Apparatus and method for isolating vibrations in a lithography machine using two active control units

A lithography apparatus, comprising:

• a lens body including an optical assembly and a reference body;
• an isolated body located near said lens body;
• a stage located on said isolated body;
• and
• a active-control vibration isolation device located between said reference body and said stage for substantially preventing the vibrations from a floor from traveling to said stage and the vibrations caused by said stage from travelling to said lens body, said active-control vibration isolation device having a first active control unit and a second active control unit for substantially reducing vibrations respectively in a first frequency range and a second frequency range.

A method of effectively isolating vibrations in a lithography apparatus, comprising the steps of:

• isolating a static reference body from externally caused vibrations via reference body isolators;
• measuring vibrations in a first distance in a first frequency range in the lithography apparatus with respect to the static reference body to generate a first measured vibration signal;
• actively controlling the vibrations in the first frequency range based upon the first measured vibration signal;
• further measuring vibrations in a second distance in a second frequency range in the lithography apparatus with respect to the frame structure to generate a second measured vibration signal;
• and
• further actively controlling the vibrations in the second frequency range based upon the second measured vibration signal.

A method of effectively isolating vibrations in a lithography apparatus, comprising the steps of:

• isolating a static reference body from externally caused vibrations via reference body isolators;
• measuring vibrations in a first distance in a first frequency range of less than approximately 20 Hz with respect to the static reference body to generate a first measured vibration signal;
• actively controlling the vibrations in the first frequency range of based upon the first measured vibration signal;
• further measuring vibrations in a second distance in a second frequency range of less than approximately 300 HZ with respect to the frame structure to generate a second measured vibration signal;
• and
• further actively controlling the vibrations in the second frequency range based upon the second measured vibration signal.