Title :
Low-Frequency Noise Characterization of Ultra-Low Equivalent-Oxide-Thickness Thulium Silicate Interfacial Layer nMOSFETs
Author :
Olyaei, Maryam ; Dentoni Litta, Eugenio ; Hellstrom, Per-Erik ; Ostling, Mikael ; Malm, Bengt Gunnar
Author_Institution :
Sch. of Inf. & Commun. Technol., KTH R. Inst. of Technol., Kista, Sweden
Abstract :
Low-frequency noise measurements were performed on n-channel MOSFETs with a novel ultra-low 0.3-nm equivalent-oxide-thickness (EOT) interfacial layer (TmSiO) and two different bulk high-k dielectrics (Tm2O3 and HfO2). The MOSFETs were fabricated in a gate-last process and the total gate-stack EOT was 1.2 and 0.65 nm for the Tm2O3 and HfO2 samples, respectively. In general, both gate-stacks resulted in 1/f type of noise spectra and noise levels comparable with the conventional SiO2/HfO2 devices with similar EOTs. The extracted average effective oxide trap density was 2.5 × 1017 and 1.5 × 1017 cm-3eV-1 for TmSiO/HfO2 and TmSiO/Tm2O3, respectively. Therefore, the best noise performance was observed for the gate-stack with Tm2O3 bulk high-k layer and we suggest that the interface free single-layer atomic layer deposition (ALD) fabrication scheme could explain this.
Keywords :
MOSFET; atomic layer deposition; dielectric materials; hafnium compounds; high-k dielectric thin films; semiconductor device noise; thulium compounds; HfO2; Tm2O3; TmSiO; bulk high-k dielectrics; extracted average effective oxide trap density; interface free single-layer atomic layer deposition; low-frequency noise characterization; size 0.3 nm; size 0.65 nm; size 1.2 nm; ultra-low equivalent-oxide-thickness thulium silicate interfacial layer nMOSFET; Dielectrics; Hafnium compounds; High K dielectric materials; Logic gates; Low-frequency noise; MOSFET; CMOS; Low-frequency noise; high- $k$; interfacial layer (IL); oxide trap density; thulium silicate (TmSiO);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2015.2494678
