Thermal phase separation of ZrSiO4 thin films and frequency-dependent electrical characteristics of the Al/ZrSiO4/p-Si/Al MOS capacitors
Yükleniyor...
Dosyalar
Tarih
2018
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Iop Publishing Ltd
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this work, the thermal phase separation and annealing optimization of ZrSiO4 thin films have been carried out. Following annealing optimization, the frequency-dependent electrical characteristics of the Al/ZrSiO4/p-Si/Al MOS capacitors were investigated in detail. The chemical evolution of the films under various annealing temperatures was determined by Fourier transform infrared spectroscopy (FTIR) measurements. The phase separation was determined by x-ray diffraction (XRD) measurements. The electrical parameters were determined via the capacitance-voltage (C-V), conductance-voltage (G/omega) and leakage-current-voltage (Ig-Vg). The results demonstrate that zirconium silicate formations are present at 1000 degrees C annealing with the SiO2 interfacial layer. The film was in amorphous form after annealing at 250 degrees C. The tetragonal phases of ZrO2 were obtained after annealing at 500 degrees C. When the temperature approaches 750 degrees C, transitions from the tetragonal phase to the monoclinic phase were observed. The obtained XRD peaks after 1000 degrees C annealing matched the crystalline peaks of ZrSiO4. This means that the crystalline zirconium dioxide in the structure has been converted into a crystalline silicate phase. The interface states increased to 5.71 x 10(10) and the number of border traps decreased to 7.18 x 10(10) cm(-2) with the increasing temperature. These results indicate that an excellent ZrSiO4/Si interface has been fabricated. The order of the leakage current varied from 10(-9) Acm(-2) to 10(-6) Acm(-2). The MOS capacitor fabricated with the films annealed at 1000 degrees C shows better behavior in terms of its structural, chemical and electrical properties. Hence, detailed frequency-dependent electrical characteristics were performed for the ZrSiO4 thin film annealed at 1000 degrees C. Very slight capacitance variations were observed under the frequency variations. This shows that the density of frequency-dependent charges is very low at the ZrSiO4/Si interface. The barrier height of the device varies slightly from 0.776 eV to 0.827 eV under frequency dispersion. Briefly, it is concluded that the devices annealed at 1000 degrees C exhibit promising electrical characteristics.
Açıklama
Anahtar Kelimeler
ZrSiO4 MOS Capacitors, High-k, Barrier Height, Electrical Characteristics, Interface States, Border Traps
Kaynak
Semiconductor Science And Technology
WoS Q Değeri
Q2
Scopus Q Değeri
Q2
Cilt
33
Sayı
5
