Manufacturing method of semiconductor structure

Abstract

A method for manufacturing a semiconductor structure includes the following steps: Providing a substrate. Forming a pad layer on the substrate. Forming a plurality of isolation structures in the substrate and the pad layer. The plurality of isolation structures have a plurality of protrusions. The top surface of the protrusions is higher than the top surface of the pad layer. Forming protective spacer walls on the sidewalls of the protrusions. Removing the pad layer using the protective spacer walls as a mask. Removing the protective spacer walls.

Claims

1. A method for manufacturing a semiconductor structure, comprising: Provide a base; A pad layer is formed on the substrate; A plurality of isolation structures are formed in the substrate and the padding layer, wherein the plurality of isolation structures have a plurality of protrusions, and the top surface of the protrusions is higher than the top surface of the padding layer; a protective gap wall is formed on the sidewall of the protrusion; Using the protective gap wall as a cover, the padding layer is removed; The method for removing the protective gap wall includes: using the protective gap wall as a mask to perform a dry etching process on the pad to remove a portion of the pad; And after the dry etching process, the pad is wet-etched using the protective spacer wall as a cover to remove the remaining pad.

2. A method for manufacturing a semiconductor structure as claimed in claim 1, wherein the method for forming a plurality of said isolation structures includes: A rigid cover layer is formed on the padding layer; Multiple trenches are formed in the rigid cover layer, the padding layer, and the substrate; And to form multiple isolation structures in multiple of the aforementioned ditches.

3. The method for manufacturing the semiconductor structure as described in claim 2 further includes: After forming multiple isolation structures, the rigid masking layer is removed.

4. A method for manufacturing a semiconductor structure as claimed in claim 1, wherein the method for forming the protective spacer wall comprises: A protective layer is formed on the padding layer and the plurality of the isolation structures; The protective layer is then etched back to form the protective spacer wall.

5. A method for manufacturing a semiconductor structure as claimed in claim 4, wherein the method for forming the protective layer includes chemical vapor deposition or atomic layer deposition.

6. A method for manufacturing a semiconductor structure as claimed in claim 4, wherein the etch-back process includes a dry etching process.

7. A method for manufacturing a semiconductor structure as claimed in claim 1, wherein after the dry etching process, the remaining pad layer is not exposed outside the substrate.

8. The method for manufacturing a semiconductor structure as described in claim 1, further comprising: After the protective gap wall is removed, a first dielectric layer is formed on the substrate; A plurality of floating gates are formed between the plurality of protrusions and on the first dielectric layer; A back-etch process is performed on the plurality of isolation structures to form a plurality of recesses; a second dielectric layer is formed on the plurality of floating gates and the plurality of isolation structures and in the plurality of recesses; and a control gate is formed on the second dielectric layer and in the plurality of recesses.

9. A method for manufacturing a semiconductor structure as claimed in claim 1, wherein the method for removing the protective spacer wall includes a wet etching method.

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