How Semiconductors Are Made ?
Integrated circuits or semiconductors are usually known as chips or ICs. It involves above hundred steps to make semiconductors. During the process, hundreds of prints of well integrated circuits are made on one wafer. Usually, 8 to 20 designed films are made into and all around the substrate, finally making the whole integrated circuit. In this procedure of making layers, electrically active areas are formed onto and inside the wafer surfaces of integrated circuits. |
First of all, the process starts with the manufacturing of wafers. Wafer is a round and thin piece made of silicon. Cleansed polycrystalline silicon is made from sand and is liquefied on heat. A tiny portion of silicon in its solid state, known as seed, is kept on the liquefied silicon, and when the solid silicon is taken out from molten liquid, the liquid solidifies to make a crystal lump. A small liquid portion goes up with the solid silicon and cools due to the outside pressure between the liquefied silicon and the seed. The crystal lump is now broken up into an even size and then cut into very thin wafers with the help of a diamond cutting blade. Then these wafers are passed through many machines to be smoothened and polished chemically to make it shine like a mirror. Now these wafers are dispatched to highly sophisticated fabrication region to be utilized as the basic substance for making semiconductors.
The whole process takes generally ten to thirty days to finish and includes a number of steps, namely thermal deposition or oxidation; masking; etching; and doping. After these four steps, all these steps are made to repeat many times till the final 'front end' coating is accomplished. After getting what is called 'front-end finish', all single procedures are unified with the help of a sequence of the metal depositions; outlining steps of insulators or dielectric films are also used. This step is called metallization and dielectric deposition. Modern semiconductor fabrication involves 3 metal layers divided by dielectric films.
Now, the steps of passivation, electrical tests, and finally assembly are followed. With the encapsulation of the chip in a plastic film for safety and the final quality check, the entire process of making a semiconductor gets completed.
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