The size of a typical computer chip has evolved significantly over the past several decades. Looking back at the size of transistors back in the 1960s, they were about 1/100th of an inch wide. While that certainly seems small, if we compare that with a transistor today, the 1960s version would be roughly the size of a football stadium by today’s standards. A 1970s transistor would be approximately the size of a minivan. Today, technology has allowed transistors to be created at the nano-level, where the smallest transistor can be comparable with a strand of DNA.
These small chips are made up of many transistors compiled together on one small flat piece of semiconductor material that is normally silicon. Smaller transistors enable more to fit on a chip which enables a smaller, faster and less expensive component. The downsizing of the chip was foreshadowed by Gordon Moore, co-founder of Intel. Moore’s Law states “The number of transistors incorporated in a chip will approximately double every 24 months”. Since the 1960s, this theory has proven true as every few years technology has created transistors that are smaller than the last. However, the future of this statement is tested as transistors become so small it may be impossible to make them smaller.
Chip size is measured in nanometers (nm) – where one nanometer is one-billionth of a meter. In 2017, Intel created 14 nm transistors. For reference, a human hair is typically 75,000 nanometers in diameter, so a single transistor cannot be seen with the naked eye. From there, 10nm and 7nm transistor are being created. The 7nm holds 20 billion transistors on a chip the size of a fingernail.
Why are researchers putting all this effort into making smaller transistors? The size of a transistor is important because the smaller a transistor gets, the more you can fit on a chip, and the faster and more efficient your processor can be. In addition, less energy is used because smaller processes have a lower capacitance so transistors can turn on and off more quickly. Lastly, as the size of transistors decrease, there is an increase in manufacturing efficiency and reduced fabrication costs per wafer due to the low costs of high volume production. Hence, in order for semiconductor companies to continue to innovate and keep costs low, they must find ways to continue shrinking.