Wafer inspection system and method thereof

A wafer inspection system, comprising:

• a wafer inspection tool;
• an illumination source in the wafer inspection tool and configured to generate a radiation beam;
• a first optical element and a second optical element in the wafer inspection tool and optically communicated with the illumination source, wherein the first optical element directs the radiation beam toward the second optical element;
• and
• a first beam checking tool between the first optical element and the second optical element, wherein the first beam checking tool comprises a first hole, and the radiation beam propagates through the first hole of the first beam checking tool.

A wafer inspection system, comprising:

• a wafer inspection tool;
• an illumination source in the wafer inspection tool and configured to generate a radiation beam;
• a first optical element and a second optical element in the wafer inspection tool and optically communicated with the illumination source, wherein the first optical element directs the radiation beam toward the second optical element;
• a first fixing lug in the wafer inspection tool;
• and
• a first beam checking tool fixed on the first fixing lug, wherein the radiation beam propagates through the first beam checking tool.