| 摘要 |
PURPOSE:To contrive improvement in the electrical characteristics by generating crystal defects over the specific quantity in a P type semiconductor substrate including boron atoms so as to give a gettering function and arranging an N type epitaxial layer having few defects on said substrate for forming a semiconductor element. CONSTITUTION:After an N type epitaxial layer 2 of about 15mum thick is formed with 1,100 deg.C on a P type Si substrate 10 including boron atoms of 1X10<17> pieces/ cm<2> followed by low-temperature treatment and high-temperature treatment to form a semiconductor element. Then crystal defects 3 of 3X10<4> pieces/ cm<3> are generated in the substrate 10, but minute defects are not observed in the epitaxial layer 2. The reason for this is thought that the minute defects in the epitaxial layer 2 are removed by IG effect of the crystal defects generated in the substrate 10. For removing the minute defects in the epitaxial layer 2 to the extent that those defects can not be observed, the crystal defects generated in the substrate 10 of 3X10<14> pieces/cm<3> or more are necessary. The concentration of boron atoms in the P type Si substrate 10 required for that is desirably 5X 10<16> pieces/cm<3>. |
