학술논문

A 1.67Tb, 5b/Cell Flash Memory Fabricated in 192-Layer Floating Gate 3D-nand Technology and Featuring a 23.3 Gb/mm2 Bit Density
Document Type
Periodical
Source
IEEE Solid-State Circuits Letters IEEE Solid-State Circuits Lett. Solid-State Circuits Letters, IEEE. 6:161-164 2023
Subject
Components, Circuits, Devices and Systems
Computing and Processing
Threshold voltage
Capacitors
Three-dimensional displays
Sensors
Error correction codes
Nonvolatile memory
Computer architecture
3-D NAND
multiple-bit-per-cell memory
nonvolatile memory
Language
ISSN
2573-9603
Abstract
We present the industry’s first 5b/cell (PLC) NAND chip, fabricated in a 192-layer floating-gate (FG) technology. With a die capacity of 1.67 Tb and an area of 73.3 mm 2 , it delivers a record bit density of 23.3 Gb/mm 2 . Key innovations to enable reliable PLC operation and the features implemented to support system-level usage are described. These include: a fast soft-bit read algorithm capable of handling the presence of defective bitlines; a fast read-calibration algorithm; a reverse-read waveform to improve the read margin; SLC-write-through; and program suspend and resume algorithm compatible with the above read operations.