Apparatus for monitoring a density profile of impurities

Abstract

A method of monitoring a density profile of impurities, the method including presetting a monitoring position of a thin layer coated on a substrate, the density profile of impurities being monitored from the monitoring position in a direction of thickness of the thin layer, moving an exposer for exposing a local area of the thin layer to the monitoring position, exposing the local area of the thin layer along the direction of thickness of the thin layer, forming a shape profile of the exposed local area of the thin layer, and monitoring the density profile of impurities by determining a density of impurities in accordance with the shape profile, and an apparatus therefor. The impurity density profile may be monitored without destroying a substrate on which a thin layer is coated, and an amount of impurities used for forming the thin layer may be monitored and controlled in real-time.

1 - 8 . (canceled)  
   
   
       9 . An apparatus for monitoring a density profile of impurities, the apparatus comprising: 
 a stage on which a substrate is disposed, a thin layer including a plurality of impurities being coated on the substrate;    an exposer that exposes a local area of the thin layer along a direction of thickness of the thin layer;    a shape profile generator that generates a shape profile of the exposed local area of the thin layer;    a density profile generator that generates a density profile of impurities by determining a density of the impurities corresponding to the shape profile; and    a controller that controls the exposer, the shape profile generator, and the density profile generator by using a preset monitoring position of the thin layer, the density profile of impurities being monitored from the preset monitoring position in the direction of thickness of the thin layer.    
   
   
       10 . The apparatus for monitoring a density profile of impurities as claimed in  claim 9 , wherein the exposer includes a container for containing an exposing material and a nozzle for injecting the exposing material into the local area of the thin layer.  
   
   
       11 . The apparatus for monitoring a density profile of impurities as claimed in  claim 10 , wherein the container includes a tube containing an etchant for performing a wet etching process, and the nozzle includes a micro pipette for injecting the etchant into the local area of the thin layer without exposing a neighboring area adjacent to the local area of the thin layer to the etchant.  
   
   
       12 . The apparatus for monitoring a density profile of impurities as claimed in  claim 9 , wherein the shape profile generator includes a light source for irradiating a light onto the exposed local area of the thin layer, a detector for detecting an intensity of the light reflected from the exposed local area of the thin layer, and a comparing part for comparing the intensity of the light reflected from adjacent reflecting points of the exposed local area.  
   
   
       13 . The apparatus for monitoring a density profile of impurities as claimed in  claim 12 , wherein the shape profile generator further includes a transformer for transforming the shape profile into an image.  
   
   
       14 . The apparatus for monitoring a density profile of impurities as claimed in  claim 13 , wherein the transformer includes a solid state imaging device.  
   
   
       15 . The apparatus for monitoring a density profile of impurities as claimed in  claim 14 , wherein the solid state imaging device includes a charge-coupled device.  
   
   
       16 . The apparatus as claimed in  claim 10 , wherein the exposing material is an etchant, the etchant exposing the local area of the thin layer along the direction of thickness of the thin layer, and the etchant causing a cross sectional surface of the exposed local area to vary when densities of the impurities vary.  
   
   
       17 . The apparatus as claimed in  claim 16 , wherein the etchant etches the local area along a second direction, the second direction perpendicular to the thickness of the thin layer, and an etching depth in the second direction varies according to a shortage or surplus of the impurities in the local area.  
   
   
       18 . The apparatus as claimed in  claim 10 , wherein the exposing material is an etchant, the etchant exposing the local area of the thin layer along the direction of thickness of the thin layer, 
 the thin layer includes a first region and a second region, the second region corresponding to a split layer, and    the etchant etches the first and second regions at different rates.    
   
   
       19 . An apparatus for monitoring a density profile of impurities, the apparatus comprising: 
 a stage on which a substrate is disposed, a thin layer including a plurality of impurities being coated on the substrate;    an exposer that exposes a local area of the thin layer along a direction of thickness of the thin layer;    a shape profile generator that generates a shape profile of the exposed local area of the thin layer; and    a density profile generator that generates a density profile of impurities by determining a density of the impurities corresponding to the shape profile;    wherein the shape profile generator includes a light source for irradiating a light onto the exposed local area of the thin layer, a detector for detecting an intensity of the light reflected from the exposed local area of the thin layer, and a comparing part for comparing the intensity of the light reflected from adjacent reflecting points of the exposed local area.,    
   
   
       20 . The apparatus for monitoring a density profile of impurities as claimed in  claim 19 , wherein the shape profile generator further includes a transformer for transforming the shape profile into an image.  
   
   
       21 . The apparatus for monitoring a density profile of impurities as claimed in  claim 20 , wherein the transformer includes a solid state imaging device.  
   
   
       22 . The apparatus for monitoring a density profile of impurities as claimed in  claim 21 , wherein the solid state imaging device includes a charge-coupled device.  
   
   
       23 . An apparatus for determining the presence of an impurity density boundary in a thin layer, comprising: 
 a stage for receiving a substrate having the thin layer disposed thereon, the thin layer extending in a first direction substantially parallel to a major surface of the substrate;    an exposer for exposing a portion of a cross section of the thin layer, the cross section extending in a second direction perpendicular to the first direction; and    an analyzer for analyzing the cross section of the thin layer, wherein the analyzer includes:    a light source for illuminating the cross section,    a detector for detecting light reflected from the cross section, and    a comparator for determining whether the impurity density boundary is present based on the intensity of the reflected light.    
   
   
       24 . The method as claimed in  claim 23 , wherein the thin layer is a BPSG layer and the impurity density boundary is at least one of a boron density boundary and a phosphorus density boundary.  
   
   
       25 . The method as claimed in  claim 24 , wherein the impurity density boundary corresponds to a split layer.  
   
   
       26 . The apparatus as claimed in  claim 23 , wherein the exposer supplies an etchant.  
   
   
       27 . The method as claimed in  claim 26 , wherein the etchant etches the thin layer in the first direction at a rate that is dependent on an impurity density.