New era started by 200mm wafers of MEMS large scale production

To meet predicted huge demands of MEMS (Micro Electrical Mechanical Systems), wafer size had to be changed from smaller diameter 100–150 mm to 200mm for mass production. To establish 200mm MEMS process, there were many technical challenges caused by differences between LSI and MEMS even though the equipments and processes were fairly similar except for some unique processes. This paper describes suggestions of the technical issues and resolutions found during development of our new 200mm MEMS mass production line focused on following three uniqueness. 1. The difficulties MEMS´ unique thicker films process using common tools and equipments with LSI line. 2. MEMS´ unique backside process and the cavity formation. 3. MEMS´ unique sacrificial oxide etching process to release movable portion.