摘要 |
The present invention discloses an improved shallow trench isolation process. A semiconductor substrate having a pad oxide disposed thereon and a pad nitride disposed directly on the pad oxide is provided. A trench is etched, through the pad oxide and the pad oxide, into the semiconductor substrate. A thermal oxide liner is then grown in the trench. A silicon nitride liner is deposited into the trench, wherein the silicon nitride liner covering the pad nitride and the thermal oxide liner has a first stress status. A stress alteration process is performed to alter the silicon nitride liner from the first stress status to a second stress status. A trench fill dielectric having the second stress status is deposited into the trench.
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