| 摘要 |
PURPOSE:To facilitate the control of the threshold values by a method wherein the two IGFET are integrated in the same semiconductor substrate and the Si3N4 film is partly formed on the Al electrode on the substrate while after the Al sintering process, the two transistors with different threshold values are formed. CONSTITUTION:A substrate 1 is coated with the field insulating film 2 and the insulating film of the active regions 3a, 3b to be formed into the transistor is removed. Firstly SiO2 to be the gate insulating film is formed by means of the thermal oxidation and the overall surface of the SiO2 is coated with the multicrystal Si. Secondly Si gates 5a, 5b, gate oxide films 4a, 4b are formed by means of the patterning process. Thirdly the overall surface is coated with the SiO2 film 8 and only the SiO2 film on the source.drain electrode fetch part is removed. fourthly Al is evaporated on the overall surface by the electronic beam evaporation to form the pattern leaving the specified wiring electrode 9. Fifthly the SiO2 10 is formed on the overall surface as the passivation film and the Si3N4 film 14 is further formed thereon. Finally the film 11 is removed excluding only the part upon the MOSFET provided with the specified high threshold values. |
