Aqueous cleaner with low metal etch rate

Abstract

A cleaning solution is provided for cleaning metal-containing microelectronic substrates, particularly for post etch, via formation and post CMP cleaning. The cleaning solution consists of a quaternary ammonium hydroxide, an organic amine, and water. A preferred cleaning solution consists of tetramethylammonium hydroxide, monoethanolamine, and water. The pH of cleaning solution is greater than 10.

1 .- 11 . (canceled) 
     
     
         12 . A cleaning composition consisting essentially of 0.30 to 9.0 wt % alkanolamine, 0.06 to 13.5 wt % potassium hydroxide, balance water. 
     
     
         13 . The cleaning composition of  claim 12 , wherein the alkanolamine comprises a species selected from the group consisting of monoethanolamine, 1-amino-2 propanol, 2-(methylamino) ethanol, triethanolamine, and mixtures thereof. 
     
     
         14 . The cleaning composition of  claim 12 , wherein the alkanolamine comprises monoethanolamine. 
     
     
         15 . A method for preparing a post-CMP cleaning solution containing 0.02 to 13.5 wt % quaternary ammonium hydroxide, 0.3 to 22.0% by weight alkanolamine, balance water, said method comprising the steps of:
 a) mixing 100% of the water and said alkanolamine;   b) adding said quaternary ammonium hydroxide to said water-alkanolamine mixture and mixing with low shear conditions to achieve a final mixture; and   c) filtering said final mixture through a 0.1 micron filter.   
     
     
         16 . The method of  claim 15 , wherein the mixing with low shear conditions is carried out for about 10 min. 
     
     
         17 . The method of  claim 15 , wherein the alkanolamine comprises a species selected from the group consisting of monoethanolamine, 1-amino-2 propanol, 2-(methylamino) ethanol; triethanolamine and mixtures thereof. 
     
     
         18 . The method of  claim 15 , wherein the quaternary ammonium hydroxide comprises a species selected from the group consisting of tetramethyl ammonium hydroxide, tetrabutyl ammonium hydroxide and mixtures thereof. 
     
     
         19 . The method of  claim 15 , wherein the alkanolamine comprises monoethanolamine and wherein the quaternary ammonium hydroxide comprises (carboxymethyl) trimethylammonium hydroxide inner salt. 
     
     
         20 . The method of  claim 15 , wherein the alkanolamine comprises monoethanolamine and wherein the quaternary ammonium hydroxide comprises tetramethylammonium hydroxide. 
     
     
         21 . A cleaning composition including 2-(2-dimethylaminoethoxy)ethanol, tetramethylammonium hydroxide, and water.