X-ray metrology for high-k atomic layer deposited HfxZr1−xO2 films

Gallegos, Jesus J.; Triyoso, Dina H.; Raymond, M.

doi:10.1016/j.mee.2007.02.013

Cited by 10 publications

(6 citation statements)

References 11 publications

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“…The thickness of the interfacial layer between the high-k and Si is estimated from the difference in thickness values obtained by ellipsometry and XRR measurement as previously reported. 13 Figure 1b compares the thickness of interfacial layers for as-deposited and annealed films. For as-deposited films, interfacial layer thicknesses increase slightly from ϳ10 to 11 Å for HfO 2 and Hf x Zr 1−x O 2 ͑x = 0.25-0.75͒ to 12.6 Å for ZrO 2 .…”

Section: Resultsmentioning

confidence: 99%

Physical and Electrical Properties of Atomic-Layer-Deposited Hf[sub x]Zr[sub 1−x]O[sub 2] with TEMAHf, TEMAZr, and Ozone

Triyoso¹,

Gregory²,

Park

et al. 2008

J. Electrochem. Soc.

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In this work, physical and electrical characteristics of atomic-layer-deposited HfxZr1−xnormalO2 formed using tetrakis-ethyl methylaminohafnium (TEMAHf), tetrakis-ethylmethylaminozirconium (TEMAZr), and ozone are reported. Confirming Zr addition, film densities decrease with increasing Zr content. A slight increase in interfacial layer thickness is observed for ZrO2 after high-temperature annealing. All films remain smooth and void-free after high-temperature annealing. Tetragonal phase stabilization is observed with increasing Zr content. Carbon impurities are low and independent of Zr content. HfxZr1−xnormalO2 transistors and capacitors are fabricated for electrical characterization. Well-behaved capacitance–voltage characteristics are observed for all devices. Only a slight increase in gate leakage current is observed as Zr content is increased from <2% (HfO2) to ∼50% (Hf0.5Zr0.5normalO2) . HfxZr1−xnormalO2 devices have ∼50mV lower threshold voltage than HfO2 devices. High field mobilities of HfxZr1−xnormalO2 devices with 50 and 60% Zr content are higher than HfO2 or ZrO2 . All these results indicate HfxZr1−xnormalO2 is a promising dielectric for SiO2 replacement.

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Section: Resultsmentioning

confidence: 99%

Physical and Electrical Properties of Atomic-Layer-Deposited Hf[sub x]Zr[sub 1−x]O[sub 2] with TEMAHf, TEMAZr, and Ozone

Triyoso¹,

Gregory²,

Park

et al. 2008

J. Electrochem. Soc.

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“…Based on the electrical data presented here and elsewhere (5,6) we propose it is not possible for interface SiO 2 to increase significantly during the DADA process and simultaneously provide 1-2 Å lower EOT. We did, however, seek to measure the interface on a series of samples for physical analysis by using a combination of spectroscopic ellipsometry (SE) with XRR (11). In this measurement we treat the HfO 2 and the interface layer as a single dielectric stack, and allow the ellipsometer to fit the thickness of the dielectric stack and the refractive index over the spectral range using a standard HfO 2 model for the layer.…”

Section: Interface Thicknessmentioning

confidence: 99%

Physical and Electrical Effects of the Dep-Anneal-Dep-Anneal (DADA) Process for HfO₂ in High K/Metal Gate Stacks

Clark¹,

Aoyama

Consiglio

et al. 2011

ECS Trans.

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In this work we present physical and electrical characterization of HfO2 films deposited using the Dep-Anneal-Dep-Anneal (DADA) deposition scheme. Electrical results from MOSCAP devices fabricated using a low temperature (Gate Last-like) integration flow are presented. In addition we report detailed physical analyses of the films and changes in the films versus as-deposited ALD HfO2 and films undergoing a single post-deposition anneal and show the correlation between observed physical changes in the film and electrical results. Observed physical changes using HR-RBS, HR-TEM, SIMS, XPS and XRR include crystallization, densification, Si intermixing, reduction of in-film carbon and improved etch resistance leading to improved leakage vs. EOT and electrical non-uniformity. Dependence of these changes on the underlying interface layer (e.g. SiO2 vs SiON) is also described.

