Structural phase transformation of Y2O3 doped HfO2 films grown on Si using atomic layer deposition

Majumder, Prodyut; Jursich, Gregory; Takoudis, Christos G.

doi:10.1063/1.3132830

Cited by 38 publications

(22 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From the device application point of view, these latter phases are preferable to the monoclinic one. It was demonstrated both theoretically [5][6][7] and experimentally [8][9][10] that the incorporation of cationic dopants in the HfO 2 matrix favors the formation and the stabilization of the tetragonal or cubic phase. At the same time, the dopants have to be chosen to avoid a significant decrease of the band gap energy and dielectric constant of the high-k materials.…”

Section: Introductionmentioning

confidence: 99%

Thermal stability of high-kSi-rich HfO₂layers grown by RF magnetron sputtering

Khomenkova¹,

Portier

Cardin

et al. 2010

Nanotechnology

View full text Add to dashboard Cite

The microstructure and optical properties of HfSiO films fabricated by RF magnetron sputtering were studied by means of x-ray diffraction, transmission electron microscopy, spectroscopic ellipsometry and attenuated total reflection infrared spectroscopy versus annealing treatment. It was shown that silicon incorporation in the HfO(2) matrix plays an important role in the structure stability of the layers. Thus, the increase of the annealing temperature up to 1000 degrees C did not lead to the crystallization of the films. The evolution of the chemical composition as well as a decrease of the density of the films was attributed to the phase separation of HfSiO on HfO(2) and SiO(2) phases in the film. An annealing at 1000-1100 degrees C results in the formation of the multilayer Si-rich/Hf-rich structure and was explained by a surface-directed spinodal decomposition. The formation of the stable tetragonal structure of HfO(2) phase was shown upon annealing treatment at 1100 degrees C.

show abstract

Section: Introductionmentioning

confidence: 99%

Thermal stability of high-kSi-rich HfO₂layers grown by RF magnetron sputtering

Khomenkova¹,

Portier

Cardin

et al. 2010

Nanotechnology

View full text Add to dashboard Cite

show abstract

“…Our earlier ALD studies with other homoleptic metal precursors having the diethylamino ligand, such as TDEAH and tris ͑diethylamino͒ aluminum, have resulted in broad ALD temperature windows and rather high growth rates. 9,11,17,18 Such results have prompted interest in examining the suitability of tetrakis ͑diethylamino͒ titanium ͑TDEAT͒ as a precursor for the ALD of TiO 2 and Hf x Ti 1−x O 2 and in studying processstructure-property relationships of the resulting thin films.In previous studies, Hf x Ti 1−x O 2 films were mainly grown with physical or chemical vapor deposition. For instance, Rhee et al 19 studied a HfO 2 /TiO 2 bilayer structure formed by sputtering, and the resulted HfO 2 /TiO 2 transistor had a value of 36 with equivalent oxide thickness ͑EOT͒ of 0.8 nm.…”

mentioning

confidence: 97%

Atomic Layer Deposition of HfO[sub 2], TiO[sub 2], and Hf[sub x]Ti[sub 1−x]O[sub 2] Using Metal (Diethylamino) Precursors and H[sub 2]O

