Post-treatment of low-k dielectric for prevention of photoresist poisoning
AssigneeAdvanced Micro Devices, Inc.
InventorsLynne A. Okada, Fei Wang, Calvin T. Gabriel
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Abstract
Deleterious poisoning of patterned photoresist masking layers accompanying plasma ashing/etching of photoresist and/or low-k dielectric layers in a nitrogen-containing atmosphere is eliminated, or at least substantially reduced, by post-treating exposed surfaces of the low-k dielectric layer(s) with hydrogen, e.g. by contact with H2 gas at an elevated temperature or with a H2 plasma subsequent to plasma ashing/etching. The invention enjoys particular utility in the formation of dual damascene openings in dielectric layers as part of metallization processing of semiconductor IC devices.
Claims26
A method of eliminating, or at least substantially reducing, photoresist poisoning during recess patterning of a layer of a material, comprising the sequential steps of:
- (a) forming a first photoresist layer on an upper surface of said layer;
- (b) patterning said first photoresist layer to include at least one opening therein having a first width;
- (c) forming at least one first recess in said upper surface of said layer utilizing said patterned first photoresist layer as a mask, said at least one first recess having a first width substantially corresponding to said first width of said at least one opening in said first photoresist layer and extending for a first depth below said surface of said layer;
- (d) removing said first photoresist layer;
- (e) treating exposed surfaces of said layer to eliminate, or at least substantially reduce the amount of nitrogen or a nitrogen-containing contaminant which can poison a second photoresist layer subsequently formed in contact with said upper surface of said layer;
- and
- (f) forming a second photoresist layer on said upper surface of said layer;
- wherein poisoning of said second photoresist layer by entry thereinto of said nitrogen or nitrogen-containing contaminant is eliminated or at least substantially reduced due to said surface treating of step (e).
A method of manufacturing a semiconductor device, comprising the sequential steps of:
- (a) providing a workpiece comprising:
- (i) a semiconductor substrate including at least one active device region or component formed therein or thereon;
- (ii) a dielectric layer overlying said semiconductor substrate and including at least one metal feature in-laid in an upper surface of said dielectric layer;
- (iii) a thin capping layer formed over at least the upper surface of said at least one metal feature;
- and
- (iv) an interlayer dielectric layer formed over said thin capping layer;
- (b) forming a first photoresist layer on an upper surface of said interlayer dielectric layer;
- (c) patterning said first photoresist layer to include at least one opening therein having a first width;
- (d) forming at least one first recess in said upper surface of said interlayer dielectric layer utilizing said patterned first photoresist layer as a mask, said at least one first recess having a first width substantially corresponding to said first width of said at least one opening in said first photoresist layer and extending through said interlayer dielectric layer to said thin capping layer;
- (e) removing said first photoresist layer;
- (f) treating exposed surfaces of said interlayer dielectric layer to eliminate, or at least substantially reduce the amount of nitrogen or a nitrogen-containing contaminant which can poison a second photoresist layer subsequently formed on said upper surface of said interlayer dielectric layer;
- (g) forming a second photoresist layer on said upper surface of said interlayer dielectric layer, wherein poisoning of said second photoresist layer by entry thereinto of said nitrogen or nitrogen-containing contaminant is eliminated or substantially reduced due to said surface treating step (f);
- (h) patterning said second photoresist layer to form at least one opening therein, said at least one opening in said second photoresist layer being vertically aligned with said at least one first recess and having a second width greater than said first width;
- and
- (i) forming at least one second recess extending partway through said interlayer dielectric layer, said at least one second recess having a second width substantially corresponding to said second, greater width of said at least one opening in said second photoresist layer and communicating with said at least one first recess.
Dependencies are inferred from the claim text.