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US 6,673,693 B2Granted
Method for forming a trench in a semiconductor substrate
AssigneeInfineon Technologies AG
InventorMarkus Kirchhoff
Life of this patent
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Abstract
A method for forming a trench in a semiconductor substrate includes configuring a mask on the substrate. The mask has a window in which a substrate surface is uncovered. The substrate is electrochemically etched proceeding from the substrate surface. A porous substrate is formed in a trench-shaped region proceeding from the substrate surface. The trench is formed by removing the porous substrate from the trench-shaped region.
Claims4
A method for forming a deep trench for a trench capacitor in a semiconductor substrate, which comprises:
- providing a substrate having a substrate surface;
- providing a mask having a window and configuring the mask on the substrate to define an uncovered portion of the substrate surface that is within the window;
- electrochemically etching the substrate, proceeding from the uncovered portion of the substrate surface that is within the window, by using an electrolyte containing hydrofluoric acid to form a porous substrate in a trench-shaped region proceeding from the uncovered portion of the substrate surface;
- oxidizing the porous substrate to form porous substrate oxide;
- and
- etching the porous substrate oxide using hydrofluoric acid.
3 more elements
Dependencies are inferred from the claim text.