| 摘要 |
<p>PURPOSE:To enhance a device production yield by a method wherein a content state of oxygen in an as-grown crystal is grasped before a device formation process is started. CONSTITUTION:A thermal history of a silicon crystal (substrate) is measured according to an evaluation method. That is to say, the following is measured regarding the silicon crystal containing impurity oxygen: an intensity TA of an impurity-oxygen infrared absorption peak which is observed to be 1107<=3cm<-1> at room temperature; an intensity IB and an intensity IC of impurity-oxygen infrared absorption peaks which are observed to be 1206 + or -3cm<-1> and 1749+ or -3cm<-1> at a temperature of 10 K or lower. A ratio IA:IB:IC of the leak intensities is found; a 'difference' between the ratio of the peak intensities and a ratio of the peak intensities in the case where impurity oxygen exists in a wholly isolated manner is found; the thermal history of the silicon crystal is found by a corresponding calibration data between the 'difference' in the ratio of the peak intensities which have been found from a plurality of crystals whose thermal history is known in advance and the thermal history. Then, a heat treatment is executed according to the obtained thermal history; after that, impurities whose conductivity type is opposite to that of the silicon substrate are introduced into the substrate to form a p-n junction (diode).</p> |
