Cleaning Agent for Substrate and Cleaning Method

Abstract

The present invention provides a cleaning agent for a substrate and a cleaning method thereof, which can effectively remove fine particles (particles) present on a surface of substrate or impurities derived from various kinds of metals (metallic impurities), without causing roughness surface of a substrate, in particular, a semiconductor substrate, and without causing corrosion or oxidation of metal wirings, in particular, copper wirings, provided on a surface of substrate, and can further remove at the same time a carbon defect present on a surface of substrate, without removing a metal corrosion inhibitor—Cu film, in particular, a Cu-BTA film. The present invention provides a cleaning agent for a substrate comprising [I] an organic acid having at least one carboxyl group and/or [II] a complexing agent, and [III] an organic solvent selected from the group consisting of (1) monohydric alcohols, (2) alkoxyalcohols, (3) glycols, (4) glycol ethers, (5) ketones and (6) nitriles, and a cleaning method for a surface of substrate, which comprises the surface of substrate is treated with said cleaning agent.

1 . A cleaning agent for a substrate comprising [I] an organic acid having at least one carboxyl group and/or [II] a complexing agent, and [III] an organic solvent selected from the group consisting of (1) monohydric alcohols, (2) alkoxyalcohols, (3) glycols, (4) glycol ethers, (5) ketones and (6) nitrites.  
     
     
         2 . The cleaning agent according to  claim 1 , wherein the learning agent contains [I] the organic acid having at least one carboxyl group and [II] the complexing agent.  
     
     
         3 . The cleaning agent according to  claim 1 , wherein the cleaning agent is an aqueous solution.  
     
     
         4 . The cleaning agent according to  claim 1 , wherein the organic solvent is one selected from the group consisting of methanol, ethanol, isopropyl alcohol, 2-methoxyethanol, 2-(2-butoxyethoxy)ethanol, ethylene glycol, diethylene glycol monomethyl ether, acetone and acetonitrile.  
     
     
         5 . The cleaning agent according to  claim 1 , wherein the complexing agent is one selected from the group consisting of a compound having at least one phosphonic acid group in a molecule, and an ammonium salt or an alkali metal salt thereof.  
     
     
         6 . The cleaning agent according to  claim 5 , wherein the compound having at least one phosphonic acid group in a molecule is one selected from the group consisting of nitrogen-containing polyphosphonic acids having 1 to 6 nitrogen atoms and 1 to 8 phosphonic acid groups in a molecule, an aryl polyphosphonic acid, an alkylene polyphosphonic acid, alkane polyphosphonic acids which may have a hydroxyl group, and an ammonium salt or an alkali metal salt thereof.  
     
     
         7 . The cleaning agent according to  claim 5 , wherein the compound having at least one phosphonic acid group in a molecule is one selected from the group consisting of nitrogen-containing polyphosphonic acids having 1 to 6 nitrogen atoms and 1 to 8 phosphonic acid groups in a molecule, alkane polyphosphonic acids which may have a hydroxyl group, and an ammonium salt or an alkali metal salt thereof.  
     
     
         8 . The cleaning agent according to  claim 6 , wherein the nitrogen-containing polyphosphonic acids having 1 to 6 nitrogen atoms and 1 to 8 phosphonic acid groups in a molecule is one selected from the group consisting of an alkylamino poly(alkylphosphonic acid), a mono- or polyalkylenepolyamine poly(alkylphosphonic acid), a nitrilo-poly(alkylphosphonic acid), and an ammonium salt or an alkali metal salt thereof.  
     
