Apparatus for charged particle lithography system

A cantilever-based sensor for leveling a substrate, the cantilever-based sensor comprising:

• an optical sensor;
• a cantilever structure disposed between the optical sensor and the substrate, wherein the cantilever structure includes:
• a first cantilever structure including a first cantilever having a first surface and a second surface opposite the first surface, a first reflective film deposited on the second surface of the first cantilever, and a first tip attached to the first surface of the first cantilever, wherein the first tip is configured to contact a surface of the substrate at a first location, and
• a second cantilever structure including a second cantilever having a first surface and a second surface opposite the first surface, a second reflective film deposited on the second surface of the second cantilever, and a second tip attached to the first surface of the second cantilever, wherein the second tip is configured to contact the surface of the substrate at a second location;
• and
• wherein the optical sensor is configured to detect light reflected from the first reflective film and the second reflective film and, based on the detected reflected light from the first reflective film and the second reflective film, respectively determine a first distance between the optical sensor and the surface of the substrate at the first location and a second distance between the optical sensor and the surface of the substrate at the second location, such that the substrate is leveled based on the first distance and the second distance.

A method of leveling a substrate in a charged particle lithography system, the method comprising:

• positioning a first cantilever structure over a surface of the substrate at a first location and a second cantilever structure over the surface of the substrate at a second location;
• measuring a first distance between a first reflective film of the first cantilever structure and a first optical sensor;
• measuring a second distance between a second reflective film of the second cantilever structure and a second optical sensor;
• determining a third distance between the first optical sensor and the surface of the substrate at the first location based on the first distance;
• determining a fourth distance between the second optical sensor and the surface of the substrate at the second location based on the second distance;
• and
• leveling the substrate based on the third distance and the fourth distance.