Strem offers one of the most promising ruthenium amidinate precursors


22-11-2018

One of the blogs posted on the Strem Chemicals UK site has been reposted from an original blog researched, produced and written by Abhishekkumar Thakur and Jonas Sunquist.

It is reposted from BALD Engineering’s site on October 30th, 2018.  Find it here or on Strem Chemicals UK website

It states ‘Strem Offers One of the Most Promising Ruthenium Amidinate Precursors for Growing Ru ALD or CVD Films’ and by estimating the rising demand for Ru Thin-films in the next generation chips

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Ru is also an excellent candidate for the electrode capacitor in DRAM applications and gate electrode material in CMOS transistor applications because of its high melting point, high oxidation resistance, and low resistivity. Ruthenium’s lower resistivity and ease of dry etching give it a significant advantage over other noble metals like iridium and platinum. Ru seed-layer deposited as a conformal via liner significantly improves copper adhesion and hinders oxygen diffusion in interconnects and through-silicon-via (TSV) applications.  Moreover, ruthenium oxide is conductive and therefore, oxygen diffusion from adjacent materials or processes does not hinder the device performance.  Recent research reports the use of ruthenium-based materials as an electrode in ferroelectric applications as well.

Thus, as the main bottleneck of next generation ICs, interconnects and contacts are nowadays the major driving factors of the market of high quality specialty chemicals for the performance or function specific materials or molecules. The physical and chemical properties of a single molecule or a formulated mixture of molecules as well as its chemical composition influence the end product performance extensively. Therefore, unlike the other sub-sectors of the chemical industry, the companies manufacturing and marketing specialty chemicals provide more often than not targeted customer service to innovative individual technical solutions for their customers.

Most of the available Ru ALD or CVD precursors have issues concerning low vapor pressure and high impurity levels, such as carbon and oxygen, which get incorporated in the films.  In addition to that, long incubation times impacting throughput and process controllability, poor film adherence, and non-uniformity in high-aspect ratio structures are some critical limitations of the field.  However, ruthenium amidinate precursors such as Bis(N,N’-di-t-butylacetamidinato)ruthenium(II) dicarbonyl (44-0056) and others are some of the most promising precursors finding a home in Strem’s product catalog for growing ALD and CVD films.  Each amidinate ligand chelates the metal center through two metal-nitrogen bonds.  These relatively weak M-N bonds and strong byproduct N-H bonds lead to lower ALD growth temperatures.  However, the M-N bonds are strong enough to provide stability to the precursor at the standard temperatures used.  Also, since the amidinate ligands chelate to the metal center, they are thermally stable yet have high and self-limited reactivity to water vapor which is essential for ALD.  Amidinates do not have any oxygen-metal bonds thus enabling the deposition of metallic films with very low oxygen content in the film and at the interface with the sub-layer.

ALD thin-films deposited using Bis(N,N’-di-t-butylacetamidinato)ruthenium(II) dicarbonyl (44-0056) exhibit high conductivity, density and purity.   Atomic probe microscopy measurements revealed nearly carbon free crystallites with far less carbon impurity segregated near the grain boundaries.  The films also showed very good conformality even inside the trenches with aspect ratios (~40:1) possessing strong adhesion. The precursor was found to be thermally stable in a bubbler at 130°C for months and showed very clean TGA vaporization with only trace residue (0.2%).

Products mentioned in this blog:

44-0056: Bis(N,N-di-t-butylacetamidinato)ruthenium(II) dicarbonyl, 98% (99.99%-Ru) PURATREM [949113-49-9]

 

For more details on our precursors and equipment please visit the links below:

Metal Amidinates

Cylinders & Adapters

Chemical Vapor Deposition/Atomic Layer Deposition (CVD/ALD) Precursors contained in Swagelok® Cylinders

MOCVD, CVD & ALD Precursors Booklet

CVD/ALD Precursors

Bubblers & Other Equipment

 

**This blog had been researched, produced and written by Abhishekkumar Thakur and Jonas Sunquist.  It is reposted from BALD Engineering's blog on October 30th, 2018.  Original blog: https://www.blog.baldengineering.com/2018/10/estimating-rising-demand-for-ru-thin.html **

 

 

For over twenty-five years, Strem Chemicals UK has been distributing high quality specialty chemicals, from Strem Chemicals, Inc, in the UK and Ireland. Strem products are used for research and development and commercial scale applications, especially in the pharmaceutical, microelectronics, chemicals and petrochemicals industries.

Strem Chemicals UK Ltd