Complete prevention of reaction at HfO2/Si interfaces by 1nm silicon nitride layer

Kobayashi, Hikaru; Imamura, Kentaro; Fukayama, Kenichi; Im, Seong-kyun; Maida, Osamu; Kim, Young‐Bae; Kim, Hyun-Chul; Choi, Duck–Kyun

doi:10.1016/j.susc.2008.03.031

Cited by 17 publications

(12 citation statements)

References 39 publications

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“…For example, HfO 2 sputter deposited onto Si can lead to hafnium silicide species. 21 Post-deposition annealing of this type of interface (in a nonoxidizing environment) yields the thermodynamically favored HfO 2 and SiO 2 species at the interface. HfO 2 and SiO 2 are also known to form a pseudo-binary oxide of (HfO 2 ) x (SiO 2 ) 1Àx , and thus inter-diffusion can lead to a stable mixed composition.…”

Section: Resultsmentioning

confidence: 99%

“…HfO 2 and SiO 2 are also known to form a pseudo-binary oxide of (HfO 2 ) x (SiO 2 ) 1Àx , and thus inter-diffusion can lead to a stable mixed composition. 21 As the ternary phase diagrams of HfO 2 with the metals used in this experiment (e.g., Cu-Hf-O, Pt-Hf-O, W-Hf-O, and Cr-Hf-O) are not well studied, it is uncertain whether binary oxides would be thermodynamically stable at the HfO 2 /metal interface after annealing. It is known that a Hf-Al-O binary oxide is stable; however, post-deposition annealing is often required in order to achieve a homogeneous film.…”

Section: Resultsmentioning

confidence: 99%

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Effects of interfacial oxide layers of the electrode metals on the electrical characteristics of organic thin-film transistors with HfO2 gate dielectric

Tang

Greiner

Helander

et al. 2011

Journal of Applied Physics

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Articles you may be interested inAtomic layer deposition grown metal-insulator-metal capacitors with RuO 2 electrodes and Al-doped rutile TiO 2 dielectric layer J. Vac. Sci. Technol. B 29, 01AC09 (2011); 10.1116/1.3534023 Electrode effects on the conduction mechanisms in HfO 2 -based metal-insulator-metal capacitors Characteristics of metal-insulator-semiconductor capacitors based on high-k HfAlO dielectric films obtained by low-temperature electron-beam gun evaporation Appl. Phys. Lett. 85, 5950 (2004); 10.1063/1.1836875Metal-insulator-metal capacitors using Y 2 O 3 dielectric grown by pulsed-injection plasma enhanced metalorganic chemical vapor deposition HfO 2 -based devices employing various electrode metals (Al, W, Pt, Cu, and Cr) were fabricated and characterized in order to examine the importance of the choice of metal electrode when sputter-depositing HfO 2 films. It was found that metal-insulator-metal capacitors with an Al bottom electrode exhibit a significantly smaller leakage current and a larger breakdown field strength than devices using W, Pt, Cu, and Cr electrodes. By examining HfO 2 /metal interfaces with x-ray photoelectron spectroscopy, it was found that metal electrodes are oxidized during the deposition of HfO 2 , resulting in interfacial oxide layers of the electrode metals (Al 2 O 3 , WO 3 , PtO, CuO, and Cr 2 O 3 þ CrO 3 ) between the metal electrode and the HfO 2 layer. The formation of a metal oxide interlayer is a consequence of the high-energy oxygen ions generated during HfO 2 sputtering. The difference in the device performance was attributed to the electronic properties of the oxide interlayers. It was found that when the oxide interlayers are semiconducting (e.g., WO 3 , PtO, CuO, or Cr 2 O 3 þ CrO 3 ), devices have high leakage currents and low breakdown field strengths, and an insulating oxide interlayer (Al 2 O 3 ) enhances these device characteristics. Organic thin-film transistors (OTFTs) using a HfO 2 dielectric layer showed that an Al gate has a much lower offstate current, larger on/off ratio, and smaller sub-threshold slope compared with OTFTs using a Cr electrode. These results demonstrate the importance of the metal gate electrode and the electrical characteristics of its oxide when using the sputter-deposition of HfO 2 to fabricate thin-film transistors.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Effects of interfacial oxide layers of the electrode metals on the electrical characteristics of organic thin-film transistors with HfO2 gate dielectric

Tang

Greiner

Helander

et al. 2011

Journal of Applied Physics

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“…Because leakage current flows via interface states, the silicate formation also resulted in a decrease in leakage current. 54 Therefore, a thin silicate IL is important for suppressing the leakage current. Low leakage current density was also attributed to the high band gap of SiO 2 , which formed a high band offset that reduced electrical conduction.…”

