Apparatus for achieving low resistance contact to a metal based thin film solar cell

Abstract

A system and method of forming a thin film solar cell with a metallic foil substrate are provided. After forming a semiconductor absorber film over the front surface of the metallic foil substrate a back surface of the metallic foil substrate is treated using a material removal process to form a treated back surface in a process chamber. In one embodiment, the material removal process is performed while depositing a transparent conductive layer over the semiconductor absorber film in the process chamber.

1 - 49 . (canceled) 
     
     
         50 . A system for depositing transparent conductive layers for manufacturing solar cells, comprising:
 a moving mechanism for supplying a continuous flexible workpiece into the system, the continuous flexible workpiece including a continuous conductive substrate having a Group IBIIIAVIA compound absorber layer disposed over a front surface of the continuous conductive substrate;   a transparent conductive layer deposition sub-system located within a process chamber to form a transparent conductive layer on the Group IBIIIAVIA compound absorber layer using at least one material deposition device; and   a treatment sub-system comprising at least one material removing device located within the process chamber to apply a material removal process to remove a surface film from a back surface of the continuous conductive substrate and obtain a treated back surface contact area as the transparent conductive layer is formed on the Group IBIIIAVIA compound absorber layer.   
     
     
         51 . The system of  claim 50  wherein the treatment sub-system further comprises at least one deposition device to deposit a conductive layer onto the treated back surface. 
     
     
         52 . The system of  claim 50 , further comprising a loading station with a feeding roll to supply the continuous flexible workpiece from the feeding roll into the process chamber. 
     
     
         53 . The system of  claim 52  further comprising an unloading station with a receiving roll to receive and wrap up the continuous flexible workpiece after it exits the process chamber. 
     
     
         54 . The system of  claim 50 , wherein the at least one material removing device comprises a dry etching device. 
     
     
         55 . The system of  claim 54 , wherein the dry etching device is one of ion milling device and sputter etching device. 
     
     
         56 . The system of  claim 55  wherein the at least one material deposition device comprises a sputtering device.