Title :
Advantage of La2O3 gate dielectric over HfO2 for direct contact and mobility improvment
Author :
Kakushima, K. ; Tachi, K. ; Adachi, M. ; Okamoto, K. ; Sato, S. ; Song, J. ; Kawanago, T. ; Ahmet, P. ; Tsutsui, K. ; Sugii, N. ; Hattori, T. ; Iwai, H.
Author_Institution :
Interdiscipl. Grad. Sch. of Sci. & Eng., Tokyo Inst. of Technol., Tokyo
Abstract :
Advantage of La2O3 over HfO2 MOSFET has been experimentally examined. Silicate reaction especially observed at La2O3/Si interface has been found to suppress the formation of SiO2 layer to realize direct contact, which is useful for further scaling in equivalent oxide thickness (EOT). Due to the lack of interfacial layer, La2O3 has showed relatively high interfacial state density, however, the effective mobility has exceeded to that of HfO2 MOSFET. Mobility analysis has revealed an additional Coulomb scattering at small EOT, suggesting the influence of metal gate. A simple mobility degradation model is pointed out using metal induced defects.
Keywords :
MOSFET; electronic density of states; hafnium compounds; interface states; lanthanum compounds; Coulomb scattering; La2O3-HfO2; MOSFET; equivalent oxide thickness; gate dielectric; interfacial state density; metal induced defects; mobility analysis; Annealing; Degradation; Fabrication; Hafnium oxide; High K dielectric materials; High-K gate dielectrics; MOSFET circuits; Semiconductor device modeling; Sputtering; Temperature;
Conference_Titel :
Solid-State Device Research Conference, 2008. ESSDERC 2008. 38th European
Conference_Location :
Edinburgh
Print_ISBN :
978-1-4244-2363-7
Electronic_ISBN :
1930-8876
DOI :
10.1109/ESSDERC.2008.4681715
