Method for inspecting substrate, substrate inspecting system and electron beam apparatus

Abstract

The present invention relates to a substrate inspection apparatus for inspecting a pattern formed on a substrate by irradiating a charged particle beam onto the substrate. The substrate inspection apparatus comprises: an electron beam apparatus including a charged particle beam source for emitting a charged particle beam, a primary optical system for irradiating the charged particle beam onto the substrate, a secondary optical system into which a secondary charged particle beam is introduced, the secondary charged particle beam being emitted from the substrate by an irradiation of the charged particle beam, a detection system for detecting the secondary charged particle beam introduced into said secondary optical system and outputting as an electric signal, and a process control system for processing and evaluating the electric signal; a stage unit for holding the substrate and moving the substrate relatively to said electron beam apparatus; a working chamber capable of shielding at least an upper region of the stage unit form outside to control under desired atmosphere; and a substrate load-unload mechanism for transferring the substrate into or out of the stage.

1 . A substrate inspection method comprising: 
 selecting a priority area in which many defects are expected to occur;    applying a sampling inspection to said priority area;    irradiating a primary charged particle beam in said priority area onto a substrate to emit a secondary charged particle beam;    scanning said primary charged particle beam relative to said substrate;    detecting said secondary charged particle beam to evaluate the substrate;    converting the detected secondary charged particle beam into an electric signal; and    evaluating the substrate based on said electric signal,    wherein an evaluation of a pattern surface whose whole pattern is formed by dividing said pattern forming surface into a plurality of areas, and by forming respective pattern for each area, is executed by selecting a boundary area between said divided areas.    
   
   
       2 . A substrate inspection method according to  claim 1 , wherein said boundary area is evaluated by using a central portion of the field of view.  
   
   
       3 . A substrate inspection method according to  claim 1 , wherein an evaluation of the pattern forming surface which is formed by dividing said pattern forming surface into a plurality of adjacent stripes and forming a pattern for each stripe by lithography, is executed by selecting a boundary area between said stripes, a boundary area between primary fields of view or a boundary area between secondary fields of view of a pattern projection in the lithography.  
   
   
       4 . A substrate inspection method according to  claim 1 , further comprising: 
 detecting an abnormal pattern from the image data generated by processing said electric signal; and    determining whether or not said detected abnormal pattern is a killer defect, base on a relation between said abnormal pattern and a predetermined reference pattern.    
   
   
       5 . A substrate inspection method comprising: 
 emitting a primary charged particle beam from a charged particle beam source;    irradiating said emitted primary charged particle beam onto a plurality of apertures to form a plurality of beams;    passing said plurality of beams through a numerical aperture;    irradiating and scanning said plurality of primary charged particle beam simultaneously onto a substrate through a primary optical system;    introducing a secondary charged particle beam into a secondary optical system, said secondary charged particle beam being emitted from said substrate by said irradiation of said primary charged particle beams;    detecting said secondary charged particle beams having been introduced into said secondary optical system and converting said detected secondary charged particle beam into an electric signal; and    processing said electric signal to evaluate the substrate;    wherein said primary optical system comprises said aperture plate for forming said primary charged particle beam into a plurality of beams and a numerical aperture for passing only the primary electron beam therethrough disposed at the location where the crossover image is formed.    
   
   
       6 . A substrate inspection method according to  claim 1 , wherein at least two functions selected from the group consisting of a defect detection of a substrate surface, a defect review of the substrate surface, a pattern line width measurement, and a pattern potential measurement are performed.  
   
   
       7 . A substrate inspection method according to  claim 1 , further comprising: 
 setting an evaluation condition such that a process condition of each substrate should be evaluated within a processing time necessary for processing one substrate by a processing unit.    
   
   
       8 . A substrate inspection method according to  claim 5 , further comprising: 
 setting an evaluation area of the substrate such that the processed condition should be evaluated only in a specified area on a substrate surface.    
   
   
       9 . A substrate inspection method according to  claim 5 , further comprising: 
 obtaining respective images of a plurality of regions to be inspected, said plurality of regions being displaced from relative to one another, and being partially superimposed relative to one another;    storing a reference image; and    comparing said obtained images of the plurality of regions to be inspected with said stored reference image and thereby determining a defect on said substrate.    
   
   
       10 . A substrate inspection method according to  claim 5 , further comprising: 
 performing irradiation of the primary charged particle beam onto said substrate within a working chamber controlled to be a desired atmosphere;    performing transfer of said substrate into and out of said working chamber through a space within a vacuum chamber;    applying a potential to said substrate within said working chamber; and    observing a surface of said substrate and aligning said substrate to an irradiation location of said primary charged particle beam.