Scanning electron microscope

Abstract

A scanning electron microscope includes an irradiation optical system for irradiating an electron beam to a sample; a sample holder for supporting the sample, arranged inside a sample chamber; at least one electric field supply electrode arranged around the sample holder; and an ion current detection electrode.

1 . A scanning electron microscope comprising:
 an irradiation optical system for irradiating an electron beam to a sample;   a sample holder for supporting the sample, arranged inside a sample chamber;   an ion current detection electrode having a first area and a second area being face to face with the first area; and   electric field supply electrode arranged between the first area and the second area.   
   
   
       2 . The scanning electron microscope according to  claim 1 , wherein the ion current detection electrode has a cylindrical shape, and the first area and the second area are included inside of the cylindrical shape. 
   
   
       3 . The scanning electron microscope according to  claim 1 , wherein the ion current detection electrode has an upper electrode and a lower electrode, and
 wherein the upper electrode includes the first area and the lower electrode includes the second area.   
   
   
       4 . The scanning electron microscope according to  claim 1 , wherein the electric field supply electrode is arranged from the sample holder in a first direction, and
 wherein the first area is arranged from the second area in a second direction which crosses the first direction.   
   
   
       5 . The scanning electron microscope according to  claim 2 , wherein the electric field supply electrode is arranged from the sample holder in a first direction, and
 wherein the first area is arranged from the second area in a second direction which crosses the first direction.   
   
   
       6 . The scanning electron microscope is arranged from the sample holder in a first direction, and
 wherein the first area is arranged from the second area in a second direction which crosses the first direction.   
   
   
       7 . A scanning electron microscope comprising:
 an irradiation optical system for irradiating an electron beam to a sample;   a sample holder for supporting the sample;   a first electrode including a first area and a second area being face to face with the first area; and   a second electrode arranged between the first area and the second area, and by which secondary electrons generated from the sample with the irradiation of the electron beam are accelerated.   
   
   
       8 . The scanning electron microscope to  claim 7 , wherein voltages are applied to the first electrode and the sample holder such that the secondary electrons are accelerated. 
   
   
       9 . The scanning electron microscope according to  claim 7 , wherein the first electrode is a detector for detecting ions generated by impingement of the secondary electrons accelerated against a residual gas inside a sample chamber. 
   
   
       10 . The scanning electron microscope according to  claim 7 , wherein the first area and the second area are arranged in a direction which an acceleration direction of the secondary electrons crosses. 
   
   
       11 . The scanning electron microscope according to  claim 7 , wherein the second electrode has an upper electrode and a lower electrode, and
 wherein the second electrode has an upper electrode and a lower electrode, and   wherein the upper electrode includes the first area and the lower electrode includes the second area.   
   
   
       12 . The scanning electron microscope according to  claim 1 , wherein the first electrode has a cylindrical shape, and the first area and the second area are included inside of the cylindrical shape. 
   
   
       13 . A scanning electron microscope comprising:
 a chamber;   a sample holder to support a sample in the chamber;   an irradiation optical system to irradiate an electron beam to the sample;   an electrode to accelerate secondary electrons generated from the sample with the irradiation of the electron beam; and   a detector having a first area and a second area which face to each other in a direction which an acceleration direction of the secondary electrons crosses.   
   
   
       14 . The scanning electron microscope according to  claim 13 , wherein voltages are applied to the electrode and the sample holder such that the secondary electrons are accelerated. 
   
   
       15 . The scanning electron microscope according to  claim 13 , wherein the detector detects ions generated by impingement of the secondary electrons accelerated against a residual gas inside a sample chamber. 
   
   
       16 . The scanning electron microscope according to  claim 13 , wherein the detector has an upper electrode and a lower electrode, and
 wherein the upper electrode includes the first area and the lower electrode includes the second area.   
   
   
       17 . The scanning electron microscope according to  claim 13 , wherein the detector has a cylindrical shape, and the first area and the second area are included inside of the cylindrical shape.