| 摘要 |
PURPOSE:To obtain a well construction device of entirely no generation of a surface crystal defect and extremely small power consumption by forming a well after processing an Si substrate formed by CZ method consecutively within two specific ranges of temperature. CONSTITUTION:An N type CZSi substrate 1 of oxygen concentration approx. 9X10<17>/cm<3> and approx. 10OMEGAcm is prepared, processed in N2 at 1,150 deg.C above 1,100 deg.C for 6hr to diffuse an oxygen atom near the surface, processed for 24hr at 750 deg.C or lower temperature to a deposit internally remaining O2 and a nucleus B is made. Then, processed in N2 at 1,100 deg.C for 6hr, the nucleus B is grown to a crystal defect C, processed again at 1,100 deg.C for 6hr for further growth and a high density minute crystal defect D is generated only within the substrate. Later, an SiO2 film 5 and an Si3N4 film 6 are formed normally, an ion B is injected, processed in N2 at 1,200 deg.C for 10hr and a P well 4 is made. The defect D of a definite critical diameter or more is grown further but that of less is shrunken and melted again and a surface crystal defect is not generated in later processing at approx. 1,000 deg.C whereby reduction of power consumption and improvement by yield are realized. |
