摘要 |
A method for manufacturing a shallow trench isolation structure comprises etching a plurality of trenches into a silicon substrate. The trenches have an upright wall portion, a bottom floor portion, and a corner portion connecting the upright wall portion and the bottom floor portion. The method further comprises conformally depositing a dielectric layer into the trenches. The dielectric layer covers at least part of the upright wall portion, at least part of the bottom floor portion, and at least part of the corner portion. The method further comprises oxidizing the dielectric layer. A portion of the dielectric layer deposited over the corner portion is oxidized at a first oxidization rate, and a portion of the dielectric layer deposited over the upright wall portion is oxidized at a second oxidization rate. The first oxidization rate is less than the second oxidization rate. The method further comprises depositing an electrically insulating material into the trenches over the dielectric layer.
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