Method for cleaning semiconductor wafer after chemical mechanical polishing on copper wiring
AssigneeNEC Corporation
InventorsHidemitsu Aoki, Shinya Yamasaki
Life of this patent
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Abstract
A copper wiring is desirable for a high-speed logic circuit integrated on a semiconductor substrate, and is patterned through a chemical mechanical polishing, wherein polishing particles are brushed away from the major surface of the resultant semiconductor structure by using hydrogen-containing water without damage to the copper wiring, and, thereafter, metallic contaminants such as copper is removed by using washer containing decontaminating agent selected from polycarboxylic acid, ammonium salts thereof and polyaminocarboxylic acid also without damage to the copper wiring.
Claims21
A method for cleaning a semiconductor wafer having a copper layer exposed to a surface thereof after a chemical mechanical polishing, comprising the steps of:
- a) treating said semiconductor wafer with a first washer selected from the group consisting of hydrogen containing water for removing polishing particles from said semiconductor wafer without damage to said copper layer;
- and
- b) treating said semiconductor wafer with a second washer containing at least one decontaminating agent selected from the group consisting of polycarboxylic acids each capable of producing a chelate compound together with copper, ammonium salts of said polycarboxylic acids for removing metallic contaminants from said semiconductor wafer.
A method for cleaning a semiconductor wafer having a tungsten layer exposed to a surface thereof after a chemical mechanical polishing, comprising the steps of:
- a) treating said semiconductor wafer with a first washer selected from the group consisting of hydrogen containing water for removing polishing particles from said semiconductor wafer without damage to said tungsten layer;
- and
- b) treating said semiconductor wafer with a second washer containing at least one decontaminating agent selected from the group consisting of oxalic acid and ammonium oxalate and ranging from 0.01 weight percent for removing metallic contaminants from said semiconductor wafer.
Dependencies are inferred from the claim text.