In the manner which configurates the heat treatment condition of the silicon substrate when the internal gettering is done in the production mannered null silicon substrate of manner,

摘要

PROBLEM TO BE SOLVED: To provide a finding method for cooling conditions, capable more effectively developing an IG capacity in accordance with the initial amount of contamination of heavy metal and the density of oxygen deposit of a silicone substrate.;SOLUTION: The heat treatment condition of the silicon substrate is set by a method, wherein the relation between a heat treatment temperature T and a heat treatment time t upon continuous cooling is calculated by equations (1): 1/τ=3 D[(C₀-C_eq)/(C_p-C_eq)]^1/3[4πn/3]^2/3, (2): t=τ1n[(CE-C_eq)/(C₀-C_eq)], (3): T=T₀-R_ct from the initial heavy metal contamination density C₀, the density of oxygen deposit n and the density CE of a desired impurity, then, a C-C-T chart, showing the calculated relation between the heat treatment temperature T and the heat treatment time t, is created and a tangential line, passing a point of a temperature T₀ on the temperature axis of the created C-C-T chart, whereat the initial heavy metal contamination density C₀ becomes the degree of solid solution C_eq of the heavy metal, while contacting with a curve in the C-C-T chart with a maximum inclination, is drawn to determine optimum cooling speed by the inclination of the tangential line.;COPYRIGHT: (C)2004,JPO