Additional Info
Frequently Asked Questions
What is the difference between N-type and P-type silicon wafers?
N-type wafers are doped with phosphorus, so electrons carry the current. P-type wafers are doped with boron, so holes carry the current. Choose based on the device or process you are building.
What does <100> orientation mean?
It is the crystal plane at the wafer surface. <100> is the most common orientation for CMOS devices and MEMS etching. <111> is used for some epitaxy and bipolar devices.
What is the difference between prime and test grade?
Prime grade wafers have the tightest specifications for flatness, thickness and particles, and are used for devices and critical research. Test grade wafers are used for process monitoring, equipment setup and practice runs.
What are intrinsic and Si/SiO2 wafers used for?
Intrinsic (undoped) wafers have very high resistivity, which suits infrared optics, RF work and substrates where conduction is unwanted. Si/SiO2 wafers carry a thermal oxide layer that insulates the surface. Oxides of about 285 or 300 nm are popular for making graphene and other 2D material flakes visible under a microscope.
What sizes are available?
Wafers come in 2, 3, 4 (100 mm), 6 (150 mm) and 8 inch (200 mm) diameters, plus small diced pieces such as 10 x 10 mm. Cassettes of 25 wafers are also available.
