Abstract
Two problems encountered in many semiconductor manufacturing are metrology delay caused by the equipments and mixture products on producing. For this thesis, we develop some controllers to eliminate the influences of two problems. First, focusing on the metrology delay problem, we deriver an analytic formula of the performance for a single EWMA controller and provide the guideline to reduce the effects of metrology delay system. Additionally, we provide VM (Virtual Metrology) system to solve it and analyze the performance of VM of modeling methods. Finally, we suggest Stepwise method to plug in VM system. Mixed-product production can reduce amount of cost and time in semiconductor manufacturing. However, each product has a different I-O model and it is a big challenge to run-to-run control. In order to solve it, we use an ANCOVA model to deal with the characteristic of mixed products in different platforms, and to correct the modeling error due to mixed products in order to impove the controller performance and quality.