System for two-step resist soft bake to prevent ILD outgassing during semiconductor processing
AssigneeMicron Technology, Inc.
InventorsPaul Shirley, Gordon Haller
Life of this patent
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Abstract
In general, the system provides for soft baking a semiconductor wafer so that photoresist layers on the wafer are free of surface voids or craters. In particular, the system provides for manufacturing a semiconductor wafer having no photoresist craters at the completion of a two-step post-apply resist bake (soft bake) in the fabrication of an integrated circuit. In the system, the semiconductor wafer is coated with resist and then baked at both a low-bake temperature and a high-bake temperature. It is theorized that the lower temperature bake either hardens the resist layer before trapped air expands through the resist or displaces the trapped air while the resist layer remains fluid and returns to its conformal shape.
Claims16
A two-bake system comprising:
- a first thermal unit configured to bake, at a low-bake temperature, a semiconductor wafer having a plurality of features coated with resist, wherein at least one unfilled void is present under the resist and between two of the plurality of features;
- and
- a second thermal unit configured to bake the semiconductor wafer at a high-bake temperature;
- wherein the two-bake system is configured to bake the semiconductor wafer such that the at least one unfilled void remains present under the resist and between the two of the plurality of features after baking.
A two-bake system comprising:
- a semiconductor wafer comprising a plurality of features, wherein a layer of resist is disposed over the plurality of features such that at least one void is present under the layer of resist and between two of the plurality of features;
- and
- a thermal unit configured to bake the semiconductor wafer at a low-bake temperature for a low-bake time and at a high-bake temperature for a high-bake time such that the at least one void remains present and unfilled under the layer of resist and between the two of the plurality of features after baking.
Dependencies are inferred from the claim text.