Electroplating method for depositing continuous thin layers of indium or gallium rich materials

Abstract

An electrochemical deposition method to form uniform and continuous Group IIIA material rich thin films with repeatability is provided. Such thin films are used in fabrication of semiconductor and electronic devices such as thin film solar cells. In one embodiment, the Group IIIA material rich thin film is deposited on an interlayer that includes 20-90 molar percent of at least one of In and Ga and at least 10 molar percent of an additive material including one of Cu, Se, Te, Ag and S. The thickness of the interlayer is adapted to be less than or equal to about 20% of the thickness of the Group IIIA material rich thin film.

1 . A method of electrodepositing a Group IIIA material rich thin film over a surface of a base for manufacturing solar cell precursors, the method comprising:
 electrodepositing an interlayer over the surface of the base, wherein the interlayer comprises a predetermined molar percent of at least one of In and Ga and at least 10 molar percent of an additive material including one of Cu, Se, Te, Ag and S, wherein the predetermined molar percent is in the range of 20-90 percent; and   electrodepositing the Group IIIA material rich thin film on the interlayer to a predetermined thickness, wherein the Group IIIA material rich thin film is one of a substantially pure In film, a substantially pure Ga film and a substantially pure In—Ga alloy, wherein the predetermined thickness of the Group IIIA material rich thin film is less than 700 nm, and wherein the thickness of the interlayer is less than or equal to 20% of the predetermined thickness.   
     
     
         2 - 16 . (canceled)