Single crystalline substrates are typically differentiated by the process by which they are made. Czochralski (CZ) wafers are the most commonly used type of silicon wafer, and are used by both the solar and integrated circuit industry. The process of making a large single crystalline silicon ingot by the Czochralski process is shown below.

Top of Czochralski ingot. The bottom cylindrical section has been cut off to make wafers. Such "tops and tails" left over from growing the semiconductor industry are a large source of silicon supply for the photovoltaics industry.