Improved diffusion barrier performance of Ru/TaN bilayer by N effusion in TaN underlayer

Wang, L.; Cao, Zhenhua; Hu, Kun; She, Q.W.; Meng, Xiangkang

doi:10.1016/j.matchemphys.2012.05.061

Cited by 10 publications

(3 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To avoid rapid copper diffusion in integrated circuits (ICs), Cu interconnects require an effective barrier to prevent interdiffusion or reaction between the Cu and adjoining materials [1][2][3][4][5]. Various refractory metals and their nitride diffusion barriers, such as Ti, Ta, Ru and Mn, which have a low electrical resistivity, high stability and good interface adhesion, are in high demand [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

“…The continuous scaling down of ICs to a few-nanometer regime has led to the issue of fabricating an ultrathin barrier layer with step coverage on the sidewalls and bottom corners of trenches and vias [12]. Moreover, barrier layers occupy an increasing fraction at the cross-sectional area of conductors, leading to an increase in the electrical resistivity of the Cu interconnects [4]. Therefore, it is urgent to explore alternative methods of removing barrier layers which will also reduce the manufacturing cost using simplified technology.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Self-Formed Diffusion Layer in Cu(Re) Alloy Film for Barrierless Copper Metallization

et al. 2022

View full text Add to dashboard Cite

The barrier properties and diffusion behavior of Cu(Re) alloy films were studied. The films were deposited onto barrierless SiO2/Si by magnetron sputtering. X-ray diffraction patterns and electric resistivity results proved that the Cu(Re) alloy films without a barrier layer were thermally stable up to 550 °C. Transmission electron microscopy images and energy-dispersive spectrometry employing scanning transmission electron microscopy provided evidence for a self-formed Re-enriched diffusion layer between the Cu(Re) alloy and SiO2/Si substrate. Furthermore, the chemical states of Re atoms at the Cu(Re)/SiO2 interface were analyzed by X-ray photoemission spectroscopy. The self-formed diffusion layer was found to be composed of Re metal, ReO and ReO3. At 650 °C, the Cu(Re) layer was completely destroyed due to atom diffusion. The low electrical resistivity in combination with the high thermal stability suggests that the Cu(Re) alloy could be the ultimate Cu interconnect diffusion barrier.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Self-Formed Diffusion Layer in Cu(Re) Alloy Film for Barrierless Copper Metallization

et al. 2022

View full text Add to dashboard Cite

show abstract

“…In addition to TaN, many nitrides have been extensively studied for applications in microelectronics, such as binary TiN 7 and WN, 8 ternary Ti-Si-N, [9][10][11] Ta-Si-N, 12,13 W-Si-N, 14 Ta-B-N, 15 W-B-N, 16 Ti-Zr-N 17 and Zr-Ge-N, 18 and bilayers of Ta/TaN, 19 Zn/ZnN, 20 Ru/TaN 21,22 and Ru/W-Si-N. 23 One of new barrier nitrides, NbN, deposited by using atomic layer deposition (ALD) with precursors of NbCl 5 and NH 3 , 24 exhibited good thermal stability up to 650 • C based on the sheet resistance measurements. Only one tetragonal Nb 4 N 5 phase was observed with the ALD conditions used, and the d-spacings were found to be in a good agreement with the references values.…”

mentioning

confidence: 99%

Growth, Thermal Stability and Cu Diffusivity of Reactively Sputtered NbN Thin Films as Diffusion Barriers between Cu and Si

Huang

Lai

Tsai

et al. 2013

ECS J. Solid State Sci. Technol.

View full text Add to dashboard Cite

NbN x films were prepared by RF reactive magnetron sputtering from a Nb target in N 2 / Ar gas mixtures and then used as diffusion barriers between Cu and Si substrates. Material characteristics of the NbN x, films were investigated and were correlated with the N 2 /Ar flow ratio. The variations in film resistivity is correlated with the change of phases and chemical compositions from α-Nb, β-Nb 2 N, γ-Nb 4 N 3 , δ-NbN + δ -NbN as the N 2 /Ar ratio is increased. The thermal stability of Cu (60 nm)/NbN x (25 nm)/Si multilayers were investigated and our results indicated that the barrier performances were significantly affected by the chemical composition of NbN x films. The diffusion coefficient of Cu in NbN x was measured by four-point probe analysis after annealing Cu/NbN x /Si multilayered samples in the temperature range of 600-850 • C. Cu diffusion in NbN x had components from the grain boundaries and the lattice. In addition, our results suggest that the NbN x can be used as a potential diffusion barrier for Cu metallization as compared to the conventional TaN.Metallization technologies become increasingly important for advanced ultra-large scale integration (ULSI) devices as geometry shrinks and complexity increases. Copper has replaced aluminum and its alloys as the interconnect metal for deep submicron ULSI circuits because of its lower bulk resistivity (1.67 μ cm) and higher resistance to electromigration and stress voiding. 1 However, Cu reacts with Si at relatively low temperatures, leading to device leakage. Therefore, it has been widely adopted to insert a diffusion barrier to suppress Cu diffusion and the subsequent reaction with Si for silicon integrated circuit applications. 2 Of the various diffusion barrier candidates, tantalum nitride (TaN) is considered as a promising material and has been widely used as the diffusion barrier for Cu metallization because of its high thermal stability and the absence of any compounds between Cu and Ta, and Cu and N. 3-5 However, TaN barrier layer needs to be further improved or be replaced with other materials because of the three issues associated with the shrinkage of Cu lines. One is the high resistivity of TaN, which increases the total resistivity of interconnects when the width of wire shrinks furthermore. The second issue is the high interface energy of Cu/TaN, which causes poor adhesion of Cu and enhances the electro-migration failure. 6 The third issue is the poor step coverage of thick or multiple TaN-based layers. The continuous demands to scale down devices require that the thickness of Cu diffusion barriers should be significantly reduced for advanced nano-meter level halfpitch application. Hence, a thin, excellent conformal diffusion barrier is required.In addition to TaN, many nitrides have been extensively studied for applications in microelectronics, such as binary TiN 7 and WN, 8 ternary Ti-Si-N, One of new barrier nitrides, NbN, deposited by using atomic layer deposition (ALD) with precursors of NbCl 5 and NH 3 , 24 exhibited good thermal sta...

show abstract

Evaluation of electric field intensity on atom diffusion of Cu/Ta/Si stacks during annealing

Wang

Jin

et al. 2015

Appl. Phys. A

View full text Add to dashboard Cite

Improved diffusion barrier performance of Ru/TaN bilayer by N effusion in TaN underlayer

Cited by 10 publications

References 32 publications

Self-Formed Diffusion Layer in Cu(Re) Alloy Film for Barrierless Copper Metallization

Self-Formed Diffusion Layer in Cu(Re) Alloy Film for Barrierless Copper Metallization

Growth, Thermal Stability and Cu Diffusivity of Reactively Sputtered NbN Thin Films as Diffusion Barriers between Cu and Si

Evaluation of electric field intensity on atom diffusion of Cu/Ta/Si stacks during annealing

Contact Info

Product

Resources

About