| 摘要 |
PURPOSE:To reduce the chip size of a RAM by forming the power lines of the capacitor of the dynamic RAM by the same metal or high density impurity-contained silicon at first layer and forming the gate electrodes of an IGFET by the same material at second layer. CONSTITUTION:Thick and thin SiO2 films 102, and 103 are formed on a P- or N- type silicon substrate 101, an opening is perforated at the film 103 to thereby form an N<+>-type or P<+>-type layer 104 thereon. Then, a molybdenum thin films 105, 106 are formed with impurity added silicon or small amount of silicon in such a manner that the film 105 is ohmic contact with the layer 104, and a film 106 is formed on a SiO2 film 103. Then, it is coated by SiO2 films 107, 108 to form the thin film 107 and thick film 108 by their oxide speed difference. The film 107 is coated completely to thereby form an impurity-contained silicon or metal 109. Thus, the gate of an IGFET is self-aligned to reduce the length of its gate. |