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“…The subtraction of SE and XRR measured thickness was used to estimate the interfacial SiO 2 thickness. 39 XRR was also performed after postmetal anneal to estimate the resultant thickness of the HfO 2 layer, Ti-based metal gate, and oxidized thickness of the top surface of the metal layer (TiO 2 ).…”

Section: Methodsmentioning

confidence: 99%

Engineering crystallinity of atomic layer deposited gate stacks containing ultrathin HfO2 and a Ti-based metal gate: Effects of postmetal gate anneal and integration schemes

Consiglio¹,

Tapily²,

Clark³

et al. 2014

Journal of Vacuum Science &Amp; Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phen

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In this study, the authors examined the effects of different annealing schemes on crystallinity in atomic layer deposition (ALD) grown Ti-containing metal gates and ultrathin ALD HfO 2 high-k dielectric layers, and corresponding electrical results in metal oxide semiconductor capacitor (MOSCAP) devices. The authors investigated the effect of a postmetal deposition anneal (PMA) on the underlying HfO 2 , which was deposited using either a standard ALD process or a process which utilized a cyclical deposition and annealing scheme (termed DADA). The effect of the starting substrate surface, either chemically grown SiO 2 or H-terminated Si, on HfO 2 crystallinity was also studied. For 40 cycle ALD HfO 2 ($32 Å ) with a TiN overlayer, a transition from an amorphous state to a cubic phase was observed with the application of a PMA treatment. Evidence of the orthorhombic phase of HfO 2 with some level of texturing was observed for 40 cycle DADA processed films annealed with a TiN cap. Concomitantly a cubic (111) texture was observed for TiN deposited on DADA processed HfO 2 and subjected to a PMA. Suppression of crystallinity for HfO 2 deposited on H-terminated Si and annealed with a TiN layer was observed which illustrates the need for an adequate nucleation layer for uniform grain growth and increased atomic ordering. The authors also investigated metal gate stacks with a bilayer of TiN overlying Ti which showed reflections from both cubic TiN and hexagonal TiN 0.3 in the as-deposited state and after annealing clear evidence of silicidation (TiSi x ) was observed. In MOSCAP structures with 40 cycle ALD HfO 2 and a TiN overlayer subjected to a PMA, although the cubic phase of HfO 2 was stabilized, there was no associated improvement in device scaling. This study highlights the importance of the initial crystalline state and nucleation of HfO 2 as well as the thermal stability of the capping metal layer material when engineering dielectric layer crystallinity by means of a postmetal cap anneal. For ultrathin HfO 2 integrated in advanced metal oxide semiconductor structures, the benefits of the stabilization of a higher-k phase through postmetal gate anneal may not be fully realized due to increased leakage along grain boundaries or decrease in effective k due to changes in the lower-k interfacial layer.

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X-ray metrology for high-k atomic layer deposited HfxZr1−xO2 films

Cited by 10 publications

References 11 publications

Physical and Electrical Properties of Atomic-Layer-Deposited Hf[sub x]Zr[sub 1−x]O[sub 2] with TEMAHf, TEMAZr, and Ozone

Physical and Electrical Properties of Atomic-Layer-Deposited Hf[sub x]Zr[sub 1−x]O[sub 2] with TEMAHf, TEMAZr, and Ozone

Physical and Electrical Effects of the Dep-Anneal-Dep-Anneal (DADA) Process for HfO₂ in High K/Metal Gate Stacks

Engineering crystallinity of atomic layer deposited gate stacks containing ultrathin HfO2 and a Ti-based metal gate: Effects of postmetal gate anneal and integration schemes

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X-ray metrology for high-k atomic layer deposited HfxZr1−xO2 films

Cited by 10 publications

References 11 publications

Physical and Electrical Properties of Atomic-Layer-Deposited Hf[sub x]Zr[sub 1−x]O[sub 2] with TEMAHf, TEMAZr, and Ozone

Physical and Electrical Properties of Atomic-Layer-Deposited Hf[sub x]Zr[sub 1−x]O[sub 2] with TEMAHf, TEMAZr, and Ozone

Physical and Electrical Effects of the Dep-Anneal-Dep-Anneal (DADA) Process for HfO2 in High K/Metal Gate Stacks

Engineering crystallinity of atomic layer deposited gate stacks containing ultrathin HfO2 and a Ti-based metal gate: Effects of postmetal gate anneal and integration schemes

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Physical and Electrical Effects of the Dep-Anneal-Dep-Anneal (DADA) Process for HfO₂ in High K/Metal Gate Stacks