Method for fabricating shallow trench isolation structure
AssigneeUnited Semiconductor Corp.
InventorShu-Ya Chuang
Life of this patent
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Abstract
A method for fabricating a shallow trench isolation (STI) structure in a semiconductor substrate. A stop layer is formed on the substrate and a first sacrificial layer is formed on the stop layer. The first sacrificial layer and the stop layer are defined to form an opening on the substrate. A conformal second sacrificial layer with rounded corners is formed on the substrate. The second sacrificial layer, the first sacrificial layer, and a portion of the substrate are anisotropically removed to form a trench in the substrate using the stop layer as a removal stop layer. The substrate is over removed using the stop layer as a mask layer so that spacers of the second sacrificial layer are remained on the substrate to cover portions of sidewalls of the stop layer.
Claims13
A method for fabricating a shallow trench isolation (STI) structure, comprising:
- providing a substrate;
- forming a stop layer on the substrate;
- forming a first sacrificial layer on the stop layer;
- defining the first sacrificial layer and the stop layer to form an opening on the substrate;
- forming a conformal second sacrificial layer with rounded corners on the substrate;
- anisotropically removing the second sacrificial layer, the first sacrificial layer, and a portion of the substrate to form a trench in the substrate using the stop layer as a removal stop layer;
- and
- over removing the substrate using the stop layer as a mask layer so that spacers of the second sacrificial layer are remained on the substrate to cover parts of sidewalls of the stop layer.
Dependencies are inferred from the claim text.