Taiwan Semiconductor Manufacturing Comp. Ltd.

Wing-Lang Zang

Cheng-Yeh Shih

Kuei-Ying Lee

Shu-Hui Chen

A new method of metallization without unwanted precipitates using a tungsten plug is achieved. Semiconductor device structures are formed in and on a semiconductor substrate. A contact hole is opened through an insulating layer to the semiconductor substrate. A glue layer is deposited conformally over the surface of the insulating layer and within the contact opening. A layer of tungsten is blanket deposited over the glue layer. The tungsten layer is etched back leaving the tungsten only within the contact opening to form a tungsten plug. The etching back leaves impurities on the surface of the glue layer. Those impurities will react with water or air to form precipitates. The precipitates are removed using a wet chemical etch. The substrate is post treated with argon ion sputtering to prevent future formation of precipitates. A second metal layer is deposited over the tungsten plug and the glue layer to complete the tungsten plug metallization without unwanted precipitates in the fabrication of an integrated circuit.

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Hsin-chu, Taiwan

Wing-Lang Zang