Patent ID: 8217261

Claim:
A method for fabricating a thin film solar cell, the method comprising: providing a soda lime glass substrate comprising a surface region and a concentration of sodium oxide of greater than about 10 percent by weight; treating the surface region with one or more cleaning process, using a deionized water rinse, to remove surface contaminants having a particles size of greater than three microns; forming a barrier layer overlying the surface region, the barrier layer being characterized to maintain the sodium within the soda lime glass substrate; forming a first molybdenum layer using a first process having a first pressure, the first molybdenum layer having a first thickness and being in tensile configuration, overlying the barrier layer; forming a second molybdenum layer using a second process having a second pressure, the second molybdenum layer having a second thickness, which is greater than the first thickness, and being in compressive configuration, overlying the first molybdenum layer, wherein the second pressure is greater than the first pressure; patterning the first molybdenum layer and the second molybdenum layer to form a lower electrode layer; forming a first interconnect structure by filling a pattern formed in the first molybdenum layer and the second molybdenum layer, wherein a first height of the first interconnect structure is substantially equal to a thickness of the lower electrode layer; forming a layer of photovoltaic material overlying the lower electrode layer; and forming a first zinc oxide layer overlying the layer of photovoltaic material.