Characterization and electrical properties of high-k GdScO3 thin films grown by atomic layer deposition

Capacitance of metal-insulator-Si structures containing high permittivity dielectric exhibits complicated behaviour when voltage and frequency dependencies are studied. From our study on metal (Al, Au, W)-Ta 2 O 5 /SiO 2 -Si structures, we identify serial C-R measurement mode to be more convenient for use than the parallel one usually used in characterization of similar structures. Strong frequency dependence that is not due to real variations in the dielectric permittivity of the layers is observed. Very high capacitance at low frequencies is due to the leakage in Ta 2 O 5 layer. We found that the above observation is mainly due to different leakage current mechanisms in the two different layers composing the stack. The effect is highly dependent on the applied voltage, since the leakage currents are strongly nonlinear functions of the electric field in the layers. Additionally, at low frequencies, transition currents influence the measured value of the capacitance. From the capacitance measurements several parameters are extracted, such as capacitance in accumulation, effective dielectric constant, and oxide charges. Extracting parameters of the studied structures by standard methods in the case of high-/interfacial layer stacks can lead to substantial errors. Some cases demonstrating these deficiencies of the methods are presented and solutions for obtaining better results are proposed.

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“…The situation is similar to most of the other high-dielectrics: TiO 2 , HfO 2 [11], LaScO 3 [12], GdScO 3 [13], Er 2 O 3 [14], and so forth.…”

Section: Introductionsupporting

confidence: 63%

Frequency Dependence of C-V Characteristics of MOS Capacitors Containing Nanosized High-κ Ta₂O₅ Dielectrics

Novkovski¹,

Atanassova²

2017

Advances in Materials Science and Engineering

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“…Among them are cerium oxide CeO 2 [16-23], cerium zirconate CeZrO 4 [24], gadolinium oxide Gd 2 O 3 [25-27], erbium oxide Er 2 O 3 [28,29], neodymium oxide Nd 2 O 3 [30,31], aluminum oxide Al 2 O 3 [32,33], lanthanum aluminum oxide LaAlO 3 [34,35], lanthanum oxide La 2 O 3 [36], yttrium oxide Y 2 O 3 [37], tantalum pentoxide Ta 2 O 5 [38], titanium dioxide TiO 2 [39], zirconium dioxide ZrO 2 [40,41], lanthanum-doped zirconium oxide La x Zr 1 −x O 2 −δ [42,43], hafnium oxide HfO 2 [44], HfO 2 -based oxides La 2 Hf 2 O 7 [45], Ce x Hf 1-x O 2 [46], hafnium silicate HfSi x O y [47], and rare-earth scandates LaScO 3 [48], GdScO 3 [49], DyScO 3 [50], and SmScO 3 [51]. Among them, HfO 2 , HfO 2 -based materials, ZrO 2 , and ZrO 2 -based materials are considered as the most promising candidates combining high dielectric permittivity and thermal stability with low leakage current due to a reasonably high barrier height that limits electron tunneling.…”

Section: Reviewmentioning

confidence: 99%

Dielectric relaxation of high-k oxides

Zhao

Werner

et al. 2013

Nanoscale Res Lett

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Frequency dispersion of high-k dielectrics was observed and classified into two parts: extrinsic cause and intrinsic cause. Frequency dependence of dielectric constant (dielectric relaxation), that is the intrinsic frequency dispersion, could not be characterized before considering the effects of extrinsic frequency dispersion. Several mathematical models were discussed to describe the dielectric relaxation of high-k dielectrics. For the physical mechanism, dielectric relaxation was found to be related to the degree of polarization, which depended on the structure of the high-k material. It was attributed to the enhancement of the correlations among polar nanodomain. The effect of grain size for the high-k materials' structure mainly originated from higher surface stress in smaller grain due to its higher concentration of grain boundary.

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“…show superior electrical properties including suitable band offsets to silicon and κ-values typically above 20 [2,3]. Recently, also the deposition of high quality rare earth scandate films (YScO 3 [4], GdScO 3 [5,6]) with atomic layer deposition (ALD) as the favorite deposition method for industrial use has been demonstrated. Another member of the rare earth based ternary oxides -lanthanum lutetium oxide (LaLuO 3 ) -shows as good electrical behavior as the scandates but an even higher dielectric constant of 32 for films deposited by pulsed laser deposition (PLD) [7].…”

Section: Introductionmentioning

confidence: 99%

Characterization of lanthanum lutetium oxide thin films grown by atomic layer deposition as an alternative gate dielectric

et al. 2008

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Characterization and electrical properties of high-k GdScO3 thin films grown by atomic layer deposition

Cited by 29 publications

References 26 publications

Frequency Dependence of C-V Characteristics of MOS Capacitors Containing Nanosized High-κ Ta₂O₅ Dielectrics

Frequency Dependence of C-V Characteristics of MOS Capacitors Containing Nanosized High-κ Ta₂O₅ Dielectrics

Dielectric relaxation of high-k oxides

Characterization of lanthanum lutetium oxide thin films grown by atomic layer deposition as an alternative gate dielectric

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Characterization and electrical properties of high-k GdScO3 thin films grown by atomic layer deposition

Cited by 29 publications

References 26 publications

Frequency Dependence of C-V Characteristics of MOS Capacitors Containing Nanosized High-κ Ta2O5 Dielectrics

Frequency Dependence of C-V Characteristics of MOS Capacitors Containing Nanosized High-κ Ta2O5 Dielectrics

Dielectric relaxation of high-k oxides

Characterization of lanthanum lutetium oxide thin films grown by atomic layer deposition as an alternative gate dielectric

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Product

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Frequency Dependence of C-V Characteristics of MOS Capacitors Containing Nanosized High-κ Ta₂O₅ Dielectrics

Frequency Dependence of C-V Characteristics of MOS Capacitors Containing Nanosized High-κ Ta₂O₅ Dielectrics