NOVELTY - The method comprises exposing a substrate to a first cleaning solution comprising hydrogen peroxide (0.1-5 vol.%) and ammonium citrate, agitating the first cleaning solution, exposing the substrate to a first rinse solution that is deionized water, scribing a surface of the substrate with a laser, exposing the substrate to a second cleaning solution having a pH of 6-7, where the second cleaning solution is different than the first cleaning solution, agitating the second cleaning solution using an ultrasonic mixer, and exposing the substrate a second rinse solution.    USE - The method for processing a substrate in the production of photovoltaic cells and modules such as amorphous silicon and microcrystalline solar cells.    ADVANTAGE - The method is capable of efficiently processing the substrate without contaminants thus economically manufacturing photovoltaic cells and modules with high conversion efficiency and reducing electrical mismatch and the occurrence of hot spots between photovoltaic cells.    DETAILED DESCRIPTION - The method comprises exposing a substrate to a first cleaning solution comprising hydrogen peroxide (0.1-5 vol.%) and ammonium citrate, agitating the first cleaning solution, exposing the substrate to a first rinse solution that is deionized water, scribing a surface of the substrate with a laser, exposing the substrate to a second cleaning solution having a pH of 6-7, where the second cleaning solution is different than the first cleaning solution, agitating the second cleaning solution using an ultrasonic mixer, exposing the substrate a second rinse solution, and depositing a silicon-containing film on a transparent conductive oxide of the substrate. The step of agitating the second cleaning solution comprises removing particles of transparent conductive oxide from the surface of the substrate. The first cleaning solution has a pH of 6-7.    DESCRIPTION OF DRAWING(S) - The figure shows a flow chart of a method for processing a substrate.    Cleaning substrate using first cleaning solution (231)    Cleaning substrate using second cleaning solution (233)    Performing post-clean process. (235)