scholarly journals Reactions of ruthenium cyclopentadienyl precursor in the metal precursor pulse of Ru atomic layer deposition

2021 ◽  
Author(s):  
Ji Liu ◽  
Hongliang Lu ◽  
David Wei Zhang ◽  
Michael Nolan
Keyword(s):  
Atomic Layer Deposition ◽  
Hydrogen Transfer ◽  
Atomic Layer ◽  
Metal Precursor ◽  
Layer Deposition

The elimination of Cp ligand on Ru(001) and (100) surfaces have high barriers and the reactions of hydrogen transfer are endothermic. The final terminations are 0.85 RuCp per nm2 on Ru(001) surface and 1.01 (Ru + RuCp2) per nm2 on Ru(100) surface.

scholarly journals Reaction Mechanism of the Metal Precursor Pulse in Plasma-Enhanced Atomic Layer Deposition of Cobalt and the Role of Surface Facet

2020 ◽  
Author(s):  
Ji Liu ◽  
hongliang lu ◽  
david wei zhang ◽  
Michael Nolan
Keyword(s):  
Reaction Mechanism ◽  
Atomic Layer Deposition ◽  
Density Functional ◽  
Hydrogen Transfer ◽  
Semiconductor Industry ◽  
Atomic Layer ◽  
Potential Candidate ◽  
Metal Precursor ◽  
Layer Deposition ◽  
Surface Facet

Cobalt is a potential candidate in replacing copper for interconnects and has been applied in the trenches and vias in semiconductor industry. A non-oxidizing reactant is required in plasma-enhanced atomic layer deposition (PE-ALD) of thin films of metals to avoid O-contamination. PE-ALD of Co has been demonstrated experimentally, but the growth mechanism and key reactions are not clear. In this paper, the reaction mechanism of metal cyclopentadienyl (Cp, C<sub>5</sub>H<sub>5</sub>) precursors (CoCp<sub>2</sub>) and NH<sub>x</sub>-terminated Co surface is studied by density functional theory (DFT) calculations. The Cp ligands are eliminated by CpH formation via a hydrogen transfer step and desorb from metal surface. The surface facet plays an important role in the reaction energies and activation barriers. The results show that on the NH<sub>x</sub>-terminated surfaces corresponding to ALD operating condition (temperature range 550K to 650K), the two Cp ligands are eliminated completely on Co(100) surface during the metal precursor pulse, resulting in Co atom deposited on the Co(100) surface. But the second Cp ligand reaction of hydrogen transfer is thermodynamically unfavourable on the Co(001) surface, resulting in CoCp fragment termination on Co(001) surface. The final terminations after metal precursor pulse are 3.03 CoCp/nm<sup>2</sup> on NH<sub>x</sub>-terminated Co(001) surface and 3.33 Co/nm<sup>2</sup> on NH<sub>x</sub>-terminated Co(100) surface. These final structures after metal precursor pulse are essential to model the reaction during the following N-plasma step..<br>

scholarly journals Reaction Mechanism of the Metal Precursor Pulse in Plasma-Enhanced Atomic Layer Deposition of Cobalt and the Role of Surface Facet

2020 ◽  
Author(s):  
Ji Liu ◽  
hongliang lu ◽  
david wei zhang ◽  
Michael Nolan
Keyword(s):  
Reaction Mechanism ◽  
Atomic Layer Deposition ◽  
Density Functional ◽  
Hydrogen Transfer ◽  
Semiconductor Industry ◽  
Atomic Layer ◽  
Potential Candidate ◽  
Metal Precursor ◽  
Layer Deposition ◽  
Surface Facet

Cobalt is a potential candidate in replacing copper for interconnects and has been applied in the trenches and vias in semiconductor industry. A non-oxidizing reactant is required in plasma-enhanced atomic layer deposition (PE-ALD) of thin films of metals to avoid O-contamination. PE-ALD of Co has been demonstrated experimentally, but the growth mechanism and key reactions are not clear. In this paper, the reaction mechanism of metal cyclopentadienyl (Cp, C<sub>5</sub>H<sub>5</sub>) precursors (CoCp<sub>2</sub>) and NH<sub>x</sub>-terminated Co surface is studied by density functional theory (DFT) calculations. The Cp ligands are eliminated by CpH formation via a hydrogen transfer step and desorb from metal surface. The surface facet plays an important role in the reaction energies and activation barriers. The results show that on the NH<sub>x</sub>-terminated surfaces corresponding to ALD operating condition (temperature range 550K to 650K), the two Cp ligands are eliminated completely on Co(100) surface during the metal precursor pulse, resulting in Co atom deposited on the Co(100) surface. But the second Cp ligand reaction of hydrogen transfer is thermodynamically unfavourable on the Co(001) surface, resulting in CoCp fragment termination on Co(001) surface. The final terminations after metal precursor pulse are 3.03 CoCp/nm<sup>2</sup> on NH<sub>x</sub>-terminated Co(001) surface and 3.33 Co/nm<sup>2</sup> on NH<sub>x</sub>-terminated Co(100) surface. These final structures after metal precursor pulse are essential to model the reaction during the following N-plasma step..<br>

scholarly journals Reactions of Ruthenium Cyclopentadienyl Praecursor in the Metal Precursor Pulse of Ru Atomic Layer Deposition