Tao¹,

Kueltzo²,

Singh³

et al. 2011

J. Electrochem. Soc.

Self Cite

View full text Add to dashboard Cite

Tetrakis ͑diethylamino͒ hafnium ͑TDEAH͒, tetrakis ͑diethylamino͒ titanium ͑TDEAT͒, and H 2 O were used for the atomic layer deposition ͑ALD͒ of HfO 2 , TiO 2 , and Hf x Ti 1−x O 2 films on silicon substrates. The ALD temperature windows were found to be 175-250°C for HfO 2 ͑0.12 nm/cycle͒ and 150-250°C for TiO 2 ͑ ϳ0.06 nm/cycle͒. The 175-250°C overlap region is ideal for the ALD of the Hf x Ti 1−x O 2 films. Different compositions of Hf x Ti 1−x O 2 were obtained by varying the ͓TDEAH/H 2 O͔/͓TDEAT/H 2 O͔ cycle ratios, and excellent tunability of film composition was found using X-ray photoelectron spectroscopy ͑XPS͒. The Hf x Ti 1−x O 2 deposition rate was found to be the superposition of the two individual growth rates. Both as-deposited and postdeposition annealed films were studied with XPS, phase shift interferometry, and grazing incidence X-ray diffraction. As-deposited HfO 2 and TiO 2 films were found to be amorphous, and they began to crystallize after annealing at 600°C in the monoclinic phase ͑HfO 2 ͒ and in weak anatase phase ͑TiO 2 ͒. The Hf x Ti 1−x O 2 films remained amorphous after annealing up to about 1000°C in N 2 for 5 min.Structural and interfacial studies of ultrathin, high dielectric constant ͑͒ films during high temperature fabrication processes are critical to the continuous scaling of microelectronic devices. In particular, these materials are of great importance for the gate insulator of metal oxide semiconductor field effect transistors and the capacitor dielectric of dynamic random access memories. 1,2 So far, many candidate materials such as have been studied for the replacement of SiO 2 . 3 From all these materials, HfO 2 and TiO 2 seem to be promising candidates due to their favorable properties. HfO 2 is known to have relatively good thermal stability and compatibility with the Si substrate, and it has a dielectric constant of 15-30 with a large bandgap ͑5.7 eV͒. 4-6 TiO 2 is even more favorable in terms of its dielectric constant which is 80 or higher; 7 however, it has a rather small bandgap ͑3.1 eV͒, 8 which could result in more leakage current than that of HfO 2 . The reported crystallization temperature of each of these two materials has been reported to be as low as ϳ550°C. 9,10The earliest atomic layer deposition ͑ALD͒ of HfO 2 from tetrakis ͑diethylamino͒ hafnium ͑TDEAH͒ and H 2 O was published by Deshpande et al. with a growth rate of ϳ0.13 nm/cycle at 300°C. 11 Titanium tetrachloride ͑TiCl 4 ͒ and titanium isopropoxide ͑TTIP͒ have typically been used as metal precursors in the ALD of TiO 2 films, with water being the oxidant. 12-16 Growth rates of 0.03 nm/cycle or lower in these systems were reported. Our earlier ALD studies with other homoleptic metal precursors having the diethylamino ligand, such as TDEAH and tris ͑diethylamino͒ aluminum, have resulted in broad ALD temperature windows and rather high growth rates. 9,11,17,18 Such results have prompted interest in examining the suitability of tetrakis ͑diethylamino͒ titanium ͑TDEAT͒ as a precursor for the ALD of TiO 2 ...

show abstract

“…These results are for e-beam deposited samples, and it is anticipated that similar observations would be found for atomic layer deposited films. [26][27][28] FIG. 8.…”

Section: Discussionmentioning

confidence: 97%

Leakage current and structural analysis of annealed HfO2/La2O3 and CeO2/La2O3 dielectric stacks: A nanoscopic study

Shubhakar

Pey

Bosman

et al. 2014

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

View full text Add to dashboard Cite

Grain boundaries in the polycrystalline microstructure of post-annealed high-κ (HK) dielectrics are a major limitation in the reliability of HK dielectrics used for advanced CMOS technologies. Another challenge in the field of HK dielectrics is to ensure higher drain drive current in CMOS, while maintaining low leakage current. In this work, the authors demonstrate enhanced performance of HfO2 and CeO2 dielectrics by incorporating lanthanum. The resulting stacks show promising dielectric characteristics with reduced leakage current and uniform (amorphous) crystal structure. The improved HK characteristics were shown to occur even over nanometer-length scales using scanning probe microscopy and transmission electron microscopy, in agreement with previous studies based on micron-scale device-level measurement.

show abstract

Structural phase transformation of Y2O3 doped HfO2 films grown on Si using atomic layer deposition

Cited by 38 publications

References 19 publications

Thermal stability of high-kSi-rich HfO₂layers grown by RF magnetron sputtering

Thermal stability of high-kSi-rich HfO₂layers grown by RF magnetron sputtering

Atomic Layer Deposition of HfO[sub 2], TiO[sub 2], and Hf[sub x]Ti[sub 1−x]O[sub 2] Using Metal (Diethylamino) Precursors and H[sub 2]O

Leakage current and structural analysis of annealed HfO2/La2O3 and CeO2/La2O3 dielectric stacks: A nanoscopic study

Contact Info

Product

Resources

About

Structural phase transformation of Y2O3 doped HfO2 films grown on Si using atomic layer deposition

Cited by 38 publications

References 19 publications

Thermal stability of high-kSi-rich HfO2layers grown by RF magnetron sputtering

Thermal stability of high-kSi-rich HfO2layers grown by RF magnetron sputtering

Atomic Layer Deposition of HfO[sub 2], TiO[sub 2], and Hf[sub x]Ti[sub 1−x]O[sub 2] Using Metal (Diethylamino) Precursors and H[sub 2]O

Leakage current and structural analysis of annealed HfO2/La2O3 and CeO2/La2O3 dielectric stacks: A nanoscopic study

Contact Info

Product

Resources

About

Thermal stability of high-kSi-rich HfO₂layers grown by RF magnetron sputtering

Thermal stability of high-kSi-rich HfO₂layers grown by RF magnetron sputtering