Method and apparatus for the solution deposition of high quality oxide material

Abstract

A metal and oxygen material such as a transparent electrically conductive oxide material is electro deposited onto a substrate in a solution deposition process. Process parameters are controlled so as to result in the deposition of a high quality layer of material which is suitable for use in a back reflector structure of a high efficiency photovoltaic device. The deposition may be carried out in conjunction with a masking member which operates to restrict the deposition of the metal and oxygen material to specific portions of the substrate. In particular instances the deposition may be implemented in a continuous, roll-to-roll process. Further disclosed are semiconductor devices and components of semiconductor devices made by the present process, as well as apparatus for carrying out the process.

1 . In a method for the electroplating of a layer of a metal and oxygen material onto a substrate wherein said substrate is disposed in an electrolyte in a spaced apart relationship with an electrode, and wherein a power supply is operative, when energized, to establish a flow of electrical current through said electrode, said electrolyte, and said substrate so as to deposit a layer of said metal and oxygen material on said substrate, characterized in that said deposition process includes at least two steps from the group consisting of:
 inputting ultrasonic energy into said electrolyte during at least a portion of the time while said layer of metal and oxygen material is being deposited onto said substrate;   periodically interrupting the flow of electrical current between said electrode, said electrolyte, and said substrate, while said layer of said metal and oxygen material is being deposited;   maintaining said substrate in a partiphobic orientation while said layer of metal and oxygen material is being deposited thereupon;   bubbling a gas through said electrolyte; and   energizing said power supply at a first level during the time that a first portion of said metal and oxygen material is being deposited on said substrate so that said first portion is deposited at a first deposition rate and thereafter energizing said power supply at a second level during the time that a second portion of said layer is being deposited atop the first portion wherein said second level of power is selected so that the deposition rate of said second portion is less than the deposition rate of said first portion.   
     
     
         2 . The method of  claim 1 , wherein the improvement comprises implementing said process so as to employ at least three of said steps. 
     
     
         3 . The method of  claim 1 , including at least one further step selected from the group consisting of:
 monitoring the composition of the electrolyte bath;   monitoring the level of a dopant in the deposited metal and oxygen material;   utilizing a dimensionally stable electrode;   utilizing an electrode configured as a hollow basket having particles of said metal contained therein; and   utilizing a filter-shielded electrode.   
     
     
         4 . The method of  claim 1 , wherein said method is operative to deposit a layer of a zinc and oxygen material onto the substrate. 
     
     
         5 . An apparatus for carrying out the method of  claim 1 . 
     
     
         6 . A layer of a zinc and oxygen material made by the method of  claim 4 .