| 摘要 |
PURPOSE:To reduce the temperature coefficient of a resistance element consisting of polycrystalline silicon further by heating a semiconductor substrate at the temperature of 700 deg.C or more. CONSTITUTION:The semicondutor substrate 1 is arranged into a quartz reaction tube 2, and heated at 600-750 deg.C by means of a heating furnace 3. The inside of the tube is evacuated from an exhaust port 4, SiH4 gas is flowed in from an inflow port 5, the degree of decompression is brought to approximately 0.2 Torr, SiH4 is decomposed onto the semiconductor substrate 1, and a polycrystalline silicon film is grown. Accordingly, a silicon board 10, an SiO2 film 11 and the polycrystalline silicon film 12 (1,000Angstrom film thickness) are formed in the semicondutor substrate 1. The ions of an impurity such as phosphorus are implanted from the upper surface of the polycrystalline silicon film, the concentration is brought to 10<10>-10<12>/cm<2>, the whole is thermally treated at approximately 1,000 deg.C and phosphorus is activated, the surface is patterned through a photo- process, an electrode 13 is shaped, and a resistance element is formed. |
