| Abstract: | An optical instrument, including a chamber, an object exposed to an
interior of the chamber, a source of low-pressure gas, the gas comprising
at least one of low-pressure molecular hydrogen gas, low-pressure
molecular oxygen and a low-pressure noble gas, the source of low pressure
gas being fluidly coupled to the chamber, a low voltage source
electrically coupled between the object and a remaining portion of the
instrument that is exposed to the interior of the chamber so as to
maintain the object at a low voltage relative to the remaining portion,
and an EUV/VUV light source adapted to direct EUV/VUV light through the
low pressure gas in the chamber onto the object. In such a system, when
the EUV/VUV light source is activated ions of the low-pressure gas are
formed and directed to the object. The ions may be ions of Hydrogen,
Oxygen or a noble gas. |