by at least 75 μm. This is more practical in mass-producing the abrasive particle disposition template.

Problems solved by technology

Moreover, the debris getting off from the wafer and the slurry will deposit on the surface of the polish pad.

The abrasive particles used in this type of abrasive tool are highly rigid and abrasive.

In a CMP process, however, the abrasive particles fixed on the surface of the abrasive tool often cannot be held tightly on the surface of the metal substrate.

Therefore, abrasive particles often get off from the abrasive tool.

These lost particles are likely to damage precision and expensive wafers.

In particular, since the abrasive particles are random disposed on the abrasive tool, their distribution may be non-uniform such that the abrasive particles are under different pressures.

This is why the abrasive particles may fall off due to insufficient adhesive power and why the polishing effect is unstable.

However, using highly sharp diamond particles may have the risk of breaking them because of their lower strength.

Although this method can achieve the goal of evenly distribute the pressure to the abrasive particles, the diamond particles sizes are limited by the pitch of the template or mesh such that the density of abrasive particles cannot be increase.

However, a mesh with a pitch as small as 250 μm to 350 μm has reached the limit of the template manufacturing for the conditioners with such diamond size.

Therefore, it is difficult to further increase the density of diamond arrangement for the primary used conditioner products in IC factory.

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