21Mar How is Microprocessor Manufactured?-Part 1

Processors are manufactured primarily from silicon, the second most common element on the planet. Silicon is the primary ingredient in beach sand, however, in that form it isn’t pure enough to be used in chips.

The manner in which silicon is formed into chips is a lengthy process that starts by growing pure silicon crystals via what is called the Czochralski method. In this method, electric arc furnaces transform the raw materials (primarily quartz rock that is mined) into metallurgical-grade silicon. Then to further weed out impurities, the silicon is converted to a liquid, distilled, and then redeposited in the form of semiconductor-grade rods, which are 99.999999% pure. These rods are then mechanically broken up into chunks and packed into quartz crucibles, which are loaded into electric crystal pulling ovens. There the silicon chunks are melted at more than 2,500° Fahrenheit. To prevent impurities, the ovens usually are mounted on very thick concrete cubesoften on a suspension to prevent any vibration, which would damage the crystal as it forms.

After the silicon is melted, a small seed crystal is inserted into the molten silicon and slowly rotated. As the seed is pulled out of the molten silicon, some of the silicon sticks to the seed and hardens in the same crystal structure as the seed. By carefully controlling the pulling speed (1040 millimeters per hour) and temperature (approximately 2,500°F), the crystal grows with a narrow neck that then widens into the full desired diameter. Depending on the chips being made, each ingot is 200mm (approximately 8″) or 300mm (12″) in diameter and more than 5 feet long, weighing hundreds of pounds.