A method for processing solar cells comprising: providing a vertical furnace to receive an array of mutually spaced circular semiconductor wafers for integrated circuit processing; composing a process chamber loading configuration for solar cell substrates, wherein a size of the solar cell substrates that extends along a first surface to be processed is smaller than a corresponding size of the circular semiconductor wafers, such that multiple arrays of mutually spaced solar cell substrates can be accommodated in the process chamber, loading the solar cell substrates into the process chamber; subjecting the solar cell substrates to a process in the process chamber.