| 摘要 |
PURPOSE: A method for fabricating a semiconductor memory device is provided to reduce a difference in height between a cell region and a peripheral circuitry region and thereby to attain a high speed operation and a low power consumption. CONSTITUTION: A first silicon substrate having a cell region and a peripheral circuitry region is first provided. Second, field oxide layers(2a,2b) having different thickness are respectively formed on the cell region and the peripheral circuitry region. Third, a first insulating layer(3) is formed on the first substrate, and contact holes are selectively formed in the insulating layer(3). Fourth, a first polysilicon layer(5) is formed on the insulating layer(3) while filling the contact holes, and then a dielectric layer(6) and a second polysilicon layer(7) are formed thereon to form a capacitor on the cell region. Next, a second insulating layer(8) is formed on the second polysilicon layer(7) and a second silicon substrate(9) is then bonded thereto. Next, the first substrate is back-lapped until the field oxide layers(2a,2b) are exposed. As a result, the first substrate remains between the field oxide layers(2a,2b), and then a first and a second transistors(20,30) are formed on the first substrate.
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