Silicon single crystal wafer

Abstract

A method of making silicon single crystal wafers free of grown-in defects is provided. These wafers are formed from silicon single crystal manufactured by the Czochralski method. Careful control of the pulling rate, V (mm/min), and the temperature gradient G (° C./mm) permits crystals to be formed that are free from OSF rings, and other types of defects.

1. A silicon single crystal comprising less than 1 spot/cm 3 . . 
     
     
       2. A silicon single crystal wafer, which contains substantially no infrared scattering defects and dislocation clusters. 
     
     
       3. An integrated semiconductor device comprising:
 A silicon wafer according to  claim 2 , or a fraction of said wafer.  
 
     
     
       4. The integrated semiconductor device of  claim 3 , wherein said device is selected from the group consisting of MOS semiconductor devices, and LSI devices. 
     
     
       5. A silicon single crystal wafer, which contains an OSF ring  OSF- ring developing region  and a defect-free zone located substantially outside the OSF ring  OSF- ring developing region.    
     
     
       6. An integrated semiconductor device comprising:
 a silicon wafer according to  claim 5 , or a fraction of said wafer.  
 
     
     
       7. The integrated semiconductor device of  claim 6 , wherein said device is selected from the group consisting of MOS semiconductor devices, and LSI devices. 
     
     
       8. A silicon wafer, which is formed from a silicon single crystal ingot (except ones having diameters not more than 75 mm) that has been pulled by the Czochralski method, comprising, exclusively:
 an OSF-ring developing region; and  
 a grown-in defect free region.  
 
     
     
       9. A silicon wafer, which is formed from a silicon single crystal ingot (except ones having diameters not more than 75 mm) that has been pulled by the Czochralski method, comprising, exclusively:
 an infrared scattering defect developing region;  
 an OSF-ring developing region; and  
 a grown-in defect free region.  
 
     
     
       10. A silicon single crystal, which is pulled using a CZ furnace that, at a high temperature range close to the melting point of silicon, has an axial temperature gradient at the surface of the crystal lower than that at the center of the crystal. 
     
     
       11. A silicon single crystal, which is pulled using a CZ furnace that, at a high temperature range close to a melting point of silicon, has an axial temperature gradient at the surface of the crystal lower than that at the center of the crystal, and on condition that the center of the crystal constitutes a grown-in defect free region. 
     
     
       12. A silicon single crystal, which is pulled using a CZ furnace that, at a high temperature range close to a melting point of silicon, has an axial temperature gradient at a surface of the crystal lower than that at a center of the crystal, and on condition that the center of the crystal constitutes an OSF-ring developing region. 
     
     
       13. A silicon single crystal, which is pulled using a CZ furnace that, at a high temperature range close to a melting point of silicon, has an axial temperature gradient at the surface of the crystal lower than that at the center of the crystal, and on condition that the center of the crystal constitutes an infrared scattering defect developing region. 
     
     
       14. A silicon single crystal, which is formed by creating a defect distribution diagram clearly showing a defect distribution in relation to a V/G′ value and a radial location in the crystal, defining a hot zone structure such that a V/G′ curve showing a changes of the V/G′ value in a radial direction of the crystal passes through a desired region in said defect distribution diagram, and pulling the crystal in the defined hot zone structure, where V is a pulling rate when a silicon single crystal is pulled by the Czochralski method, and G′ is an axial temperature gradient at a high temperature range close to the melting point of silicon. 
     
     
       15. A silicon single crystal according to  claim 14 , wherein the axial temperature gradient G′ is a mean value (G) of the temperature gradient of the axial direction in a range from the melting point of silicon to 1300° C. 
     
     
       16. A silicon single crystal according to  claim 14 , wherein the axial temperature gradient G′ is determined from an axial temperature distribution which is calculated from the temperature at a surface of the crystal given by a global heat transfer model calculation and the temperature (the melting point of silicon) at the solid-liquid interface given by measuring the shape of the solid-liquid interface of the actual crystal as boundary conditions. 
     
     
       17. A silicon single crystal, which is formed by pulling the crystal by adjusting a pulling rate V such that a V/G′ value is constant to changes of an axial temperature gradient G′ associated with the progress of pulling of the crystal, where V is a pulling rate when pulling a silicon crystal by the Czochralski method, and G′ is the axial temperature gradient at a high temperature range close to a melting point of silicon. 
     
     
       18. A silicon single crystal according to  claim 17 , wherein the target V/G′ value is maintained by keeping a mean value of the pulling rate V at a target value while changing the pulling rate V in combination with, or independently of, the control of heater power to control a crystal diameter. 
     
     
       19. A silicon single crystal according to  claim 17 , wherein the axial temperature gradient G′ is a mean value (G) of a temperature gradient of the axial direction in a range from the melting point of silicon to 1300° C. 
     
     
       20. A silicon single crystal according to  claim 17 , wherein the axial temperature gradient G′ is determined from a temperature distribution which is calculated from the temperature at a surface of the crystal given by a global heat transfer model calculation and the temperature (the melting point of silicon) at a solid-liquid interface given by measuring the shape of the solid-liquid interface of the actual crystal as boundary conditions. 
     
     
       21. A silicon single crystal, which is formed by the process comprising: surveying the axial changes in a radial defect distribution in the crystal being pulled, setting a target pulling rate V in a direction of a pulling axis to maintain the V/G′ at constant value in a direction of the pulling axis, and pulling the crystal according to the target V, where V is a pulling rate when a silicon single crystal is pulled by the Czochralski method, and G′ is an axial temperature gradient at a high temperature range close to a melting point of silicon. 
     
     
       22. A silicon single crystal according to  claim 21 , wherein the axial temperature gradient G′ is a mean value (G) of the temperature gradient in axial direction in a range from the melting point of silicon to 1300° C. 
     
     
       23. A silicon single crystal according to  claim 21 , wherein the axial temperature gradient G′ is determined from a temperature distribution which is calculated from the temperature at a surface of the crystal given by a heat transfer model calculation and a temperature (the melting point of silicon) at a solid-liquid interface given by measuring the shape of the solid-liquid interface of the actual crystal as boundary conditions.