Methods for trench isolation with reduced step height

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Abstract:

Shallow trench isolation techniques are disclosed in which a nitride layer is formed on a semiconductor substrate, and a trench is formed through the nitride layer and into the semiconductor substrate. The nitride layer is removed prior to filling the isolation trench, and the fill material is planarized using a fixed-abrasive CMP process to mitigate or avoid step height in the shallow trench isolation process.