| 摘要 |
PURPOSE:To produce a semiconductor device with high quality at high yield minimizing the leak current of semiconductor-element to be formed by a method wherein a semiconductor substrate with specific oxygen concentration is cryoheat-treated and polycrystalline silicon is grown on the back-side of substrate. CONSTITUTION:A silicon substrate 1 with concentration of oxgen contained in silicon crystal Oi<=10X10<17>atom/cm<2> is cryoheattreated at the temperature not exceeding 600 deg.C. The inter-lattice oxygen in the substrate 1 forms minor defective nuclei 2 by the cryo-heat-treatment. Next polycrystalline silicon 3 is grown on the backside of substrate 1. Laser when the substrate 1 is heat-treated to form semiconductor element. The minor defective nuclei 2 formed by two step heat-treatment are grown to form minor defects 4. Through these procedures, both gettering effects of intrinsic and extrinsic may be combined with each other while minimizing the leak current of semiconductor element to be formed. |
