Reliability Analysis And Test For Dual-stage System Of Lithography

The rapid development of microelectronics technology speed up the technologicalchange of lithography equipment at the same time, while lithography is still located onthe first of many technologies. Lithography is an important equipment of manufacturinglarge scale IC, whose integrity increasing4times a year, to nearly1.5times smallerfeature size, that requires lithography with reliable machining precision and stability ofthe production efficiency.Stage system is core part of lithography, and reticle stage and wafer stage asimportant component of stage system directly determine the product is in compliancewith industry standards and meet the demand of the market. At home, lack of reliableperformance precision stages has become an important factors restrict lithographyequipment development, so to improve the reliability level of domestic precision stageis very necessary. This paper comes from National Grand Science and TechnologySpecial sub-project, mainly to reticle stage and wafer stage in dual-stage as the researchobject, including reliability analysis and reliability test plan design in the followingaspects:(1)According to the structure of dual-stage, seperating dual-stage into three parts,reticle stage, wafer stage and control system. For reticle stage and wafer stage requiredto complete the task, function and the characteristics of reliability, which can be furtherseperating into components, to determine the hierarchy of comprehensive evaluationand risk analysis.(2)Using Fuzzy Comprehensive Evaluation Method, in view of the breakdown ofthe items constituting the system carries on the comprehensive evaluation of risk. Theweaknesses of wafer stage system part are platform moving and micro platform. On thisbasis, sort all fault risk of component, and the conclusion we got is safe in the generalcase at last.(3)According to the weaknesses by the analysis result of Fuzzy ComprehensiveEvaluation Method, top event can be selected with precision to meet the requirements,create a reticle stage and wafer stage fault tree of precision for qualitative analysis. And convert precision of fault tree into a BDD for quantitative analysis, as an extension ofthe result of Fuzzy Comprehensive Evaluation.(4)According to the weaknesses by the analysis result of Fuzzy ComprehensiveEvaluation Method, the selection of mask and wafer stage key parts gas bearing andvoice coil motor as test object, develop reliability test outline, for exposing potentialfailures and provide guidance to the corresponding proposal of reliability growth.