Background for High-K Gate

Silicon dioxide (SiO2) has been used to make for the gate of transistor for a long time. As the thickness of SiO2 is becoming thinner, the leakage of current is getting remarkable. According to Misra et al. [1], the leakage current density of 1.2nm–SiO2 gate is beyond 100A/m2 when applies 1V voltage. The situation is not allowed in most of application. However, when applying high-k materials, the capacitor of gate is becoming bigger than SiO2. In the other word, the gate can store more electric charge and the leakage current becomes less. The replacement of the SiO2 gate dielectric by high-k dielectric material is to improve the performance and simultaneously extend the scalability of Si MOSFETs.[2] HfSiO is one of high-k material which has better thermal stability is preferred to replace SiO2.

Posted on 3rd Feb. 2014 by Danyu Li and Saisai Wen

[1]. D. Misra, et al. (2005, Sumer). “High-k Gate Dielectrics” [Online]. Available: http://www.electrochem.org/dl/Interface/sum/sum05/IF08-05_Pg30-34.pdf. [Accessed: Jan. 1, 2014]

[2] Y. Taur, et al., “CMOS scaling into the nanometer regime,” Proc.IEEE, vol. 85, p. 486, Apr. 1997.