Growth and properties of LPCVD W–Si–N barrier layers

Bystrova, S.; Holleman, J.; Woerlee, P.H.

doi:10.1016/s0167-9317(00)00447-0

Cited by 19 publications

(6 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Even with the sensitive grazing-angle XRD analysis, the result does not show any specific peaks related to tungsten silicides or tungsten nitrides at all. This indicates that the ALD-grown W–Si–N film might form an amorphous phase, as similar in other deposition systems such as sputtering and chemical vapor deposition. − ,, The plan-view TEM image of the W–Si–N film (∼20 nm thick) (Figure b) shows the microstructure of the film more obviously. It seems to be featureless, which is typical in the amorphous structure.…”

Section: Resultssupporting

confidence: 58%

“…This indicates that the ALD-grown W−Si−N film might form an amorphous phase, as similar in other deposition systems such as sputtering and chemical vapor deposition. [31][32][33]39,40 The plan-view TEM image of the W−Si−N film (∼20 nm thick) (Figure 7b) shows the microstructure of the film more obviously. It seems to be featureless, which is typical in the amorphous structure.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Highly Conformal Amorphous W–Si–N Thin Films by Plasma-Enhanced Atomic Layer Deposition as a Diffusion Barrier for Cu Metallization

Hong¹,

Jung

Yeo

et al. 2015

J. Phys. Chem. C

View full text Add to dashboard Cite

Ternary and amorphous tungsten silicon nitride (W–Si–N) thin films were grown by atomic layer deposition (ALD) using a sequential supply of a new fluorine-free, silylamide-based W metallorganic precursor, bis(tert-butylimido)bis(bis(trimethylsilylamido))tungsten(VI) [W(N t Bu)2{N(SiMe3)2}2], and H2 plasma at a substrate temperature of 300 °C. Here, W(N t Bu)2{N(SiMe3)2}2 was prepared through a metathesis reaction of W(N t Bu)2Cl2(py)2 (py = pyridine) with 2 equiv of LiN(SiMe3)2 [Li(btsa)]. The newly proposed ALD system exhibited typical ALD characteristics, such as self-limited film growth and linear dependency of the film growth on the number of ALD cycles, and showed a high growth rate of 0.072 nm/cycle on a thermally grown SiO2 substrate with a nearly zero incubation cycle. Such ideal ALD growth characteristics enabled excellent step coverage of ALD-grown W–Si–N film, ∼100%, onto nanotrenches with a width of 25 nm and an aspect ratio ∼4.5. Rutherford backscattering spectrometry and X-ray photoelectron spectroscopy analysis confirmed that the incorporated Si and W were mostly bonded to N, as in Si–N and W–N chemical bonds. The film kept its amorphous nature until annealing at 800 °C, and crystallization happened at local areas after annealing at a very high temperature of 900 °C. An ultrathin (only ∼4 nm thick) ALD-grown W–Si–N film effectively prevented diffusion of Cu into Si after annealing at a temperature up to 600 °C.

show abstract

Section: Resultssupporting

confidence: 58%

Section: Resultsmentioning

confidence: 99%

Highly Conformal Amorphous W–Si–N Thin Films by Plasma-Enhanced Atomic Layer Deposition as a Diffusion Barrier for Cu Metallization

Hong¹,

Jung

Yeo

et al. 2015

J. Phys. Chem. C

View full text Add to dashboard Cite

show abstract

“…Owing to their high stability and excellent conductivity, refractory metal binary and ternary nitrides are widely recognized as an attractive class of materials that can be used as diffusion barriers in metal-semiconductor contacts. [3][4][5][6][7][8][9][10][11][12] Most of the barrier layers still have the problem of high resistivity, high process temperature, and narrow process window. Among those refractory metal nitrides, zirconium-based nitride thin films such as Zr-N and Zr-Si-N have been studied extensively as suitable diffusion barriers for Cu metallization.…”

mentioning

confidence: 99%

Application of Zr-Si Film as Diffusion Barrier in Cu Metallization

Wang

Cao

Song

et al. 2007

Electrochem. Solid-State Lett.

View full text Add to dashboard Cite

The diffusion barrier's performance of Zr-Si film in Cu/Si contacts has been investigated. Cu/Zr-Si/Si contact system was deposited by using radio frequency reactive sputtering technique. Annealing studies for Cu/Zr-Si/Si were then carried out in nitrogen to investigate Cu diffusion and barrier film crystallization. The contact system was characterized by using four-point probe sheet resistance measurements, X-ray diffraction, scanning electron microscope, and Auger electron spectroscopy ͑AES͒, respectively. It is observed that the sheet resistance of Cu/Zr-Si/Si contact system is lower than that of as-deposited specimens even after annealing at 700°C. The Cu/Zr-Si/Si contacts tolerated annealing at 800°C for an hour without structural change of the barrier. AES depth profiles of the annealed Cu/Zr-Si/Si samples are similar to each other and have no intermixing evidence. Zr-Si was found to be a promising diffusion barrier material for Cu metallization.Copper has been intensively investigated to overcome high resistivity and low electromigration resistance of the conventional aluminum and aluminum alloys with the current trends to smaller and smaller device feature sizes. However, Cu reacts with Si or diffuses fast in SiO 2 at relatively low temperature, which can deteriorate device operation. 1,2 Therefore, it is necessary to insert a diffusion barrier between Cu and Si to suppress Cu diffusion and the subsequent reaction with Si. Owing to their high stability and excellent conductivity, refractory metal binary and ternary nitrides are widely recognized as an attractive class of materials that can be used as diffusion barriers in metal-semiconductor contacts. [3][4][5][6][7][8][9][10][11][12] Most of the barrier layers still have the problem of high resistivity, high process temperature, and narrow process window. Among those refractory metal nitrides, zirconium-based nitride thin films such as Zr-N and Zr-Si-N have been studied extensively as suitable diffusion barriers for Cu metallization. [13][14][15][16] It is well known that these thin films generally show excellent barrier properties due to their high crystallization temperatures. Zirconium silicide has a lower resistivity ͑ϳ32 ⍀ cm with thickness of 50 nm͒ 17 than Zr-N film ͑ϳ50 ⍀ cm with thickness of 140 nm͒ 13 and Zr-Si-N film ͑ϳ136 ⍀ cm with thickness of 100 nm͒. 16 In addition, zirconium silicide/silicon interface is a low-resistance ohmic contact. The 0.55 eV barrier height between the silicide and silicon shows that this contact may be useful for both n-and p-type regions. 17 It is true that Zr-Si has not been studied carefully with Cu but with Al it has been tested. 18 In this article, we introduce Zr-Si thin films as Cu diffusion barrier and focus on investigating the diffusion barrier's performance of these films. ExperimentalSubstrates of n-type Si͑100͒ were progressively cleaned in an ultrasonic bath with acetone, methanol, isopropyl alcohol, and diluted HF solution and then rinsed in deionized water before the activation process, in order to r...

show abstract

“…For the material used as a diffusion barrier, it is required that the barrier should prevent the undesired diffusion and/or reaction, and also should be sufficiently low in resistivity [1,2]. Refractory metal binary and ternary nitrides are widely recognized as an attractive class of materials which can be used as diffusion barriers in metal-semiconductor contacts [3][4][5][6][7][8][9][10][11][12]. Among those refractory metal nitrides, zirconium-base nitride thin films such as Zr-N and Zr-Si-N have been studied extensively as suitable diffusion barriers for Cu metallization [13][14][15].…”

Section: Introductionmentioning

confidence: 99%