Patent ID: 9291794
Filing Date: 2016-03-22
CPC Classification: G02B,G03F

Claim Text:
1. A temperature balancing device for a projection objective of a lithography machine comprising: a first temperature sensor disposed on a top of the projection objective and a second temperature sensor disposed at a bottom of the projection objective for sensing a temperature difference between the top and the bottom of the projection objective; a heat-absorbing light-transmitting layer positioned below the projection objective for absorbing radiation energy in laser beams transmitted from the lithography machine and transmitting the laser beams; an objective temperature balancing control unit for controlling an absorption and light transmission degree of the heat-absorbing light-transmitting layer according to the temperature difference sensed by the first and second temperature sensors, wherein when the temperature difference exceeds a predetermined threshold value, the objective temperature balancing control unit controls the heat-absorbing light-transmitting layer to directly absorb the radiation energy and give off heat to only raise the temperature of the bottom of the projection objective, so as to reduce the temperature difference between the top of the projection objective and the bottom of the projection objective.