Even though we use devices containing them every day, the silicon microchip at the heart of modern technology is barely understood by the average consumer. True, the details of microchip manufacture are fairly technical, but in broad strokes the process is surprisingly simple: a wafer of prepared silicon is chemically treated to create what are essentially pipes for electrons. Then, when a charge is applied to the chip, the electrons flow through the pipes to perform calculations.
Building the Foundation
The life cycle of a microchip begins with a prepared foundation of silicon, created using a process such as silicon wafer dicing. Silicon is a semiconductor, a crucial chemical property for these chips. Rather than always conduct electricity (like copper) or always resist electricity (like wood) silicon can either conduct or not conduct electricity depending on certain conditions. It is this property that allows the creation of the aforementioned ‘electron pipes’ which allow the chip to perform calculations.
A Leap of Logic
How a series of pipes can be used to perform mathematical operations and read computer instructions is where the subject becomes unavoidably technical, but as a primer, imagine the electrons as little marbles rolling through tubes to their destinations. The operations performed in a semiconductor basically compare two tubes and send a third marble rolling down another tube depending on the pattern of marbles. These operations are better known as, and with some clever mathematics, they can be used to do just about anything. The process of using logic gates to perform useful tasks is the foundation of the discipline of .
Putting It All Together
The electron pipe has a more technical name, the ‘transistor’. Once the desired pattern of transistors is created using techniques from computer science, the last step is simply to place the transistors on the wafer. You might expect the transistors to be printed or drawn on, but it’s actually “baked on” using a. Silicon wafers are photosensitive, meaning they react to light—so the pattern of transistors used for the finished chip is projected onto the wafer. This process can be repeated to create layers of transistors throughout the chip, allowing it to perform mind-boggling numbers of operations every second.
The semiconducting microchip is a true marvel, a marriage of mathematical concepts long thought theoretical with chemical processes that were originally considered mere curiosities. The next time your cell phone is giving you grief, spare a thought for the hard-working electron racing through transistors to bring you your cat videos.