Ti Source Precursors for Atomic Layer Deposition of TiO2, STO and BST

Katamreddy, Rajesh; Omarjee, Vincent; Feist, Benjamin; Dussarrat, Christian

doi:10.1149/1.2979986

Cited by 34 publications

(16 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ALD growth rates of 0.39 and 0.40 Å per cycle were observed at 200 and 250 °C, respectively. Literature indicates increased ALD growth rates for temperatures in excess of 200 °C, but we did not encounter these until ∼270 °C for our reactor configuration. We have observed significant ALD process changes even with simple system modifications, so this was not surprising.…”

Section: Methodsmentioning

confidence: 66%

Atomic Layer Deposition of Undoped TiO₂ Exhibiting p-Type Conductivity

Iancu

Logar

Park

et al. 2015

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

With prominent photocatalytic applications and widespread use in semiconductor devices, TiO2 is one of the most popular metal oxides. However, despite its popularity, it has yet to achieve its full potential due to a lack of effective methods for achieving p-type conductivity. Here, we show that undoped p-type TiO2 films can be fabricated by atomic layer deposition (ALD) and that their electrical properties can be controlled across a wide range using proper postprocessing anneals in various ambient environments. Hole mobilities larger than 400 cm(2)/(V·s) are accessible superseding the use of extrinsic doping, which generally produces orders of magnitude smaller values. Through a combination of analyses and experiments, we provide evidence that this behavior is primarily due to an excess of oxygen in the films. This discovery enables entirely new categories of TiO2 devices and applications, and unlocks the potential to improve existing ones. TiO2 homojunction diodes fabricated completely by ALD are developed as a demonstration of the utility of these techniques and shown to exhibit useful rectifying characteristics even with minimal processing refinement.

show abstract

Section: Methodsmentioning

confidence: 66%

Atomic Layer Deposition of Undoped TiO₂ Exhibiting p-Type Conductivity

Iancu

Logar

Park

et al. 2015

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

“…This liquid precursor, Cp*Ti(OMe) 3 (Cp* = pentamethylcyclopentadienyl, C 5 (CH 3 ) 5 ), was introduced very recently by Blasco et al Their report concentrated on the precursor synthesis and characterization. Initial ALD investigations revealed a very wide ALD process window with deposition temperatures up to 375−400 °C. , In the present paper we have studied the ALD growth of TiO 2 using Cp*Ti(OMe) 3 and ozone on 300 mm wafers in detail. An important part of this study was to investigate the ALD growth mechanism in situ, using a quadrupole mass spectrometer (QMS).…”

Section: Introductionmentioning

confidence: 98%

Atomic Layer Deposition of Titanium Dioxide Thin Films from Cp*Ti(OMe)₃ and Ozone

et al. 2009

View full text Add to dashboard Cite

The thermal atomic layer deposition of TiO2 from Cp*Ti(OMe)3 and ozone was studied in a 300 mm wafer reactor by quadrupole mass spectrometry (QMS). The deposited thin films were analyzed by X-ray reflectivity (XRR), X-ray photoelectron spectroscopy (XPS), grazing incident X-ray diffraction, and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The XRR and XPS measurements revealed that nearly stoichiometric TiO2 films were grown in a self-limiting growth mode. The growth per cycle increased from 0.22 Å at 235 °C to 0.29 Å at 330 °C. Films deposited on titanium nitride showed an anatase crystal structure, while films deposited on ruthenium crystallized in the rutile phase. The ToF-SIMS analysis indicated that the carbon contamination reduced to very low levels at a deposition temperature of 295 °C. The QMS studies revealed the release of MeOH during the precursor pulse. CO2 and H2O were released during the ozone pulse at a process pressure of 7 mbar. At a pressure of 3 × 10−3 mbar, the release of the Cp* ligand and the remaining OMe ligands during the ozone pulse could be observed. It was demonstrated that QMS studies can be used in a 300 mm reactor at very low pressures to study the process chemistry.

show abstract

“…However, due to the high stability of strontium chloride, TiCl 4 is not suitable for the atomic layer deposition of SrTiO 3 . TiO 2 has also been deposited from various alkoxide, − alkylamide, , cyclopentadienyl, , and heteroleptic precursors. , …”

Section: Introductionmentioning

confidence: 99%

“…10 However, due to the high stability of strontium chloride, TiCl 4 is not suitable for the atomic layer deposition of SrTiO 3 . 11 TiO 2 has also been deposited from various alkoxide, 12−14 alkylamide, 15,16 cyclopentadienyl, 16,17 and heteroleptic precursors. 18,19 The limited thermal stability of alkoxides and alkylamides has generally been problematic, as temperatures higher than 300 °C are needed to deposit crystalline films in the as-deposited state.…”

Section: ■ Introductionmentioning

confidence: 99%

Novel Heteroleptic Precursors for Atomic Layer Deposition of TiO₂

et al. 2012

Self Cite

View full text Add to dashboard Cite

Two novel heteroleptic titanium precursors for the atomic layer deposition (ALD) of TiO 2 were investigated, namely, titanium (N,N′diisopropylacetamidinate)tris(isopropoxide) (Ti(O i Pr) 3 (N i Pr-Me-amd)) and titanium bis(dimethylamide)bis(isopropoxide) (Ti(NMe 2 ) 2 (O i Pr) 2 ). Water was used as the oxygen source. These two precursors are liquid at room temperature and present good volatility, thermal stability and reactivity. The self-limiting ALDgrowth mode was confirmed at 325 °C for both precursors. The titanium (N,N′diisopropylacetamidinate)tri(isopropoxide)/water process showed an ALD window at 300−350 °C, and titanium bis(dimethylamide)bis(isopropoxide) exhibited an interestingly high growth rate of 0.75 Å/cycle at 325 °C. The films were crystallized to the anatase phase in the as-deposited state. X-ray photoelectron spectroscopy analysis demonstrated that the films were pure and close to the stoichiometric composition. The refractive indexes and absorption coefficient of the films were measured by spectroscopic ellipsometry.

show abstract

Ti Source Precursors for Atomic Layer Deposition of TiO2, STO and BST

Cited by 34 publications

References 13 publications

Atomic Layer Deposition of Undoped TiO₂ Exhibiting p-Type Conductivity

Atomic Layer Deposition of Undoped TiO₂ Exhibiting p-Type Conductivity

Atomic Layer Deposition of Titanium Dioxide Thin Films from Cp*Ti(OMe)₃ and Ozone

Novel Heteroleptic Precursors for Atomic Layer Deposition of TiO₂

Contact Info

Product

Resources

About

Ti Source Precursors for Atomic Layer Deposition of TiO2, STO and BST

Cited by 34 publications

References 13 publications

Atomic Layer Deposition of Undoped TiO2 Exhibiting p-Type Conductivity

Atomic Layer Deposition of Undoped TiO2 Exhibiting p-Type Conductivity

Atomic Layer Deposition of Titanium Dioxide Thin Films from Cp*Ti(OMe)3 and Ozone

Novel Heteroleptic Precursors for Atomic Layer Deposition of TiO2

Contact Info

Product

Resources

About

Atomic Layer Deposition of Undoped TiO₂ Exhibiting p-Type Conductivity

Atomic Layer Deposition of Undoped TiO₂ Exhibiting p-Type Conductivity

Atomic Layer Deposition of Titanium Dioxide Thin Films from Cp*Ti(OMe)₃ and Ozone

Novel Heteroleptic Precursors for Atomic Layer Deposition of TiO₂