Eschweiler & Potashnik, LLC
Deep trench isolation shrinkage method for enhanced device performance
Some embodiments of the present disclosure relate to a method in which a functional layer is formed over an upper semiconductor surface of a semiconductor substrate, and a capping layer is formed over the functional layer. A first etchant is used to form a recess through the capping layer and through the functional layer. The recess has a first depth and exposes a portion of the semiconductor substrate there through. A protective layer is formed along a lower surface and inner sidewalls of the recess. A second etchant is used to remove the protective layer from the lower surface of the recess and to extend the recess below the upper semiconductor surface to a second depth to form a deep trench. To prevent etching of the functional layer, the protective layer remains in place along the inner sidewalls of the recess while the second etchant is used.
Taiwan Semiconductor Manufacturing Co., Ltd.
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Chih-Yu Shih Pei Sheng-Chau Chia-Shiung Cheng-Hsien Chih-Ta Yeur-Luen
Lai Chou Chen Tsai Chou Chen Tu