Electron spin resonance study of interface defects in atomic layer deposited hafnium oxide on Si

Kang, Ai-Guo; Lenahan, P. M.; Conley, John F.; Solanki, R.

doi:10.1063/1.1494123

Cited by 54 publications

(27 citation statements)

References 21 publications

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“…However, the peak locations in the band-gap are not precisely the energies expected for P b0 centers [1,2,10]. This is consistent with several electron spin resonance studies which have shown that interface defects in Si/SiO 2 /HfO 2 gate stacks are very similar but not quite identical to the Si/SiO 2 P b0 centers [11][12][13]. Thus, it is reasonable to assume that interface defects in the HfO 2 based gate stack will have a different density of states distribution.…”

Section: The Second Bulk Trap Effect Is Due To Trapped Charge Inducedsupporting

confidence: 86%

Spectroscopic charge pumping in the presence of high densities of bulk dielectric traps

Ryan

Southwick

Campbell

et al. 2012

2012 IEEE International Reliability Physics Symposium (IRPS)

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We demonstrate the extension of the recently developed spectroscopic charge-pumping (CP) technique to high-k gate stacks. To deal with the high density of bulk traps, we develop an experimentally based methodology to remove the bulk trap contribution from the measured CP data. We demonstrate the capability of the spectroscopic CP technique to measure band edge states and show that the traditional U-shaped continuum of band edge states is not intrinsic to Si/SiO 2 interfaces.

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Section: The Second Bulk Trap Effect Is Due To Trapped Charge Inducedsupporting

confidence: 86%

Spectroscopic charge pumping in the presence of high densities of bulk dielectric traps

Ryan

Southwick

Campbell

et al. 2012

2012 IEEE International Reliability Physics Symposium (IRPS)

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“…9 This feature can be reduced by a forming gas anneal at 400°C. 5,7 A profile of the density of states ͑DOS͒ across the full energy gap for a hydrogen free interface of Au/HfO 2 /Si(100) structures reveal an interface state profile very similar to that measured for the hydrogen-free thermally oxidized Si(100)/SiO 2 system, but with a factor of two to three increase in defect density. 10 The purpose of this article is to build on these previous publications, with the aim of investigating if the frequency dependent kink commonly observed in the capacitancevoltage characteristics of high-MOS structures can be linked to the density of P b centers measured by ESR, with a view to providing atomic identification for the defects responsible for the observed atypical CV effects.…”

mentioning

confidence: 77%

“…2 In relation to the electrical activity of the interface defects in the Si͑100͒/high-system, it has been reported that capacitance-voltage ͑CV͒ characteristics have a nonideal behavior, with a frequency-dependent feature in the region between accumulation and strong inversion for ZrO 2 and HfO 2 MOS structures. [5][6][7][8][9] Modeling of the CV characteristics of this frequencydependent feature over n-type silicon, reveals a peak at 0.82 eV from the valence band edge, whose capture cross-section and location are independent of measurement frequency. 9 This feature can be reduced by a forming gas anneal at 400°C.…”

mentioning

confidence: 99%

Interface States and P[sub b] Defects at the Si(100)/HfO[sub 2] Interface

Hurley

O’Sullivan

Afanasʼev

et al. 2005

Electrochem. Solid-State Lett.