Section: Resultsmentioning

confidence: 99%

The impact of atomic layer deposited SiO₂passivation for high-k Ta_1−xZr_xO on the InP substrate

Mahata

Yoon

et al. 2015

J. Mater. Chem. C

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Metal-oxide-semiconductor (MOS) capacitors with an amorphous Ta 1Àx Zr x O composite gate dielectric film and a SiO 2 passivation layer were fabricated on an indium phosphide (InP) substrate. To investigate the impact of the passivation layer, the interfacial chemical, physical and electrical properties of the Ta 1Àx Zr x O/InP and Ta 1Àx Zr x O/SiO 2 /InP MOS structures were studied in detail. Electrical conductivity measurements combined with chemical bonding analysis using X-ray photoelectron spectroscopy (XPS) and electron dispersive spectroscopy (EDS) were conducted in order to evaluate the suitability of a Ta 1Àx Zr x O alloy as a gate dielectric film for an InP substrate. XPS results showed that the Ta 1Àx Zr x O film retained its insulating characteristics and was thermally stable even after annealing at 500 1C. However, Fermi-level pinning and significant diffusion of indium through the Ta 1Àx Zr x O were observed. The diffusion of In was remarkably reduced after introducing the SiO 2 passivation layer, which resulted in an overall reduction in interfacial layer thickness. Parallel conductance contour measurements showed that the SiO 2 passivation layer resulted in unpinning of the Fermi-level. The introduction of a SiO 2 passivation layer with the Ta 1Àx Zr x O composite gate dielectric film was found to provide remarkably improved dielectric performance, which was mainly attributed to reduced In diffusion and the passivation of interfacial and bulk dielectric defects.

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“…Correction curves thus obtained for He ions at energies of 50, 100 and 200 keV scattered through 70.5° (i.e. [- [1][2][3][4][5][6][7][8][9][10][11] in, [111] out) are shown in Figure 1 as a function of Z. It shows that this correction is both mass and energy dependent, as expected, as the energy after scattering depends on the target atomic mass.…”

Section: Quantitative Meis Analysismentioning

confidence: 99%

High Depth Resolution Depth Profile Analysis of Ultra Thin High-κ Hf Based Films using MEIS Compared with XTEM, XRF, SE and XPS

et al. 2009

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Nanometre thin high-k hafnium oxide (HfO 2 ) or Hf silicate layers combined with a sub-nm SiO 2 layers have become Si compatible gate dielectrics. Medium energy ion scattering (MEIS) analysis has been applied to a range of such MOCVD grown HfO 2 /SiO 2 and HfSiOx(60%Hf)/SiO 2 gate oxide films of thickness between 1 and 2 nm on top of Si(100), before and after decoupled plasma nitridation (DPN). MEIS in combination with energy spectrum simulation provides quantitative layer information with sub-nm resolution on these layer structures and their atomic composition that is in excellent agreement with a) the as grown layer parameters and b) results obtained from techniques, such as SE, XPS, XRF and XTEM. MEIS analysis of a metal gate, high-k TiN/Al 2 O 3 /HfO 2 /SiO 2 /Si stack shows the interdiffusion, after thermal treatment, of Hf and Al from the caplayer, which was inserted to modify the metal gate work function.

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Complete prevention of reaction at HfO2/Si interfaces by 1nm silicon nitride layer

Cited by 17 publications

References 39 publications

Effects of interfacial oxide layers of the electrode metals on the electrical characteristics of organic thin-film transistors with HfO2 gate dielectric

Effects of interfacial oxide layers of the electrode metals on the electrical characteristics of organic thin-film transistors with HfO2 gate dielectric

The impact of atomic layer deposited SiO₂passivation for high-k Ta_1−xZr_xO on the InP substrate

High Depth Resolution Depth Profile Analysis of Ultra Thin High-κ Hf Based Films using MEIS Compared with XTEM, XRF, SE and XPS

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Complete prevention of reaction at HfO2/Si interfaces by 1nm silicon nitride layer

Cited by 17 publications

References 39 publications

Effects of interfacial oxide layers of the electrode metals on the electrical characteristics of organic thin-film transistors with HfO2 gate dielectric

Effects of interfacial oxide layers of the electrode metals on the electrical characteristics of organic thin-film transistors with HfO2 gate dielectric

The impact of atomic layer deposited SiO2passivation for high-k Ta1−xZrxO on the InP substrate

High Depth Resolution Depth Profile Analysis of Ultra Thin High-κ Hf Based Films using MEIS Compared with XTEM, XRF, SE and XPS

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The impact of atomic layer deposited SiO₂passivation for high-k Ta_1−xZr_xO on the InP substrate