Unless you are a chemist, physicist, or an IT professional, you might not be that familiar with a silicon wafer. The two words seem odd to be combined together. And to better understand it, it requires a lot of chemistry and physics.
As per its technical definition, a silicon wafer is a circular and thin slice of material that is usually used in the production of integrated circuits and semiconductor devices. Other types of wafer include silicon on insulator (SOI) wafer and Gallium Arsenide (GaAs) wafer. These wafers are useful materials in electronics that require careful wafer processing for better efficiency.
Considering that a silicon wafer is just a tiny material, the process being done to produce it is not simple. Before a single wafer can be produced, a lot of extensive work is needed. A perfect silicon wafer undergoes these following steps before it can be used for production:
- Producing a perfect silicon crystal - A pure silicon crystal needs to be slowly submerged into a container with molten sand, and then withdrawn carefully thereafter. The result is called an ingot, a pure silicon cylinder.
- Slicing of the wafer - After the preparation of the ingot, it is cut into thin slices of wafer with the use of a diamond saw.
- Thickness sorting - Once the ingots are sliced, the wafers needs to be properly sorted depending on their thickness. During this wafer processing, defects that may be caused by the slicing process are being eyed by the manufacturers.
- Lapping and Etching Processes - Lapping is the removal of a cracked or damaged silicon surface after the slicing process. On the other hand, etching is the removal of any crystal damage.
- Thickness Sorting and Flatness Checking - The silicon wafers are measured for flatness to better see any defects caused by the lapping and etching process. Afterwards, the wafers undergo a thickness sorting through an automated machine.
- Polishing Process - Any uneven surface in the silicon wafers is ensured to be smoothed and flattened into perfection.
- Final Qualification - The supplier makes a final test in terms of the thickness, smoothness and other consumer specifications before the products become ready for production. Depending on the quality and thickness of the wafers, the prices are determined.
Silicon alone is a very unique kind of element because of its capacity to conduct heat and electricity in a very controlled manner, thus called a semiconductor. When silicon wafers undergo several other processes like wafer fabrication and photolithography, they become useful electronic materials.
Usually, silicon wafers are used in making integrated circuits or microchips in the microelectronics industry. A silicon chip manufacturer takes care of a lot of processes including selecting a reliable wafer supplier and wafer fabrication to be able to come up with efficient devices. In fact, top manufacturers like IBM and Intel have used SOI wafer in the production of their microprocessors. Aside from this, a silicon, SOI and GaAs wafer are manufactured to become solar cells for the solar power technology.
Truly, a silicon wafer undergoes a tedious process of creation, fabrications and a lot more before you feel its advantage. So the next time you hear about silicon wafers, you can easily locate in your mind that it is something that the microelectronics cannot live without.