Patent Number: 7,821,080

Title: N-ary three-dimensional mask-programmable read-only memory

Abstract: N-ary three-dimensional mask-programmable read-only memory (N-3DMPROM) stores multi-bit-per-cell. Its memory cells can have N states (N>2) and data are stored as N-ary codes. N-3DMPROM has a larger storage density than the prior-art binary 3D-MPROM. One advantage of N-3DROM over other N-ary memory (e.g. multi-level-cell flash) is that its array efficiency can be kept high. N-3DMPROM could be geometry-defined, junction-defined, or a combination thereof.

Inventors: Zhang; Guobiao (Stateline, CA)

Assignee:

International Classification: H01L 29/72 (20060101)

Expiration Date: 2018-10-26 0:00:00