半导体器件硅衬底化学机械平坦化研究

Research on Chemical Mechanical Planarization of Silicon Substrate for Semiconductor Devices

主要对分立器件硅衬底化学机械平坦化(CMP)进行了研究。首先通过正交实验方法研究活性剂、螯合剂、磨料浓度和有机碱对硅材料去除速率的影响,得出活性剂体积分数对去除速率的影响最大,并且研究出去除速率最快的抛光液的最优配比,去除速率可以达1 410nm/min。同时平坦化后的硅衬底具有良好的表面状态:表面粗糙度仅为0.469nm,表面总厚度变化小于工业标准指标5μm。在考虑工艺影响的情况下,硅衬底制造双极型晶体管的成品率达到90%以上,满足工业成品率要求。

The chemical mechanical planarization（CMP） of the silicon substrate for discrete devices was mainly investigated.Firstly,the effects of surfactant,chelator,abrasive concentration and organic base on material removal rate were researched by the orthogonal test.It is found that the volume fraction of surfactant influences the material removal rate mostly.Then the optimal proportion of the slurry for the fastest removal rate was obtained.The removal rate can reach 1 410 nm/min,meanwhile the silicon substrate has good surface status after panarization,the surface roughness is just 0.469 nm,and the surface total thinkness varation is less than industrial standard norm of 5 μm.In the circumstance of considering the process influence,the yield of the bipolar transistors fabricated by the silicon substrate is above 90%,satisfying the industrial yield requirements.