高密度等离子体淀积工艺对颗粒度的影响

Effect of High Density Plasma Deposition Process on Particle Size

高密度等离子体(High Density Plasma,HDP)淀积工艺具有卓越的沟槽填充性能,广泛应用于深亚微米及更先进的集成电路制造的关键工艺环节.由于其淀积与溅射相结合的工艺特点,HDP中颗粒水平直接影响器件量产的良率与可靠性,是HDP工艺中的最大问题.针对集成电路量产工艺中频繁出现的HDP颗粒问题,通过分析HDP淀积颗粒成分,发现其中含有非反应气体成分氟(F)和铝(Al).利用等离子体中的氧离子修复工艺设备的腔室穹顶,降低由于预淀积薄膜黏附不足而造成剥离性颗粒;研发出氧气(O_2)钝化工艺,应用于硅片淀积间隙的腔室原位清洗工艺;通过实验设计,分析和优化O_2钝化的具体工艺条件.研究表明,将优化后的带有O_2钝化的原位清洗工艺方案应用于集成电路实际量产制造,HDP工艺的颗粒水平整体降低50%.

High density plasma（HDP）deposition process has excellent gap fill performance, which is widely used in deep sub-micron and critical process step of more advanced integrated circuits. Because of its process characteristics of deposition and sputtering combination,particles in HDP process has directly affect the device yield and reliability, which is a major process problem. Regarding the HDP particle problem frequently appeared in semiconductor mass product line, compositions of HDP particles were analyzed,and elements F and A1 were found which are non-reaction gases. Oxygen ion in plasma was used to repair the chamber dome surface, and the peeling particles was reduced through enhancing the precoat film adhesion. The oxygen passivation process was applied into in-situ clean which was performed between silicon depositions. Oxygen passivation process condition was optimized and analyzed by experiments. The result shows that by applying the optimized solution of in-situ clean with oxygen passivation in actual production of integrated circuit,particles can reduce 50% in HDP process.