DocumentCode :
1445756
Title :
Electrical and Reliability Characteristics of HfLaTiO-Gated Metal–Oxide–Semiconductor Capacitors With Various Ti Concentrations
Author :
Cheng, Chin-Lung ; Horng, Jeng-Haur ; Wu, Yu-Zhen
Author_Institution :
Dept. of Electro-Opt. Eng., Nat. Formosa Univ., Yunlin, Taiwan
Volume :
12
Issue :
2
fYear :
2012
fDate :
6/1/2012 12:00:00 AM
Firstpage :
399
Lastpage :
405
Abstract :
Electrical and reliability characteristics of metal-oxide-semiconductor (MOS) capacitors with various-Ti-concentration-doped HfLaTiO/interfacial layer (IL)/P-Si(100) stacked structures are presented. Charge carrier generation/trapping and the related mechanisms of a thin HfLaTiO/IL stack in n-type MOS capacitors have been investigated under constant gate voltage stress. The mechanisms related to larger positive charge generation in the HfLaTiO gate dielectric bulk can be attributed to Ti-doped HfLaTiO dielectric. This is confirmed from the density of stress-induced oxide trapped charges. Moreover, more positive charges are induced in the HfLaTiO dielectric with increasing postdeposition annealing temperature. By developing proper Ti concentration in HfLaTiO dielectrics, the enhanced equivalent oxide thickness (EOT = ~ 0.5 nm) and the interface trap density (Dit) were demonstrated. Furthermore, the Ti-doped HfLaTiO dielectric is helpful for enhanced k-value of the HfLaTiO film (lower EOT), but the optical bandgap properties could be degraded. Energy band diagram of MOS capacitor with an HfLaTiO dielectric was achieved by the measurement of the effective work function of Ta metal gate deposited on HfLaTiO dielectric, the optical bandgaps of HfLaTiO dielectric, and Schottky barrier height (ΦB) at the Ta/HfLaTiO interface.
Keywords :
MOS capacitors; hafnium compounds; lanthanum compounds; semiconductor device reliability; titanium compounds; HfLaTiO:Ti; Schottky barrier height; charge carrier generation-trapping; constant gate voltage stress; electrical characteristics; gate dielectric bulk; gated MOS capacitors; gated metal-oxide-semiconductor capacitors; interface trap density; n-type MOS capacitors; optical bandgap properties; positive charge generation; postdeposition annealing temperature; reliability characteristics; stress-induced oxide trapped charge density; Dielectrics; Films; Hafnium; High K dielectric materials; Logic gates; Reliability; Silicon; Charge trapping; HfLaTiO dielectric; energy band diagram; high-$k$ dielectric; metal–oxide–semiconductor (MOS); stress-induced leakage current (SILC);
fLanguage :
English
Journal_Title :
Device and Materials Reliability, IEEE Transactions on
Publisher :
ieee
ISSN :
1530-4388
Type :
jour
DOI :
10.1109/TDMR.2012.2187294
Filename :
6151076
Link To Document :
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