1. Field of the Invention
The present invention relates to a chemical mechanical polishing conditioner and manufacturing methods thereof, and more particularly to a chemical mechanical polishing conditioner which has a deformation compensation in the manufacturing process.
2. Description of Related Art
Chemical mechanical polishing (CMP) is a common polishing process in various industries, which can be used to grind the surfaces of various articles, including ceramics, silicon, glass, quartz, or a metal chip. In addition, with the rapid development of integrated circuits, chemical mechanical polishing becomes one of the common techniques for wafer planarization because it can achieve an object of whole planarization.
During the chemical mechanical polishing process of semiconductor, impurities or uneven structure on the surface of a wafer are removed by contacting the wafer (or the other semiconductor elements) with a polishing pad and using a polishing liquid if necessary, through the chemical reaction and mechanical force. When the polishing pad has been used for a certain period of time, the polishing performance and efficiency are reduced because the debris produced in the polishing process may accumulate on the surface of the polishing pad. Therefore, a conditioner can be used to condition the surface of the polishing pad, such that the surface of the polishing pad is re-roughened and maintained at an optimum condition for polishing. In the process for manufacturing a conditioner, it is necessary to dispose an abrasive layer by mixing abrasive particles and a binding layer on the substrate surface, and to fix the abrasive layer to the surface of the substrate by brazing or sintering methods. However, during curing of the abrasive layer, the surface of the substrate may be deformed because of the difference in thermal expansion coefficient between the abrasive layer and the substrate, thus destroying flatness of the abrasive particles of the conditioner and thereby adversely affecting the polishing efficiency and service life of the conditioner.
In the known technology, the surface flatness of a chemical mechanical polishing conditioner is typically controlled by two ways. One way is to dispose the abrasive particles and the binding layer on the surface of the substrate, followed by pressing down the abrasive particles using a rigid plate to embed and fix the abrasive particles into the abrasive layer such that the surfaces of the abrasive particles and the rigid flat may have the same flatness. Another way is to dispose the abrasive particles into a recess of a mold, followed by covering the non-working surface of the abrasive particles with a binding layer and a substrate, and performing heat curing, and finally, flipping the mold upside down to separate the cured chemical mechanical polishing conditioner from the recess of the mold. In the above two methods for manufacturing the chemical mechanical polishing conditioner, they could be only aimed at controlling a tip height of the abrasive particle before heat-curing the abrasive layer; however, during heat-curing the binding layer, the difference in thermal expansion coefficient between the binding layer and the substrate may result in deformation of the substrate of the chemical mechanical polishing conditioner after curing, which results in deformation of the surface of the chemical mechanical polishing conditioner and destroys the flatness of the abrasive particles of the conditioner.
Besides, in the other known technology, it discloses to provide a non-planar substrate in which a planar substrate is formed by compensation for the deformation of non-planar substrate during curing the bonding layer, and thereby obtaining a chemical mechanical polishing conditioner having a planarization surface. A non-planar substrate used in the known technology is a surface having a curved surface contour, such as a spherical surface contour or a non-spherical surface contour; however, the non-planar substrate of the curved surface contour still has many problems in the precision of a design of the curved surface thereof or manufacturing cost.
Therefore, there is an urgent need for a chemical mechanical polishing conditioner with a surface planarization, which cannot only solve a problem of surface deformation of the chemical mechanical polishing conditioner in a curing and molding process, but also further control the surface flatness of the chemical mechanical polishing conditioner.