Microchip Making

They are the electronic brains that are present in almost devices. They are just small pieces and usually placed inside a device that is why at a mere look into a device, they are not emphasized. But how great is their contribution for a device’s function. Their role is indeed extraordinary! You may not realize that we are surrounded by this. In fact, they are present in TVs, computers, home appliances, watches, traffic lights and much more. These are the silicon chips.

They are produced in a very clean environment.

Through heating and other processes, silicon and other elements are cast into a block which has a high level of purity and is called ingot. The block then is cut into wafers of desired thickness from 0.5 to 1.5 mm. Then, it will be polished, subject to inspection and proceed to the first step of production which is called the front end of line. A layer of silicon dioxide is laid down on top of the wafer which a layer of silicon nitride and a thin coating of photoresist is applied.

Next step involves a prefabricated stencil composed of transparent glass and opaque chrome. It is projected onto lens and the lens reduces the size of the stencil pattern. Finally is the cleaning of the photoresist and a further chemical etching of the silicon regions. Afterwards, another layer of silicon dioxide is applied which will insulate between the transistors. Etching and grinding processes will be done. Implanted electrons should be able to move freely thus able to carry electrical current.

The back end of line then begins from here. Application of undoped silicate glass in which holes for connection purposes are created. Electrical connections between transistors will be created. It is a way for chips to be separated from each other. Through the process of bonding, the chip is attached within the housing. A housing cover serves a protection from external elements.

Microchip is basically a collection of billions of transistors. To understand how microchip works, we need to have an insight regarding transistors. Transistor has two major functions. First, it serves as an amplifier, example for microphones, cellphones, guitars and the like. Second, it serves as a switch. Functionally, each transistor has two positions on and off. It is translated as 0 and 1 (the binary number system), the basis for modern computers.