A block-oriented RAM with half-sized DRAM cell and quasi-foldeddata-line architecture

The authors describe a block-oriented random-access memory (BORAM) based on a series-connected cell concept and a quasi-folded data-line architecture. The series-connected cell concept allows a nearly half-sized DRAM cell even when using the same fabrication process as for conventional DRAMs. The low-noise quasi-folded data-line architecture allows the data-line capacitance to be one eighth the conventional value at the minimum, or the number of cells per amplifier to be 64 times the conventional number at the maximum. In addition, this architecture provides a more relaxed layout for the READ/WRITE circuits. The operation of four series-connected cells is observed successfully through a test device which includes a voltage-to-current conversion circuit, a current-mirror amplifier, and a 0.76-μm² crown-shaped stack-capacitor (STC) cell