Research On Rate Stability Of Alkaline Slurry

Nowadays with the developing of large-scale industrialization of very large scale integrated circuits, the requirements of planarization technology are also increasing. Currently, the universal application of planarization process is the chemical mechanical planarization(CMP), in the process of chemical mechanical planarization, the quality of polishing machine, craft of polishing process and polishing materials used in the polishing which is polishing directly determines the effect of chemical mechanical planarization,and polishing liquid plays a most important role in the process, the quality of polishing liquid directly determines the quality of the CMP results. Currently acidic polishing liquidis generally used in industrial polishing solution, but with the development of very large scale integrated circuit to the 22 nm and below, only the alkaline polishing liquid solution canmeet the requirements of planarization. As an alkaline polishing liquid use hydrogen peroxide(H2O2) as an oxidizing agent, hydrogen peroxide itself exists instability and is relatively stable in the acidic environment, hydrogen peroxide(H2O2)easily decomposed in an alkaline environment to produce water and oxygen, thus hydrogen peroxide(H2O2) brings instability to alkaline polishing solution, instability such as metamorphosis is occurred shortly after the configuration is complete. Internationally, most alkaline polishing liquidcan only be stable in a few hours, some even become unstable after only one hour. Therefore, research on the stability of alkaline slurry has very important significance.This paper studies the influence of each component in alkaline polishing liquid on stability of alkaline polishing liquidand how to extend the stable time of alkalinepolishing liquid using the following methods: use the copper CMP polishing liquid developed by Microelectronics, Hebei University Professor Liu Yuling, the composition of this polishing liquid is simple, non-toxic and non-pollution. By changing the basic components of the polishing liquid, the chelating agents, active agents, abrasives, oxidizing agents and deionized water content and the ratio of each composition to find the effect of each component on the rate stability; additionallyby changing the configuration of the polishing liquid,add stabilizer, adjust p H of the liquid and other methodsto find the effect of other factors on the rate stability of the polishing liquid. Developing one or more solutions by adjusting various factors of the alkaline polishing liquid to extended the rate stability of a polishing liquid.Through various experiments discovered the influence of the various components in alkaline polishing liquidon the rate of stability of alkaline polishing liquid.For each components in the alkaline polishing liquid, the chelating agent, abrasive and an oxidizing agent are the main factors of the rate stability of the alkaline polishing; active agent, and deionized have less effect on the rate of stability. By the adjustment of various factors,to obtainalkaline polishing liquidthat rate can be stable for five days and stable for 8 hours at a rate of 5000 ? / min.