Facts and figures. 1  Transistors in a microprocessor can be less than one micrometer wide—one millionth of a meter. By comparison, a single hair can be over 100 microns wide. 2  The transistors are mostly MOSFETs. 3  Microprocessors are made from silicon, quartz, metals, and other chemicals. From start to finish, it takes about 2 months to make a microprocessor. Microprocessors are classified by the size of their data bus or address bus.