| Integrated circuit manufacturing enterprise is a very important part of the integrated circuit industry chain which has the characteristics of high-tech,high cost and fierce competition.The quality management system’s establishment and optimization of IC manufacturing enterprise is related to the chip production quality,process stability and the comprehensive competitiveness.So the avoidance and effective management of non-conforming wafers can directly reflect the quality management ability.How to improve the quality management system of non-conforming wafers has become the focus of attention.As the leading foundry in IC manufacturing industry,according to the concept and method of quality control,process characteristics and learning from other advanced foundries,Huali has constructed a management mechanism of non-conforming wafers successfully which integrated with auto process and chip quality.Quality management is a process of continues improvement,reference to other foundry,Huali has higher non-conforming ratio.Meanwhile,there are some weak points of management scope and disposition about non-conforming wafers.Such us the root cause investigation cycle time(30% case didn’t handled in time)and the accuracy of non-conforming wafers’ root cause analysis.Based on the situation,firstly,the author has made a research and analysis about the quality management system between Huali and another typical foundry.As a result,there are 2 main differences: 1.Huali’s management scope is narrower.2.Different foundry has different emphasis about non-conforming wafers’ disposition.Secondly,this thesis has done an analysis for weak points about non-conforming wafers’ management.Such us lacking of 8D concept、root cause analysis inaccurate and not in-depth、preventive actions not enough.And then,this thesis proposed the direction of problem solving and improving which including how to push 8D review、how to help our engineers to understand 8D concept and how to set up the macro measures to improve quality system.At last,this thesis carefully explained that in order to improve and optimize non-conforming wafers’ management,both the normal management system and task force have taken improve actions.Such us improving the efficiency of non-conforming wafers’ review(Root cause、Preventive actions etc.)、8D concept and reporting capabilities 、 validation preventive actions’ effectiveness.And also raised the macro measures to reduce the occurrence of non-conforming wafers(zero excursion task force project),such as reduction of miss operations,process control(steps、windows、metrology etc.)、defense system to prevent the generation of non-conforming wafers.After the analysis and improve actions implement,the effect of non-conforming wafers’ improvement is obvious:Occurrence rate reduced gradually(Huge impact case counts dropped about 48% in the same time、scarp wafer counts controlled within 0.5%)、 root cause confirmed efficiently and accurately(single case counts controlled within 30%),non-conforming wafers’ detection and customer satisfaction improved(100% gated in advance). |
