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US 2002/0160616 A1Published application
Integrated circuit trench etch with incremental oxygen flow
OwnerThomas E. Grebs, Joseph L. Cumboinventors
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Abstract
Trenches are made in an integrated circuit by a process that incrementally increases the amount of oxygen during a trench etch. The trench may be an isolation trench or a gate trench for a QVDMOS device.
Claims9
A method for forming a trench in a device layer of an integrated circuit formed on a semiconductor substrate comprising the steps of:
- covering the device layer with an etch resistant trench masking layer to form a plurality of trench regions;
- removing semiconductor material from the exposed trench regions by applying an etching fluid that selectively etches the semiconductor substrate with respect to the trench masking layer;
- increasing an amount of oxygen during the removing operation to passivate the silicon sidewalls of the trench.
Dependencies are inferred from the claim text.