| 摘要 |
PURPOSE:To increase the electrostatic capacity value of a capacitor for storing the information of a dynamic memory cell without extending an occupying area on an silicon substrate in the capacitor for storing information by utilizing a recessed shape generated when etching a thick silicon dioxide film constituted by selectively oxidizing the surface of the silicon substrate. CONSTITUTION:An silicon nitride film 3 is deposited onto an silicon substrate 1 with an silicon dioxide film 2 for dielectric isolation, and formed to a predetermined pattern, and a thick silicon dioxide film 4 is shaped, using the silicon nitride film 3 as a mask. The silicon dioxide film 4 is removed through wet etching to form a groove 8, and the silicon nitride film 3 is gotten rid of to expose the surface of the silicon substrate 1 with the groove 8 indented to a recessed shape. Lastly, a thin silicon dioxide film 5 is shaped onto the recessed surface of the silicon substrate 1, an silicon nitride film 6 is formed, and a polycrystalline silicon film 7 as an uppermost layer is deposited. The polycrystalline silicon film 7 is patterned, and the silicon nitride film 6 and the silicon dioxide film 5 are taken away, thus acquiring a capacitor for storing the information of a dynamic memory cell. |
