DeepUV

Deep ultraviolet (DUV) refers to the portion of the ultraviolet spectrum with wavelengths typically between about 200 and 280 nanometers, though some definitions extend down to around 100 nanometers (vacuum ultraviolet). In many contexts, DUV is distinguished from near UV (around 300–400 nm) and from UV-C, and it often includes wavelengths used for specialized photolithography and disinfection applications.

DUV light is generated by several sources. Excimer lasers produce prominent lines at 193 nm (argon fluoride, ArF) and 222 nm (krypton chloride, KrCl), while other wavelengths such as 157 nm (fluorine, F2) are used in vacuum environments. Solid-state options include aluminum gallium nitride (AlGaN) based deep UV light-emitting diodes (LEDs) and lasers that cover portions of the 200–280 nm range. Mercury lamps emitting at 254 nm are also employed in disinfection and analytical contexts. Propagation of DUV light often requires vacuum or inert environments due to strong absorption by air, and optical components must be made from materials with high transmission in the DUV, such as fused silica or calcium fluoride, with specialized coatings.

Key applications include deep UV lithography for semiconductor manufacturing, where 193 nm light is used to pattern features at sub-micrometer scales, and sterilization or surface disinfection, where DNA and RNA absorbance leads to inactivation of microorganisms. DUV systems also find use in spectroscopy, fluorescence analysis, and certain photochemical processes.

Safety and handling are critical, as DUV radiation can cause eye and skin damage and can degrade materials over time. Ongoing development aims to improve source efficiency, material durability, and the availability of compact DUV devices.