Zr–Ti–Ni thin film metallic glass as a diffusion barrier between copper and silicon

Wang, Chih‐Wei; Yiu, Pakman; Chu, Jinn P.; Shek, C.H.; Hsueh, Chun‐Hway

doi:10.1007/s10853-014-8770-6

Cited by 33 publications

(15 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3,5,10,[17][18][19] Therefore, the understanding and control of this size-dependent phenomenon is a major concern and a key issue to the entire microelectronics industry, since copper is expected to continue dominating the interconnect technology. 9,11 Most copper thin films are grown by physical vapor deposition (PVD) processes, in particular, by conventional direct current magnetron sputtering (DCMS), [2][3][4]17,[20][21][22] and by metal-organic chemical vapor deposition (MOCVD). 15,[23][24][25] Compared to the conventional PVD processes, the copper films deposited by CVD exhibit a better step coverage and higher deposition rates.…”

Section: Introductionmentioning

confidence: 99%

Low electrical resistivity in thin and ultrathin copper layers grown by high power impulse magnetron sputtering

Cemin

Lundin

Cammilleri

et al. 2016

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

View full text Add to dashboard Cite

Ultrathin copper (Cu) layers are in continuous demand in several areas, such as within microelectronics and space, as well as in instrumentation technology requiring an electrical resistivity as low as possible. However, the performance of modern copper connections is limited by the size-dependent value of the film resistivity, which is known to increase when the layer thickness is reduced to a few tens of nanometer. In this work, the authors have successfully deposited Cu thin films from 20 to 800 nm exhibiting reduced electrical resistivity by using a high power impulse magnetron sputtering (HiPIMS) process. The electrical and microstructural properties of such films were compared to samples deposited by conventional direct current magnetron sputtering (DCMS) within the same thickness range. For films as thin as 30 nm, the electrical resistivity was reduced by $30% when deposited by HiPIMS compared to DCMS, being only three times larger than the copper bulk value. The HiPIMS Cu films exhibit larger grain size and reduced grain boundary density, which reduce the scattering of charge carriers and thereby the resistivity of the thin film. These larger grains are likely due to the highly ionized precursor flux of the HiPIMS discharge, which in the present work is controlled by an external substrate bias. V

show abstract

Section: Introductionmentioning

confidence: 99%

Low electrical resistivity in thin and ultrathin copper layers grown by high power impulse magnetron sputtering

Cemin

Lundin

Cammilleri

et al. 2016

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

View full text Add to dashboard Cite

show abstract

“…These kinds of barriers block the interaction between the interconnect materials and the silicon, and they are potentially useful as a diffusion barrier in other systems, in addition to those between the interconnect materials and the silicon [16,17]. Recently, TFMGs were gradually recognized and accepted as the most effective barriers layer for Cu metallization due to the absence of grain boundaries and immiscibility with copper [18][19][20]. Since the diffusion coefficient for Sn in Cu is 10 orders of magnitude smaller than that for Cu in Sn [21], IMCs are scarcely found and grown in Sn.…”

Section: Introductionmentioning

confidence: 99%

Material Properties of Zr–Cu–Ni–Al Thin Films as Diffusion Barrier Layer

Sung

Chen

2020

Crystals

View full text Add to dashboard Cite

Due to the rapid increase in current density encountered in new chips, the phenomena of thermomigration and electromigration in the solder bump become a serious reliability issue. Currently, Ni or TiN, as a barrier layer, is widely academically studied and industrially accepted to inhibit rapid copper diffusion in interconnect structures. Unfortunately, these barrier layers are polycrystalline and provide inadequate protection because grain boundaries may presumably serve as fast diffusion paths for copper and could react to form Cu–Sn intermetallic compounds (IMCs). Amorphous metallic films, however, have the potential to be the most effective barrier layer for Cu metallization due to the absence of grain boundaries and immiscibility with copper. In this article, the diffusion properties, the strength of the interface between polycrystalline and amorphous ZrCuNiAl thin film, and the effects of quenching rate on the internal microstructures of amorphous metal films were individually investigated by molecular dynamics (MD) simulation. Moreover, experimental data of the diffusion process for three different cases, i.e., without barrier layer, with an Ni barrier layer, and with a Zr53Cu30Ni9Al8 thin film metallic glass (TFMG) barrier layer, were individually depicted. The simulation results show that, for ZrCuNiAl alloy, more than 99% of the amorphous phase at a quenching rate between 0.25 K/ps and 25 K/ps can be obtained, indicating that this alloy has superior glass-forming ability. The simulation of diffusion behavior indicated that a higher amorphous ratio resulted in better barrier performance. Moreover, a very small and uniformly distributed strain appears in the ZrCuNiAl layer in the simulation of the interfacial tension test; however, almost all the voids are initiated and propagated in the Cu layer. These phenomena indicate that the strength of the ZrCuNiAl/Cu interface and ZrCuNiAl layer is greater than polycrystalline Cu. Experimental results show that the Zr53Cu30Ni9Al8 TFMG layer exhibits a superior barrier effect. Almost no IMCs appear in this TFMG barrier layer even after aging at 125 °C for 500 h.

show abstract

“…Amorphous metallic alloys, which are commonly called metallic glasses (MGs), possess a number of outstanding properties such as a high elastic limit and strength 1–3 , good corrosion and wear resistance 4–6 , excellent diffusion barrier properties 7,8 , as well as good biocompatibility or even antimicrobial effect 9–11 . However, the application of MGs as structural or functional materials is hindered due to their intrinsic brittleness which is manifested by a catastrophic fracture through propagation of highly localized shear deformation within shear bands 2,3 .…”

Section: Introductionmentioning

confidence: 99%

Exceptional fracture resistance of ultrathin metallic glass films due to an intrinsic size effect

Глушко

Mühlbacher

Gammer

et al. 2019

Sci Rep

View full text Add to dashboard Cite

Metallic glasses typically fail in a brittle manner through shear band propagation but can exhibit significant ductility when the sample size is reduced below a few hundreds of nanometers. To date the size effect was mainly demonstrated for free-standing samples and the role of extrinsic setup parameters on the observed behavior is still under debate. Therefore, in the present work we investigated the mechanical properties of polymer-supported sputtered amorphous Pd 82 Si 18 thin films with various thicknesses. We show that the films exhibit brittle fracture for thicknesses far below 100 nm. A pronounced size effect resulting in extended crack-free deformation up to 6% strain was observed only in films as thin as 7 nm – a thickness which is lower than the typical shear band thickness. This size effect results in exceptional cyclic reliability of ultrathin metallic glass films which can sustain cyclic strains of 3% up to at least 30,000 cycles without any indication of fatigue damage or electrical conductivity degradation. Since the enhancement of mechanical properties is observed at ambient conditions using inexpensive substrates and an industrially scalable sputter deposition technique, a new research avenue for utilization of ultrathin metallic glasses in microelectronics, flexible electronics or nanoelectromechanical devices is opened up.

show abstract

Zr–Ti–Ni thin film metallic glass as a diffusion barrier between copper and silicon

Cited by 33 publications

References 34 publications

Low electrical resistivity in thin and ultrathin copper layers grown by high power impulse magnetron sputtering

Low electrical resistivity in thin and ultrathin copper layers grown by high power impulse magnetron sputtering

Material Properties of Zr–Cu–Ni–Al Thin Films as Diffusion Barrier Layer

Exceptional fracture resistance of ultrathin metallic glass films due to an intrinsic size effect

Contact Info

Product

Resources

About