| 摘要 |
PURPOSE: A method for manufacturing semiconductor devices is provided to reduce the depth of a contact hole upon formation of the contact for forming a capacitor, by reducing the step of an insulating film on an upper side of a semiconductor memory cell. CONSTITUTION: A method for manufacturing semiconductor devices forms a trench at one portion of a substrate. An oxide film is left within the trench to form a field oxide film, thus defining a device formation region. A gate oxide film and polysilicon are deposited to form a gate(9) independently located from the device formation region and a bit line located on the top of the field oxide film and parallel to the device formation region is also formed. Impurity ions are injected into the device formation region of the gate(9) to form drains and common sources of each of cell transistors. After an insulating film is deposited on the entire surface, the insulating film is dry-etched to form a sidewall at the sidewall of the gate(9). Polysilicon is deposited on the entire surface and is then flattened to expose the top of the gate. Then, the polysilicon is patterned by lithography process to form a capacitor plug located on the drain of the cell transistor and a bit line plug connecting the common source of the cell transistor and the bit line. After an insulating film is deposited on the entire surface, a contact hole is formed in the insulating film to expose the top of the gate(9). Then, a word line(3) connected to the gate(9) and vertically crossing the device formation region is formed by metal wiring process. An insulating film is formed on the entire surface of the word line(3). Then, a contact hole is in the insulating below the word line(3) by self-alignment method to expose the capacitor plug. A capacitor(8) connected to the capacitor plug is then formed.
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