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Defects present at the Si(100)/HfO 2 interface are analyzed using a combination of electron spin resonance ͑ESR͒ and frequencydependent impedance analysis. The 3.4 nm HfO 2 layers were formed by injection metalorganic chemical vapor deposition on boron-doped silicon ͑100͒ substrates. ESR spectra indicate the presence of P b0 defects ((5.0 Ϯ 0.4) ϫ 10 12 cm Ϫ2 ), while analysis of the low-frequency ͑20 Hz͒ capacitance-voltage ͑CV͒ response indicates a defect density of (5.8 Ϯ 1.1) ϫ 10 12 cm Ϫ2 , between 0.1 and 0.56 eV above the valence bandedge (E v ), with the peak density located at E v ϩ 0.28 eV. Analysis of conductance data reveals an interface state density of (8.4 Ϯ 2.1) ϫ 10 12 cm Ϫ2 , with a peak density observed at E v ϩ 0.27 eV. These results provide a link between the density of P b centers measured by ESR, and the electrical active defects measured from CV and conductance analysis. This provides an explanation for the nonideal, frequency-dependent features in the region between accumulation and strong inversion for high-MOS structures.One of the major challenges associated with the continued scaling of silicon based metal oxide silicon ͑MOS͒ technology is the requirement for high dielectric constant ͑high-͒ materials to replace SiO 2 as the gate layer of MOS field-effect transistors ͑MOSFETs͒. High-materials research is driven by the need to reduce gate insulator leakage current densities while maintaining the capacitance per unit area of the gate stack. A wide range of metal oxides are currently being studied, including ZrO 2 , HfO 2 , Al 2 O 3 , Pr 2 O 3 as well as metal silicates and aluminates. 1 The understanding and control of the properties of the interface between silicon and the high-material is one of the most important issues for the successful integration of high-films as the gate oxide layer of MOSFETs.Previous studies based on electron spin resonance ͑ESR͒ have established that for Al 2 O 3 and ZrO 2 layers deposited on silicon by atomic layer chemical vapor deposition ͑ALCVD͒, the dominant ESR active interface defects are the P b silicon dangling bond defects 2 detected at the Si͑100͒/insulator interface. 3,4 The density of the P b0 and P b1 centers were characteristic of an SiO 2 film grown at a low temperature (ϳ300°C). It was necessary to expose the samples to UV irradiation at 8.48 eV for photodissociation of hydrogen from the interface defects, to observe the P b centers. An ESR analysis of HfO 2 films deposited on Si͑111͒ by ALCVD using a Hf(NO 3 ) 4 precursor, also indicated an interface dominated by silicon dangling bond centers, albeit with some dissimilarities as compared to the standard high-temperature Si(111)/SiO 2 interface, 5 as outlined previously. 2 In relation to the electrical activity of the interface defects in the Si͑100͒/high-system, it has been reported that capacitance-voltage ͑CV͒ characteristics have a nonideal behavior, with a frequency-dependent feature in the region between accumulation and strong inversion for ZrO 2 and HfO 2 MOS structures. 5-9 Modeling ...

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“…This hump, together with the stretch-out of the C±V curves, has been observed in HfO 2 and ZrO 2 films on silicon, [31,32] and arises from the capacitive response of fast interface states, in particular dangling Si bonds, i.e., P b centers. [33,34] Forming gas annealing is known to passivate dangling bonds, [35] thereby reducing the interface state density. Indeed, the hump vanished, and the slope of the C±V curves around the flat-band voltage increased significantly, after a forming gas anneal at 400 C (Fig.…”

Section: Dielectric Propertiesmentioning

confidence: 99%

Atomic Layer Deposition of Hafnium Dioxide Films from Hafnium Hydroxylamide and Water

Kukli

Ritala

Leskelä

et al. 2004

Chemical Vapor Deposition

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HfO 2 films were grown by atomic layer deposition (ALD) from a new liquid precursor, Hf(ONEt 2 ) 4 and H 2 O, at temperatures between 250 C and 350 C on borosilicate glass and Si(100) substrates. The highest growth rate was achieved at 300 C, whereas the growth was essentially slower at 250 C and ceased at 350 C. The films possessed an O:Hf ratio of 2.15 ± 0.12, as determined by ion beam analysis. The films were weakly crystallized, showing X-ray diffraction (XRD) peaks characteristic of monoclinic phase. The refractive index of the films varied between 1.93 and 1.96. The effective permittivities of the dielectric layers in Al/HfO 2 /n-Si(100) capacitor structures were close to 10.

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Electron spin resonance study of interface defects in atomic layer deposited hafnium oxide on Si

Cited by 54 publications

References 21 publications

Spectroscopic charge pumping in the presence of high densities of bulk dielectric traps

Spectroscopic charge pumping in the presence of high densities of bulk dielectric traps

Interface States and P[sub b] Defects at the Si(100)/HfO[sub 2] Interface

Atomic Layer Deposition of Hafnium Dioxide Films from Hafnium Hydroxylamide and Water

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