Haynes and Boone, LLP
Method to solve alignment mark blinded issues and technology for application of semiconductor etching at a tiny area
A method of unblinding an alignment mark comprising the following steps. A substrate having a cell area and an alignment mark within an alignment area is provided. An STI trench is formed into the substrate within the cell area. A silicon oxide layer is formed over the substrate, filling the STI trench and the alignment mark. The silicon oxide layer is planarized to form a planarized STI within the STI trench and leaving silicon oxide within the alignment mark to form a blinded alignment mark. A wet chemical etchant is applied within the alignment mark area over the blinded alignment mark to at least partially remove the silicon oxide within the alignment mark. The remaining silicon oxide is removed from within the blinded alignment mark to unblind the alignment mark. A drop etcher apparatus is also disclosed.
Taiwan Semiconductor Manufacturing Company, Ltd.
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inventional inventional inventional inventional
Chung-Long Shang-Ting Yu-Liang Jui-Cheng
Chang Tsai Lin Lo