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US 2006/0051931 A1Published application
Method for fabricating a trench isolation structure having a high aspect ratio
AssigneeInfineon Technologies AG
InventorUwe Wellhausen
Life of this patent
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Abstract
A method for fabricating a trench isolation structure wherein a trench is formed in a silicon body and an oxide layer is formed in the trench. The silicon body is exposed at the bottom of the trench by means of an etching step, and silicon oxide is selectively grown on the silicon exposed at the bottom of the trench, the silicon oxide being grown from the bottom of the trench toward an upper edge of the trench.
Claims20
A method for fabricating a trench isolation structure, the method comprising:
- forming a trench in a silicon body;
- forming an oxide layer in the trench;
- exposing the silicon body at the bottom of the trench by means of an etching step;
- and
- selectively growing silicon oxide on the silicon exposed at the bottom of the trench, the silicon oxide being grown from the bottom of the trench toward an upper edge of the trench.
2 more elements
A method for the trench isolation of DT-DRAM memory cells on a wafer, the method comprising:
- etching isolation trenches having a high aspect ratio by means of an RIE step;
- performing a thermal oxidation to form an oxide layer along sidewalls and a bottom of the trench;
- removing the oxide layer at the bottom of the trench by means of an anisotropic RIE etching step;
- implanting a species suitable for surface conditioning into the bottom of the trench;
- and
- selectively growing silicon oxide on the silicon uncovered at the bottom of the trench, the silicon oxide being grown from the bottom toward the upper edge of the trench.
3 more elements
Dependencies are inferred from the claim text.