解决集成电路漏电和中点电位异常的实例分析

摘要

During the manufacturing process of integrated circuits (IC), sometimes certain processing anomalies can cause defects in the relevant diffusion region, which results in abnormal performance of IC chips and low yield of wafers. In the case study of a bipolar power amplifier IC chip, defects in the emitter region of NPN transistor cause leakage current and abnormal midpoint potential at output end, which results in low yield of wafers. It is introduced by a beginning of circuitous philosophy, followed with an analysis of procedurally establishing midpoint potential and deduction of the relation between midpoint potential and device parameters. Combined with IC chip leakage, it continues by analyzing the relation between manufacturing process and these device parameters, concluding that the chip failure results from defects of the emitter region in the NPN transistor through dissection and corrosion of the failed chip. Finally, defects are improved with changing the processing of the emitter region from P-SOD to ion implantation PAs, which solves the problem of abnormal performance and low yield.%集成电路(IC)制造中,某些工艺的异常会使得相关的扩散区域产生缺陷,导致IC芯片性能异常,圆片中测低良.一款双极功放集成电路芯片,由于NPN管发射区缺陷,引起IC芯片漏电和输出端中点电位异常,导致中测低良.从电路原理出发,分析如何建立中点电位,推导中点电位与器件参数的关系.结合IC芯片漏电,分析了相关器件参数跟工艺的关系,通过对失效管芯进行解剖腐蚀,定位到管芯失效的原因是NPN管的发射区存在缺陷.通过将发射区磷SOD工艺改变为磷砷离子注入工艺,改善了工艺缺陷,解决了该产品的性能异常和中测低良率.