A 4 kb Metal-Fuse OTP-ROM Macro Featuring a 2 V Programmable 1.37 $\mu$ m$^{2}$ 1T1R Bit Cell in 32 nm High-k Metal-Gate CMOS

A 4 kb high-density PROM array featuring the first high-volume manufacturable metal-fuse technology in 32 nm high-k metal-gate CMOS is introduced. In contrast to traditional salicided polysilicon based 2-D fuse cells, the metal-fuse technology enables a 3-D cell topology with program device and fuse element stacked on each other, achieving a 1.37 μm
²
cell footprint. The 128-row by 32-column array with an asymmetric tunable static sense scheme can operate down to 0.5 V and provides multi-bit programming capability. Programming success using a 2 V-1 μs pulse condition is demonstrated. The technology is scalable and maintains full compatibility with modern high-k metal-gate processes.