DocumentCode :
138283
Title :
Effective workfunction control in TmSiO/HfO2 high-k/metal gate stacks
Author :
Litta, Eugenio Dentoni ; Hellstrom, Per-Erik ; Ostling, Mikael
Author_Institution :
Sch. of ICT, KTH R. Inst. of Technol., Kista, Sweden
fYear :
2014
fDate :
7-9 April 2014
Firstpage :
69
Lastpage :
72
Abstract :
Integration of high-k interfacial layers in CMOS technology has been proposed to overcome the scaling limitations of the SiOx/HfO2 dielectric stack. Candidate high-k interfacial layers have to be compatible with strict requirements in terms of EOT, inversion layer mobility, threshold voltage control and device reliability. We have previously demonstrated a CMOS-compatible process for integration of thulium silicate (TmSiO) as interfacial layer, providing advantages in terms of EOT and channel mobility. This work demonstrates the compatibility of the TmSiO/HfO2 stack with the threshold voltage control techniques commonly employed in gate-last and gate-first integration schemes, namely the use of a dual-metal process and the integration of dielectric capping layers. We show that the flatband voltage can be set from -1V to +0.5V by proper choice of gate metal, while a shift of 150-400 mV is achievable by means of integration of Al2O3 or La2O3 capping layers.
Keywords :
CMOS integrated circuits; hafnium compounds; high-k dielectric thin films; silicon compounds; thulium compounds; voltage control; CMOS technology; CMOS-compatible process; EOT; TmSiO-HfO2; channel mobility; device reliability; dielectric capping layers; dielectric stack; dual-metal process; effective work function control; gate metal; gate-first integration schemes; gate-last integration schemes; high-k interfacial layers; high-k-metal gate stacks; inversion layer mobility; threshold voltage control techniques; voltage -1 V to 0.5 V; voltage 150 mV to 400 mV; Dielectrics; Hafnium compounds; High K dielectric materials; Logic gates; Threshold voltage; Tin; CMOS; HfO2; TmSiO; high-k; interfacial layer; thulium;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Ultimate Integration on Silicon (ULIS), 2014 15th International Conference on
Conference_Location :
Stockholm
Type :
conf
DOI :
10.1109/ULIS.2014.6813908
Filename :
6813908
Link To Document :
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