The Application Design And Implementation Of A Real-time Monitoring System In Wet Bench Area

Wet Bench is very important technology in the IC(Integrated Circuit)manufacturing process.Almost every process stage need use this process technology during the wafer fabrication.Therefore,the cleaning quality of the silicon wafer will be directly affect performance of the chip device.With the increasing complexity of integrated circuit technology,it is necessary to real-time monitoring key process parameter status,and then improve production yield.Considering the cost and efficiency,based on original tool foundation to design and implementation of a real-time monitoring system in Wet Bench Area.In this paper,the real-time monitoring system design is only focus on DNS FC3000 tool as study object,considering wafer defect reduction and cost to reform tool hardware,successfully implement HEPA,Exhaust,and SC1 concentration real-time monitor function.Firstly,defined the expectation of real-time monitoring system should be including real-time monitoring,warning and early detection,multi azimuth data communication,and data backup function.Then according to different parameter monitor requirement,using sample pipe method to completed the signal acquisition system on HEPA,Exhaust,SC1 chemical concentration.Due to the output signal of the signal acquisition system is analog voltage or current signal,considering sampling frequency,conversion accuracy,and number of channels to choose suitable ADC complete digitize the analog quantities function,finally complete the design of analog to digital conversion system.Installing 485 to 232 interface converters to solves ADC and computer ports inconsistent issue.At last,digital signal of tool parameter can transmit the signals to the specified database in real time,the automation engineers will collect the data collection and software programming,and then complete the data storage,processing and early detection function.According to the above system design,the whole system should be including signal acquisition system,ADC system,data collection of automation system,next step need install and debug these three systems meanwhile solve the problem during this process.Finally,the system test data showed that modified DNS FC3000 tool can real time monitoring HEPA,Exhaust,SC1 concentration,meanwhile real time,consistency and accuracy of data transmission all can meet the requirements.Currently the Wet Bench real time monitor system have already used an IC manufacturing plat,the operation result showed that new system is fully compliance with our expectation.Now the key parameters of silicon wafer manufacturing process can monitor by the system,which greatly improve the quality of the production wafer.Meanwhile the system has obvious advantage of low cost,simple installation and generality,it will be having great market advantage in future.