IC Knowledge - Glossary

Glossary of Integrated Circuit Terminology - N

N-type - a semiconductor with more free electrons than free holes.
NAND - a type of flash memory commonly used for mass storage application like digital cameras and MP3 players. NAND is a serial memory cell that has 1 less contact per pair of cells than NOR memory making NAND less expensive to produce.
NAND Gate - a basic logic gate similar to an AND gate but with an inverted output. NAND stands for Not AND. See also AND, and inverter.
Nano - prefix meaning one billionth (x10^-9), symbol is n.
Near Ultraviolet Light - electromagnetic waves with a wavelength of 350 to 450 nanometers.
Negative Photoresist - a type of photoresist that becomes relatively insoluble to developer when exposed to light.
Net Die Per Wafer - the number of good die on a wafer after wafer test.
Nitric Acid - chemical formula HNO₃, nitric acid a relatively strong acid primarily used as part of the aluminum etch. Nitric acid is commonly sold as a 70% solution and has a density of 1.42Kg/L. Nitric acid burns on contact with skin or eyes and the vapors will irritate or burn eyes or lungs.
Nitride - see Silicon Nitride
Nitrogen - atomic symbol, N, nitrogen is the 7th element in the periodic table (atomic number 7), with an atomic weight of 14.01. Nitrogen is a group VB element and is relatively inert. Nitrogen is widely used during IC processing as an inert purge gas due to it's low cost, but must be used carefully because it will react under certain circumstances. For example, at >950^oC nitrogen will thermally react with silicon to form silicon nitride in an oxygen starved environment. A small amount of oxygen is commonly added during furnace ramp-up and ramp-down in nitrogen when 950^oC temperatures will be exceeded to suppress silicon nitride formation.
Nitrogen Trifluoride - chemical formula NF₃, nitrogen trifluoride is an oxidizer and toxic gas with a TLV of 10ppm. Nitrogen trifluoride has a mold like odor. Nitrogen trifluoride is used as an etch gas and as a cleaning agent in CVD systems.
Nitrous Oxide - chemical formula N₂O, nitrous oxide is an oxidizer and a mildly toxic gas with a TLV of 50ppm. Nitrous oxide has a sweet odor. Nitrous oxide is used to nitride silicon dioxide and metals and during silicon oxynitride deposition. NMOS - an MOS device that uses N-type carriers, electrons for conduction in the on-state.
Non Volatile Memory - memory that maintains data storage when power is removed.
NOR - a type of flash memory cell widely used to store code, for example personal computers BIOS and cell phone data.
NOR Gate - a basic logic gate similar to an OR gate but with the output inverted. See also OR and inverter.
NOT Gate - see Inverter.
Novalac Resin - the backbone polymer of most G-line and I-line positive photoresists. N-type -a semiconductor material that has been doped creating a much larger number of mobile electrons than mobile holes.
Numerical Aperture - a measure of the acceptance angle of a lens. Higher numerical aperture means the lens gather more diffraction orders yielding higher resolution but at the expense of depth of focus.