硅衬底化学机械抛光后去除有机物残留的研究

Study of Removing Organic Residue on Silicon Wafer Surface in Post-CMP Cleaning

化学机械抛光后,Si片表面残留有机物会影响清洗的综合效果,并会造成器件失效。针对上述问题提出了一种新的清洗方案,用金刚石膜电化学法制备氧化性强的过氧焦磷酸盐溶液,可有效氧化分解表面有机沾污,配合FA/O I型活性剂溶液进行预清洗,去除表面颗粒的同时降低了表面粗糙度。此外,过氧焦磷酸盐被还原成的焦磷酸盐具有很强的络合力,它能与Cu等金属离子络合,达到同时去除金属杂质的目的。研究了氧化液的体积分数对有机物清洗效果的影响,发现氧化液的体积分数为60%～100%时残留有机物去除效果最佳。作为一种新型的清洗方法,清洗效率高且成本低,操作简单可控且环保,符合新时期半导体清洗工艺的要求。

Residue organics on silicon surface can affect the comprehensive effect of post-CMP cleaning,and lead completely failure of the devices.A new cleaning method used to remove the residual organic was introduced.Pyrophosphate peroxide can be synthesized through an electrochemical reaction on boron-doped diamond film anode,using the oxidability of peroxide to oxidative decomposes residue organic matter on a silicon wafer surface,and coordinated with the cleaning agent model containing surfactants FA/O-I,thus can remove particles and reduce the surface roughness.In addition,the pyrophosphate peroxide was deoxidized into pyrophosphate.Pyrophosphate,a good complexing agent,has strong complexation ability to copper or other metal ions.The best concentration of oxidation was confirmed by further experiment.When the concentration of the oxidation is more than 60%,the effect of removal residue organics is best.As a kind of new cleaning method,this method has advantages as follows：high efficiency and low cost,simple and controllable operation,and also environmental protection.It meets the requirements of the semiconductor cleaning process in the new period.