超大规模集成电路铜布线化学机械抛光材料研究

At present, the technology of copper dual-damascene has been applied in Ultra.Large Scale Integrated Circuit. In the process, CMP(Chemical mechanical polishing) is essential to copper inrterconnection. Slurry is the ciutial factor influencing the quality of copper global planarization during the process of copper CMP. The slurry used for copper CMP is the classified.into two kinds: the acidic medium slurry and the alkaline medium slurry. Now, the.usual mechanism of copper CMP in the world is based on mechanical effect, and it.usually uses the maturely developed acidic medium as its slurry as well as Al2O3 as its abrasives.There has more difficulties in alkaline slurry’s confecting compared with acidic slurry. Moreover, alkaline slurry is easy to emerge sediment of Cu(OH)2. Through plenty experiments we first discovered that organic alkali with multy-hydroxide and multi-amine, can complex copper ion and produce a kind of complex reagent which is easily dissolving in water, thus we established the copper CMP mechanism in alkaline medium, which improving the chemical effect. The features of the mechanism are.strongly complex, weak oxidize, high concentration, little particle and high activity. We also confected a kind of new type alkaline copper CMP slurry, which is practical controlled metal ion stain effectively, faster polishing rate, higher selectivity and no pollution to environment. According to the react mechanism that the big molecular organic alkali has strongly with copper ion, we chose organic alkali as the medium and silicon colloid as abrasives, and it solved the key problem in silicon colloid based slurry, that the copper’s removal rate is slow and emerge gelatin in solution easily. Meamwhile, adding the surfactant and the complex reagent to polishing solution, it can be controlled the metal ion stain in the chip, and the absorbing state of surface particles..The process of copper CMP can be divided into tow stages. In the first stage, the.major act is polishing in the high area of copper. We can select high concentration.abrasive of nano-SiO2 to optimize the mechanical effects of polish process. We chose organic alkali with multi-hydroxide and multi-amine as the complex reagent H2O2 as oxidant, that can accelerate the dissolving of copper ion and the chemical effects are improved. The experiment results showed that the slurry and the method were suit for the first copper polishing stage well, and reached high polishing rate as well as the high selectivity of copper, tantalum and insulation lager. The second stage is the.polish process of copper and tantalum, the key of this stage is to remove the tantalum layer, insulation layer and the excess copper. No oxidant reagent in and increased pH value of slurry, the polished rate of tantalum and insulation layer was increased. At the same time, copper polished rate was decreased. By this way, the selectivity of copper,tantalum and insulation layer is decreased, production of dishing and erosion iscontrolled.

针对目前国际上超大规模集成电路制备中多层布线铜的化学机械抛光这个前沿课题,通过对浠砟Ｐ徒醒芯?对相应的铜氧化作用机理,络合作用机理,颗粒在表面的吸附状态,化学饔糜牖底饔孟嗷ス叵档冉醒芯?有效解决铜布线化学机械抛光材料的高选择.高分散性,高速率,易清洗等国内外亟待解决的前沿课题,促进集成电路向微细化的发展...