Processing CIGS in a Belt Furnace

The fabrication of CIGS solar cells within a production environment contains the deposition of copper, indium and gallium on the selected substrate material while annealing them at elevated temperatures in controlled atmospheres.  First, the substrate material is cleaned and then heated to an elevated temperature.  Afterwards, copper, indium, gallium and selenium are deposited through a sputtering process and then the deposited parts are selenized in an elevated temperature profile.  The selenization process involves ramping up from room temperature to 450°C in about 4 minute’s.  The samples are soaked at this temperature for 7 minutes and then elevated to 550°C for approximately 4 minutes.  The samples are then held at 550°C for another 7 minutes and then cooled down.  Finally, while held at an elevated temperature, hydrogen sulphide gas is introduced to sulphurization.