應用實驗設計法提升蝕刻機台再啟動時線寬穩定性-以P公司為例

Abstract

台灣半導體產業受到全球景氣不佳及大陸積極佈局的影響，面臨不少的壓力，半導體產業在製程上必須力求進步，在成本控制上也需要努力改善。半導體製程中蝕刻主要是藉由臨界尺寸(Critical Dimension，CD)來控制晶圓質量的好壞。晶圓質量不好的原因很多，主要都是機台造成，半導體的機台又特別複雜，閒置後再運轉往往會因為某些因子不穩而導致CD值不穩定，然而，控制每一個影響機台不穩定之因子所花費的成本太高，不符合效益，因此大多數廠商會採用測試片使機台處於穩定的狀態。本研究之主要目的即是針對台灣某半導體公司的蝕刻製程，運用實驗設計(Design of Experiments, DOE)手法找出最佳之測試片種類及機台參數的組合，使機台處於穩定的狀態，以有效提升蝕刻製程之穩定性。本研究最後以案例公司之實際蝕刻製程資料，驗證了本研究方法確實可提升蝕刻機台再啟動時CD穩定性及最大化之機台產能。

Semiconductor industry in Taiwan is facing huge pressure because of global recession and aggressive overall arrangement of Chinese Semiconductor Companies. Semiconductor industry has to seek advanced progress in manufacturing process as well as the improve-ment of cost control. In semiconductor manufacturing process, we mainly rely on Critical Dimension (CD) to control the quality of wafers. There are many factors raising poor quali-ties of wafers, however, most of them are caused by the instability of equipments. Semi-conductor equipment is particularly complex. To restart equipment after being idle for a while will come out unstable CD values because some factors change and turn to be unsta-ble. However, the cost is extremely high to stabilize every factory that affects the instability of the equipment. Therefore, most of the manufactures utilize dummy wafers to retain the stability of equipments. The main purpose of this study is to effectively reduce the failure rate of etching process by utilizing the methodology of Design of Experiments (DOE) to find out the best combination of the type of dummy wafers and equipment parameters for etching process of a specific semi-conductor company in Taiwan. In this study, the real data from an etching process was used to verify that the proposed method is effective in enhance the CD’s stability when the etch equipment is restarted and the productivity of equipment can be maximized.