Evaluation of the Stability on the New Alkaline Copper Bulk Slurry

At present, the chemical mechanical polishing is the only means for global planarization of an integrated circuit. After the node of the integrated circuit processing comes into 45nm, the diameter of wafer is 300mm, and the copper interconnect layer is above the 10 layer. In the same time the new low dielectric constant materials are used to the integrated circuit processing. That requires the property of the slurry used in the chemical mechanical polishing stricter. So the domestic and international companies carry out a series research works. Based on investigation and research for many years, the new alkaline copper rough slurry has been developed by the teachers and students in the Hebei University of Technology. The slurry has advantages as disadvantages. The composition of cost-effective slurry is simple and the effect of chemical mechanical polishing is good. But its stability is poor. In order to improve the stability, the compositions of the slurry need to adjust.The new alkaline copper rough slurry composed by abrasive, surface, chelating agent, oxidizing agent and deionized water. Experiments investigate the influence rule of copper polishing rate by the concentration of abrasive, the content of surface, the content of oxidizing agent and the content of chelating agent. The conclusion is arrived. When the concentration of abrasive is 4%, the content of surfactant is 10ml/l, the content of chelating agent is 10ml/l and the content of oxidizing agent is 5ml/l, the copper polishing rate keep 5000 Å /min.

Study of Slurry Composition Transition in a Rotary Copper CMP Process

The polishing pad is one of the prime components in a typical Chemical Mechanical Polishing (CMP) process. The structure and transport properties of a polishing pad are critical in determining the particle and chemical utilization in a conventional CMP process. Our earlier paper investigated the particle retention and transport on two different polishing pads, IC-1400 and Suba-500, during copper polishing. In this paper, the results of chemical retention and transport of IC-1400 and Suba-500 pads during copper polishing are presented. The polish rate results from slurry-step-flow experiments with H2O2-glycine based slurries, where the concentrations of chemicals in the slurry are altered in steps during polishing, are correlated to the chemical retention and transport characteristics of these pads. It is found that IC-1400 has a higher chemical transport capability than Suba-500 pad, which is shown to affect the polish rates of copper.

Advances in Chemical-Mechanical Planarization

The primary aim of this issue of MRS Bulletin is to present an overview of the materials issues in chemical–mechanical planarization (CMP), also known as chemical–mechanial polishing, a process that is used in the semiconductor industry to isolate and connect individual transistors on a chip. The CMP process has been the fastest-growing semiconductor operation in the last decade, and its future growth is being fueled by the introduction of copper-based interconnects in advanced microprocessors and other devices. Articles in this issue range from providing a fundamental understanding of the CMP process to the latest advancements in the field. Topics covered in these articles include an overview of CMP, fundamental principles of slurry design, understanding wafer–pad–slurry interactions, process integration issues, the formulation of abrasive-free slurries for copper polishing, understanding surface topography issues in shallow trench isolation, and emerging applications.