Polycrystalline silicon rod

Abstract

Provided is a polycrystalline silicon rod suitable as a raw material for production of single-crystalline silicon. A crystal piece (evaluation sample) is collected from a polycrystalline silicon rod grown by a Siemens method, and a polycrystalline silicon rod in which an area ratio of a crystal grain having a particle size of 100 nm or less is 3% or more is sorted out as the raw material for production of single-crystalline silicon. When single-crystalline silicon is grown by an FZ method using the polycrystalline silicon rod as a raw material, the occurrence of dislocation is remarkably suppressed.

What is claimed is: 
     
         1 . A polycrystalline silicon rod grown by a Siemens method,
 wherein, when a crystal piece is collected from a region excluding a portion corresponding to a silicon core, and evaluated, an area ratio of a crystal grain having a particle size of 100 nm or less is 3% or more.   
     
     
         2 . The polycrystalline silicon rod according to  claim 1 , wherein the area ratio of the crystal grain of 100 nm or less is 6% or more. 
     
     
         3 . The polycrystalline silicon rod according to  claim 1 , wherein the polycrystalline silicon rod is grown by using trichlorosilane or monosilane as a raw material. 
     
     
         4 . The polycrystalline silicon rod according to  claim 1 , wherein the crystal piece has a principal surface set in an axis direction of the silicon core. 
     
     
         5 . The polycrystalline silicon rod according to  claim 4 , wherein the area ratio of the crystal grain of 100 nm or less is 6% or more. 
     
     
         6 . The polycrystalline silicon rod according to  claim 4 , wherein the polycrystalline silicon rod is grown by using trichlorosilane or monosilane as a raw material. 
     
     
         7 . The polycrystalline silicon rod according to  claim 1 , wherein the crystal piece has a principal surface set in a radial direction perpendicular to an axis direction of the silicon core. 
     
     
         8 . The polycrystalline silicon rod according to  claim 7 , wherein the area ratio of the crystal grain of 100 nm or less is 6% or more. 
     
     
         9 . The polycrystalline silicon rod according to  claim 7 , wherein the polycrystalline silicon rod is grown by using trichlorosilane or monosilane as a raw material.