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The Slurry Of Copper Chemical Mechanical Polishing And Planarization Process

Posted on:2011-01-15Degree:MasterType:Thesis
Country:ChinaCandidate:W ZhengFull Text:PDF
GTID:2178330332961282Subject:Mechanical Manufacturing and Automation
Abstract/Summary:PDF Full Text Request
With the increase of chip size and integrated circuit density, the decrease of IC feature size and depth of lithography focus, copper has replaced aluminium for the fabrication of interconnections in integrated circuits (ICs). CMP (chemical mechanical planarization, CMP) is employed as a viable method for planarizing the surface globally and locally. It is the most effective and practical method of planarization process to attain an ultra-smooth surface without damages and is one of the key technologies in ULSI manufacturing. However, the low efficiency, surface defects and post-polishing cleaning, and with the introduction of mechanically fragile low-k dielectric that the low polishing pressure should be used have restricted the development of next-generation chip technology. Therefore, how to achieve efficient copper CMP is a great challenge.The subject of this paper is the study of slurry prescription and planarization process in ULSI manufacturing. In order to achieve high copper chemical mechanical planarization, material removal rate and good surface quality, anionic-nonionic surfactant compound system of copper CMP slurry and planarization is put forward in this paper on the basis of the removal mechanism and the results have been studied.In this paper the experiments have been carried on ZYP200 lapping/polishing machine. The effect of compound system of anionic surfactant (Ammonium Dodecyl Sulfate, ADS) and nonionic surfactant (Nonylphenoxypoly (ethyleneoxy) ethanol, NP-10) on polishing rate and polished surface quality have been studied firstly. Surface roughness and morphology, agglomeration, corrosion potential and corrosion current are detected by 3D Optical Profiler, SEM, TEM and Tafel electrochemical test. The experiment results show that the corrosion potential will decrease and the polishing rate will increase by use of NP-10, but it will also result in agglomeration of abrasive.3mM ADS+0.3mM NP-10 is selected as the optimized formulation by analyzing the effects of different concentrations of NP-10 on polishing removal rate and polished surface quality, the Tafel electrochemical test, stability test and viscosity test; and the verification test of the optimized process parameters which are chosen by analyzing the effect of single factor experiment on polishing rate and polished surface quality is carried out by use of the optimized formulation (3mM ADS+0.3mM NP-10). The results show that the roughness is around 13-14nm and the polishing rate attains 160nm/min.
Keywords/Search Tags:Chemical mechanical planarization, Copper, Slurry, Material removal rate
PDF Full Text Request
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