2020 ◽  
Author(s):  
Ji Liu ◽  
hongliang lu ◽  
david wei zhang ◽  
Michael Nolan
Keyword(s):  
Atomic Layer Deposition ◽  
Hydrogen Transfer ◽  
Activation Barrier ◽  
Semiconductor Industry ◽  
Atomic Layer ◽  
Surface Binding ◽  
Metal Precursor ◽  
Rate Limiting Step ◽  
Layer Deposition ◽  
Initial Activation

Ruthenium is a promising material in the semiconductor industry and is investigated as the interconnect metal or as a seed layer for Cu interconnects. Non-oxidative reactants are required in a plasma-enhanced atomic layer deposition (PE-ALD) process for metals to avoid oxygen contamination. The PE-ALD of Ru has been explored experimentally, but the growth mechanism is not clear. In this paper, the reaction mechanism of the cyclopentadienyl (Cp, C<sub>5</sub>H<sub>5</sub>) precursor RuCp<sub>2</sub> and NH<sub>x</sub>-terminated Ru surfaces that result from the plasma cycle is studied in detail by first-principle calculations. The Cp ligands are eliminated by hydrogen transfer and desorb from metal surface as CpH. The results show that on the NH<sub>x</sub>-terminated Ru surface at typical ALD operating condition (temperature range 550K to 650K), the first hydrogen transfer is the rate-limiting step and has high barriers, which are -1.51eV for Ru(001) and 2.01eV for Ru(100). Assuming that the initial activation barrier for the first hydrogen transfer can be overcome, the two Cp ligands will be completely eliminated completely on Ru(100) surface during the metal precursor pulse, resulting in Ru atoms on the surface, binding to N atom. But at most only one Cp ligand is eliminated on Ru(001) surface, resulting in an RuCp termination on (001) surface. Investigating the precursor coverage, the final surface coverages of final terminations after the metal precursor pulse are 0.85 RuCp/nm<sup>2</sup> on the NH<sub>x</sub>-terminated Ru(001) surface and 2.02 Ru/nm<sup>2</sup> on the NH<sub>x</sub>-terminated Ru(100) surface. However, if the first H transfer barrier cannot be overcome, leaving RuCp<sub>2</sub> on NH<sub>x</sub>-terminated Ru surfaces, the maximum coverages of RuCp<sub>2</sub> on Ru(001) and Ru(100) surfaces are 2.54 RuCp<sub>2</sub>/nm<sup>2</sup> and 2.02 RuCp<sub>2</sub>/nm<sup>2</sup>. These structures are vital to model the following N-plasma step.

scholarly journals Reaction Mechanism of the Metal Precursor Pulse in Atomic Layer Deposition of Ruthenium and Cobalt and the Role of Surface Facet NH/NH2 Coverage

2019 ◽  
Author(s):  
Ji Liu ◽  
Michael Nolan
Keyword(s):  
Reaction Mechanism ◽  
Atomic Layer Deposition ◽  
Density Functional ◽  
Hydrogen Transfer ◽  
Semiconductor Industry ◽  
Atomic Layer ◽  
Potential Candidate ◽  
Metal Precursor ◽  
Layer Deposition ◽  
Surface Facet

Ruthenium and Cobalt are potential candidate in replacing copper for interconnects and have been applied in the trenches and vias in semiconductor industry. A non-oxidizing reactant is required in atomic layer deposition (ALD) of thin films of these metals to avoid O-contamination. ALD of Ru and Co has been demonstrated experimentally, but the growth mechanism and key reactions are not clear. In this paper, the reaction mechanism of metal cyclopentadienyl (Cp, C5H5) precursors (RuCp2 and CoCp2) and NHx-terminated metal surfaces (Ru and Co) is studied by density functional theory (DFT) calculations. The Cp ligands are eliminated by CpH formation via a hydrogen transfer step and may desorb from metal surface. The nature of the NHx-termination plays an important role in the reaction energies and barriers as does the surface facet on Ru and Co, with (001) and (100) surfaces showing different reaction energetics. The results show that on the NHx-terminated surfaces corresponding to ALD operating condition (temperature range 550K to 650K), the two Cp ligands can be eliminated completely on both Ru and Co (100) surface during the metal precursor pulse, resulting in Ru or Co atom deposited on the (100) surface. But the second Cp ligand reaction of hydrogen transfer is thermodynamically unfavourable on the (001) surface, resulting in RuCp or CoCp fragment termination on (001) surface, along with the possibility of surface boned CpH. CoCp2 always has lower reaction barriers than RuCp2, regardless of surface facets or NHx coverage. These final structures after metal precursor pulse are essential to model the reaction during the following N-plasma step.<br>

scholarly journals Reactions of Ruthenium Cyclopentadienyl Praecursor in the Metal Precursor Pulse of Ru Atomic Layer Deposition

