A method for producing silicon substrates includes growing the silicon crystal body at a relatively high rate of growth. It has been found that the growth rate of the silicon crystal body exerts substantial influence upon generation of crystal defects in the silicon crystal body or silicon substrate. Furthermore, the oxygen concentration in the silicon crystal body or the silicon substrate is significantly higher than that in conventional silicon crystals or substrates. The high growth rate of the silicon crystal body suppresses separation of the oxygen from the crystal body. This reduces the number of defects or faults formed in the crystal body during heat treatment during production of the semiconductor devices. In the preferred process, according to the present invention, the growth rate of the silicon crystal body is greater than or equal to 1.2 mm/min. Furthermore, the preferred oxygen concentration in the grown silicon crystal body is selected to be greater than or equal to 1.8 x 10<18>cm<-3>. |