Title :
A split wordline cell for 16 Mb SRAM using polysilicon sidewall contacts
Author :
Itabashi, K. ; Mizutani, K. ; Koga, T. ; Matumiya, M. ; Kawashima, S. ; Sakata, M. ; Ema, T. ; Yabu, T. ; Toyoda, K. ; Suzuki, N. ; Shimada, H.
Author_Institution :
Fujitsu Ltd., Kawasaki, Japan
Abstract :
A 16-Mb SRAM (static RAM) cell having three significant features in comparison with conventional cells has been developed. First, a split wordline memory cell layout was adopted. Second, a double-gated PMOS thin film transistor (TFT) load was used. Third, polysilicon sidewall contacts were applied to the cell storage-node to reduce the number of fabrication process steps. The cell size was 2.1 mu m*4.15 mu m and it was fabricated using a conventional i-line stepper; and two phase-shift masks were required for the fabrication process. Memory cell operation was verified using a 64-kb test chip. In order to reduce soft errors, the ´fin´ capacitor was applied to the 16-Mb SRAM cell.<>
Keywords :
CMOS integrated circuits; SRAM chips; thin film transistors; 16 Mbit; SRAM; Si; TFT; double-gated PMOS thin film transistor; fabrication process; fin capacitor; i-line stepper; memory cell; phase-shift masks; polysilicon sidewall contacts; split wordline cell; static RAM; CMOS technology; Capacitors; Driver circuits; Electrodes; Error analysis; Fabrication; MOSFET circuits; Random access memory; Stability; Thin film transistors;
Conference_Titel :
Electron Devices Meeting, 1991. IEDM '91. Technical Digest., International
Conference_Location :
Washington, DC, USA
Print_ISBN :
0-7803-0243-5
DOI :
10.1109/IEDM.1991.235352
