Data Retention Time and Electrical Characteristics of Cell Transistor According to STI Materials in 90 nm DRAM

  • Shin, S.H. (Semiconductor R&D Center, Samsung Electronics Company., Ltd.) ;
  • Lee, S.H. (Semiconductor R&D Center, Samsung Electronics Company., Ltd.) ;
  • Kim, Y.S. (Semiconductor R&D Center, Samsung Electronics Company., Ltd.) ;
  • Heo, J.H. (Semiconductor R&D Center, Samsung Electronics Company., Ltd.) ;
  • Bae, D.I. (Semiconductor R&D Center, Samsung Electronics Company., Ltd.) ;
  • Hong, S.H. (Semiconductor R&D Center, Samsung Electronics Company., Ltd.) ;
  • Park, S.H. (Semiconductor R&D Center, Samsung Electronics Company., Ltd.) ;
  • Lee, J.W. (Semiconductor R&D Center, Samsung Electronics Company., Ltd.) ;
  • Lee, J.G. (Semiconductor R&D Center, Samsung Electronics Company., Ltd.) ;
  • Oh, J.H. (Semiconductor R&D Center, Samsung Electronics Company., Ltd.) ;
  • Kim, M.S. (Semiconductor R&D Center, Samsung Electronics Company., Ltd.) ;
  • Cho, C.H. (Semiconductor R&D Center, Samsung Electronics Company., Ltd.) ;
  • Chung, T.Y. (Semiconductor R&D Center, Samsung Electronics Company., Ltd.) ;
  • Kim, Ki-Nam (Semiconductor R&D Center, Samsung Electronics Company., Ltd.)
  • Published : 2003.06.01

Abstract

Cell transistor and data retention time characteristics were studied in 90 nm design rule 512M-bit DRAM, for the first time. And, the characteristics of cell transistor are investigated for different STI gap-fill materials. HDP oxide with high compressive stress increases the threshold voltage of cell transistor, whereas the P-SOG oxide with small stress decreases the threshold voltage of cell transistor. Stress between silicon and gap-fill oxide material is found to be the major cause of the shift of the cell transistor threshold voltage. If high stress material is used for STI gap fill, channel-doping concentration can be reduced, so that cell junction leakage current is decreased and data retention time is increased.

Keywords

References

  1. Kinam Kim, Chang-Gyu Hwang and Jong-Gil Lee, IEEE Trans. Electron Dev. 45, 598 (1998) https://doi.org/10.1109/16.661221
  2. Soo-Ho Shin, Dong-Il Bae, Jae-Kyu Lee, Sang-Ho Song, and Kinam Kim, Journal of the Korean Physical Society, Vol. 39, No.1, 112, July (2001)
  3. T. Hamamoto, S. Sugiura, and S. Sawada, IEDM Tech. Dig., 915(1995)
  4. Jin-Hwa Heo, Soo-Jin Hong, Dong-Ho Ahn, Hyun-Duk Cho, and Joo-Tae Moon, VLSI Technical Digest, 302 (2002)
  5. K. Saino. S. Horiba, S. Uchiyama, Y. Takaishi, M. Takenaka, and C. Hu, IEDM Technical Digest, 837 (2000) https://doi.org/10.1109/IEDM.2000.904447
  6. T. Hamamoto, S. Sugiura, and S. Sawada, IEEE Trans. Elect. Dev. 45,1300(1998) https://doi.org/10.1109/16.678551