System and method for simultaneous detection of secondary electrons and light in a charged particle beam system

A charged particle system, comprising:

• a charged particle beam source for generating charged particles;
• a charged particle beam optical column for focusing a beam of charged particles from the charged particle beam source onto a sample;
• a sample stage for holding a sample in a sample position, a sample plane through the sample position dividing space into a region above the sample plane including the charged particle beam source and a region below the sample plane;
• a secondary electron detector for collecting secondary electrons emitted from the sample due to the impact of the charged particle beam with the sample, the secondary electron detector positioned above the sample plane;
• a light detector for detecting light emitted by the sample upon impact of the charged particle beam;
• and
• an electrically conductive mirror positioned above the sample plane, the mirror configured to deflect light emitted by the sample onto the light detector without the light passing completely through the sample, and to deflect secondary particles from the sample.

A method for examining a sample, comprising the steps of:

• directing a charged particle beam in a pattern onto the sample surface, the charged particle impacting the sample in a region;
• detecting light emitted from the region, the light from the sample being reflected by an electrically conductive first mirror toward a detector, the first mirror having an opening therein for passage of the charged particle beam;
• moving the charged particle beam across the surface of the sample in a pattern;
• deflecting away from the first mirror and towards the detector charged particles from the sample caused by the impact of the charged particle beam on the sample;
• and
• determining from the detected light the composition of the sample.