Yosiaki Hisamune

A high capacitive-coupling ratio (HiCR) cell for 3 V-only 64 Mbit and future flash memories

A novel contactless cell with high capacitive-coupling ratio (HiCR) of 0.8, which is programmed and erased by Fowler-Nordheim tunneling, has been developed for 3 V-only 64 Mbit and future flash memories. A 1.50 /spl mu/m/sup 2/ cell area is obtained by using a 0.4 /spl mu/m technology. The HiCR cell structure is realized by 1) self-aligned definition of small tunneling regions underneath the floating-gate side wall and 2) advanced rapid thermal process for 7.5-nm thick tunnel oxynitride. The internal voltages used for program and erase are +8 V and +12 V, respectively. The total process-step numbers can be reduced to 85% compared to reported memory cells so far.<<ETX>>