Method for forming metallic layer using inspected mask
AssigneeUnited Semiconductor Corp.
InventorChia-Chieh Yu
Life of this patent
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Abstract
A method for forming a high-quality aluminum-copper alloy pattern over a semiconductor substrate. The method first forms an aluminum-copper alloy layer over a semiconductor substrate, and then performs a rapid thermal processing operation to remelt copper extracts into the alloy bulk. Subsequently, a photoresist layer is formed over the alloy layer. Finally, the alloy layer is etched to transfer the pattern from the photoresist layer to the metallic alloy layer. Unlike a conventional method that can lead to abnormal conduction due to the presence of extracts that are difficult to etch, this invention uses a thermal operation to remove the extracts before etching is conducted. Hence, the masking effect due to etching is mostly prevented.
Claims22
A method for manufacturing a metallic layer comprising:
- (a) providing a semiconductor substrate having a MOS device already formed thereon;
- (b) forming a copper-containing alloy layer over the semiconductor substrate after step (a);
- (c) performing a thermal processing operation at a temperature in the range of 120.degree. C. to about 350.degree. C. after step (b);
- (d) forming a photoresist layer over the alloy layer and then patterning the photoresist layer after step (c);
- (e) performing an etching operation to transfer the pattern from the photoresist layer to the alloy layer after step (d);
- and
- (f) removing the photoresist layer after step (e).
A method for manufacturing a metallic layer comprising the steps of:
- (a) providing a semiconductor substrate having an MOS device already formed thereon;
- (b) forming an alloy layer comprising at least copper and aluminum over the semiconductor substrate after step (a);
- (c) performing a thermal process operation for re-melting any copper extracts into the alloy layer after step (b);
- (d) forming a patterned photoresist layer having a pattern over the alloy layer after step (c);
- (e) checking the pattern and repeating steps (c) to (e) if the pattern is found to be defective after step (d);
- (f) performing an etching operation to transfer the pattern from the photoresist layer to the alloy after step (e);
- and
- (g) removing the photoresist layer after step (f).
A method for forming a metallic layer capable for depositing an aluminum-copper alloy layer over a semiconductor substrate such that the quality of the alloy layer after a pattern etching operation can still be maintained, the method comprising:
- (a) forming an aluminum-copper alloy layer over the semiconductor substrate l;
- (b) performing a thermal processing operation for removing any copper extracts from the aluminum-copper alloy layer that could interfere with a subsequent etching operation after step (a);
- (c) forming an etching mask over the aluminum-copper alloy layer, where the etching mask is developed to form the desired etching pattern after step (b);
- additionally carrying out a quality control check to ensure the quality of the patterned etching mask;
- whenever the quality control check reveals a defective etching mask, removing the defective etching mask and repeating steps (b) and (c);
- and
- (d) performing the etching process after step (c).
Dependencies are inferred from the claim text.