Tyler J. Thorp

512-Mb PROM with a three-dimensional array of diode/antifuse memory cells

A 512-Mb one-time-programmable memory is described, which uses a transistorless two-terminal memory cell containing an antifuse and a diode. Cells are fabricated in polycrystalline silicon, stacked vertically in eight layers above a 0.25-/spl mu/m CMOS substrate. One-time programming is performed by applying a high voltage across the cell terminals, which ruptures the antifuse and permanently encodes a logic 0. Unruptured antifuses encode a logic 1. Cells are arranged in 8-Mb tiles, 1 K rows by 1 K columns by 8 bits high. The die contains 72 such tiles: 64 tiles for data and eight tiles for error-correcting code bits. Wordline and bitline decoders, bias circuits, and sense amplifiers are built in the CMOS substrate directly beneath the memory tiles, improving die efficiency. The device supports a generic standard NAND flash interface and operates from a single 3.3-V supply.

512 Mb PROM with 8 layers of antifuse/diode cells

A 3.3 V, 512 Mb PROM uses a transistorless memory cell containing an antifuse and diode. A bit area of 1.4F/sup 2/ including all overhead is achieved by stacking cells 8 high above the 0.25 /spl mu/m CMOS substrate. Read bandwidth is 1 MB/s and write bandwidth is 0.5 MB/s. A 72 b Hamming code provides fault tolerance.