| 摘要 |
PROBLEM TO BE SOLVED: To prevent, as further as possible, a furnace from being contaminated, by introducing only a target impurity element such as Fe into a silicon wafer, in a heat treatment method of intentionally contaminating the inside of the silicon wafer with the impurity element.SOLUTION: A front face 11 of a silicon wafer 1 (intentional contamination wafer) of a contamination object is coated beforehand with a heavy metal impurity 3 such as Fe. Front and rear faces of the contamination object wafer 1 are held between silicon wafers 24 (dummy wafers) with oxide films 22. At such a time, a small piece 5 (spacer) formed from a silicon wafer is held between the contamination object wafer 1 and the dummy wafer 24, thereby forming a gap 6 between the contamination object wafer 1 and the dummy wafer 24. Heat treatment is performed thereafter and the heavy metal impurity 3 applied to the front face 11 is dispersed over the contamination object wafer 1. Thus, the heavy metal impurity 3 can be prevented from being dispersed into a furnace and an extrinsic contamination atom 4 can be prevented from being mixed into the contamination object wafer 1. |
