Title :
Characteristics of high quality hafnium oxide gate dielectric
Author :
Zhan, N. ; Ng, K.L. ; Poon, M.C. ; Kok, C.W. ; Chan, M. ; Wong, H.
Author_Institution :
Dept. of Electr. & Electron. Eng., Hong Kong Univ. of Sci. & Technol., China
Abstract :
Hafnium oxide (HfO2) was investigated as an alternative possible gate dielectric. A MOS capacitor using HfO2 as dielectric was fabricated and studied. The HfO2 film was formed by direct sputtering of Hf in O2 and Ar ambient on to a Si substrate and post-sputtering rapid thermal annealing (RTA). XPS results showed that the interface layer formed between the HfO2 and the Si substrate was affected by the RTA time within the 500°C to 600°C annealing temperature. The interface layer was mainly composed of hafnium silicate and had high interface trap density. Increase in RTA time was found to lower the effective barrier height of the layer and the FN tunneling current.
Keywords :
CMOS integrated circuits; MOS capacitors; X-ray photoelectron spectra; dielectric thin films; electronic density of states; hafnium compounds; integrated circuit testing; interface states; interface structure; permittivity; rapid thermal annealing; semiconductor-insulator boundaries; sputter deposition; tunnelling; 500 to 600 C; CMOS devices; FN tunneling current; HfO2 gate dielectric; HfO2-Si; MOS capacitor; O2-Ar; O2-Ar ambient; RTA; Si; Si substrate; XPS; annealing temperature; annealing time; direct sputtering; effective barrier height; hafnium oxide gate dielectric; hafnium silicate interface layer; high-k gate dielectrics; interface layer; interface trap density; post-sputtering rapid thermal annealing; Bonding; Capacitors; Chemicals; Dielectric substrates; Hafnium oxide; High K dielectric materials; Leakage current; Rapid thermal annealing; Sputtering; Temperature;
Conference_Titel :
Electron Devices Meeting, 2002. Proceedings. 2002 IEEE Hong Kong
Print_ISBN :
0-7803-7429-0
DOI :
10.1109/HKEDM.2002.1029153
