Specific Process Knowledge/Etch/Wet Silicon Oxide Etch (BHF): Difference between revisions
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==Life time of the photoresist and blue film in BHF== | ==Life time of the photoresist and blue film in BHF== | ||
Photoresist delaminates from the substrate in BHF. For standard photoresist this | Photoresist delaminates from the substrate in BHF. For standard photoresist this process starts after about or less than ½ hour but the time can vary with resist pattern. It starts by under etching the photoresist at the edges. The life time can be prolonged a little to ½ hour - 40 minutes if the photoresist is baked at 120<sup>o</sup>C. | ||
Blue film also has a limited life time in BHF. Blue film is mainly used for back side protecting the wafer while etching on the front side. The life time of Blue film is also about ½ hour. | Blue film also has a limited life time in BHF. Blue film is mainly used for back side protecting the wafer while etching on the front side. The life time of Blue film is also about ½ hour. | ||