High density and ultra small cell size of Contact ReRAM (CR-RAM) in 90nm CMOS logic technology and circuits

A new contact RRAM cell realized by TiN/TiON layers stacked between the W-plug and n+ diffusion region inside a small 80 × 80 nm contact hole is demonstrated using 90nm CMOS logic technology. This work reports the first time a resistive switching characteristics of the TiON layers sandwiched between the metal and Si substrate. The new Contact ReRAM cell exhibits highly stable read window and very small cell size of 0.19¿m 2 . By limiting the active ReRAM film in a small contact hole region, the cell effectively operates under a very low set voltage of 4V and a reset current of 150¿A, while achieving fast set and reset speed of less than 100ns and 10us, respectively. Excellent endurance of more than 1000k cycles and stable data retention characteristics further support the new Contact ReRAM (CR-RAM) cell will be a superior NVM technology for the future.