5 Stages Of IC Fabrication, You Will Be Amazed at Knowing!
An integrated Circuit – IC, is the term that even every kid is aware of! The IC fabrication itself an interesting process to explore about. Imagine an IC which can’t be viewed with a naked eye and requires a microscope for, then what would be its manufacturing process like? Do you know an IC incorporates millions of components within? These components are transistors, capacitors, diodes etc. Let’s have a glance at a bunch of processes towards semiconductor fabrication.
1. Wafer Production
Only wafer production consists of series of processes one after another. Firstly, silicon, fetched from sand, is heated to form a liquid. Silicon’s small piece is dipped in this liquid and then taken out to cool. With the use of wafer slicing machine, it’s cut into thin wafers with a thickness around 0.1 to 0.25 inches. After that, it passes through the process of polishing and cleansing followed by exposure to ultra pure oxygen.
2. Masking
Masking is an essential part of IC fabrication process because it’s protection process. Once the wafer is ready, a photoresist film is applied to it, followed by alignment using photo aligner. An ultraviolet light is passed through the mask to make it ready.
3. Etching
The process is the removal of the mask by two ways – wet etching and dry etching. Wet etching uses chemicals to remove the mask and dry etching takes gases to do so. After that, the check is made to ensure that the wafer is imprinted with the mask or not. This imprinting makes a crucial role in semiconductor fabrication, it must be done carefully.
4. Doping
To alter the conducting characteristics of silicon; boron and phosphorous are used. For this doping process, atomic infusion and ion implantation processes are used for small and larger areas respectively. The aim of both the process is to enable the penetration of boron and phosphorus into silicon in a controlled way.
5. Metallization
In order to make interconnections on a chip, a thin layer of aluminum is masked on the wafer. Because aluminum offers low resistance and fits easily with the silicon, it’s chosen as best metal for this process.
Each wafer holds hundreds of ICs. So once fabrication completes, the process of separation and the packaging has to start on the manufacturing line. Once each IC is separated, the individual testing takes place. After each and every quality tests, the ICs go to the warehouse, finally.