| 摘要 |
PURPOSE:To obtain the titled device of high integration degree and high speed action by a method wherein a Ta film is formed on an insulation film of the first region located on an Si substrate and on a poly Si film of the second region, and is then changed into a Ta oxide and a Ta silicide, respectively, by heat treatment. CONSTITUTION:An element isolating oxide film 2 and a gate oxide film 3 are provided on a P type Si substrate 1, and a phosphorus-doped poly Si 4 is superposed; then, the whole is covered with the Ta 6 after selective formation of a thermal oxide film 5. When regions 21 and 22 are formed by RIE and heated, Ta2O5 61 can be obtained on a poly Si floating gate 7 via SiO2 5, and at the same time Ta4Si5 62 of good conductivity can be obtained on a poly Si gate 8. The upper surface and the side surface of each gate are covered with SiO2 9. Next, a poly Si control gate 10 is attached, and N type sources and drains 11 are provided. Finally, the whole is covered with a protection film after attachment of electrodes. Since a Ta2O5 61 of high dielectric constant is present between the floating gate 7 and the control gate 10, the coupling capacitance per unit area increases and integration can be increased. The gate resistance is low in the presence of the Ta4Si5 62, and high speed action becomes enabled. |
