SEMICONDUCTOR DEVICE
A semiconductor device in which capacitance per unit area can be enlarged without imposing any limitations upon layout has both a DRAM region and a logic region. The DRAM region and the logic region each have a plurality of cells provided with a respective capacitance element. Each capacitance element has an upper electrode, a lower electrode and a dielectric film sandwiched between the upper and lower electrodes. At least one of the upper electrode and lower electrode in the DRAM region is electrically isolated for every cell. In the logic region, the upper electrode, lower electrode and dielectric film are extended so as to be continuous from cell to cell of the plurality of cells.
1 . A semiconductor device comprising:
a mixture of a dynamic random-access memory (termed DRAM hereinafter) region and a logic region;
wherein the DRAM region and the logic region each have a plurality of cells provided with a capacitance element;
said capacitance element has an upper electrode, a lower electrode and a dielectric film sandwiched between the upper and lower electrodes; and
the upper electrode, lower electrode and dielectric film in said logic region are extended so as to be continuous from cell to cell of the plurality of cells.
2 . The device according to claim 1 , further comprising transistors electrically connected to said capacitance elements;
wherein the number of transistors in said logic region is smaller than the number of the plurality of cells.
3 . The device according to claim 1 , wherein the capacitance element in said logic region has a contact hole that passes through the capacitance element; and
an edge portion of the lower electrode is not exposed to an inner surface of the contact hole.
4 . The device according to claim 2 , wherein the capacitance element in said logic region has a contact hole that passes through the capacitance element; and
an edge portion of the lower electrode is not exposed to an inner surface of the contact hole.
5 . The device according to claim 3 , wherein an opening in the lower electrode in the contact hole is larger than an opening in the upper electrode; and
an inner surface of the opening in the lower electrode is covered by the dielectric film and the upper electrode.
6 . The device according to claim 4 , wherein an opening in the lower electrode in the contact hole is larger than an opening in the upper electrode; and
an inner surface of the opening in the lower electrode is covered by the dielectric film and the upper electrode.
7 . The device according to claim 1 , wherein the capacitance element is a cylinder-type or parallel-plate-type capacitance element.
8 . The device according to claim 1 , wherein the capacitance element comprises a cylinder-type capacitance element.
9 . The device according to claim 1 , wherein the capacitance element comprises a parallel-plate-type capacitance element.