Taiwan Semiconductor Manufacturing Comp. Ltd.

Kun-I Lee

Bao-Ru Young

Hung-Chih Chen

Tai-Yuan Wu

Ren-Jyh Leu

Der-Fang Huang

Correction of overlay shift of an epitaxial silicon layer deposited on a semiconductor wafer, and of post-epitaxial silicon layers subsequently deposited, is disclosed. When an epitaxial silicon layer of a given thickness is deposited, the zero mark coordinates for the deposition are shifted relative to alignment marks on the wafer by a distance based on the thickness of the layer. The distance is preferably proportional to the thickness of the epi layer. This prevents overlay shift of the epi layer. For post-epitaxial silicon layers subsequently deposited, preferably except for the first post-epi layer, a clear out process is initially performed to maintain the alignment marks on the semiconductor wafer. In this way, overlay shift, or misalignment, of the post-epi layers is also prevented.

Overlay shift correction for the deposition of epitaxial silicon layer and post-epitaxial silicon layers in a semiconductor device

A method for spin-coating a high viscosity liquid on a wafer surface capable of producing an improved uniformity in the coating thickness and a reduced material usage is disclosed. In the method, a liquid that has a high viscosity of at least 1000 cp is first provided. A wafer is then rotated to a speed of less than 300 rpm while simultaneously, a first volume of a high viscosity liquid is dispensed onto the wafer surface forming a cup-shaped pattern. The spinning of the wafer is then stopped and a second volume of the high viscosity liquid is dispensed into a cavity formed in the cup-shaped pattern to substantially fill the cavity. The wafer is then rotated again to a high rotational speed of at least 3000 rpm such that liquid in the cup-shaped pattern spreads out to substantially cover an entire surface of the wafer resulting in improved coating uniformity.

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Sanchung, Taiwan

Kun-I Lee