Contamination reduction electrode for particle detector

Abstract

A charged particle detector arrangement is described. The detector arrangement includes a detection element and a collector electrode configured to collect charged particles released from the detection element upon impact of signal charged particles.

1 . A charged particle detector arrangement, comprising a detection element and a collector electrode configured to collect charged particles released from the detection element upon impact of signal charged particles. 
     
     
         2 . The charged particle detector arrangement according to  claim 1 , wherein the collector electrode is a plate having an opening for passing secondary charged particles. 
     
     
         3 . The charged particle detector arrangement according to  claim 1 , further comprising a voltage supply electrically connected to the collector electrode for biasing the collector electrode to collect charged particles. 
     
     
         4 . The charged particle detector arrangement according to  claim 3 , wherein the voltage supply is further connected to the detection element. 
     
     
         5 . The charged particle detector arrangement according to  claim 3 , wherein the collector electrode is positively biased with respect to the detection element. 
     
     
         6 . The charged particle detector arrangement according to  claim 5 , wherein the collector electrode is biased with a voltage in the range of 100-500 Volts. 
     
     
         7 . The charged particle detector arrangement according to  claim 1 , wherein the collector electrode is arranged in a plane positioned in direction of the signal charged particles before the plane of the detection element. 
     
     
         8 . The charged particle detector arrangement according to  claim 1 , wherein the collector electrode is a ring arranged coaxially with an optical axis of the detector arrangement. 
     
     
         9 . The charged particle detector arrangement according to  claim 1 , wherein the collector electrode is arranged in a plane of the detection element, surrounding the detection element. 
     
     
         10 . The charged particle detector arrangement according to  claim 1 , wherein charged particles are electrons. 
     
     
         11 . A charged particle beam device, comprising a charged particle detector arrangement comprising a detection element and a collector electrode configured to collect charged particles released from the detection element upon impact of signal charged particles. 
     
     
         12 . The charged particle beam device according to  claim 11 , wherein the collector electrode is a plate having an opening for passing secondary charged particles. 
     
     
         13 . The charged particle beam device according to  claim 11 , further comprising a voltage supply electrically connected to the collector electrode for biasing the collector electrode to collect charged particles. 
     
     
         14 . The charged particle beam device according to  claim 13 , wherein the voltage supply is further connected to the detection element. 
     
     
         15 . A method of operating a charged particle detector arrangement, the method comprising:
 providing a charged particle detector arrangement, comprising a detection element and a collector electrode arranged to collect charged particles released from the detection element upon impact of signal charged particles;   applying a biasing potential to the collector electrode, wherein the potential is positive with respect to the detection element.   
     
     
         16 . The method according to  claim 15 , wherein the collector electrode ( 30 ) is positively biased with respect to the detection element. 
     
     
         17 . The method according to  claim 16 , wherein the collector electrode is biased with a voltage in the range of 100-500 Volts.