Abstract: A memory system that includes a DRAM cell that includes an access transistor and a storage capacitor. The storage capacitor is fabricated by forming a polysilicon crown electrode, a dielectric layer overlying the polysilicon crown, and a polysilicon plate electrode overlying the dielectric layer. A first set of thermal cycles are performed during the formation of the storage capacitor to form and anneal the elements of the capacitor structure. Subsequently, shallow P+ and/or N+ regions are formed by ion implantation, and metal salicide is formed. As a result, the relatively high first set of thermal cycles required to form the capacitor structure does not adversely affect the shallow P+ and N+ regions or the metal salicide. A second set of thermal cycles, which are comparable to or less than the first set of thermal cycles, are performed during the formation of the shallow regions and the metal salicide.
Abstract: A method is provided for operating a memory system having a plurality of memory blocks. The method includes (1) periodically asserting a timing signal; (2) asserting a refresh pending signal in each of the memory blocks when the asserted timing signal is received; (3) within each of the memory blocks, performing a refresh operation if the refresh pending signal in the memory block is asserted and an idle cycle exists in the memory block; (4) within each of the memory blocks, asserting a refresh acknowledge signal if a refresh operation is performed in the memory block; (5) within each of the memory blocks, de-asserting the refresh pending signal in the memory block if the refresh acknowledge signal is asserted in the memory block; (6) asserting a refresh forcing signal if the refresh pending signal in any of the memory blocks is asserted when the timing signal is asserted; and (7) forcing an idle cycle in all of the memory blocks if the refresh forcing signal is asserted.
Abstract: A semi-conductor memory device having a wide write data bandwidth is provided with high speed read-write circuitry having data amplifiers that are activated to accelerate amplification of write data signals being driven by write data drivers onto data lines of the cell array of the device during memory write cycles, as well as activated to amplify read data signals on the data lines during memory read cycles. Moreover, the data amplifiers are activated in a self-timed manner. In one embodiment, the device is further provided with a read data buffer that is constituted with a regenerative latch and an input stage, and a write data buffer having multiple entries. The input stage of the read data buffer isolates or couples the regenerative latch to the data lines depending on whether the data lines are in a pre-charged state or not.