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Mini Marvel

Imagine your mobile phone being twice as big as your house and the computer bigger than an apartment building. That’s how gigantic they would be if it weren’t for one small thing: the Microchip. An Integrated Circuit (or microchip as it is generally called) is a tiny component that is heart and soul of every single electronic device from washing machines to traffic signals. This revolutionary invention has itself given birth to many other revolutions in the modern world, from computers to Internet to information and communications.

The microchip is made of tiny little electronic components called transistors. Hey wait you’ll say, isn’t that another name for portable radios? Yes, indeed. The reason being that portable radios contain a component called, you guessed it, transistor. So, transistor is this electronic device that amplifies signals or acts as a tiny switch in an electronic circuit. The predecessor of the transistor is the Vacuum Tube, which was used for same functions. Vacuum tubes were made of glass and they looked like light bulbs. They were clunky, fragile and extremely power hungry. ENIAC, the first “modern” computer made in 1946 contained around 17,500 vacuum tubes, weighed about 30 tonnes and guzzled 150 kilowatts of power!

Transistors replaced vacuum tubes as they were smaller, faster, cheaper and extremely efficient. These transistors are made of semi-conductors like Silicon. The semi-conductors are called so, is because they conduct electricity, but only slightly. When small quantities of other elements like Boron and Phosphorus are added to these semi-conductors, their behaviour can be modified. So the transistor was created!

Now an average transistor is about the size of a fingernail. So, scientists and engineers now carved out transistors on a chip of Silicon and thus was born, The Microchip! The distance between individual transistor components is in the order of micrometres (that’s one thousandth of a millimetre) and in the current generation of processors the distance is actually 65 nanometres (and a nanometre is one millionth of a millimetre)! The microchips contain these transistors and tiny circuitries which calculate at blazing speeds. And they get tinier and faster every year...

Like everything else, the journey of the microchip begins at designing. Engineers first design the whole chip with its components and circuits on special software, keeping the use of the in mind. This is as extremely critical process and allows the engineers to create, test and modify designs without actually making even a single chip for real, thus saving a lot of time, money and energy.

The next process is growing of the wafer from which the chips are made, and crystalline silicon of extremely high purity is used for this. Silicon as such is a widely abundant element, but is almost always found in the form of its oxide, more commonly known as silica or sand. First, ingots of high purity silicon are made from which thin wafers are sliced.

Then comes the process of fabrication, which makes the block of silicon into the microchip. This is done in exceptionally clean environments with people wearing protective suits (to protect the chips, not themselves). The chip fabrication rooms are about half a million times cleaner than operation theatres, as even a tiny dust particle can ruin the entire microchip.

The fabrication is done by the machines according to the designs which were made earlier. They shape the wafer, creating the microscopic transistors, and add elements to change the properties of the semiconductors and make connections with thin metal layers. These steps are repeated up to 300 times.

The microchip is then rigorously tested for all the functions. Each wafer contains many copies of the circuit and now individual chips are sawed off. They are then added with connector pins, and packed inside plastic casing. Then the chip finds its home inside the device it was made for!

● The Silicon Valley in California, the US, gets its name for being the birth place for many electronics and computers companies, silicon being the vital ingredient in microchips.
● The microprocessors are the most complex of the microchips and they contain hundreds of millions of transistors. So more the number of transistors, more powerful the chip gets.
● The number of transistors on a microchip is doubled roughly every two years. This trend has continued for more than five decades and it is called the Moore’s Law (after Gordon Moore, co- founder of Intel).

Microchip manufacturing is a high resource intensive process. It includes usage of toxic metals like arsenic, as well as highly corrosive chemicals like acids and solvents. The chip is a highly synthesized product. It cannot be recycled nor can any of the raw materials be obtained back. Disposed chips are incinerated. But the chip in itself is an extremely energy efficient device and the world would definitely be a different place without them.

No! A microchip’s practical applications will astound you. It is the one invention that has permeated every level of technology, so to speak. Here are some major areas where you never thought a tiny chip could be the driving force:
● Automobiles: Your car keys have an embedded microchip that is required to start the car. Once you insert the key the engine will start only if the microchip is present in it.
● Mobiles: It’s a microchip inside your cell phone that lets you connect to the Internet and hold a video conference.
● Washing machines: Yes, that’s right. A microchip gives ‘intelligence’ to home appliances like a washing machine or even a toaster. It is because of the chip that the machine can ‘tell’ the dryer how the load of clothes needs to be washed and prepares it for the dry cycle.
● Cameras: The capacitor inside a microchip stores and then releases large amounts of energy; cameras use this for the "flash."