Compatibility of polycrystalline silicon gate deposition with HfO2 and Al2O3/HfO2 gate dielectrics

Gilmer, D. C.; Hegde, Rama I.; Cotton, R.; Garcia, R. D. M.; Dhandapani, V.; Triyoso, Dina H.; Roan, D.; Franke, Alexander; Rai, R.; Prabhu, L.; Hobbs, C.; Grant, John M.; La, L.B.; Samavedam, S.; Taylor, B.; Tseng, Hsing‐Huang; Tobin, Philip J.

doi:10.1063/1.1499514

Cited by 78 publications

(32 citation statements)

References 7 publications

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“…[11±14] In the case of CVD, oxygen-containing chemicals such as b-diketonates, [15] hafnium nitrate, [16] hafnium tert-butoxide, [8,9] and mononuclear alkoxide complexes such as Hf(O t Bu) 2 (mmp) 2 , and Hf(mmp) 4 (mmp = 1-methoxy-2-methyl-2-propanolate, OCMe 2 -CH 2 OMe), [10,17,18] can be regarded as the most common class of the metal precursors. In the case of ALD, halide precursors have been used.…”

Section: Introductionmentioning

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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Section: Introductionmentioning

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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“…12,13 Van Dover and co-workers have reported Zr 0.62 Al 0.38 O 1.8 thin film in which the crystallinity starts to appear at 850°C. 14 Accommodation of Al 2 O 3 layer with HfO 2 films in order to increase the interfacial stability with Si has been reported recently, 8,9 and some thermal stability studies on Hf-Al-O films have also been reported recently. 15 Electrical properties such as electron trapping and band alignment in amorphous Hf-Al-O have also been reported.…”

mentioning

confidence: 99%

Growth and characterization of Hf–aluminate high-k gate dielectric ultrathin films with equivalent oxide thickness less than 10 Å

Lee

Wong

Chan

et al. 2003

Journal of Applied Physics

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Ultrathin amorphous Hf-aluminate ͑Hf-Al-O͒ films have been deposited on p-type ͑100͒ Si substrates by pulsed-laser deposition using a composite target containing HfO 2 and Al 2 O 3 plates. Transmission electron microscopy observation of Hf-Al-O films showed that the amorphous structure of Hf-Al-O films was stable under rapid thermal annealing at temperatures up to at least 1000°C. Capacitance-voltage measurement of a 38 Å Hf-Al-O film revealed that the relative permittivity of the film was about 16. Such a film showed very low leakage current density of 4.6ϫ10 Ϫ3 A/cm 2 at 1 V gate bias. The Hf-Al-O film under optimized condition did not show any significant interfacial layer at the interface and an equivalent oxide thickness of less than 10 Å has been achieved. The formation of Hf-O and Al-O bonds in the film was revealed by x-ray photoelectron spectroscopy. © 2003 American Institute of Physics. ͓DOI: 10.1063/1.1554764͔A gate dielectric with a relative permittivity higher than that of SiO 2 is required to meet the next generation complementary metal-oxide-semiconductor ͑MOS͒ technology requirement. [1][2][3] Recent publications show that HfO 2 and ZrO 2 as well as their silicates are becoming leading candidates for high-k gate dielectric application due to their thermodynamic stability in contact with Si. 4 -9 However, due to the weakness as an oxygen diffusion barrier of HfO 2 and ZrO 2 , formation of interfacial SiO 2 rich layer in contact with Si substrate or polysilicon gate material is still a problem affecting the application. Formation of silicide at the interface without oxygen is another serious problem.Al 2 O 3 is a well-known good oxygen diffusion barrier that may protect the Si surface from oxidation, 10,11 and Al 2 O 3 is thermodynamically stable in contact with Si. Similar to SiO 2 , Al 2 O 3 is also a good glass former; thus, if alloyed with ZrO 2 and HfO 2 , their amorphous structure can be stabilized during high temperature annealing. 12,13 In addition, Al 2 O 3 has a large band gap ͑8.8 eV͒ and large band offset with Si. To take advantage of both HfO 2 and Al 2 O 3 , it is desirable to make multicomponent MAl x O y ͑MϭHf, Zr͒ films with high dielectric constant that are thermodynamically stable in contact with Si. Recent results on aluminates of Zr ͑Zr-Al-O͒ indicate that such material system exhibits encouraging gate dielectric properties. 12,13 Van Dover and co-workers have reported Zr 0.62 Al 0.38 O 1.8 thin film in which the crystallinity starts to appear at 850°C. 14 Accommodation of Al 2 O 3 layer with HfO 2 films in order to increase the interfacial stability with Si has been reported recently, 8,9 and some thermal stability studies on Hf-Al-O films have also been reported recently. 15 Electrical properties such as electron trapping and band alignment in amorphous Hf-Al-O have also been reported. 16,17 However, the understanding of thermodynamic stability and interfacial structure of the Hf-Al-O thin film is still limited. In this article we report the synthesis and characterization of ...

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“…A convenient approach for depositing such films ͑oxides and mixed oxides͒ is the atomic layer deposition ͑ALD͒ technique, where self-saturating surface chemical reactions are employed. This approach 5,6 has been successfully applied to control chemical reactions at the Si/ high-k and high-k / gate electrode interfaces, as well as to obtain ͑HfO 2 ͒ x ͑Al 2 O 3 ͒ 1−x structures retaining sufficiently high dielectric constant and remaining amorphous up to high processing temperatures. Metastable defect configurations owing to the low-temperature film deposition process can be suppressed by postdeposition annealing.…”

mentioning

confidence: 99%

“…[3][4][5] A good tradeoff between the characteristics of these two materials 1, [6][7][8][9][10][11] can be achieved by forming ͑HfO 2 ͒ x ͑Al 2 O 3 ͒ 1−x mixed oxides, either homogeneous in composition or in nanolaminated structures. A convenient approach for depositing such films ͑oxides and mixed oxides͒ is the atomic layer deposition ͑ALD͒ technique, where self-saturating surface chemical reactions are employed.…”

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confidence: 99%

Compositional stability of hafnium aluminates thin films deposited on Si by atomic layer deposition

et al. 2005

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Compatibility of polycrystalline silicon gate deposition with HfO2 and Al2O3/HfO2 gate dielectrics

Cited by 78 publications

References 7 publications

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

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

Growth and characterization of Hf–aluminate high-k gate dielectric ultrathin films with equivalent oxide thickness less than 10 Å

Compositional stability of hafnium aluminates thin films deposited on Si by atomic layer deposition

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