The thermal management and method for large scale processing of CIS and/or CIGS based thin film overlaying glass substrates. According to an embodiment, the present invention provides a method for fabricating a copper indium diselenide semiconductor film. The method includes providing a plurality of substrates, each of the substrates having a copper and indium composite structure. The method also includes transferring the plurality of substrates into a furnace, each of the plurality of substrates provided in a vertical orientation with respect to a direction of gravity, the plurality of substrates being defined by a number N, where N is greater than 5. The method further includes introducing a gaseous species including a selenide species and a carrier gas into the furnace and transferring thermal energy into the furnace to increase a temperature from a first temperature to a second temperature, the second temperature ranging from about 350° C. to about 450° C. to at least initiate formation of a copper indium diselenide film from the copper and indium composite structure on each of the substrates.