2020 ◽  
Author(s):  
Ji Liu ◽  
hongliang lu ◽  
david wei zhang ◽  
Michael Nolan
Keyword(s):  
Atomic Layer Deposition ◽  
Hydrogen Transfer ◽  
Activation Barrier ◽  
Semiconductor Industry ◽  
Atomic Layer ◽  
Surface Binding ◽  
Metal Precursor ◽  
Rate Limiting Step ◽  
Layer Deposition ◽  
Initial Activation

Ruthenium is a promising material in the semiconductor industry and is investigated as the interconnect metal or as a seed layer for Cu interconnects. Non-oxidative reactants are required in a plasma-enhanced atomic layer deposition (PE-ALD) process for metals to avoid oxygen contamination. The PE-ALD of Ru has been explored experimentally, but the growth mechanism is not clear. In this paper, the reaction mechanism of the cyclopentadienyl (Cp, C<sub>5</sub>H<sub>5</sub>) precursor RuCp<sub>2</sub> and NH<sub>x</sub>-terminated Ru surfaces that result from the plasma cycle is studied in detail by first-principle calculations. The Cp ligands are eliminated by hydrogen transfer and desorb from metal surface as CpH. The results show that on the NH<sub>x</sub>-terminated Ru surface at typical ALD operating condition (temperature range 550K to 650K), the first hydrogen transfer is the rate-limiting step and has high barriers, which are -1.51eV for Ru(001) and 2.01eV for Ru(100). Assuming that the initial activation barrier for the first hydrogen transfer can be overcome, the two Cp ligands will be completely eliminated completely on Ru(100) surface during the metal precursor pulse, resulting in Ru atoms on the surface, binding to N atom. But at most only one Cp ligand is eliminated on Ru(001) surface, resulting in an RuCp termination on (001) surface. Investigating the precursor coverage, the final surface coverages of final terminations after the metal precursor pulse are 0.85 RuCp/nm<sup>2</sup> on the NH<sub>x</sub>-terminated Ru(001) surface and 2.02 Ru/nm<sup>2</sup> on the NH<sub>x</sub>-terminated Ru(100) surface. However, if the first H transfer barrier cannot be overcome, leaving RuCp<sub>2</sub> on NH<sub>x</sub>-terminated Ru surfaces, the maximum coverages of RuCp<sub>2</sub> on Ru(001) and Ru(100) surfaces are 2.54 RuCp<sub>2</sub>/nm<sup>2</sup> and 2.02 RuCp<sub>2</sub>/nm<sup>2</sup>. These structures are vital to model the following N-plasma step.

Trimethylsilylcyclopentadienyl tris(dimethylamino)zirconium as a single-source metal precursor for the atomic layer deposition of ZrxSi1-xO4

2014 ◽  
Vol 564 ◽  
pp. 140-145 ◽  
Author(s):  
Yoon Jang Chung ◽  
Dae-Chul Moon ◽  
Jeong Hwan Han ◽  
Mira Park ◽  
Jung Woo Park ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Single Source ◽  
Metal Precursor ◽  
Layer Deposition

scholarly journals Plasma-Enhanced Atomic Layer Deposition of Cobalt Films Using Co(EtCp)2 as a Metal Precursor

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Bao Zhu ◽  
Zi-Jun Ding ◽  
Xiaohan Wu ◽  
Wen-Jun Liu ◽  
David Wei Zhang ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Metal Precursor ◽  
Cobalt Films ◽  
Layer Deposition

Plasma-assisted atomic layer deposition and post-annealing enhancement of low resistivity and oxygen-free nickel nano-films using nickelocene and ammonia precursors

2016 ◽  
Vol 4 (47) ◽  
pp. 11059-11066 ◽  
Author(s):  
Yong-Ping Wang ◽  
Zi-Jun Ding ◽  
Qi-Xuan Liu ◽  
Wen-Jun Liu ◽  
Shi-Jin Ding ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Low Resistivity ◽  
Metal Precursor ◽  
Post Annealing ◽  
Layer Deposition

Oxygen-free and low resistivity nickel (Ni) thin films are successfully prepared by plasma-assisted atomic layer deposition using nickelocene (NiCp2) as a metal precursor and ammonia (NH3) as a reactant.

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