| CPC G03F 7/709 (2013.01) [G03F 7/70825 (2013.01); G03F 7/70891 (2013.01)] | 22 Claims |

|
1. An apparatus, comprising:
a vibration damper, comprising:
a holder;
a mass;
a damping element connecting the holder and the mass, the damping element having a natural frequency which depends on a temperature of the damping element; and
a temperature control device; and
a controller configured to:
i) received a signal from a sensor; and
ii) based on the signal received from the sensor and a desired natural frequency of the damping element, dynamically control the temperature control device so that the temperature control device either heats or cools the damping element to adjust a temperature of the damping element so that the damping element has the desired natural frequency,
wherein the apparatus is a semiconductor lithography projection exposure apparatus.
|