Term of the Moment
analog
Definition: ultraviolet light
An invisible band of radiation with wavelengths from 400 to 10 nm, ultraviolet (UV) light starts at the end of visible light and ends at the beginning of X-rays. The primary source of ultraviolet light is the sun, and most of the UV light that reaches earth is in the lower-frequency UVA region (see below).
Ultraviolet for Chip Making
Chips are made by using lithography to create the layers of a transistor. Each layer is exposed to light through a pattern (mask), and for a long time, far ultraviolet (FUV) was the light source for state-of-the-art chips. However, because light cannot create a pattern smaller than its own wavelength, to make the transistor elements even smaller, extreme ultraviolet (EUV) has become the latest light source for chips 5 nm and below. Netherlands-based ASML Holding makes the EUV stepper machines, which are extremely expensive. See reticle, photolithography and EUV machine.
Before and After EUV
EUV is state-of-the-art, but larger-wavelength DUV and FUV are more than adequate for the billions of microcontrollers made every year. There are myriad applications for chips that do not require the fastest and most advanced processing. Of course, microcontroller chips costing as little as 50 cents today are much more powerful than the first commercial computers that in today's dollars cost more than a million (see microcontroller and UNIVAC I).
Ultraviolet in the Spectrum
Ultraviolet for Chip Making
Chips are made by using lithography to create the layers of a transistor. Each layer is exposed to light through a pattern (mask), and for a long time, far ultraviolet (FUV) was the light source for state-of-the-art chips. However, because light cannot create a pattern smaller than its own wavelength, to make the transistor elements even smaller, extreme ultraviolet (EUV) has become the latest light source for chips 5 nm and below. Netherlands-based ASML Holding makes the EUV stepper machines, which are extremely expensive. See reticle, photolithography and EUV machine.
Before and After EUV
EUV is state-of-the-art, but larger-wavelength DUV and FUV are more than adequate for the billions of microcontrollers made every year. There are myriad applications for chips that do not require the fastest and most advanced processing. Of course, microcontroller chips costing as little as 50 cents today are much more powerful than the first commercial computers that in today's dollars cost more than a million (see microcontroller and UNIVAC I).
Wavelength
Ultraviolet Region (nm)
UVA Long-wave "A" 315-400
UVB Medium-wave "B" 280-315
UVC Short-wave "C" 100-280
NUV Near ultraviolet 300-400
MUV Middle ultraviolet 200-300
DUV Deep Ultraviolet < 300
FUV Far ultraviolet 122-200
Ly-a Lyman-alpha 121.6
VUV Vacuum ultraviolet < 200
EUV Extreme ultraviolet 10-121
The ultraviolet band is between visible light and X-rays.