Silicon single crystal wafer for particle monitor

Abstract

A silicon single crystal wafer for a particle monitor is presented, which wafer has an extremely small amount in the surface density of light point defects and is capable of still maintaining a small surface density even after repeating the SC-1. The wafer is prepared by slicing a silicon single crystal ingot including an area in which crystal originated particles are generated, and the surface density of particles having a size of not less than 0.12 μm is not more than 15 counts/cm 2 after repeating the SC-1. More preferably, a silicon single crystal wafer having a nitrogen concentration of 1×10 13 -1×10 15 atoms/cm 3 provides a surface density of not more than 1 counts/cm 2 for the particles having a diameter of not less than 0.12 μm even after repeating the SC-1. Hence, a high quality wafer optimally used for a particle monitor can be obtained and a very small number of defects in the wafer make it possible to produce devices.

What is claimed is:  
     
         1 . A silicon single crystal wafer for a particle monitor, wherein said wafer is prepared by slicing a silicon single crystal ingot grown by the Czochralski method, 
 wherein said wafer includes an area in which crystal originated particles are generated,    wherein a surface density of particles having a particle size of not less than 0.12 μm on the wafer surface is not more than 15 counts/cm 2 , even after repeating the Standard Cleaning-1.    
     
     
         2 . A silicon single crystal wafer for a particle monitor according to  claim 1 , wherein said wafer has an oxygen concentration of not more than 13×10 17  atoms/cm 3  (old ASTM).  
     
     
         3 . A silicon single crystal wafer for a particle monitor, wherein said wafer is prepared by slicing a silicon single crystal ingot grown by the Czochralski method, 
 wherein said wafer includes an area in which crystal originated particles are generated, and further said silicon single crystal ingot has a nitrogen concentration of 1×10 13 -1×10 15  atoms/cm 3 ,    wherein a surface density of particles having a particle size of not less than 0.12 μm on the wafer surface is not more than 1 count/cm 2 , even after repeating the Standard Cleaning-1.    
     
     
         4 . A silicon single crystal wafer for a particle monitor according to  claim 3 , wherein said wafer has an oxygen concentration of not more than 13×10 17  atoms/cm 3  (old ASTM).  
     
     
         5 . A silicon single crystal wafer for a particle monitor, wherein said wafer is prepared by slicing a silicon single crystal ingot grown by the Czochralski method, 
 wherein, in said Czochralski method, the time period of passing the temperature range from 1150° C. to 1070° C. is within 20 min and the time period of passing the temperature range from 900° C. to 800° C. is within 40 min,    wherein a surface density of particles having a particle size of not less than 0.12 μm on the wafer surface is not more than 15 counts/cm 2 , even after repeating the Standard Cleaning-1.    
     
     
         6 . A silicon single crystal wafer for a particle monitor according to  claim 5 , wherein said wafer has an oxygen concentration of not more than 13×10 17  atoms/cm 3  (old ASTM).  
     
     
         7 . A silicon single crystal wafer for a particle monitor, wherein said wafer is prepared by slicing a silicon single crystal ingot grown by the Czochralski method, 
 wherein, in said Czochralski method, the time period of passing the temperature range from 1150° C. to 1070° C. is within 20 min and the time period of passing the temperature range from 900° C. to 800° C. is within 40 mm,    wherein said silicon single crystal ingot has a nitrogen concentration of 1×10 13 -1×10 15  atoms/cm 3 ,    wherein a surface density of particles having a particle size of not less than 0.12 μm on the wafer surface is not more than 1 count/cm 2 , even after repeating the Standard Cleaning-1.    
     
     
         8 . A silicon single crystal wafer for a particle monitor according to  claim 7 , wherein said wafer has an oxygen concentration of not more than 13×10 17  atoms/cm 3  (old ASTM).  
     
     
         9 . A silicon single crystal wafer for a particle monitor according to any one of  claim 1 ,  3 ,  5  or  7 , wherein, in said Standard Cleaning-1, the chemical component of the used solution is H 2 O 2 :NH 4 OH:H 2 O=1:1:5, and the cleaning is repeated six times and each cleaning is carried out for 10 min.