The demand for increased storage capacity in memory or rigid disks and the trend towards miniaturization of memory or rigid disks (due to the requirement for smaller hard drives in computer equipment) continues to emphasize the importance of the memory or rigid disk manufacturing process, including the planarization or polishing of such disks for ensuring maximal performance. While there exist several chemical-mechanical polishing (CMP) compositions and methods for use in conjunction with semiconductor device manufacture, few conventional CMP methods or commercially available CMP compositions are well-suited for the planarization or polishing of memory or rigid disks.
As the demand for increased storage capacity has increased, so has the need for improved processes for the polishing of such memory or rigid disks. The term “memory or rigid disk” refers to any magnetic disk, hard disk, rigid disk, or memory disk for retaining information in electromagnetic form. The memory or rigid disk typically has a surface that comprises nickel-phosphorus, but the memory or rigid disk surface can comprise any other suitable material. The planarity of the memory or rigid disks must be improved, as the distance between the recording head of a disk drive and the surface of the memory or rigid disk has decreased with improvements in recording density that demand a lower flying height of the magnetic head with respect to the memory or rigid disk. In order to permit a lower flying height of the magnetic head, improvements to the surface finish of the memory or rigid disk are required.
In addition, environmental regulations in many countries limit the amount of organic material in wastewater streams that can be released into the environment. Many polishing compositions used in semiconductor manufacturing are based on water as the liquid carrier. Disposal of waste polishing compositions requires treatment of the compositions to reduce the levels of pollutants, such as the content of organic material in the polishing compositions, which adds to the cost of manufacturing processes. One measure of water quality is known as chemical oxygen demand. Chemical oxygen demand is a measure of the amount of oxygen required to fully oxidize organic material in a waste stream to carbon dioxide, ammonia, and water. Accordingly, there is a need in the art for polishing compositions exhibiting a reduced chemical oxygen demand in order to meet increasing stringent environmental demands.