Frequently Asked Questions：About Our Products

Excimer lamps/Excimer irradiation unit

• Does use require light blocking?

  The 172nm wavelength is rapidly attenuated in air. Longer wavelengths of light are also emitted at about 1/100th the intensity of 172nm. Although light from this lamp can be viewed for short periods without injury from a distance of 10cm or more, eye protection should always be worn when working while the lamp is lit.

• Why is N2 purity of at least 99.99% required?

  When the purity of N2 is low, the concentration of oxygen and ozone increases inside the lamp housing. Consequently, the radiation divergence strength is reduced, damage to the mirror can result, and operating life of the lamp is shortened.

• How should exhaust of ozone be handled?

  Often used in drafters, with exhaust emitted through a duct. Make sure that the exhaust meets specified requirements. This also applies to exhaust of purge gas. An exhaust unit with ozone filter is available for situations in which adequate exhaust cannot be provided. In that case, exhaust to the open atmosphere is possible through the exhaust unit with ozone filter. Refer to the provided installation precautions for details.

• Can the cleaning effect obtained in air?

  Cleaning performance depends on the intensity of irradiation reaching the target object and the concentration of active oxygen at the object's surface. If the gap is too great, light will not reach the target object and cleaning will not take place. A diagram showing correlation between the gap and irradiation intensity is shown on the next page.

• What are the optimum oxygen atmosphere and gap?

  Because the cleaning effect of excimer light is affected by the substance irradiated, there is a need to determine the optimum parameters matching the substance. The parameters for cleaning of glass substrates are given for reference.

• How can cleaning be evaluated?

  The most common method is to use a water drop and measure the contact angle between water and material. Simple methods of checking include judging from the degree of fogging that results from breathing on the surface, and use of a Dyne pen. If the above methods do not suffice, wettability can be determined at the atomic level using X-ray photoelectron spectroscopy.