     
         9 . The cleaning agent according to  claim 1 , wherein the complexing agent is one selected from the group consisting of: 
 ethylenediaminebis(methylenephosphonic acid) [EDDPO];    ethylenediaminetetrakis(ethylenephosphonic acid);    ethylenediaminetetrakis(methylenephosphonic acid) [EDTPO]; hexamethylenediaminetetrakis(methylenephosphonic acid);    isopropylenediaminebis(methylenephosphonic acid);    isopropylenediamintetra(methylenephosphonic acid);    propanediaminetetra(ethylenephosphonic acid)[PDTMP];    diaminopropanetetra(methylenephosphonic acid)[PDTPO];    diethylenetriaminepenta(ethylenephosphonic acid) [DEPPO];    diethylenetriaminepenta(methylenephosphonic acid) [DETPPO];    triethylenetetraminehexa(ethylenephosphonic acid) [TETHP];    triethylenetetraminehexa(methylenephosphonic acid) [TTHPO];    nitrilotris(methylenephosphonic acid)[NTPO];    ethylidenediphosphonic acid;    1-hydroxyethylidene-1,1′-diphosphonic acid [HEDPO];    1-hydroxypropylidene-1,1′-diphosphonic acid; and    1-hydroxybutylidene-1,1′-diphosphonic acid.    
     
     
         10 . The cleaning agent according to  claim 1 , wherein the organic acid is an organic acid having 2 or 3 carboxyl groups.  
     
     
         11 . The cleaning agent according to  claim 1 , wherein the organic acid is a dicarboxylic acid or an oxycarboxylic acid.  
     
     
         12 . The cleaning agent according to  claim 11 , wherein the oxycarboxylic acid is an oxydicarboxylic acid or an oxytricarboxylic acid.  
     
     
         13 . The cleaning agent according to  claim 11 , wherein the dicarboxylic acid is one selected from the group consisting of an oxalic acid, a malonic acid, a succinic acid, a glutaric acid, an adipic acid, a pimelic acid, a maleic acid, a fumaric acid and a phthalic acid.  
     
     
         14 . The cleaning agent according to  claim 11 , wherein the oxycarboxylic acid is a malic acid, a tartaric acid, or a citric acid.  
     
     
         15 . The cleaning agent according to  claim 1 , wherein the organic acid is a dicarboxylic acid or an oxycarboxylic acid; the complexing agent is one selected from the group consisting of nitrogen-containing polyphosphonic acid having 1 to 6 nitrogen atoms and 1 to 8 phosphonic acid groups in a molecule, alkane polyphosphonic acids which may have a hydroxyl group, and an ammonium salt or an alkali metal salt thereof; and the organic solvent is one selected from the group consisting of monohydric alcohols, alkoxyalcohols, glycols, glycol ethers, ketones and nitrites.  
     
     
         16 . The cleaning agent according to  claim 1 , wherein pH of the cleaning agent is 0.5 to 6.5.  
     
     
         17 . The cleaning agent according to  claim 1 , wherein the substrate is a semiconductor.  
     
     
         18 . The cleaning agent according to  claim 1 , wherein the substrate is one with metallic wiring provided thereon.  
     
     
         19 . The cleaning agent according to  claim 18 , wherein the metallic wiring is a copper wiring.  
     
     
         20 . The cleaning agent according to  claim 1 , wherein the substrate is one treated with a slurry containing benzotriazole or a derivative thereof.  
     
     
         21 . A cleaning method for a surface of substrate, which comprises treating the surface of substrate with the cleaning agent according to  claim 1 .  
     
     
         22 . The cleaning method according to  claim 21 , wherein the treatment with the cleaning agent is dipping the surface of substrate in the cleaning agent according to  claim 1  or spraying said cleaning agent on the surface of substrate.  
     
     
         23 . The cleaning method according to  claim 21 , wherein physical cleaning is further used in combination.  
     
     
         24 . The cleaning method according to  claim 21 , wherein the substrate is one after subjecting to a chemical mechanical polishing process.  
     
     
         25 . The cleaning method according to  claim 21 , wherein the substrate is a semiconductor.  
     
     
         26 . The cleaning method according to  claim 21 , wherein the substrate is one with metallic wiring provided thereon.  
     
     
         27 . The cleaning method according to  claim 26 , wherein the metallic wiring is a copper wiring.  
     
     
         28 . The cleaning method according to  claim 21 , wherein the substrate is one after subjecting to the treatment process with a slurry containing benzotriazole or a derivative thereof.