Silicon wafer is an important material for making integrated circuits. Various semiconductor devices can be made by means of photography and ion implantation on a silicon wafer.
What are silicon wafers？
Silicon wafer is an important material for making integrated circuits. Various semiconductor devices can be made by means of photography and ion implantation on a silicon wafer.
Silicon chips have amazing computing power. The development of science and technology is constantly promoting the development of semiconductors. Advances in automation and computers have reduced the cost of silicon wafers (integrated circuits) to a very low level. As a result, silicon wafers are now widely used in aerospace, industry, agriculture and defense, and even crept into every home.
The earth's crust contains 25.8% silicon, providing an inexhaustible source for the production of monocrystalline silicon. Since silicon is one of the most abundant elements in the earth's crust, the advantage of reserves is also one of the reasons that silicon has become the main material of photovoltaic for products destined for mass markets such as solar cells.
Tips to choose right silicon wafer
1. Choose the right size
There are at least 4 types of large silicon chip sizes on the market: 5 inch (125mm), 6 inch (150mm), 8 inch (200mm), 12 inch (300mm). Wafer Dicing equipment should also be compatible with the size of the wafer.
2. Choose the right type
There are at least 2 main types of semiconductor wafers: undoped semiconductor wafers and doped Semiconductor wafers.
- Undoped Semiconductor wafers – made from pure crystalline silicon.
- Doped Semiconductor wafers do not contain 100% silicon, dopant impurities are added. These impurities do not compromise overall purity. It allows for finer control of the physical and electrical properties of the wafer. Common dopants for Semiconductor wafer application include P/Boron, N/Sb, N/As or N/Ph..
3. Choose the Orientation (Flat / Notch)
Common orientations for semiconductor wafers are:
- Under 8inch (200mm) = flat
- Over 8inch (200mm) = notch
Some users prefer a specific type of orientation. This will be modified by the manufacturer according to the customers preference.
4. Check for Resistivity
Resistivity is the resistance to current flow and movement of electrons in silicon wafers. Common resistivity for dummy wafers ranges between 0-100 Ohm-cm.
5. Choose wafer thickness
Semiconductor wafer thickness is essential to determine the height of the package. Common Dummy wafer thicknesses include:
- 5inch = >500um
- 6inch = >600um
- 8inch = >700um
- 12inch = >750um
Wafer thickness can be customized by manufacturer as desired by the end user.
6. Choose wafer surface finish
There are 2 common types of semiconductor wafer surface finish:
- Polished wafers where one or both sides of the Wafers are polished to a mirror finish.
- Etched Wafers in which the backside of the wafer is etched.
Wafer surface finish can be customized by the manufacturer as desired by the end user.
7. Choose correct wafer application
- Good wafer – Wafers used to assemble semiconductor packages. Extracting die from wafer is the start of semiconductor assembly.
- Dummy Wafer - Silicon wafers or dummy wafers are used in production to improve safety before processing good wafers. Silicon wafers or dummy wafers are also used for experiments and tests.
- Aluminized wafers, patterned wafers, custom wafers, test wafers are specialized wafers used for engineering evaluations, tests, experiments, qualifications, etc.
Gennex, with years of experience in the semiconductor industry, is willing to share knowledge about silicon wafers, helping you make the best choice in choosing a suitable silicon wafer for your needs or requirements.